We gratefully thank the DFG for financial support (HO 1779/21-1) as well as Katrin Kumke and Dr. Veit Schubert (IPK, Gatersleben) for technical advice.

1. Kromozom Hazırlık <ol><li> Çimlenme ve kök uçları tespit <ol><li> 22-24 ° C&#39;de 2 gün boyunca, karanlık koşullar altında bir Petri kabı içinde nemli filtre kağıdı, iki katmanlar üzerinde 10-20 arpa tohumları filizlenmeye. Bir jilet kullanılarak tohum 1-2 cm uzunluğunda güçlü kökleri kesin. </li><li> Parçalanmış buz-su içine soğuk musluk suyu ihtiva eden 500 ml&#39;lik bir cam şişe yerleştirerek buz soğukluğunda su hazırlayın. Buz soğuk su havalandırmak ve metafaz hücrelerinin sıklığını artırmak için 20 saat boyunca kök ipuçları batırmayın. </li><li> 50 ml etanol, su kökleri transfer: asetik asit (3: 1) sabitleyici 2 gün oda sıcaklığında bunları düzeltmek için. Taze hazırlanmış etanol içerisinde mağazası kökleri: asetik asit (3: 1) ile 4 ° C &#39;de sabitleyici bir yıla kadar kullanana kadar. </li></ol></li><li> Yıkama ve enzim tedavisi <ol><li> 5 dk iki kez 50 ml&#39;lik bir cam beher kullanarak 30 ml buz gibi soğuk musluk suyu ile 10-20 kökleri yıkayın. Binoküler mikroskop kullanın. Içine birer kökleri tek Transferi30 mi, 0.01 M sitrat tampon maddesi (± 0.01 M sodyum sitrat, 0.01 M sitrik asit, pH 4.8) forseps kullanılarak iki kez 5 dakika boyunca bir cam beher çalkalayarak yıkayın. Tamamen sıvının ve kesme arzu edilmeyen olmayan meristematik doku bir ustura kullanılarak filtre kağıdına kökleri yerleştirin. </li><li> Bir saat cam bitki dokusunun yumuşatmak için yaklaşık 50 dakika boyunca (Tablo 1) 37 ° C &#39;de, 1 ml enzim karışımında 20 kök uçları kadar inkübe edin. Enzim karışımı, 0.01 M sitrat tampon maddesi içinde seyreltilmiş,% 0.7 Selülaz R10,% 0.7 selülaz,% 1 ve% 1 Pektoliaz cytohelicase içerir. -20 ° C&#39;de enzim karışımı saklayın ve beş kata kadar yeniden. </li><li> Pipetleme enzim çıkarın ve artık enzimin yerine iki kez 5 mi, 0.01 M sitrat tampon maddesi ile buz kök ipuçları yıkayın. </li></ol></li><li> Kök maserasyon <ol><li> Iki kez dikkatli bir şekilde aynı saat camı 1 ml% 96 ​​etanol ile yıkayın kök uçları. Taze hazırlanmış fiksatif (25% etanol% 75 asetik asit), etanol ile değiştirin. 10-15 kullanınKök ucu başına ul fiksatif. </li><li> Diseksiyon iğne veya forseps ile 2 ml tüp içine fiksatif ile birlikte Aktarım kök uçları ve parçalanmaya kök meristemleri. Bir hücre süspansiyonu elde etmek için hücrelerin yeniden askıya almak için boru 20 kez vurun. İki ay -20 ° C hücre süspansiyonu saklayın. </li></ol></li><li> Hücre süspansiyonunun Damlama <ol><li> 50 ° C&#39;de bir sıcak plaka üzerinde su ile ıslatılmış kağıt dokusunun 2-3 katmanları yerleştirin. 