Agradecemos aos nossos colegas do Departamento de Biologia, Universidade de Fribourg para discussões proveitosas. Agradecemos ao Bloomington Banco Central para fornecer estoques de voar. Este trabalho foi apoiado financeiramente pela Swiss National Science Foundation (PP00P3_123339) ea Fundação Velux para SGS

1. Larvicultura <ol><li> Mantenha voar estirpes ou cruzamentos genéticos na cultura de massa a 25 ° C em meio a farinha de milho em uma hora de luz 12 ciclo de 12 horas de escuro em uma mosca incubadora equipado com luz e timer. </li><li> Diluir Backer levedura em água para formar uma pasta fluida (10 g de levedura Backer diluída com 3-4 ml de H2O destilada). Adicione uma pequena queda para o milho refeição e cobrir os frascos. Deixar secar durante pelo menos uma hora, para evitar moscas adultas adere à pasta de levedura. Colocar uma pequena gota de levedura diluída em água sobre a superfície do alimento pode melhorar a oviposição. Alternativamente pasta de levedura de panificação, ácido acético a 20% (AcOH) (Sigma Aldrich, Suiça A6283-100ml) pode ser usado. Para isso, molhar a ponta de um Q-tip na solução e espalhe sobre a superfície da refeição de milho. </li><li> Coloque moscas adultas (pelo menos quatro dias de idade, mas não mais do que 10 dias), em farelo de frascos de alimentos. Coloque adultos suficientes para cada frasco, a fim de obter larvas suficiente para repetir a preferênciatestar várias vezes e permitir a comparação estatística. Para cruzamentos genéticos, que normalmente usam um mínimo de 20 fêmeas e machos 5-10 por frasco, mas algumas linhas precisam de mais fêmeas para obter uma prole larval suficiente. </li><li> Permitem que os adultos põem ovos para 12 horas e transferi-los para novos frascos. Os adultos podem ser transferidas, de manhã e à noite. Costumamos transferir adultos por sete a dez dias e se necessário tomar novas adultos. </li><li> Manter as colecções de ovo tomadas cada 12 horas na incubadora e deixar crescer as larvas a 25 ° C, 12 horas de ciclo claro-escuro de 12 horas e 60% de humidade. Para testar componentes circadianos de movimento larvas visuais comportamento à escuridão constante (DD) 48 horas após a coleta de ovos (correspondente a dois ciclos claro-escuro). Para isso, use uma incubadora separado, sem luz, mas manter todas as outras condições, tais como temperatura e umidade idênticos. Certifique-se de transferir os frascos para o DD incubadora pouco antes da mudança para a fase escura. Antes de mover os frascos another incubadora colocar os frascos em uma caixa de papelão ou embrulhar os frascos com papel alumínio para evitar a exposição à luz durante a transferência (embalagem em caixa de papelão ou embalagem tem que ser feito durante o &quot;apagar as luzes da fase&quot; antes da mudança entre incubadoras). Impedir que os animais de qualquer exposição à luz após este ponto e até experimentos início. </li><li> Após 4 dias (84-108 hr de postura de ovos) recolher cedo L3 (larvas de alimentação) nos pontos de tempo para serem testados (ver 4. Luz preferência teste, ponto. 4.4.). </li></ol> 2. Test Setup <ol><li> Realizar experiências em um quarto escuro, com temperatura constante e umidade. </li><li> Para manter dois quadrantes da placa de Petri em trevas, cobrir a tampa com fita preta e folha de alumínio. A fim de fazer isso, marcar o centro da circunferência da tampa. Mark também quatro pontos na borda da tampa, com 90 ° de separação entre eles. Para torná-lo mais fácil, desenhar um quadrado 20 centímetros dividido em quatro quadrantes, de 10 cm de comprimento em umfolha de papel ou com a ajuda de um computador. Corte de 10 centímetros quadrados de papel de alumínio e uma fita preta (Figura 1A). Cubra dois quadrantes opostos colando um quadrado de papel alumínio, como primeira camada e fita preta cobrindo-o, tenha cuidado para também cobrir a borda da tampa. No passado foram usadas duas formas ligeiramente diferentes desta ensaios. Nós, aqui utilizar o ensaio &quot;quarter-placa&quot;, em que a placa de Petri é dividido em quatro partes iguais de 10. Em alternativa o ensaio de &quot;meia-placa&quot;, a placa de Petri é dividido metade (metade exposto à luz, em meia escuro) 1,7,8. Até hoje não há diferenças significativas entre os dois testes foi publicada. </li><li> Cola uma folha de quadrante, como a utilizada para a marcação das tampas direito sob a fonte de luz sobre a mesa. Marque a circunferência de uma placa de Petri centrada na intersecção quadrantes. Use as marcas de referência para colocar a placa de teste sempre na mesma posição, sob a fonte de luz. </li><li> Instale umlâmpada, ou uma simples lâmpada de luz branca (Phillips, Softtone 5W) ou uma lâmpada de LED (lâmpadas LED, 80012 Branco, Osram) acima da placa de Petri com a ajuda de um carrinho suporte de ferro (Fisher Scientific, S47808). Ajustar a altura de uma forma que toda a chapa de teste é iluminado de forma homogénea. Recomendamos o uso de lâmpadas LED, uma vez que emitem comprimentos de onda mais específicas do que as lâmpadas convencionais. Além disso, LEDs emitem menos calor. </li><li> Ajustar a intensidade da luz com a ajuda de um fotômetro (Ambiente Medidor PCE EM882). Para alcançar a intensidade da luz necessária de 350-760 lux, mover a lâmpada para cima ou para baixo, conforme necessário. Ligar a lâmpada de uma fonte de alimentação ajustável dá mais flexibilidade para mudar as intensidades, sem mover a lâmpada (Figura 1B). </li></ol> 3. Placas de Preparação <ol><li> Adicione 200 ml de 2,5% de agar (Sigma-Aldrich, Suiça A5093-500G), com água bi-destilada (Millipore). </li><li> Coloque