Mutant worm strains were kindly provided by the Caenorhabditis Genetics Center. This research was supported by a grant of the Korea Health Technology R&amp;D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health &amp; Welfare, Republic of Korea (grant number: HI14C1277).

<ol>
	<li>Reddel, R. R., Bryan, T. M., Murnane, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immortalized+cells+with+no+detectable+telomerase+activity.+A+review.">Immortalized cells with no detectable telomerase activity. A review.</a> Biochemistry-Moscow. 62, 1254-1262 (1997).</li><li>Seo, B., 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=Telomere+maintenance+through+recruitment+of+internal+genomic+regions.">Telomere maintenance through recruitment of internal genomic regions.</a> Nat Commun. 6, 8189 (2015).</li><li>Cesare, A. J., Reddel, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alternative+lengthening+of+telomeres:+models,+mechanisms+and+implications.">Alternative lengthening of telomeres: models, mechanisms and implications.</a> Nat Rev Genet. 11, 319-330 (2010).</li><li>Meier, B., 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=trt-1+is+the+Caenorhabditis+elegans+catalytic+subunit+of+telomerase.">trt-1 is the Caenorhabditis elegans catalytic subunit of telomerase.</a> Plos Genetics. 2, 187-197 (2006).</li><li>Cawthon, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Telomere+measurement+by+quantitative+PCR.">Telomere measurement by quantitative PCR.</a> Nucleic Acids Res. 30, 47 (2002).</li><li>Raices, M., Maruyama, H., Dillin, A., Karlseder, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uncoupling+of+longevity+and+telomere+length+in+C.+elegans.">Uncoupling of longevity and telomere length in C. elegans.</a> PLoS Genet. 1, 30 (2005).</li><li>Southern, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+Specific+Sequences+among+DNA+Fragments+Separated+by+Gel-Electrophoresis.">Detection of Specific Sequences among DNA Fragments Separated by Gel-Electrophoresis.</a> Journal of Molecular Biology. 98, 503 (1975).</li><li>Lee, M., 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=Telomere+extension+by+telomerase+and+ALT+generates+variant+repeats+by+mechanistically+distinct+processes.">Telomere extension by telomerase and ALT generates variant repeats by mechanistically distinct processes.</a> Nucleic Acids Res. 42, 1733-1746 (2014).</li><li>Cheung, I., 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=Strain-specific+telomere+length+revealed+by+single+telomere+length+analysis+in+Caenorhabditis+elegans.">Strain-specific telomere length revealed by single telomere length analysis in Caenorhabditis elegans.</a> Nucleic Acids Res. 32, 3383-3391 (2004).</li><li>Shtessel, L., 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=Caenorhabditis+elegans+POT-1+and+POT-2+repress+telomere+maintenance+pathways.">Caenorhabditis elegans POT-1 and POT-2 repress telomere maintenance pathways.</a> G3. 3, 305-313 (2013).</li><li>Duerr, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunohistochemistry.">Immunohistochemistry.</a> WormBook (The C. elegans Research Community). , (2006).</li><li>Phillips, C. M., McDonald, K. L., Dernburg, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytological+analysis+of+meiosis+in+Caenorhabditis+elegans.">Cytological analysis of meiosis in Caenorhabditis elegans.</a> Meiosis: Volume 2, Cytological Methods. , 171-195 (2009).</li><li>Emanuel, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simple+and+efficient+system+for+synthesis+of+non-radioactive+nucleic+acid+hybridization+probes+using+PCR.">Simple and efficient system for synthesis of non-radioactive nucleic acid hybridization probes using PCR.</a> Nucleic acids research. 19, 2790 (1991).</li><li>Stiernagle, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maintenance+of+C.+elegans.">Maintenance of C. elegans.</a> WormBook. , 1-11 (2006).</li><li>Porta-de-la-Riva, M., Fontrodona, L., Villanueva, A., Ceron, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+Caenorhabditis+elegans+methods:+synchronization+and+observation.">Basic Caenorhabditis elegans methods: synchronization and observation.</a> J Vis Exp. , e4019 (2012).</li><li>Poon, S. S. S., Martens, U. M., Ward, R. K., Lansdorp, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Telomere+length+measurements+using+digital+fluorescence+microscopy.">Telomere length measurements using digital fluorescence microscopy.</a> Cytometry. 36, 267-278 (1999).</li><li>Ferreira, H. C., Towbin, B. D., Jegou, T., Gasser, S. 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+shelterin+protein+POT-1+anchors+Caenorhabditis+elegans+telomeres+through+SUN-1+at+the+nuclear+periphery.">The shelterin protein POT-1 anchors Caenorhabditis elegans telomeres through SUN-1 at the nuclear periphery.</a> J Cell Biol. 203, 727-735 (2013).</li><li>Lee, M. H., Schedl, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA+in+situ+hybridization+of+dissected+gonads.">RNA in situ hybridization of dissected gonads.</a> WormBook. , 1-7 (2006).</li><li>Tabara, H., Motohashi, T., Kohara, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+multi-well+version+of+in+situ+hybridization+on+whole+mount+embryos+of+Caenorhabditis+elegans.">A multi-well version of in situ hybridization on whole mount embryos of Caenorhabditis elegans.</a> Nucleic Acids Res. 24, 2119-2124 (1996).</li><li>Poon, S. S., Lansdorp, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+fluorescence+in+situ+hybridization+(Q-FISH).">Quantitative fluorescence in situ hybridization (Q-FISH).</a> Curr Protoc Cell Biol. 18, 14 (2001).</li></ol>

The authors have nothing to disclose.