30 dakika boyunca buzdolabında buz soğuk musluk suyu altında mikroskopik slaytlar bırakın. Ve bir yerde nemli kağıt mendil üstünde kayar. </li><li> Pipet 7-10 hücre süspansiyonu ul ve sıcak plaka üzerine yerleştirilir soğutulmuş slayt üzerine 20 cm mesafeden bırakın. Pipet 10 slayt hücre süspansiyonu aynı yerde asetik asit-etanol karışımı ul ve ek 2 dakika süreyle sıcak plaka slayt tutun. Islak doku olmadan sıcak plaka slayt yerleştirin ve 1 dakika boyunca kurumaya bırakın. </li></ol></li><li> Kalite kontrolü ve Saklamaslaytlar e <ol><li> Kromozom yayılması kalitesini kontrol etmek için bir faz-kontrast mikroskobu kullanarak slaytları edin. -20 ° C&#39;da bir Coplin kavanoz% 96 etanol içinde daldırarak aynı gün veya mağaza ya slaytlar kullanın. </li></ol></li><li> FISH önce slaytların Tedavi öncesi; Tüm adımlar, oda sıcaklığında yürütülür <ol><li> 2x SSC, 50 ml ihtiva eden bir Coplin kavanoza Slaytları 5 dakika boyunca (20x SSC 3 M NaCl ve 300 mM trisodyum sitrat içeren). 3-10 dakika için% 45 asetik asit 50 ml ihtiva eden bir Coplin kavanoza forseps, transfer slaytlar kullanılması. </li><li> Aktarım, 10 dakika boyunca 2 x SSC, 50 ml ihtiva eden bir Coplin kavanoza kayar. 10 dakika boyunca (2x SSC)% 4 formaldehit, 50 ml ihtiva eden bir Coplin kavanoza transfer slaytlar ve bırakın slaytlar kromozom düzeltmek için. </li><li> 50 ml 2x SSC içeren bir Coplin kavanoza, 4 dakika her biri için slaytlar 3 kez durulama formaldehit çıkarın. Dikey% 70 seri 2 dakika,% 90 ve% 100 etanol, sırasıyla, ve kuru, slaytlar için Coplin kavanoza slaytlar kurutmakpozisyon. </li></ol></li></ol> İn Situ Hibridizasyon 2. Floresan (FISH) <ol><li> Her bir slayt için deiyonize formamid 10 ul 4x hibritleme tamponu, 5 ul kullanılarak toplam 20 ul hibridizasyon solüsyonu hazırlamak (200 ul tampon 80 ul 20x SSC, 8 ul 1 M Tris-HCI pH 8.0, içeren 1.6 ul 0.5 M EDTA, 11,2 ul 10 ug / ml somon spermi ve 99,2 ul DNase içermeyen su), probun 3 ul DNase içermeyen su 2 ul. </li><li> 24 x 32 mm kapak kayma slayt ve kapak başına melezleme solüsyonu 20 ul ekleyin ve kauçuk çimento ile kapak kayma tutuklama. Sıcak bir plaka üzerinde 2 dakika boyunca 80 ° C&#39;de, aynı anda probları ile slaytlar denatüre. </li><li> Transferi nemli odasına slaytlar ve 37 ° CO / N kaçınarak ışık slaytlar kuluçkaya yatmaktadır. 2x SSC ile Coplin kavanoza slaytlar durulama kapak fişleri çıkarın. Ve 55-60 ° C 2x SSC içeren bir Coplin kavanoza yerleştirin slaytlar 20 dakika inkübe. </li><li> Oda sıcaklığında 2 dakika boyunca bir Coplin kavanoza SSC 2x slaytlar yerleştirin. Sırasıyla,% 70,% 90 ve% 100 etanol içinde seri 2 dakika boyunca, bir Coplin kavanoza slaytlar kurutmak. </li><li> Yoğun ışık önlemek antifade montaj orta / ml 4 &#39;, 6-diamidino-2-phenylindoline 1 ug (DAPI) ile slaytlar ve counterstain hava içinde kurutulur. </li></ol> 3. Mikroskobik Analizi ve Depolama <ol><li> Epifloresans mikroskop kullanılarak slaytlar analiz edin. Filtrenin seçimi prob etiketleme için kullanılan florokrom bağlıdır. Gerekirse, bir yıla kadar karanlık koşullarda 4 ° C&#39;de mağaza slaytlar. </li></ol>