placas de Petri sobre uma mesa (90 mm de diâmetro;Greiner Bio-One GmbH, 4550 Kremsmeinster, Áustria) em linhas para permitir derramar quente agarose. </li><li> Ferver a agarose em um forno de microondas até que a solução é completamente transparente e de fluido. Certifique-se de que a solução líquida não contém bolhas. ATENÇÃO: Transporte cuidadosamente a tabela já que a solução pode ser muito quente! </li><li> Verter a quente de agarose em placas de Petri até que toda a superfície seja homogeneamente coberto com uma fina camada da solução, cerca de dois ou três milímetros são suficientes. Seja rápido para evitar agarose solidificar antes de todas as placas de revestimento. Deixe as placas esfriar. Armazenar as placas à temperatura ambiente, e utilizá-los apenas no mesmo dia da preparação. </li></ol> 4. Luz teste de preferência <ol><li> O trabalho sob condições de luz vermelha na sala de ensaio para evitar a influência de luz antes do ensaio, uma vez Drosophila não é capaz de detectar a luz de comprimentos de onda vermelhos. Use uma lâmpada vermelha (Phillips, PFE712E * 8) montado em uma lâmpada para iluminar tele Place to Work. </li><li> Manter a temperatura por meio de todas as experiências a 25 ° C. Temperatura ambiente de controle por meio de um dispositivo de aquecimento ou arrefecimento, se necessário. </li><li> Tome um pouco de comida dos frascos criados para ciclos de dois dias sob constante escuridão (na seção 1). Uma vez que as larvas são geralmente de escavação na superfície da comida, tomar a camada superior (cerca de 5 mm de profundidade) com a ajuda de uma espátula (Fisher Scientific, 14-373-25A). Espalhar a comida no lado exterior de uma tampa da caixa de Petri, adicionar um pouco de água e misturar cuidadosamente com uma espátula. </li><li> Colete alimentando larvas L3 do alimento. Como preferência luz vai ser testado, escolhendo apenas no início / alimentação das larvas L3 é crucial, pois o phototaxis negativa está garantida. Tarde / vagando larvas L3 ou grande larva rastejando sobre a comida provavelmente já mudaram seu photobehavior. Alimentando larvas L3 (fototáxico negativo) pode ser reconhecida porque seus espiráculos anteriores estão abertas e se projetava para o exterior de forma finger-like. O espiráculo posteriors têm três aberturas de cada um, e quatro grupos de grandes pêlos ramificados. As glândulas salivares estender-se ao segundo segmento abdominal 11. Estadiamento larva sob um microscópio é conveniente, ao passo que a luz branca não devem ser usados. Uma lâmpada de luz vermelha é necessária para iluminar as larvas se encenar sob microscópio estereoscópico antes dos experimentos é necessária. </li><li> Lave as larvas brevemente em água corrente e recolher cedo alimentando larvas de terceiro instar (ainda na luz vermelha). Antes de transferir as larvas na placa de teste, tomar as larvas com um pincel molhado e absorver cuidadosamente o excesso de água com uma toalha de papel ou papel-filtro. Não seque as larvas também excessivamente, pois pode prejudicar o animal e influenciar o seu comportamento. </li><li> Usando o pincel molhado transferir cuidadosamente as larvas de placas. Coloque um grupo de cerca de 30 larvas no centro do prato. Cobrir a placa com a tampa já preparada com os quadrantes e colocou o prato com a fonte de luz pronto para a experiência (ver secção 2). </li><li> Ligue a lâmpada de luz branca e iniciar o temporizador. Deixe a larva mover-se livremente sobre a placa durante 5 minutos, em seguida, rapidamente remover a tampa e contar o número de larvas no escuro e nos quadrantes de luz. Marcação da posição de cada larva com um marcador pode facilitar a contagem. Alternativamente tirar uma foto da placa e contar a posteriori. Larvas de luz de uma preferência clara, como larvas rastejar nas paredes ou enterrando-ágar devem ser considerados como preferências neutro e apenas ser incluídos no número total de larvas, quando o índice de preferência luz é calculado. </li><li> Após a contagem, rejeitar a placa com larvas e substitua por uma nova placa de teste para o seguinte experimento. Colete placas usadas em um saco plástico autoclave para o tratamento e despejo posterior. </li><li> Depois de ter realizado um número suficiente de experimentos de um novo genótipo podem ser testados. 10-15 ensaios por genótipo são suficientes para análise. </li></ol> 5. Dados Analysis <ol><li> Por conveniência transferir os dados para uma folha de dados como o Excel (Microsoft) ou de origem (origem Lab) em um computador para análise estatística. Dispor em uma coluna o número de animais no escuro, numa segunda coluna o número de animais nos quadrantes de luz e no terceiro o total de animais na placa (incluindo larvas &quot;neutro&quot;). </li><li> Calcular o índice de preferência (PREF) para a escuridão para cada experiência com a seguinte fórmula: PREF (escuridão) = (número de larvas no escuro - número de larvas na luz) / número total de larvas </li><li> Comparar estatisticamente um conjunto de dados com uma análise apropriada para grupos. Aqui, usamos um teste de Wilcoxon para comparar estatisticamente dois grupos. Um teste de ANOVA com-comparação múltipla de Tukey post hoc teste pode ser feito, se o pressuposto de distribuição normal é cumprida em uma comparação grupo distribuidor. </li><li> Adicione gráficos que mostram claramente as comparações entre as linhas e pontos de tempo ao longo do ciclo de dia. We uso do software Origin (Origin Lab) para testar a significância estatística e gerar gráficos apropriados, mas qualquer outro software de estatística pode ser útil. </li></ol>