والميزة الرئيسية لبروتوكول لدينا هي بساطة الإجراء دون ضرر ملحوظ على التشكل من الهيكل الخلوي. تم الأمثل عدة خطوات لC. FISH ايليجانس في هذا البروتوكول. وتشمل الخطوات الحاسمة لFISH الناجح وضع العلامات من تحقيقات، تثبيت الأجنة والاختراق. يوفر Digoxigenin-dUTP طريقة وضع ال?...

التيلومير يحمي نهايات الكروموسومات من الانصهار الشاذة والتدهور. يتكون التيلومير الثدييات يكرر G الغنية hexameric، TTAGGG، والمجمعات shelterin. تسلسل التيلومير تكرار الديدان الخيطية هي مماثلة لتلك التي من الثدييات (TTAGGC). معظم حقيقيات النوى الاستفادة تيلوميراز إضافة يكرر التيلومير إلى غاياتهم الكروموسومات. ومع ذلك، 10 - 15٪ من الخلايا السرطانية تستخدم التيلوميراز آلية مستقلة، والمعروفة باسم البديل تطويل التيلوميرات (ALT) 3. سابقا، وذكرت أن يكرر شريط الحامض النووي ومتواليات المرتبطة به، ويدعى تالت، وتضخمت في التيلوميرات من خطوط متحولة التيلوميراز التي نجت العقم حرجة 2. وقد تم قياس طول التيلومير بواسطة PCR الكمي أو اللطخة الجنوبية، التي تنص على متوسط ​​طول التيلومير من إجمالي 4،5،6،7. قراءة عدد من تكرار التيلومير في كامل البيانات تسلسل الجينوم هو أيضا مؤشرا من إجمالي محتويات التيلومير 8. على الرغم من الخطيئةغلي التيلومير طول تحليل (STELA) يمكن أن توفر طول التيلومير واحد، فإنه لا يمكن أن توفر معلومات المكانية التيلومير 9. في حين POT-1 :: mCherry البروتين مراسل يوفر المعلومات المكانية التيلومير في الجسم الحي، فإنه لا يمكن أن تمثل أطوال التيلومير المزدوج تقطعت بهم السبل، كما POT-1 هو التيلومير واحد حبلا البروتين 10 ملزمة. بينما توفر طرق المذكورة أعلاه المعلومات المتوسط ​​من تسلسل المتكررة، مضان في الموقع التهجين (FISH) يسمح لمراقبة كمية ونمط المكاني للتسلسل الفردية للاهتمام على نطاق والكروموسومات. بدلا من تنقية الحمض النووي، يتم إصلاح الأنسجة أو الخلايا للحفاظ على المعلومات المكانية المحلية في الأسماك. وهكذا، FISH هو أداة الكمية والنوعية على حد سواء لرصد تسلسل تكرار الفردية، مثل تكرار التيلومير. يوفر هذا البروتوكول وسيلة فعالة للكشف في وقت واحد على حد سواء TELOمجرد وأخرى يكرر على أساس التحسينات من الأساليب المذكورة سابقا 11،12. C. ايليجانس اليرقات أو البالغين متعددة الخلايا مع خلايا متباينة للغاية. عدم تجانس الخلايا يعرقل على التحليل الكمي لعدد كبير من البقع التيلومير. لزيادة عدد الخلايا تحليلها والأجنة معزولة وانتشرت على الشرائح المغلفة متعدد الليزين للأسماك. وبالإضافة إلى ذلك، يمكن لهذا البروتوكول أيضا أن تقترن المناعي. كبرهان أن يعمل البروتوكول، وتبين لنا أنه من الممكن لمراقبة وتحديد اثنين من سلاسل متكررة مختلفة. تم إنشاء مسبار الحمض النووي ضد TALT1 مع بسيطة PCR دمج digoxigenin-dUTP. ثم تم تهجين هذه مسبار TALT1 ومضان المسمى التيلومير السلطة الوطنية الفلسطينية التحقيق في وقت واحد. وفي وقت لاحق، تم الكشف عن digoxigenin بالطرق المناعي الكنسي. نقدم هنا الصور التمثيلية حيث TALT1 colocalized مع التيلومير في TRT-1 </eم&gt; الناجين.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>PNA probe</td>
			<td>PANAGENE</td>
			<td>custom order</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Digoxigenin-Fluorescein, Fab fragments</td>
			<td>Roche</td>
			<td>11207741910</td>
			<td>use 1:200 diluted in PBST</td>
		</tr>
		<tr>
			<td>Digoxigenin-dUTP</td>
			<td>Roche</td>
			<td>11573152910</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine serum albumin</td>
			<td>SIGMA-ALDRICH</td>
			<td>A-7906</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>SIGMA-ALDRICH</td>
			<td>P-6148</td>
			<td>prepare 4% paraformaldehyde by heating in DW with few drops of NaOH. add 0.1 volume of 10x PBS.</td>
		</tr>
		<tr>
			<td>Vectashield</td>
			<td>Vector Laboratories</td>
			<td>H-1200</td>
			<td></td>
		</tr>
		<tr>
			<td>Hybridizaiton solution</td>
			<td></td>
			<td></td>
			<td>3X SSC, 50% formamide, 10% (w/v) dextran sulfate, 50 ug/ml heparin, 100 ug/ml yeast tRNA , 100ug/ml sonicated salmon sperm DNA</td>
		</tr>
		<tr>
			<td>Hybridizaiton wash solution</td>
			<td></td>
			<td></td>
			<td>2X SSC, 50% formamide</td>