<ol><li>Geber, G., Schweizer, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Cytochemical+heterochromatin+differentiation+in+Sinapis+alba+%28Cruciferae%29+using+a+simple+air-drying+technique+for+producing+chromosome+spreads%5BTitle%5D)+AND+%22Pl+Syst+Evol%22%5BJournal%5D)">Cytochemical heterochromatin differentiation in Sinapis alba (Cruciferae) using a simple air-drying technique for producing chromosome spreads.</a> Pl Syst Evol. 158 (2-4), 97-106 (1988).</li>
<li>Andras, S. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+drop-spreading+technique+to+produce+cytoplasm-free+mitotic+preparations+from+plants+with+small+chromosomes%5BTitle%5D)+AND+%22Chromosome+Res%22%5BJournal%5D)">A drop-spreading technique to produce cytoplasm-free mitotic preparations from plants with small chromosomes.</a> Chromosome Res. 7 (8), 641-647 (1999).</li>
<li>Rothfels, K. H., Siminovitch, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((An+air-drying+technique+for+flattening+chromosomes+in+mammalian+cells+grown+in+vitro%5BTitle%5D)+AND+%22Stain+Technology%22%5BJournal%5D)">An air-drying technique for flattening chromosomes in mammalian cells grown in vitro.</a> Stain Technology. 33 (2), 73-77 (1958).</li>
<li>Martin, R., Busch, W., Herrmann, R. G., Wanner, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Efficient+preparation+of+plant+chromosomes+for+high-resolution+scanning+electron+microscopy%5BTitle%5D)+AND+%22Chromosome+Res%22%5BJournal%5D)">Efficient preparation of plant chromosomes for high-resolution scanning electron microscopy.</a> Chromosome Res. 2 (5), 411-415 (1994).</li>
<li>Kato, A., Albert, P. S., Vega, J. M., Birchler, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Sensitive+fluorescence+in+situ+hybridization+signal+detection+in+maize+using+directly+labeled+probes+produced+by+high+concentration+DNA+polymerase+nick+translation%5BTitle%5D)+AND+%22Biotech.+Histochem%22%5BJournal%5D)">Sensitive fluorescence in situ hybridization signal detection in maize using directly labeled probes produced by high concentration DNA polymerase nick translation.</a> Biotech. Histochem. 81 (2-3), 71-78 (2006).</li>
<li>Kirov, I., Divashuk, M., Van Laere, K., Soloviev, A., Khrustaleva, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((An+easy+%27SteamDrop%27+method+for+high+quality+plant+chromosome+preparation%5BTitle%5D)+AND+%22Mol.+Cytogenet%22%5BJournal%5D)">An easy 'SteamDrop' method for high quality plant chromosome preparation.</a> Mol. Cytogenet. 7, 21(2014).</li>
<li>Spurbeck, J. L., Zinsmeister, A. R., Meyer, K. J., Jalal, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Dynamics+of+chromosome+spreading%5BTitle%5D)+AND+%22Am+J+Med+Genet%22%5BJournal%5D)">Dynamics of chromosome spreading.</a> Am J Med Genet. 61 (4), 387-393 (1996).</li>
<li>Ma, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Synteny+between+Brachypodium+distachyon+and+Hordeum+vulgare+as+revealed+by+FISH%5BTitle%5D)+AND+%22Chromosome+Res%22%5BJournal%5D)">Synteny between Brachypodium distachyon and Hordeum vulgare as revealed by FISH.</a> Chromosome Res. 18 (7), 841-850 (2010).</li>
<li>Kato, A., Lamb, J. C., Birchler, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Chromosome+painting+using+repetitive+DNA+sequences+as+probes+for+somatic+chromosome+identification+in+maize%5BTitle%5D)+AND+%22Proc.+Natl.+Acad.+Sci.+U+S+A%22%5BJournal%5D)">Chromosome painting using repetitive DNA sequences as probes for somatic chromosome identification in maize.</a> Proc. Natl. Acad. Sci. U S A. 101 (37), 13554-13559 (2004).</li>
<li>Pan, W. H., Houben, A., Schlegel, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Highly+effective+cell+synchronization+in+plant-roots+by+hydroxyurea+and+amiprophos-methyl+or+colchicine%5BTitle%5D)+AND+%22Genome%22%5BJournal%5D)">Highly effective cell synchronization in plant-roots by hydroxyurea and amiprophos-methyl or colchicine.</a> Genome. 36 (2), 387-390 (1993).</li>
<li>Kim, J. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Integrated+karyotyping+of+sorghum+by+in+situ+hybridization+of+landed+BACs%5BTitle%5D)+AND+%22Genome%22%5BJournal%5D)">Integrated karyotyping of sorghum by in situ hybridization of landed BACs.</a> Genome. 45 (2), 402-412 (2002).</li>
<li>Lapitan, N. L. V., Brown, S. E., Kennard, W., Stephens, J. L., Knudson, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((FISH+physical+mapping+with+barley+BAC+clones%5BTitle%5D)+AND+%22Plant+J%22%5BJournal%5D)">FISH physical mapping with barley BAC clones.</a> Plant J. 11 (1), 149-156 (1997).</li>
<li>Aliyeva-Schnorr, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Cytogenetic+mapping+with+centromeric+BAC+contigs+shows+that+this+recombination-poor+region+comprises+more+than+half+of+barley+chromosome+3H%5BTitle%5D)+AND+%22Plant+J%22%5BJournal%5D)">Cytogenetic mapping with centromeric BAC contigs shows that this recombination-poor region comprises more than half of barley chromosome 3H.</a> Plant J. 84, 385-394 (2015).</li>
</ol>