<ol>
	<li>Sawin-McCormack, E. P., Sokolowski, M. B., Campos, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+and+genetic+analysis+of+Drosophila+melanogaster+photobehavior+during+larval+development.">Characterization and genetic analysis of Drosophila melanogaster photobehavior during larval development.</a> J. Neurogenet. 10, 119-135 (1995).</li><li>Sprecher, S. G., Pichaud, F., Desplan, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adult+and+larval+photoreceptors+use+different+mechanisms+to+specify+the+same+Rhodopsin+fates.">Adult and larval photoreceptors use different mechanisms to specify the same Rhodopsin fates.</a> Genes Dev. 21, 2182-2195 (2007).</li><li>Sprecher, S. G., Desplan, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Switch+of+rhodopsin+expression+in+terminally+differentiated+Drosophila+sensory+neurons.">Switch of rhodopsin expression in terminally differentiated Drosophila sensory neurons.</a> Nature. 454, 533-537 (2008).</li><li>Xiang, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-avoidance-mediating+photoreceptors+tile+the+Drosophila+larval+body+wall.">Light-avoidance-mediating photoreceptors tile the Drosophila larval body wall.</a> Nature. 468, 921-926 (2010).</li><li>Diaz, N. N., Sprecher, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoreceptors:+unconventional+ways+of+seeing.">Photoreceptors: unconventional ways of seeing.</a> Curr. Biol. 21, R25-R27 (2011).</li><li>Emery, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drosophila+CRY+is+a+deep+brain+circadian+photoreceptor.">Drosophila CRY is a deep brain circadian photoreceptor.</a> Neuron. 26, 493-504 (2000).</li><li>Mazzoni, E. O., Desplan, C., Blau, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circadian+pacemaker+neurons+transmit+and+modulate+visual+information+to+control+a+rapid+behavioral+response.">Circadian pacemaker neurons transmit and modulate visual information to control a rapid behavioral response.</a> Neuron. 45, 293-300 (2005).</li><li>Keene, A. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distinct+visual+pathways+mediate+Drosophila+larval+light+avoidance+and+circadian+clock+entrainment.">Distinct visual pathways mediate Drosophila larval light avoidance and circadian clock entrainment.</a> J. Neurosci. 31, 6527-6534 (2011).</li><li>Gong, Z. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two+Pairs+of+Neurons+in+the+Central+Brain+Control+Drosophila+Innate+Light+Preference.">Two Pairs of Neurons in the Central Brain Control Drosophila Innate Light Preference.</a> Science. 330, 499-502 (2010).</li><li>Lilly, M., Carlson, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=smellblind:+a+gene+required+for+Drosophila+olfaction.">smellblind: a gene required for Drosophila olfaction.</a> Genetics. 124, 293-302 (1990).</li><li>Bodenstein, D., Demerec, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+postembryonic+development+of+Drosophila.">The postembryonic development of Drosophila.</a> Biology of Drosophila. , 275-367 (1950).</li><li>Pittendrigh, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circadian+systems:+Entrainment.">Circadian systems: Entrainment.</a> Biological Rhythms. 4 Handbook of Behavioral Neurobiology, 95-124 (1981).</li><li>Collins, B., Kane, E. A., Reeves, D. C., Akabas, M. H., Blau, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Balance+of+Activity+between+LN(v)s+and+Glutamatergic+Dorsal+Clock+Neurons+Promotes+Robust+Circadian+Rhythms+in+Drosophila.">Balance of Activity between LN(v)s and Glutamatergic Dorsal Clock Neurons Promotes Robust Circadian Rhythms in Drosophila.</a> Neuron. 74, 706-718 (2012).</li><li>Keene, A. C., Sprecher, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seeing+the+light:+photobehavior+in+fruit+fly+larvae.">Seeing the light: photobehavior in fruit fly larvae.</a> Trends Neurosci. 35, 104-110 (2012).</li><li>von Essen, A. M., Pauls, D., Thum, A. S., Sprecher, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capacity+of+visual+classical+conditioning+in+Drosophila+larvae.">Capacity of visual classical conditioning in Drosophila larvae.</a> Behav. Neurosci. 125, 921-929 (2011).</li></ol>

Os autores não têm nada a revelar.

O teste de preferência light descrito aproveita o photobehavior inata larval. O ensaio é fácil de estabelecer, permite que muitas repetições com baixo custo e oferece informações valiosas sobre detecção de luz e de processamento. O paradigma experimental permite a quantificação relativamente rápido de quantas pessoas preferem clara ou escura. Essa preferência pode ser exibido como percentagens brutas ou, alternativamente, como Índice de Preferência (PREF). O PREF é expressa como a diferença entre os ani...