		</tr>
		<tr>
			<td>Formamide</td>
			<td>BIONEER</td>
			<td>C-9012</td>
			<td>toxic</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Carlo Erba</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Carlo Erba</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Heparin</td>
			<td>SIGMA-ALDRICH</td>
			<td>H3393</td>
			<td>make 10 mg/ml for stock solution</td>
		</tr>
		<tr>
			<td>Dextran sulfate</td>
			<td>SIGMA-ALDRICH</td>
			<td>67578</td>
			<td></td>
		</tr>
		<tr>
			<td>10X PBS</td>
			<td></td>
			<td></td>
			<td>For 1 Liter DW : 80 g NaCl, 2.0 g KCl, 27 g Na2HPO4:7H2O, 2.4 g KH2PO</td>
		</tr>
		<tr>
			<td>PBST</td>
			<td></td>
			<td></td>
			<td>1X PBS, 0.1% tween-20</td>
		</tr>
		<tr>
			<td>Polysorbate 20</td>
			<td>SIGMA-ALDRICH</td>
			<td>P-2287</td>
			<td>Commercial name is Tween-20</td>
		</tr>
		<tr>
			<td>Poly-L-Lysine solution (0.1 % w/v)</td>
			<td>SIGMA-ALDRICH</td>
			<td>P-8920</td>
			<td>prepare fresh 0.01 % w/v solution before use</td>
		</tr>
		<tr>
			<td>M9</td>
			<td></td>
			<td></td>
			<td>3 g KH2PO4, 6 g Na2HPO4, 5 g NaCl, 1 ml 1 M MgSO4, H2O to 1 L</td>
		</tr>
		<tr>
			<td>Bleaching solution</td>
			<td></td>
			<td></td>
			<td>20% sodium hypochlorite, 0.5 M KOH</td>
		</tr>
		<tr>
			<td>Antibody buffer</td>
			<td></td>
			<td></td>
			<td>1X PBST, 1mM EDTA, 0.1% BSA, 0.05% Sodium azide (toxic)</td>
		</tr>
		<tr>
			<td>Blocking solution</td>
			<td></td>
			<td></td>
			<td>Antibody buffer with 5% bovine serum albumin (BSA)</td>
		</tr>
		<tr>
			<td>illustra Microspin G-50</td>
			<td>GE healthcare</td>
			<td>27-53310-01</td>
			<td></td>
		</tr>
		<tr>
			<td>20X SSC</td>
			<td></td>
			<td></td>
			<td>To make 1L, 175.3 g of NaCl, 88.2 g of sodium citrate, H2O to 1 L, adjust pH to 7.0</td>
		</tr>
		<tr>
			<td>2X SSCT</td>
			<td></td>
			<td></td>
			<td>2X SSC, 0.1 % tween-20</td>
		</tr>
		<tr>
			<td>10x digoxigenin-dUTP mix</td>
			<td></td>
			<td></td>
			<td>1 mM dATP, 1 mM dGTP, 1 mM dCTP, 0.65mM dTTP, 0.35mM DIG-11-dUTP</td>
		</tr>
		<tr>
			<td>PCR purification columns</td>
			<td>Cosmo genetech</td>
			<td>CMR0112</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass cleaner / ULTRA CLEAN</td>
			<td>Dukssan pure chemicals</td>
			<td>8AV721</td>
			<td></td>
		</tr>
		<tr>
			<td>Multi-well glass slide</td>
			<td>MP biomedicals</td>
			<td>96041205</td>
			<td></td>
		</tr>
		<tr>
			<td>Nematode growth media</td>
			<td></td>
			<td></td>
			<td>to make 1 L, 3 g of NaCl, 17 g of agar, 2.5 g of peptone, H2O to 974 mL. Autoclave and cool the flask. Add 1 mL of 1M CaCl2, 1 ml of 4 mg/mL cholesterol in ethanol, 1 ml of 1 M MgSO4, 25 mL of 1 M KPO4.</td>
		</tr>
		<tr>
			<td>Levamisole</td>
			<td>SIGMA-ALDRICH</td>
			<td>196142</td>
			<td></td>
		</tr>
		<tr>
			<td>Razor</td>
			<td>Feather</td>
			<td>blade No. 11</td>
			<td></td>
		</tr>
		<tr>
			<td>Rnase A</td>
			<td>Enzynomics</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>SIGMA-ALDRICH</td>
			<td>A7906</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Equipments</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal microsope</td>
			<td>Zeiss</td>
			<td>LSM 510</td>
			<td>EC Plan-Neofluar 100x was used as objective lens.</td>
		</tr>
		<tr>
			<td>Dry block / aluminum block</td>
			<td>Labtech</td>
			<td>LBH-T03</td>
			<td>Set temperature to 80&#8451;</td>
		</tr>
		<tr>
			<td>Humid chamber</td>
			<td></td>
			<td></td>
			<td>Plastic box filled with paper towel soaked in DW</td>
		</tr>
		<tr>
			<td>Image Analysis Software&#160;</td>
			<td>Dr. Peter Landsdorp</td>
			<td>TFL-telo</td>
			<td><a href="http://www.flintbox.com/public/project/502">http://www.flintbox.com/public/project/502</a></td>
		</tr>
	</tbody>
</table>