The authors have nothing to disclose.

Kromozom, hazırlanışı deney ot familyasının (Poaceae) ait olan hububat genç kökleri kullanılarak gerçekleştirilmiştir. Tüm analiz türler diploid genom sette 14 nispeten uzun mitotik metafaz kromozomları (11-15 mikron) ve büyük genom türlerinin (5,1-7,9 Sterlin) aittir. Çimlenmiş köklerinin uzunluğu meristematik doku maksimum elde etmek için en fazla 2 cm değildi. Bölünen hücrelerin eşitleme mitotik metafaz miktarı 10 yayılır geliştirilmiş bir 20 sa...

In situ hibridizasyon (FISH) Floresan kromozom düzeyinde tek ve yüksek kopya dizilerinin fiziksel haritalama için etkili bir araçtır. Koşul, yüksek kaliteli kromozom yayılımlarının hazırlanmasıdır. Hayvan ve bitki hücreleri için aynı derecede uygun olacaktır genel kromozom hazırlama protokolü vardır. Bitki kromozomların hazırlanması nedeniyle farklı türlerin içinde sert hücre duvarı ve çeşitli sitoplazma kıvamına özellikle zordur. Bitki kromozom hazırlanması için olan uygun yöntemlerden biri de damla yayılan tekniği ve hava-kurutma tekniği 1,2 olarak bilinen olarak adlandırılan bir damla bir tekniktir. Bu yöntem ilk olarak, in vitro yetiştirilen memeli hücrelerinin 3 Rothfels ve Siminovitch tarafından 1958 yılında tanıtıldı. Daha sonra Martin ve ark. 4 ve Kato ve diğ. 5 bitkiler için bu yöntemi uyarlanmıştır. Daha yakın zamanlarda, adlı bir yöntem &#39;SteamDrop ve# 39; örtüşmeyen kromozom 6 hazırlanması için kullanılan su buharına geliştirildi. , Yüksek nem olumlu etkisi daha erken 7 gözlenmesine rağmen, &#39;SteamDrop&#39; yüksek kaliteli kromozom hazırlıkları 6 kontrollü bir iş akışı sağlar. Buhar tedavi muhtemelen kromozomal proteinler, bazı değişikliklere bağlı kromozomların gerilmesine neden olur. Tam metafaz yeterli sayıda tutma sonraki FISH deneyler için teknik uzmanlık gerektirir yayılır rağmen metafazlarda sonuçlanan kalitesi çok yüksektir. Burada tek ve yüksek kopya probları 5,8 FISH tespiti için uygun mitotik tahıl kromozom hazırlanması için bir protokol mevcut. Bu yöntem, Kato 50% -55% bağıl nem altında gerçekleştirilir 9 (Şekil 1) tarafından tarif havada kuru damlatma yöntemi geliştirilmiş bir varyantıdır. Bu protokol daha az sayıda içerenuygulaması kolay, verimli ve tekrarlanabilir hale yıkama adımları. Biz Hordeum vulgare H. bulbosum, H. marinum, H. murinum, H. pubiflorum ve Secale cereale&#39;den için yüksek kaliteli kromozom yayılır ve FISH sonuçları elde bu protokolü kullanarak.

<table><tbody><tr><td>Hot Plate</td><td>MEDAX GmbH</td><td>12603</td><td></td></tr><tr><td>Cellulase R10</td><td>Duchefa</td><td>C8001</td><td></td></tr><tr><td>Cellulase&amp;nbsp;</td><td>CalBioChem</td><td>219466</td><td></td></tr><tr><td>Pectolyase</td><td>Sigma</td><td>P3026</td><td></td></tr><tr><td>Cytohelicase</td><td>Sigma</td><td>C8274</td><td></td></tr><tr><td>Texas Red-12-dUTP</td><td>Invitrogen</td><td>C3176</td><td>direct fluorochrome&amp;nbsp;</td></tr><tr><td>Fluor488-5-dUTP</td><td>Invitrogen</td><td>C11397</td><td>direct fluorochrome&amp;nbsp;</td></tr><tr><td>Fluorecsence microscope</td><td>Olympus BX61</td><td>BX61</td><td></td></tr><tr><td>CCD camera</td><td>Orca ER, Hamamatsu</td><td>C10600</td><td></td></tr><tr><td>4&amp;rsquo;,6-diamidino-2-phenylindole (DAPI)&amp;nbsp;</td><td>Vector Laboratories</td><td>H-1200</td><td>fluorecsent dye</td></tr></tbody></table>

a fast air-dry dropping chromosome preparation method suitable for fish in plants

Kromozom yayılır hazırlanması floresan in situ hibridizasyon başarılı performansı (FISH) için bir ön koşuldur. Yüksek kaliteli bitki kromozom yayılır hazırlanması nedeniyle sert hücre duvarına zordur. Bitki kromozomlarına hazırlanması için onaylanmış yöntemlerden biri olarak adlandırılan bir damla hazırlanması da damla yayılan ya da hava-kurutma tekniği olarak bilinmektedir. Burada, mitotik kromozom hızlı hazırlanması için bir protokol tek ve yüksek kopya DNA probları BALIK tespiti için uygundur yayılır sunuyoruz. Bu yöntem, 50% -55% arasında bağıl nem altında gerçekleştirilen havada kuru damla yöntemin geliştirilmiş bir varyantıdır. Bu protokol, uygulama, kolay, verimli ve tekrarlanabilir hale yıkama aşamaları, daha az sayıda içerir. Bu yaklaşımın bariz faydaları başarılı FISH analizi için mükemmel bir önkoşul olarak hizmet veren iyi yayılmış, hasarsız ve çok sayıda metafaz kromozomları vardır. Bu protokolü kullanarak yüksek kaliteli chrom eldeosome yayılır ve Hordeum vulgare H. bulbosum, H. marinum, H. murinum, H. pubiflorum ve Secale cereale&#39;den için tekrarlanabilir FISH sonuçları.