Aqui nós descrevemos um ensaio comportamental com base na preferência larval para escuro (ou luz). Larvas reagir com uma resposta fotonegativo forte e estereotipados durante os estágios de forrageio (L1 até o início L3) 1. O ensaio é destinado a avaliar o comportamento photophobic da larva e compara o claro ou escuro preferência de um grupo de larvas de mover-se livremente em uma placa de Petri revestidas com ágar. Este ensaio comportamental não só fornece informações sobre a sensibilidade, a integração temporal e plasticidade do sistema visual, proporciona ainda dicas sobre como sensibilidade à luz e ao seu processo é controlado pelo sistema circadiano. A Drosophila olho larval (também denominado Órgão Bowlig; BO), é o principal órgão de percepção luminosa. Cada olho é composto de 12 fotorreceptores (PR), oito PRs expressar a rhodopsin6 verde-sensível (RH6) e quatro PRs expressar a rhodopsin5 blue-sensível (RH5) 2,3. Além de PRs, alsÔ classe IV neurônios multidendritic, que cobrem a parede do corpo larval, foram identificados para responder a intensidades de luz nocivos 4,5. Sabe-se também que os neurónios do pacemaker situados no centro do cérebro larval expressar a proteína sensível à luz criptocromo (Cry), que age como relógio sensor de luz azul intrínseca dentro do cérebro 6,7. Curiosamente photophobicity de animais de tipo selvagem mostra um componente circadiano em diferentes pontos de tempo durante o decurso do dia e da noite, quando um teste com este ensaio. Respostas a luz de forrageamento larva L3 mostrou photophobicity forte na madrugada e inferior photophobicity ao entardecer, quando testado para a preferência claro-escuro 7. Curiosamente só RH5-PRs são necessários para evitar a luz, enquanto RH6-PRs são dispensáveis. Ambos, RH5-PRs e RH6-PRs estão envolvidos em como acertar o relógio molecular pela luz 8. O caminho Cry deve ser coordenada com as outras vias de luz sensores de orquestrar uma saída de comportamento apropriado nodecorrer do dia. A acetilcolina em RP desempenha um papel essencial no comportamento de evasão luz, bem como o arrastamento do relógio molecular. Bloqueio de neurotransmissão acetilcolina dos PRs aos neurônios marcapasso circadiano reduz a resposta photophobic no ensaio de preferência light-escuridão 8. Utilizando o mesmo ensaio, os dois pares simétricos de neurónios foram recentemente identificados para exibir a preferência luz do terceiro instar de larvas de Drosophila 9. Esses dois pares de neurônios pode estar funcionando durante a fase larval final, quando os animais deixam a comida para encontrar provavelmente um site pupariation apropriado. No entanto, a questão de como as vias visuais interagir e controlar o comportamento visual de uma forma larval circadiano permanece praticamente sem resposta. O ensaio de preferência light permite comparações entre os momentos circadianos, voar linhas e estaduais circadiano sob diferentes qualidades de luz. O ensaio é barato e facilmente preparado e tem sido útil anteriormente in vários laboratórios para descrever e estudar a luz comportamento derivado da larva.

<table border="1">
 <tbody>
 <tr>
 <td>Name of Reagent/Material</td>
 <td>Company</td>
 <td>Catalog Number</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>Agar</td>
 <td>Sigma-Aldrich</td>
 <td>A5093-500G</td>
 <td>2.5%; Sigma-Aldrich, 9471 Buchs, Switzerland </td>
 </tr>
 <tr>
 <td>Petri dishes</td>
 <td>Greiner Bio-One GmbH</td>
 <td>633180</td>
 <td>90-mm diameter; Greiner Bio-One GmbH, 4550 Kremsmeinster, Austria</td>
 </tr>
 <tr>
 <td>LEDs Lamp</td>
 <td>OSARAM </td>
 <td>80012 White</td>
 <td>LED lamp, 80012 White</td>
 </tr>
 <tr>
 <td>Environment Meter</td>
 <td>PCE</td>
 <td>PCE EM882</td>
 <td>Lux, Temp, RH%</td>
 </tr>
 <tr>
 <td>Thermostatic cabinet</td>
 <td>Aqua Lytic (Liebherr)</td>
 <td>ET636-6</td>
 <td></td>
 </tr>
 <tr>
 <td>Light timer</td>
 <td>Timer T</td>
 <td>6185.104</td>
 <td>230V/50HZ (check specifications for your country)</td>
 </tr>
 <tr>
 <td>Universal thermostat</td>
 <td>Conrad</td>
 <td>UT200</td>
 <td></td>
 </tr>
 <tr>
 <td>Humidifier</td>
 <td>Boneco</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Balck tape</td>
 <td>Tesa</td>
 <td></td>
 <td>5 cm </td>
 </tr>
 <tr>
 <td>Glue</td>
 <td>Uhu</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>lncubator lamp</td>
 <td>Phillips</td>
 <td>Softtone</td>
 <td>5W</td>
 </tr>
 <tr>
 <td>Timer clock</td>
 <td>Ziliss</td>
 <td></td>
 <td>Ziliss, Switzerland</td>
 </tr>
 <tr>
 <td>Excel Software</td>
 <td>Microsoft</td>
 <td></td>
 <td>Excel</td>
 </tr>
 <tr>
 <td>Origin Software 8.5</td>
 <td>OriginLab</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Backer Yeast</td>
 <td>Migros Switzerland</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Iron support stand 17X28CM</td>
 <td>Fisher Scientific</td>
 <td>S47808</td>
 <td></td>
 </tr>
 <tr>
 <td>Acetic acid</td>
 <td>Sigma Aldrich</td>
 <td>A6283-100ML</td>
 <td>20% acetic acid dilluted in H2O</td>
 </tr>
 <tr>
 <td>Red light lamp</td>
 <td>Phillips</td>
 <td>PFE712E*8C</td>
 <td></td>
 </tr>
 <tr>
 <td>Spatula </td>
 <td>Fisher Scientific</td>
 <td>14-373-25A</td>
 <td></td>
 </tr>
 <tr>
 <td>Power supply</td>
 <td>EA</td>
 <td>EA PS 2042-06B</td>
 <td>Optional</td>
 </tr>
 <tr>
 <td>Aluminium foil</td>
 <td>Prix Coop</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Heater</td>
 <td>GOON</td>
 <td>NSB200C</td>
 <td></td>
 </tr>
 <tr>
 <td>Microwave Oven</td>
 <td>Intertronic</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Standard corn meal fly food</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Destilled water </td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 </tbody>
</table>

light preference assay to study innate and circadian regulated photobehavior in drosophila larvae