observation and quantification of telomere and repetitive sequences using fluorescence in situ hybridization (fish) with pna probes in caenorhabditis elegans

Telomere is a ribonucleoprotein structure that protects chromosomal ends from aberrant fusion and degradation. Telomere length is maintained by telomerase or an alternative pathway, known as alternative lengthening of telomeres (ALT)1. Recently, C. elegans has emerged as a multicellular model organism for the study of telomere and ALT2. Visualization of repetitive sequences in the genome is critical in understanding the biology of telomeres. While telomere length can be measured by telomere restriction fragment assay or quantitative PCR, these methods only provide the averaged telomere length. On the contrary, fluorescence in situ hybridization (FISH) can provide the information of the individual telomeres in cells. Here, we provide protocols and representative results of the method to determine telomere length of C. elegans by fluorescent in situ hybridization. This method provides a simple, but powerful, in situ procedure that does not cause noticeable damage to morphology. By using fluorescently labeled peptide nucleic acid (PNA) and digoxigenin-dUTP-labeled probe, we were able to visualize two different repetitive sequences: telomere repeats and template of ALT (TALT) in C. elegans embryos and gonads.

وذكر في وقت سابق أن الناجين ALT يمكن أن تنشأ من المسخ-التيلوميراز ناقصة، TRT-1 (ok410)، في التردد المنخفض من تكرار محلية داخليا قالب من ALT &quot;(تالت) تسلسل للصيانة التيلومير 2. عن طريق السلطة الوطنية الفلسطينية التحقيق، كنا قادرين على تصور التيلوم?...

Watch this Scientific Journal Video about Observation and Quantification of Telomere and Repetitive Sequences Using Fluorescence In Situ Hybridization FISH with PNA Probes in Caenorhabditis elegans at

Observation and Quantification of Telomere and Repetitive Sequences Using Fluorescence In Situ Hybridization FISH with PNA Probes in Caenorhabditis elegans

We report a concise procedure of fluorescence in situ hybridization (FISH) in the gonad and embryos of Caenorhabditis elegans for observing and quantifying repetitive sequences. We successfully observed and quantified two different repetitive sequences, telomere repeats and template of alternative lengthening of telomeres (TALT).

المراقبة والكمي لالتيلومير وتسلسل المتكررة عن طريق الإسفار<em&gt; في الموقع</em&gt; التهجين (FISH) مع السلطة الوطنية الفلسطينية تحقيقات في<em&gt; انواع معينة ايليجانس</em

Telomere is a ribonucleoprotein structure that protects chromosomal ends from aberrant fusion and degradation. Telomere length is maintained by telomerase ...

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Biology

Observation and Quantification of Telomere and Repetitive Sequences Using Fluorescence In Situ Hybridization (FISH) with PNA Probes in Caenorhabditis elegans

10.3K Views.  Seoul National University. We report a concise procedure of fluorescence in situ hybridization (FISH) in the gonad and embryos of Caenorhabditis elegans for observing and quantifying repetitive sequences. We successfully observed and quantified two different repetitive sequences, telomere repeats and template of alternative lengthening of telomeres (TALT). 