Mitotik metafaz yayılır mikroskopik slaytlar yukarıda tarif edilen hızlı bir havayla kurumaya bırakarak kromozom hazırlama metodu ile hazırlandı (Suppl. Şekil 1). FISH analizi, her iki, tekrarlayıcı ve tek kopyalı sekansları kullanılarak gerçekleştirilmiştir. Görüntüler mukabil fluorophores uyarım sağlayan bir filtre seti ile bir Epifloresans mikroskop ile elde edilen ve yüksek hassasiyetli CCD monokrom kamera tarafından ele geçirildi. Görüntü alımı için biz bir görünt?...

Watch this Scientific Journal Video about A Fast Air-dry Dropping Chromosome Preparation Method Suitable for FISH in Plants at JoVE.com

A Fast Air-dry Dropping Chromosome Preparation Method Suitable for FISH in Plants

A protocol is described for the preparation of high-quality mitotic plant chromosome spreads by a fast air-dry dropping method suitable for the FISH detection of single and high copy DNA probes.

Bitkilerde FISH için uygun bir Hızlı Hava kuru Damlama Kromozom Hazırlama Yöntemi

Preparation of chromosome spreads is a prerequisite for the successful performance of fluorescence in situ hybridization (FISH). Preparation of high ...

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JoVE Journal

Biology

13.2K Görüntüleme.  Leibniz Institute of Plant Genetics and Crop Plant Research (IPK). A protocol is described for the preparation of high-quality mitotic plant chromosome spreads by a fast air-dry dropping method suitable for the FISH detection of single and high copy DNA probes.

Video: A Fast Air-dry Dropping Chromosome Preparation Method Suitable for FISH in Plants

Profiling DNA Replication Timing Using Zebrafish as an In Vivo Model System

DNA replication timing is an important cellular characteristic, exhibiting significant relationships with chromatin structure, transcription, and DNA mutation rates. Changes in replication timing occur during development and in cancer, but the role replication timing plays in development and disease is not known. Zebrafish were recently established as an in vivo model system to study replication timing. Here is detailed the protocols for using the zebrafish to determine DNA replication timing. After sorting cells from embryos and adult zebrafish, high-resolution genome-wide DNA replication timing patterns can be constructed by determining changes in DNA copy number through analysis of next generation sequencing data. The zebrafish model system allows for evaluation of the replication timing changes that occur in vivo throughout development, and can also be used to assess changes in individual cell types, disease models, or mutant lines. These methods will enable studies investigating the mechanisms and determinants of replication timing establishment and maintenance during development, the role replication timing plays in mutations and tumorigenesis, and the effects of perturbing replication timing on development and disease.

Profiling DNA Replication Timing Using Zebrafish as an In Vivo Model System

Zebrafish were recently used as an in vivo model system to study DNA replication timing during development. Here is detailed the protocols for using zebrafish embryos to profile replication timing. This protocol can be easily adapted to study replication timing in mutants, individual cell types, disease models, and other species.

Zebra balığı bir Vivo içinde Model sistemi olarak kullanarak DNA çoğaltma zamanlaması profil oluşturma

DNA replication timing is an important cellular characteristic, exhibiting significant relationships with chromatin structure, transcription, and DNA ...

Genetik

Ploidy Manipulation of Zebrafish Embryos with Heat Shock 2 Treatment

Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, specifically the generation of homozygous gynogenetic diploids is useful in genetic analysis because it allows the direct production of homozygotes from a single heterozygous mother. This article describes a modified protocol for ploidy duplication based on a heat pulse during the first cell cycle, Heat Shock 2 (HS2). Through inhibition of centriole duplication, this method results in a precise cell division stall during the second cell cycle. The precise one-cycle division stall, coupled to unaffected DNA duplication, results in whole genome duplication. Protocols associated with this method include egg and sperm collection, UV treatment of sperm, in vitro fertilization and heat pulse to cause a one-cell cycle division delay and ploidy duplication. A modified version of this protocol could be applied to induce ploidy changes in other animal species.

A modified protocol for ploidy manipulation uses a heat shock to induce a one-cycle stall in cytokinesis in the early embryo. This protocol is demonstrated in the zebrafish but may be applicable to other species.

Isıl Şok 2 Tedavi ile Zebra balığı Embriyolar ploidisi Manipülasyon

Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, ...