Atos de luz como sinal ambiental para controlar o comportamento de animais em vários níveis. O sistema nervoso Drosophila larval é usado como um modelo único para responder a perguntas básicas sobre como informação de luz é processada e compartilhada entre os comportamentos rápidos e circadiano. Larvas Drosophila exibir um comportamento de evitação estereotipada quando expostos à luz. Para investigar comportamentos dependentes leves testes comparativamente simples de preferência claro-escuro podem ser aplicadas. Em vertebrados e artrópodes as vias neurais envolvidos na percepção e processamento de informações visuais se sobrepõem parcialmente com os de processamento de informações circadiano photic. A questão fascinante de como o sistema de detecção de luz e o sistema circadiano interagem para manter as saídas de comportamento coordenado permanece largamente inexplorado. Drosophila é um modelo de impacto biológico para abordar estas questões, devido a um pequeno número de neurónios no cérebro e na disponibilidade de ferramentas genéticas para manipul neuronalração. O ensaio de preferência claro-escuro apresentado permite a investigação de uma série de comportamentos visuais, incluindo controle circadiano da phototaxis.

Seguindo o protocolo descrito acima, foi testada preferência claro-escuro no terceiro estádio larvar precoce do tipo selvagem Canton-S opera em dois tempos diferentes e circadianos CT0 CT12. Os adultos foram criados 12 horas de luz de 12 horas escuro e deixou de botar ovos de 12 horas. As larvas crescem os primeiros dois dias no mesmo regime de luz-escuro. Uma vez que nós quisemos testar modulação circadiano em condições constantes (de funcionamento livre do relógio circadiano), as larvas foram então transferid...

Watch this Scientific Journal Video about Light Preference Assay to Study Innate and Circadian Regulated Photobehavior in Drosophila Larvae at JoVE.com

Light Preference Assay to Study Innate and Circadian Regulated Photobehavior in Drosophila Larvae

Aqui nós descrevemos um teste de preferência claro-escuro para Drosophila larva. Este ensaio fornece informações sobre regulação inata e circadiano da luz de sensoriamento e processamento photobehavior.

Luz Ensaio Preferências para estudar inata e circadiano Photobehavior Regulamentado<em&gt; Drosophila</em&gt; As larvas

Light acts as environmental signal to control animal behavior at various levels. The Drosophila larval nervous system is used as a unique model to answer ...

light-preference-assay-to-study-innate-circadian-regulated

Research

JoVE Journal

Neuroscience

Light Preference Assay to Study Innate and Circadian Regulated Photobehavior in Drosophila Larvae

12.8K visualizações.  University of Fribourg. Aqui nós descrevemos um teste de preferência claro-escuro para Drosophila larva. Este ensaio fornece informações sobre regulação inata e circadiano da luz de sensoriamento e processamento photobehavior.

Vídeo: Light Preference Assay to Study Innate and Circadian Regulated Photobehavior in Drosophila Larvae

Laser Capture Microdissection of Drosophila Peripheral Neurons

The dendritic arborization (da) neurons of the Drosophila peripheral nervous system (PNS) provide an excellent model system in which to investigate the molecular mechanisms underlying class-specific dendrite morphogenesis1,2. To facilitate molecular analyses of class-specific da neuron development, it is vital to obtain these cells in a pure population. Although a range of different cell, and tissue-specific RNA isolation techniques exist for Drosophila cells, including magnetic bead based cell purification3,4, Fluorescent Activated Cell Sorting (FACS)5-8, and RNA binding protein based strategies9, none of these methods can be readily utilized for isolating single or multiple class-specific Drosophila da neurons with a high degree of spatial precision. Laser Capture Microdissection (LCM) has emerged as an extremely powerful tool that can be used to isolate specific cell types from tissue sections with a high degree of spatial resolution and accuracy. RNA obtained from isolated cells can then be used for analyses including qRT-PCR and microarray expression profiling within a given cell type10-16. To date, LCM has not been widely applied in the analysis of Drosophila tissues and cells17,18, including da neurons at the third instar larval stage of development. 
Here we present our optimized protocol for isolation of Drosophila da neurons using the infrared (IR) class of LCM. This method allows for the capture of single, class-specific or multiple da neurons with high specificity and spatial resolution. Age-matched third instar larvae expressing a UAS-mCD8::GFP19 transgene under the control of either the class IV da neuron specific ppk-GAL420 driver or the pan-da neuron specific 21-7-GAL421 driver were used for these experiments. RNA obtained from the isolated da neurons is of very high quality and can be directly used for downstream applications, including qRT-PCR or microarray analyses. Furthermore, this LCM protocol can be readily adapted to capture other Drosophila cell types a various stages of development dependent upon the cell type specific, GAL4-driven expression pattern of GFP.

Laser Capture Microdissection of Drosophila Peripheral Neurons

In this video-article we present a method for isolating single or multiple Drosophila da neurons from third instar larvae using the infrared capture (IR) class of Laser Capture Microdissection (LCM). RNA obtained from the isolated neurons can be readily used for downstream applications including qRT-PCR or microarray analyses.

Laser Microdissecção Captura de Drosophila Neurônios periféricos

The dendritic arborization (da) neurons of the Drosophila peripheral nervous system (PNS) provide an excellent model system in which to investigate the ...