Video: Observation and Quantification of Telomere and Repetitive Sequences Using Fluorescence In Situ Hybridization FISH with PNA Probes in Caenorhabditis elegans

Fluorescence in situ hybridization (FISH) Protocol in Human Sperm

Aneuploidies are the most frequent chromosomal abnormalities in humans. Most of these abnormalities result from meiotic errors during the gametogenic process in the parents. In human males, these errors can lead to the production of spermatozoa with numerical chromosome abnormalities which represent an increased risk of transmitting these anomalies to the offspring.
For this reason, the technique of fluorescence in situ hybridization (FISH) on sperm nuclei has become a protocol widely incorporated in the context of clinical diagnosis. This practice provides an estimate of the frequencies of numerical chromosome abnormalities in the gametes of the patients that seek for genetic reproductive advice.
To date, the chromosomes most frequently included in sperm FISH analysis are chromosomes X, Y, 13, 18 and 21.
This video-article describes, step by step, how to process and fix a human semen sample, how to decondense and denature the sperm chromatin, how to proceed to obtain sperm FISH preparations, and how to visualize the results at the microscope. Special remarks of the most relevant steps are given to achieve the best results.

Fluorescence in situ hybridization FISH Protocol in Human Sperm

This video-article describes, step by step, how to process a semen sample to achieve good-quality fluorescence in situ hybridization on human spermatozoa. Preparations obtained can be used for aneuploidy screening in the context of clinical diagnosis.

مضان في الموقع التهجين (FISH) البروتوكول في الحيوانات المنوية البشرية

Aneuploidies are the most frequent chromosomal abnormalities in humans. Most of these abnormalities result from meiotic errors during the gametogenic ...

Time-lapse Microscopy of Early Embryogenesis in Caenorhabditis elegans

Caenorhabditis elegans has often been used as a model system in studies of early developmental processes. The transparency of the 
embryos, the genetic resources, and the relative ease of transformation are qualities that make C. elegans an excellent model for early embryogenesis. Laser-based 
confocal microscopy and fluorescently labeled tags allow researchers to follow specific cellular structures and proteins in the developing embryo. For example, 
one can follow specific organelles, such as lysosomes or mitochondria, using fluorescently labeled dyes. These dyes can be delivered to the early embryo by means 
of microinjection into the adult gonad. Also, the localization of specific proteins can be followed using fluorescent protein tags. Examples are presented here 
demonstrating the use of a fluorescent lysosomal dye as well as fluorescently tagged histone and ubiquitin proteins. The labeled histone is used to visualize 
the DNA and thus identify the stage of the cell cycle. GFP-tagged ubiquitin reveals the dynamics of ubiquitinated vesicles in the early embryo. Observations 
of labeled lysosomes and GFP:: ubiquitin can be used to determine if there is colocalization between ubiquitinated vesicles and lysosomes. A technique for 
the microinjection of the lysosomal dye is presented. Techniques for generating transgenenic strains are presented elsewhere (1, 2). For imaging, embryos 
are cut out of adult hermaphrodite nematodes and mounted onto 2% agarose pads followed by time-lapse microscopy on a standard laser scanning confocal 
microscope or a spinning disk confocal microscope. This methodology provides for the high resolution visualization of early embryogenesis.

Time-lapse Microscopy of Early Embryogenesis in Caenorhabditis elegans

This article describes a technique for the visualization of the early events of embryogenesis in the nematode Caenorhabditis elegans.

الوقت الفاصل بين مرحلة التطور الجنيني المبكر من الميكروسكوب في انواع معينة ايليجانس

Caenorhabditis elegans has often been used as a model system in studies of early developmental processes.  The transparency of the 
embryos, the genetic ...

Detection of Viral RNA by Fluorescence in situ Hybridization (FISH)

Viruses that infect cells elicit specific changes to normal cell functions which serve to divert energy and resources for viral replication. Many aspects of host cell function are commandeered by viruses, usually by the expression of viral gene products that recruit host cell proteins and machineries. Moreover, viruses engineer specific membrane organelles or tag on to mobile vesicles and motor proteins to target regions of the cell (during de novo infection, viruses co-opt molecular motor proteins to target the nucleus; later, during virus assembly, they will hijack cellular machineries that will help in the assembly of viruses). Less is understood on how viruses, in particular those with RNA genomes, coordinate the intracellular trafficking of both protein and RNA components and how they achieve assembly of infectious particles at specific loci in the cell. The study of RNA localization began in earlier work. Developing lower eukaryotic embryos and neuronal cells provided important biological information, and also underscored the importance of RNA localization in the programming of gene expression cascades. The study in other organisms and cell systems has yielded similar important information. Viruses are obligate parasites and must utilise their host cells to replicate. Thus, it is critical to understand how RNA viruses direct their RNA genomes from the nucleus, through the nuclear pore, through the cytoplasm and on to one of its final destinations, into progeny virus particles 1.
FISH serves as a useful tool to identify changes in steady-state localization of viral RNA. When combined with immunofluorescence (IF) analysis 22, FISH/IF co-analyses will provide information on the co-localization of proteins with the viral RNA3. This analysis therefore provides a good starting point to test for RNA-protein interactions by other biochemical or biophysical tests 4,5, since co-localization by itself is not enough evidence to be certain of an interaction. In studying viral RNA localization using a method like this, abundant information has been gained on both viral and cellular RNA trafficking events 6. For instance, HIV-1 produces RNA in the nucleus of infected cells but the RNA is only translated in the cytoplasm. When one key viral protein is missing (Rev) 7, FISH of the viral RNA has revealed that the block to viral replication is due to the retention of the HIV-1 genomic RNA in the nucleus 8. 
Here, we present the method for visual analysis of viral genomic RNA in situ. The method makes use of a labelled RNA probe. This probe is designed to be complementary to the viral genomic RNA. During the in vitro synthesis of the antisense RNA probe, the ribonucleotide that is modified with digoxigenin (DIG) is included in an in vitro transcription reaction. Once the probe has hybridized to the target mRNA in cells, subsequent antibody labelling steps (Figure 1) will reveal the localization of the mRNA as well as proteins of interest when performing FISH/IF.