Gelişim Biyolojisi

Fluorescent in situ Hybridization on Mitotic Chromosomes of Mosquitoes

Fluorescent in situ hybridization (FISH) is a technique routinely used by many laboratories to determine the chromosomal position of DNA and RNA probes. One important application of this method is the development of high-quality physical maps useful for improving the genome assemblies for various organisms. The natural banding pattern of polytene and mitotic chromosomes provides guidance for the precise ordering and orientation of the genomic supercontigs. Among the three mosquito genera, namely Anopheles, Aedes, and Culex, a well-established chromosome-based mapping technique has been developed only for Anopheles, whose members possess readable polytene chromosomes 1. As a result of genome mapping efforts, 88% of the An. gambiae genome has been placed to precise chromosome positions 2,3 . Two other mosquito genera, Aedes and Culex, have poorly polytenized chromosomes because of significant overrepresentation of transposable elements in their genomes 4, 5, 6. Only 31 and 9% of the genomic supercontings have been assigned without order or orientation to chromosomes of Ae. aegypti 7 and Cx. quinquefasciatus 8, respectively. Mitotic chromosome preparation for these two species had previously been limited to brain ganglia and cell lines. However, chromosome slides prepared from the brain ganglia of mosquitoes usually contain low numbers of metaphase plates 9. Also, although a FISH technique has been developed for mitotic chromosomes from a cell line of Ae. aegypti 10, the accumulation of multiple chromosomal rearrangements in cell line chromosomes 11 makes them useless for genome mapping. Here we describe a simple, robust technique for obtaining high-quality mitotic chromosome preparations from imaginal discs (IDs) of 4th instar larvae which can be used for all three genera of mosquitoes. A standard FISH protocol 12 is optimized for using BAC clones of genomic DNA as a probe on mitotic chromosomes of Ae. aegypti and Cx. quinquefasciatus, and for utilizing an intergenic spacer (IGS) region of ribosomal DNA (rDNA) as a probe on An. gambiae chromosomes. In addition to physical mapping, the developed technique can be applied to population cytogenetics and chromosome taxonomy/systematics of mosquitoes and other insect groups.

Fluorescent in situ Hybridization on Mitotic Chromosomes of Mosquitoes

Among the three mosquito genera, namely Anopheles, Aedes, and Culex, physical genome mapping techniques were established only for Anopheles, whose members possess readable polytene chromosomes. For the genera of Aedes and Culex, however, cytogenetic mapping remains challenging because of the poor quality of polytene chromosomes. Here we present a universal protocol for obtaining high-quality preparations of mitotic chromosomes and an optimized FISH protocol for all three genera of mosquitoes.

Floresan<em&gt; In situ</emSivrisinekler ve Mitotik Kromozomlar üzerinde&gt; Hibridizasyon

Fluorescent in situ hybridization (FISH) is a technique routinely used by many laboratories to determine the chromosomal position of DNA and RNA probes. ...

İmmünoloji ve Enfeksiyon

Preparation of Meiotic Chromosome Spreads from Zebrafish Spermatocytes

Meiosis is the key cellular process required to create haploid gametes for sexual reproduction. Model organisms have been instrumental in understanding the chromosome events that take place during meiotic prophase, including the pairing, synapsis, and recombination events that ensure proper chromosome segregation. While the mouse has been an important model for understanding the molecular mechanisms underlying these processes, not all meiotic events in this system are analogous to human meiosis. We recently demonstrated the exciting potential of the zebrafish as a model of human spermatogenesis. Here we describe, in detail, our methods to visualize meiotic chromosomes and associated proteins in chromosome spread preparations. These preparations have the advantage of allowing high resolution analysis of chromosome structures. First, we describe the procedure for dissecting testes from adult zebrafish, followed by cell dissociation, lysis, and spreading of the chromosomes. Next, we describe the procedure for detecting the localization of meiotic chromosome proteins, by immunofluorescence detection, and nucleic acid sequences, by fluorescence in situ hybridization (FISH). These techniques comprise a useful set of tools for the cytological analysis of meiotic chromatin architecture in the zebrafish system. Researchers in the zebrafish community should be able to quickly master these techniques and incorporate them into their standard analyses of reproductive function.

Nuclear surface spreads are an indispensable tool for studying chromosome events during meiosis. Here we demonstrate a method to prepare and visualize meiotic chromosomes during prophase I from zebrafish spermatocytes.

Zebrabalığı Spermatositlerinden Meiotik Kromozom Spreadlerinin Hazırlanması

Meiosis is the key cellular process required to create haploid gametes for sexual reproduction. Model organisms have been instrumental in understanding ...