Neurociência

Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila

Most life forms exhibit daily rhythms in cellular, physiological and behavioral phenomena that are driven by endogenous circadian (&equiv;24 hr) pacemakers or clocks. Malfunctions in the human circadian system are associated with numerous diseases or disorders. Much progress towards our understanding of the mechanisms underlying circadian rhythms has emerged from genetic screens whereby an easily measured behavioral rhythm is used as a read-out of clock function. Studies using Drosophila have made seminal contributions to our understanding of the cellular and biochemical bases underlying circadian rhythms. The standard circadian behavioral read-out measured in Drosophila is locomotor activity. In general, the monitoring system involves specially designed devices that can measure the locomotor movement of Drosophila. These devices are housed in environmentally controlled incubators located in a darkroom and are based on using the interruption of a beam of infrared light to record the locomotor activity of individual flies contained inside small tubes. When measured over many days, Drosophila exhibit daily cycles of activity and inactivity, a behavioral rhythm that is governed by the animal's endogenous circadian system. The overall procedure has been simplified with the advent of commercially available locomotor activity monitoring devices and the development of software programs for data analysis. We use the system from Trikinetics Inc., which is the procedure described here and is currently the most popular system used worldwide. More recently, the same monitoring devices have been used to study sleep behavior in Drosophila. Because the daily wake-sleep cycles of many flies can be measured simultaneously and only 1 to 2 weeks worth of continuous locomotor activity data is usually sufficient, this system is ideal for large-scale screens to identify Drosophila manifesting altered circadian or sleep properties.

Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila

We describe procedures for recording daily locomotor activity rhythms of Drosophila and subsequent data analysis. Locomotor activity rhythms are a reliable behavioral output of animal circadian clocks and are used as the standard readout of clock function when studying circadian mutants or examining how the environment regulates the circadian system.

Assaying atividade locomotora para estudar ritmos circadianos e sono Parâmetros em Drosophila</em

Most life forms exhibit daily rhythms in cellular, physiological and behavioral phenomena that are driven by endogenous circadian (&equiv;24 hr) ...

Measuring Circadian and Acute Light Responses in Mice using Wheel Running Activity

Circadian rhythms are physiological functions that cycle over a period of approximately 24 hours (circadian- circa: approximate and diem: day)1, 2. They are responsible for timing our sleep/wake cycles and hormone secretion. Since this timing is not precisely 24-hours, it is synchronized to the solar day by light input. This is accomplished via photic input from the retina to the suprachiasmatic nucleus (SCN) which serves as the master pacemaker synchronizing peripheral clocks in other regions of the brain and peripheral tissues to the environmental light dark cycle3-7. The alignment of rhythms to this environmental light dark cycle organizes particular physiological events to the correct temporal niche, which is crucial for survival8. For example, mice sleep during the day and are active at night. This ability to consolidate activity to either the light or dark portion of the day is referred to as circadian photoentrainment and requires light input to the circadian clock9. Activity of mice at night is robust particularly in the presence of a running wheel. Measuring this behavior is a minimally invasive method that can be used to evaluate the functionality of the circadian system as well as light input to this system. Methods that will covered here are used to examine the circadian clock, light input to this system, as well as the direct influence of light on wheel running behavior.

This article will review methods that can be used to determine circadian function and light responsiveness in mice.

Medição Responses Luz circadianos e aguda em ratos usando Atividade Roda Executando

Circadian rhythms are physiological functions that cycle over a period of approximately 24 hours (circadian- circa: approximate and diem: day)1, 2.  They ...

Methods to Assay Drosophila Behavior

Drosophila melanogaster, the fruit fly, has been used to study molecular mechanisms of a wide range of human diseases such as cancer, cardiovascular disease and various neurological diseases1. We have optimized simple and robust behavioral assays for determining larval locomotion, adult climbing ability (RING assay), and courtship behaviors of Drosophila. These behavioral assays are widely applicable for studying the role of genetic and environmental factors on fly behavior. Larval crawling ability can be reliably used for determining early stage changes in the crawling abilities of Drosophila larvae and also for examining effect of drugs or human disease genes (in transgenic flies) on their locomotion. The larval crawling assay becomes more applicable if expression or abolition of a gene causes lethality in pupal or adult stages, as these flies do not survive to adulthood where they otherwise could be assessed. This basic assay can also be used in conjunction with bright light or stress to examine additional behavioral responses in Drosophila larvae. Courtship behavior has been widely used to investigate genetic basis of sexual behavior, and can also be used to examine activity and coordination, as well as learning and memory. Drosophila courtship behavior involves the exchange of various sensory stimuli including visual, auditory, and chemosensory signals between males and females that lead to a complex series of well characterized motor behaviors culminating in successful copulation. Traditional adult climbing assays (negative geotaxis) are tedious, labor intensive, and time consuming, with significant variation between different trials2-4. The rapid iterative negative geotaxis (RING) assay5 has many advantages over more widely employed protocols, providing a reproducible, sensitive, and high throughput approach to quantify adult locomotor and negative geotaxis behaviors. In the RING assay, several genotypes or drug treatments can be tested simultaneously using large number of animals, with the high-throughput approach making it more amenable for screening experiments.

Methods to Assay Drosophila Behavior

Drosophila melanogaster is a genetically and behaviorally tractable model system that has been used to understand the molecular and cellular basis of many important biological processes for over a century 1. Drosophila has been well exploited to gain insights into the genetic basis of fly behavior.

Métodos de Ensaio para Drosophila Comportamento

Drosophila melanogaster, the fruit fly, has been used to study molecular mechanisms of a wide range of human diseases such as cancer, cardiovascular ...