Detection of Viral RNA by Fluorescence in situ Hybridization FISH

A fluorescence in situ hybridization (FISH) method was developed to visually detect viral genomic RNA using fluorescence microscopy. A probe is made with specificity to the viral RNA that can then be identified using a combination of hybridization and immunofluorescence techniques. This technique offers the advantage of identifying the localization of the viral RNA or DNA at steady-state, providing information on the control of intracellular virus trafficking events.

الكشف عن الحمض النووي الريبي الفيروسي بواسطة الإسفار<em&gt; في الموقع</em&gt; التهجين (FISH)

Viruses  that infect cells elicit specific changes to normal cell functions which serve  to divert energy and resources for viral replication. Many ...

Basic Caenorhabditis elegans Methods: Synchronization and Observation

Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has since been used extensively as a model organism 1. C. elegans possesses key attributes such as simplicity, transparency and short life cycle that have made it a suitable experimental system for fundamental biological studies for many years 2. Discoveries in this nematode have broad implications because many cellular and molecular processes that control animal development are evolutionary conserved 3.
C. elegans life cycle goes through an embryonic stage and four larval stages before animals reach adulthood. Development can take 2 to 4 days depending on the temperature. In each of the stages several characteristic traits can be observed. The knowledge of its complete cell lineage 4,5 together with the deep annotation of its genome turn this nematode into a great model in fields as diverse as the neurobiology 6, aging 7,8, stem cell biology 9 and germ line biology 10. 
An additional feature that makes C. elegans an attractive model to work with is the possibility of obtaining populations of worms synchronized at a specific stage through a relatively easy protocol. The ease of maintaining and propagating this nematode added to the possibility of synchronization provide a powerful tool to obtain large amounts of worms, which can be used for a wide variety of small or high-throughput experiments such as RNAi screens, microarrays, massive sequencing, immunoblot or in situ hybridization, among others. 
Because of its transparency, C. elegans structures can be distinguished under the microscope using Differential Interference Contrast microscopy, also known as Nomarski microscopy. The use of a fluorescent DNA binder, DAPI (4',6-diamidino-2-phenylindole), for instance, can lead to the specific identification and localization of individual cells, as well as subcellular structures/defects associated to them.

Basic Caenorhabditis elegans Methods: Synchronization and Observation

The easiness of maintaining and propagating the nematode C. elegans make it a nice model organism to work with. The possibility of synchronizing worms allows the work with a significant amount of subjects at the same developmental stage, what facilitates the study of one particular process in many animals.

الأساسية<em&gt; Caenorhabditis ايليجانس</em&gt; طرق: التزامن والمراقبة

Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has ...

Analysis of Single-cell Gene Transcription by RNA Fluorescent In Situ Hybridization (FISH)

Adhesion of Plasmodium falciparum infected erythrocytes (IE) to human endothelial receptors during malaria infections is mediated by expression of PfEMP1 protein variants encoded by the var genes.
The haploid P. falciparum genome harbors approximately 60 different var genes of which only one has been believed to be transcribed per cell at a time during the blood stage of the infection. How such mutually exclusive regulation of var gene transcription is achieved is unclear, as is the identification of individual var genes or sub-groups of var genes associated with different receptors and the consequence of differential binding on the clinical outcome of P. falciparum infections. Recently, the mutually exclusive transcription paradigm has been called into doubt by transcription assays based on individual P. falciparum transcript identification in single infected erythrocytic cells using RNA fluorescent in situ hybridization (FISH) analysis of var gene transcription by the parasite in individual nuclei of P. falciparum IE1.
Here, we present a detailed protocol for carrying out the RNA-FISH methodology for analysis of var gene transcription in single-nuclei of P. falciparum infected human erythrocytes. The method is based on the use of digoxigenin- and biotin- labeled antisense RNA probes using the TSA Plus Fluorescence Palette System2 (Perkin Elmer), microscopic analyses and freshly selected P. falciparum IE. The in situ hybridization method can be used to monitor transcription and regulation of a variety of genes expressed during the different stages of the P. falciparum life cycle and is adaptable to other malaria parasite species and other organisms and cell types.