Co-expression of Multiple Chimeric Fluorescent Fusion Proteins in an Efficient Way in Plants

Information about the spatiotemporal subcellular localization(s) of a protein is critical to understand its physiological functions in cells. Fluorescent proteins and generation of fluorescent fusion proteins have been wildly used as an effective tool to directly visualize the protein localization and dynamics in cells. It is especially useful to compare them with well-known organelle markers after co-expression with the protein of interest. Nevertheless, classical approaches for protein co-expression in plants usually involve multiple independent expression plasmids, and therefore have drawbacks that include low co-expression efficiency, expression-level variation, and high time expenditure in genetic crossing and screening. In this study, we describe a robust and novel method for co-expression of multiple chimeric fluorescent proteins in plants. It overcomes the limitations of the conventional methods by using a single expression vector that is composed of multiple semi-independent expressing cassettes. Each protein expression cassette contains its own functional protein expression elements, and therefore it can be flexibly adjusted to meet diverse expression demand. Also, it is easy and convenient to perform the assembly and manipulation of DNA fragments in the expression plasmid by using an optimized one-step reaction without additional digestion and ligation steps. Furthermore, it is fully compatible with current fluorescent protein derived bio-imaging technologies and applications, such as FRET and BiFC. As a validation of the method, we employed this new system to co-express fluorescently fused vacuolar sorting receptor and secretory carrier membrane proteins. The results show that their perspective subcellular localizations are the same as in previous studies by both transient expression and genetic transformation in plants.

We have developed a novel method for co-expressing multiple chimeric fluorescent fusion proteins in plants to overcome the difficulties of conventional methods. It takes advantage of using a single expression plasmid that contains multiple functionally independent protein expressing cassettes to achieve protein co-expression.

Bitkilerde etkin bir şekilde birden fazla Chimeric floresan Fusion proteinlerin ortak ifade

Information about the spatiotemporal subcellular localization(s) of a protein is critical to understand its physiological functions in cells. Fluorescent ...

Kimya

2D and 3D Chromosome Painting in Malaria Mosquitoes

Fluorescent in situ hybridization (FISH) of whole arm chromosome probes is a robust technique for mapping genomic regions of interest, detecting chromosomal rearrangements, and studying three-dimensional (3D) organization of chromosomes in the cell nucleus. The advent of laser capture microdissection (LCM) and whole genome amplification (WGA) allows obtaining large quantities of DNA from single cells. The increased sensitivity of WGA kits prompted us to develop chromosome paints and to use them for exploring chromosome organization and evolution in non-model organisms. Here, we present a simple method for isolating and amplifying the euchromatic segments of single polytene chromosome arms from ovarian nurse cells of the African malaria mosquito Anopheles gambiae. This procedure provides an efficient platform for obtaining chromosome paints, while reducing the overall risk of introducing foreign DNA to the sample. The use of WGA allows for several rounds of re-amplification, resulting in high quantities of DNA that can be utilized for multiple experiments, including 2D and 3D FISH. We demonstrated that the developed chromosome paints can be successfully used to establish the correspondence between euchromatic portions of polytene and mitotic chromosome arms in An. gambiae. Overall, the union of LCM and single-chromosome WGA provides an efficient tool for creating significant amounts of target DNA for future cytogenetic and genomic studies.

Chromosome painting is a useful method for studying organization of the cell nucleus and evolution of the karyotype. Here, we demonstrate an approach to isolate and amplify specific regions of interest from single polytene chromosomes that are subsequently used for two- and three-dimensional fluorescent in situ hybridization (FISH).

Sıtma Sivrisineklerinde 2D ve 3D Kromozom Boyama

Fluorescent in situ hybridization (FISH) of whole arm chromosome probes is a robust technique for mapping genomic regions of interest, detecting ...

A High-Throughput Method For Zebrafish Sperm Cryopreservation and In Vitro Fertilization

This is a method for zebrafish sperm cryopreservation that is an adaptation of the Harvey method (Harvey et al., 1982).  We have introduced two changes to the original protocol that both streamline the procedure and increase sample uniformity.  First, we normalize all sperm volumes using freezing media that does not contain the cryoprotectant. Second, cryopreserved sperm are stored in cryovials instead of capillary tubes.  The rates of sperm freezing and thawing (&delta;&deg;C/time) are probably the two most critical variables to control in this procedure.  For this reason, do not substitute different tubes for those specified.  Working in teams of 2 it is possible to freeze the sperm of 100 males per team in ~2 hrs.  Sperm cryopreserved using this protocol has an average of 25% fertility (measured as the number of viable embryos generated in an in vitro fertilization divided by the total number of eggs fertilized) and this percent fertility is stable over many years.

A High-Throughput Method For Zebrafish Sperm Cryopreservation and In Vitro Fertilization

This is a high-throughput sperm cryopreservation protocol for zebrafish. Sperm cryopreserved using this protocol has an average of 25% fertility in subsequent vitro fertilization and is stable over many years.

Zebra balığı sperm Kriyoprezervasyon için bir Yüksek Verim Yöntem ve In Vitro Gübreleme

This is a method for zebrafish sperm cryopreservation that is an adaptation of the Harvey method (Harvey et al., 1982).  We have introduced two changes to ...