Local and Global Methods of Assessing Thermal Nociception in Drosophila Larvae

In this article, we demonstrate assays to study thermal nociception in Drosophila larvae. One assay involves spatially-restricted (local) stimulation of thermal nociceptors1,2 while the second involves a wholesale (global) activation of most or all such neurons3. Together, these techniques allow visualization and quantification of the behavioral functions of Drosophila nociceptive sensory neurons.
The Drosophila larva is an established model system to study thermal nociception, a sensory response to potentially harmful temperatures that is evolutionarily conserved across species1,2. The advantages of Drosophila for such studies are the relative simplicity of its nervous system and the sophistication of the genetic techniques that can be used to dissect the molecular basis of the underlying biology4-6 In Drosophila, as in all metazoans, the response to noxious thermal stimuli generally involves a "nocifensive" aversive withdrawal to the presented stimulus7. Such stimuli are detected through free nerve endings or nociceptors and the amplitude of the organismal response depends on the number of nociceptors receiving the noxious stimulus8. In Drosophila, it is the class IV dendritic arborization sensory neurons that detect noxious thermal and mechanical stimuli9 in addition to their recently discovered role as photoreceptors10. These neurons, which have been very well studied at the developmental level, arborize over the barrier epidermal sheet and make contacts with nearly all epidermal cells11,12. The single axon of each class IV neuron projects into the ventral nerve cord of the central nervous system11 where they may connect to second-order neurons that project to the brain.
Under baseline conditions, nociceptive sensory neurons will not fire until a relatively high threshold is reached. The assays described here allow the investigator to quantify baseline behavioral responses or, presumably, the sensitization that ensues following tissue damage. Each assay provokes distinct but related locomotory behavioral responses to noxious thermal stimuli and permits the researcher to visualize and quantify various aspects of thermal nociception in Drosophila larvae. The assays can be applied to larvae of desired genotypes or to larvae raised under different environmental conditions that might impact nociception. Since thermal nociception is conserved across species, the findings gleaned from genetic dissection in Drosophila will likely inform our understanding of thermal nociception in other species, including vertebrates.

Local and Global Methods of Assessing Thermal Nociception in Drosophila Larvae

In this article, we demonstrate assays to study thermal nociception in Drosophila larvae. One assay involves spatially-restricted (local) stimulation of thermal nociceptors1,2 while the second involves a wholesale (global) activation of most or all such neurons3. Together, these techniques allow visualization and quantification of the behavioral functions of Drosophila nociceptive sensory neurons.

Métodos locais e globais de Avaliação nocicepção térmica em<em&gt; Drosophila</em&gt; Larvas

In this article, we demonstrate assays to study thermal nociception in Drosophila larvae. One assay involves spatially-restricted (local) stimulation of ...

Visualization of Proprioceptors in Drosophila Larvae and Pupae

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other insects proprioception is provided by specialized sensory organs termed chordotonal organs (ChOs) 2. Like many other organs in Drosophila, ChOs develop twice during the life cycle of the fly. First, the larval ChOs develop during embryogenesis. Then, the adult ChOs start to develop in the larval imaginal discs and continue to differentiate during metamorphosis.
The development of larval ChOs during embryogenesis has been studied extensively 10,11,13,15,16. The centerpiece of each ChO is a sensory unit composed of a neuron and a scolopale cell. The sensory unit is stretched between two types of accessory cells that attach to the cuticle via specialized epidermal attachment cells 1,9,14. When a fly larva moves, the relative displacement of the epidermal attachment cells leads to stretching of the sensory unit and consequent opening of specific transient receptor potential vanilloid (TRPV) channels at the outer segment of the dendrite 8,12. The elicited signal is then transferred to the locomotor central pattern generator circuit in the central nervous system.
Multiple ChOs have been described in the adult fly 7. These are located near the joints of the adult fly appendages (legs, wings and halters) and in the thorax and abdomen. In addition, several hundreds of ChOs collectively form the Johnston's organ in the adult antenna that transduce acoustic to mechanical energy 3,5,17,4.
In contrast to the extensive knowledge about the development of ChOs in embryonic stages, very little is known about the morphology of these organs during larval stages. Moreover, with the exception of femoral ChOs 18 and Johnston's organ, our knowledge about the development and structure of ChOs in the adult fly is very fragmentary.
Here we describe a method for staining and visualizing ChOs in third instar larvae and pupae. This method can be applied together with genetic tools to better characterize the morphology and understand the development of the various ChOs in the fly.

Visualization of Proprioceptors in Drosophila Larvae and Pupae

A method to immunostain and visualize chordotonal organs in larvae and pupae of Drosophila melanogaster is described.

Visualização de Propriocepção em<em&gt; Drosophila</em&gt; As larvas e pupas

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other ...

Appetitive Associative Olfactory Learning in Drosophila Larvae

In the following we describe the methodological details of appetitive associative olfactory learning in Drosophila larvae. The setup, in combination with genetic interference, provides a handle to analyze the neuronal and molecular fundamentals of specifically associative learning in a simple larval brain.
Organisms can use past experience to adjust present behavior. Such acquisition of behavioral potential can be defined as learning, and the physical bases of these potentials as memory traces1-4. Neuroscientists try to understand how these processes are organized in terms of molecular and neuronal changes in the brain by using a variety of methods in model organisms ranging from insects to vertebrates5,6. For such endeavors it is helpful to use model systems that are simple and experimentally accessible. The Drosophila larva has turned out to satisfy these demands based on the availability of robust behavioral assays, the existence of a variety of transgenic techniques and the elementary organization of the nervous system comprising only about 10,000 neurons (albeit with some concessions: cognitive limitations, few behavioral options, and richness of experience questionable)7-10.
Drosophila larvae can form associations between odors and appetitive gustatory reinforcement like sugar11-14. In a standard assay, established in the lab of B. Gerber, animals receive a two-odor reciprocal training: A first group of larvae is exposed to an odor A together with a gustatory reinforcer (sugar reward) and is subsequently exposed to an odor B without reinforcement 9. Meanwhile a second group of larvae receives reciprocal training while experiencing odor A without reinforcement and subsequently being exposed to odor B with reinforcement (sugar reward). In the following both groups are tested for their preference between the two odors. Relatively higher preferences for the rewarded odor reflect associative learning - presented as a performance index (PI). The conclusion regarding the associative nature of the performance index is compelling, because apart from the contingency between odors and tastants, other parameters, such as odor and reward exposure, passage of time and handling do not differ between the two groups9.