Analysis of Single-cell Gene Transcription by RNA Fluorescent In Situ Hybridization FISH

Fluorescent in situ hybridization (FISH) to identify mRNA transcripts in individual cells allows analysis of polygenic activity such as the simultaneous transcription of more than one member of the var multigene family in Plasmodium falciparum infected erythrocytes 1. The technique is adaptable and can be used on different types of genes, cells and organisms.

تحليل النسخ الجيني وحيدة الخلية التي كتبها نيون RNA<em&gt; في الموقع</em&gt; التهجين (FISH)

Adhesion of Plasmodium falciparum infected erythrocytes (IE) to human endothelial receptors during malaria infections is mediated by expression of PfEMP1 ...

Chromosome Replicating Timing Combined with Fluorescent In situ Hybridization

Mammalian DNA replication initiates at multiple sites along chromosomes at different times during S phase, following a temporal replication program. The specification of replication timing is thought to be a dynamic process regulated by tissue-specific and developmental cues that are responsive to epigenetic modifications. However, the mechanisms regulating where and when DNA replication initiates along chromosomes remains poorly understood. Homologous chromosomes usually replicate synchronously, however there are notable exceptions to this rule. For example, in female mammalian cells one of the two X chromosomes becomes late replicating through a process known as X inactivation1. Along with this delay in replication timing, estimated to be 2-3 hr, the majority of genes become transcriptionally silenced on one X chromosome. In addition, a discrete cis-acting locus, known as the X inactivation center, regulates this X inactivation process, including the induction of delayed replication timing on the entire inactive X chromosome. In addition, certain chromosome rearrangements found in cancer cells and in cells exposed to ionizing radiation display a significant delay in replication timing of &gt;3 hours that affects the entire chromosome2,3. Recent work from our lab indicates that disruption of discrete cis-acting autosomal loci result in an extremely late replicating phenotype that affects the entire chromosome4. Additional 'chromosome engineering' studies indicate that certain chromosome rearrangements affecting many different chromosomes result in this abnormal replication-timing phenotype, suggesting that all mammalian chromosomes contain discrete cis-acting loci that control proper replication timing of individual chromosomes5.
Here, we present a method for the quantitative analysis of chromosome replication timing combined with fluorescent in situ hybridization. This method allows for a direct comparison of replication timing between homologous chromosomes within the same cell, and was adapted from6. In addition, this method allows for the unambiguous identification of chromosomal rearrangements that correlate with changes in replication timing that affect the entire chromosome. This method has advantages over recently developed high throughput micro-array or sequencing protocols that cannot distinguish between homologous alleles present on rearranged and un-rearranged chromosomes. In addition, because the method described here evaluates single cells, it can detect changes in chromosome replication timing on chromosomal rearrangements that are present in only a fraction of the cells in a population.

Chromosome Replicating Timing Combined with Fluorescent In situ Hybridization

A quantitative method for the analysis of chromosome replication timing is described. The method utilizes BrdU incorporation in combination with fluorescent in situ hybridization (FISH) to assess replication timing of mammalian chromosomes. This technique allows for the direct comparison of rearranged and un-rearranged chromosomes within the same cell.

التوقيت كروموسوم النسخ المتماثل جنبا إلى جنب مع نيون<em&gt; في الموقع</em&gt; التهجين

Mammalian DNA replication initiates at multiple sites along chromosomes at different times during S phase, following a temporal replication program. The ...

Visualization and Analysis of mRNA Molecules Using Fluorescence In Situ Hybridization in Saccharomyces cerevisiae

The Fluorescence in situ Hybridization (FISH) method allows one to detect nucleic acids in the native cellular environment. Here we provide a protocol for using FISH to quantify the number of mRNAs in single yeast cells. Cells can be grown in any condition of interest and then fixed and made permeable. Subsequently, multiple single-stranded deoxyoligonucleotides conjugated to fluorescent dyes are used to label and visualize mRNAs. Diffraction-limited fluorescence from single mRNA molecules is quantified using a spot-detection algorithm to identify and count the number of mRNAs per cell. While the more standard quantification methods of northern blots, RT-PCR and gene expression microarrays provide information on average mRNAs in the bulk population, FISH facilitates both the counting and localization of these mRNAs in single cells at single-molecule resolution.

Visualization and Analysis of mRNA Molecules Using Fluorescence In Situ Hybridization in Saccharomyces cerevisiae

This protocol describes an experimental procedure for performing Fluorescence in situ Hybridization (FISH) for counting mRNAs in single cells at single-molecule resolution.

التصور والتحليل من جزيئات الرنا المرسال عن طريق الإسفار<em&gt; في الموضع</em&gt; التهجين في<em&gt; خميرة الخباز</em

The Fluorescence in situ Hybridization (FISH) method allows one to detect nucleic acids in the native cellular environment. Here we provide a protocol for ...