Biyoloji

Making Gynogenetic Diploid Zebrafish by Early Pressure

Heterozygosity in diploid eukaryotes often makes genetic studies cumbersome. Methods that produce viable homozygous diploid offspring directly from heterozygous females allow F1 mutagenized females to be screened directly for deleterious mutations in an accelerated forward genetic screen. Streisinger et al.1,2 described methods for making gynogenetic (homozygous) diploid zebrafish by activating zebrafish eggs with ultraviolet light-inactivated sperm and preventing either the second meiotic or the first zygotic cell division using physical treatments (heat or pressure) that deploymerize microtubules. The "early pressure" (EP) method blocks the meiosis II, which occurs shortly after fertilization. The EP method produces a high percentage of viable embryos that can develop to fertile adults of either sex. The method generates embryos that are homozygous at all loci except those that were separated from their centromere by recombination during meiosis I. Homozygous mutations are detected in EP clutches at between 50% for centromeric loci and less than 1% for telomeric loci. This method is reproduced verbatim from the Zebrafish Book3.

This is a method for generating gynogenetic diploid zebrafish embryos (embryos whose only genetic contribution comes from the mother) by blocking the second meiotic division immediately after fertilization with ultraviolet light-inactivated sperm. EP embryos are not fully homozygous due to recombination during the first meiotic division, however they are homozygous at all loci that have not been separated from their centromere by recombination.

Erken Basınç Gynogenetic Diployid Zebra balığı

Heterozygosity in diploid eukaryotes often makes genetic studies cumbersome. Methods that produce viable homozygous diploid offspring directly from ...

Slide Preparation Method to Preserve Three-dimensional Chromatin Architecture of Testicular Germ Cells

During testicular germ cell differentiation, the structure of nuclear chromatin dynamically changes. The following describes a method designed to preserve the three-dimensional chromatin arrangement of testicular germ cells found in mice; this method has been termed as the three-dimensional (3D) slide method. In this method, testicular tubules are directly treated with a permeabilization step that removes cytoplasmic material, followed by a fixation step that fixes nuclear materials. Tubules are then dissociated, the cell suspension is cytospun, and cells adhere to slides. This method improves sensitivity towards detection of subnuclear structures and is applicable for immunofluorescence, DNA, and RNA fluorescence in situ hybridization (FISH) and the combination of these detection methods. As an example of a possible application of the 3D slide method, a Cot-1 RNA FISH is shown to detect nascent RNAs. The 3D slide method will facilitate the detailed examination of spatial relationships between chromatin structure, DNA, and RNA during testicular germ cell differentiation.

The material here describes a method developed to preserve the three-dimensional chromatin structure of testicular germ cells. This has been termed the three-dimensional (3D) slide method. This method improves sensitivity for detection of subnuclear structures and is applicable for immunofluorescence, DNA, and RNA fluorescence in situ hybridization (FISH).

Testis Germ Hücrelerinin Üç Boyutlu Kromatin Mimarisini Korumak için Slayt Hazırlama Yöntemi

During testicular germ cell differentiation, the structure of nuclear chromatin dynamically changes. The following describes a method designed to preserve ...

Silencing the Spark: CRISPR/Cas9 Genome Editing in Weakly Electric Fish

Electroreception and electrogenesis have changed in the evolutionary history of vertebrates. There is a striking degree of convergence in these independently derived phenotypes, which share a common genetic architecture. This is perhaps best exemplified by the numerous convergent features of gymnotiforms and mormyrids, two species-rich teleost clades that produce and detect weak electric fields and are called weakly electric fish. In the 50 years since the discovery that weakly electric fish use electricity to sense their surroundings and communicate, a growing community of scientists has gained tremendous insights into evolution of development, systems and circuits neuroscience, cellular physiology, ecology, evolutionary biology, and behavior. More recently, there has been a proliferation of genomic resources for electric fish. Use of these resources has already facilitated important insights with regards to the connection between genotype and phenotype in these species. A major obstacle to integrating genomics data with phenotypic data of weakly electric fish is a present lack of functional genomics tools. We report here a full protocol for performing CRISPR/Cas9 mutagenesis that utilizes endogenous DNA repair mechanisms in weakly electric fish. We demonstrate that this protocol is equally effective in both the mormyrid species Brienomyrus brachyistius and the gymnotiform Brachyhypopomus gauderio by using CRISPR/Cas9 to target indels and point mutations in the first exon of the sodium channel gene scn4aa. Using this protocol, embryos from both species were obtained and genotyped to confirm that the predicted mutations in the first exon of the sodium channel scn4aa were present. The knock-out success phenotype was confirmed with recordings showing reduced electric organ discharge amplitudes when compared to uninjected size-matched controls.

Here, a protocol is presented to produce and rear CRISPR/Cas9 genome knockout electric fish. Outlined in detail are the required molecular biology, breeding, and husbandry requirements for both a gymnotiform and a mormyrid, and injection techniques to produce Cas9-induced indel F0 larvae.

Bitkilerde FISH için uygun bir Hızlı Hava kuru Damlama Kromozom Hazırlama Yöntemi

Özet

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