Appetitive Associative Olfactory Learning in Drosophila Larvae

Drosophila larvae are able to associate odor stimuli with gustatory reward. Here we describe a simple behavioral paradigm that allows the analysis of appetitive associative olfactory learning.

Aprendizagem associativa apetitiva olfativa em<em&gt; Drosophila</em&gt; As larvas

In the following we describe the methodological  details of appetitive associative olfactory learning in Drosophila larvae. The setup, in combination with ...

Taste Preference Assay for Adult Drosophila

Olfactory and gustatory perception of the environment is vital for animal survival. The most obvious application of these chemosenses is to be able to distinguish good food sources from potentially dangerous food sources. Gustation requires physical contact with a chemical compound which is able to signal through taste receptors that are expressed on the surface of neurons. In insects, these gustatory neurons can be located across the animal's body allowing taste to play an important role in many different behaviors. Insects typically prefer compounds containing sugars, while compounds that are considered bitter tasting are avoided. Given the basic biological importance of taste, there is intense interest in understanding the molecular mechanisms underlying this sensory modality. We describe an adult Drosophila taste assay which reflects the preference of the animals for a given tastant compound. This assay may be applied to animals of any genetic background to examine the taste preference for a desired soluble compound.

Taste Preference Assay for Adult Drosophila

Taste is an important sensory process which facilitates attraction to beneficial substances and avoidance of toxic substances. This protocol describes a simple ingestion assay for determining Drosophila gustatory preference for a given chemical compound.

Ensaio de Preferência gosto para Adulto<em&gt; Drosophila</em

Olfactory and gustatory perception of the environment is vital for animal survival.  The most obvious application of these chemosenses is to be able to ...

Novel Assay for Cold Nociception in Drosophila Larvae

How organisms sense and respond to noxious temperatures is still poorly understood. Further, the mechanisms underlying sensitization of the sensory machinery, such as in patients experiencing peripheral neuropathy or injury-induced sensitization, are not well characterized. The genetically tractable Drosophila model has been used to study the cells and genes required for noxious heat detection, which has yielded multiple conserved genes of interest. Little is known however about the cells and receptors important for noxious cold sensing. Although, Drosophila does not survive prolonged exposure to cold temperatures (&#8804;10 &#186;C), and will avoid cool, preferring warmer temperatures in behavioral preference assays, how they sense and possibly avoid noxious cold stimuli has only recently been investigated.
Here we describe and characterize the first noxious cold (&#8804;10 &#186;C) behavioral assay in Drosophila. Using this tool and assay, we show an investigator how to qualitatively and quantitatively assess cold nociceptive behaviors. This can be done under normal/healthy culture conditions, or presumably in the context of disease, injury or sensitization. Further, this assay can be applied to larvae selected for desired genotypes, which might impact thermosensation, pain, or nociceptive sensitization. Given that pain is a highly conserved process, using this assay to further study&#160;thermal nociception will likely glean important understanding of pain processes in other species, including vertebrates.

Novel Assay for Cold Nociception in Drosophila Larvae

Here we demonstrate a novel assay to study cold nociception in Drosophila larvae. This assay utilizes a custom-built Peltier probe capable of applying a focal noxious cold stimulus and results in quantifiable cold-specific behaviors. This technique will allow further cellular and molecular dissection of cold nociception.

Romance Ensaio para Fria nocicepção em<em&gt; Drosophila</em&gt; Larvas

How organisms sense and respond to noxious temperatures is still poorly understood. Further, the mechanisms underlying sensitization of the sensory ...

Single-cell Resolution Fluorescence Live Imaging of Drosophila Circadian Clocks in Larval Brain Culture

The circadian pacemaker circuit orchestrates rhythmic behavioral and physiological outputs coordinated with environmental cues, such as day/night cycles. The molecular clock within each pacemaker neuron generates circadian rhythms in gene expression, which underlie the rhythmic neuronal functions essential to the operation of the circuit. Investigation of the properties of the individual molecular oscillators in different subclasses of pacemaker neurons and their interaction with neuronal signaling yields a better understanding of the circadian pacemaker circuit. Here, we present a time-lapse fluorescent microscopy approach developed to monitor the molecular clockwork in clock neurons of cultured Drosophila larval brain. This method allows the multi-day recording of the rhythms of genetically encoded fluorescent circadian reporters at single-cell resolution. This setup can be combined with pharmacological manipulations to closely analyze real-time response of the molecular clock to various compounds. Beyond circadian rhythms, this multipurpose method in combination with powerful Drosophila genetic techniques offers the possibility to study diverse neuronal or molecular processes in live brain tissue.

Single-cell Resolution Fluorescence Live Imaging of Drosophila Circadian Clocks in Larval Brain Culture

The goal of this protocol is to establish ex vivo Drosophila larval brain culture optimized to monitor circadian molecular rhythms with long-term fluorescence time-lapse imaging. The application of this method to pharmacological assays is also discussed.

Fluorescência de célula única resolução vivo Imaging de Drosophila relógios circadianos em cultura cérebro Larval

The circadian pacemaker circuit orchestrates rhythmic behavioral and physiological outputs coordinated with environmental cues, such as day/night cycles. ...