Prostaglandin Extraction and Analysis in Caenorhabditis elegans

Caenorhabditis elegans is emerging as a powerful animal model to study the biology of lipids1-9. Prostaglandins are an important class of eicosanoids, which are lipid signals derived from polyunsaturated fatty acids (PUFAs)10-14. These signalling molecules are difficult to study because of their low abundance and reactive nature. The characteristic feature of prostaglandins is a cyclopentane ring structure located within the fatty acid backbone. In mammals, prostaglandins can be formed through cyclooxygenase enzyme-dependent and -independent pathways10,15. C. elegans synthesizes a wide array of prostaglandins independent of cyclooxygenases6,16,17. A large class of F-series prostaglandins has been identified, but the study of eicosanoids is at an early stage with ample room for new discoveries. Here we describe a procedure for extracting and analyzing prostaglandins and other eicosanoids. Charged lipids are extracted from mass worm cultures using a liquid-liquid extraction technique and analyzed by liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The inclusion of deuterated analogs of prostaglandins, such as PGF2 &alpha;-d4 as an internal standard is recommended for quantitative analysis. Multiple reaction monitoring or MRM can be used to quantify and compare specific prostaglandin types between wild-type and mutant animals. Collision-induced decomposition or MS/MS can be used to obtain information on important structural features. Liquid chromatography mass spectrometry (LC-MS) survey scans of a selected mass range, such as m/z 315-360 can be used to evaluate global changes in prostaglandin levels. We provide examples of all three analyses. These methods will provide researchers with a toolset for discovering novel eicosanoids and delineating their metabolic pathways.

Prostaglandin Extraction and Analysis in Caenorhabditis elegans

In this paper, we describe an optimized procedure for extracting and analyzing prostaglandins and other eicosanoids from C. elegans using LC-MS/MS.

استخراج البروستاجلاندين والتحليل في<em&gt; انواع معينة ايليجانس</em

Caenorhabditis elegans is emerging as a powerful animal model to study the biology of lipids1-9. Prostaglandins are an important class of eicosanoids, ...

Using Caenorhabditis elegans as a Model System to Study Protein Homeostasis in a Multicellular Organism

The folding and assembly of proteins is essential for protein function, the long-term health of the cell, and longevity of the organism. Historically, the function and regulation of protein folding was studied in vitro, in isolated tissue culture cells and in unicellular organisms. Recent studies have uncovered links between protein homeostasis (proteostasis), metabolism, development, aging, and temperature-sensing. These findings have led to the development of new tools for monitoring protein folding in the model metazoan organism Caenorhabditis elegans. In our laboratory, we combine behavioral assays, imaging and biochemical approaches using temperature-sensitive or naturally occurring metastable proteins as sensors of the folding environment to monitor protein misfolding. Behavioral assays that are associated with the misfolding of a specific protein provide a simple and powerful readout for protein folding, allowing for the fast screening of genes and conditions that modulate folding. Likewise, such misfolding can be associated with protein mislocalization in the cell. Monitoring protein localization can, therefore, highlight changes in cellular folding capacity occurring in different tissues, at various stages of development and in the face of changing conditions. Finally, using biochemical tools ex vivo, we can directly monitor protein stability and conformation. Thus, by combining behavioral assays, imaging and biochemical techniques, we are able to monitor protein misfolding at the resolution of the organism, the cell, and the protein, respectively.

Using Caenorhabditis elegans as a Model System to Study Protein Homeostasis in a Multicellular Organism

To study the relationship between protein homeostasis, stress and aging, we monitored changes in protein folding by following protein dysfunction, protein localization in the cell and protein stability at the organismal, cellular and protein levels, using the genetically tractable metazoan Caenorhabditis elegans as a model system.

The folding and assembly of proteins is essential for protein function, the long-term health of the cell, and longevity of the organism. Historically, the ...

Simple Method for Fluorescence DNA In Situ Hybridization to Squashed Chromosomes

DNA in situ hybridization (DNA ISH) is a commonly used method for mapping sequences to specific chromosome regions. This approach is particularly effective at mapping highly repetitive sequences to heterochromatic regions, where computational approaches face prohibitive challenges. Here we describe a streamlined protocol for DNA ISH that circumvents formamide washes that are standard steps in other DNA ISH protocols. Our protocol is optimized for hybridization with short single strand DNA probes that carry fluorescent dyes, which effectively mark repetitive DNA sequences within heterochromatic chromosomal regions across a number of different insect tissue types. However, applications may be extended to use with larger probes and visualization of single copy (non-repetitive) DNA sequences. We demonstrate this method by mapping several different repetitive sequences to squashed chromosomes from Drosophila melanogaster neural cells and Nasonia vitripennis spermatocytes. We show hybridization patterns for both small, commercially synthesized probes and for a larger probe for comparison. This procedure uses simple laboratory supplies and reagents, and is ideal for investigators who have little experience with performing DNA ISH.

Simple Method for Fluorescence DNA In Situ Hybridization to Squashed Chromosomes

Here, we present a simple method for performing fluorescence DNA in situ hybridization (DNA ISH) to visualize repetitive heterochromatic sequences on slide-mounted chromosomes. The method requires minimal reagents and it is versatile for use with short or long probes, different tissues, and detection with fluorescence or non-fluorescence-based signals.