우리는 휴고 Bellen 및 시약 블루밍턴 증권 센터 감사의 말씀을 전합니다. 우리는 더 도움이 토론 공원 Venken, 휴고 Bellen 및 Buszczak 및 Hiesinger 연구소의 모든 구성원을 감사드립니다. 이 작품은 ACR에 건강의 국립 연구소 (T32GM083831), PRH (RO1EY018884)에서 교부금에 의해와 MB (RO1GM086647), MB와 PRH (RP100516)에 텍사스​​의 암 예방 연구소 부여, 그리고 웰치에 대한 지원 PRH에 기초 (I-1657). MB는 생물 의학 연구 및 PRH에서 전자와 그리어 GARSON Fogelson 학술 것은 UT 남서 의료 센터에 생물 의학 연구에 유진 맥 더못 학자이다.

<ol>
	<li>Rong, Y. S., Golic, K. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+targeted+gene+knockout+in+Drosophila.">A targeted gene knockout in Drosophila.</a> Genetics. 157, 1307-1312 (2001).</li><li>Rong, Y. S., Golic, K. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+targeting+by+homologous+recombination+in+Drosophila.">Gene targeting by homologous recombination in Drosophila.</a> Science. 288, 2013-2018 (2000).</li><li>Gong, W. J., Golic, K. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ends-out,+or+replacement,+gene+targeting+in+Drosophila.">Ends-out, or replacement, gene targeting in Drosophila.</a> Proc. Natl. Acad. Sci. U.S.A. 100, 2556-2561 (1073).</li><li>Warming, S., Costantino, N., Court, D. L., Jenkins, N. A., Copeland, N. G. <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+highly+efficient+BAC+recombineering+using+galK+selection.">Simple and highly efficient BAC recombineering using galK selection.</a> Nucleic Acids Res. 33, e36 (2005).</li><li>Copeland, N. G., Jenkins, N. A., Court, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recombineering:+a+powerful+new+tool+for+mouse+functional+genomics.">Recombineering: a powerful new tool for mouse functional genomics.</a> Nat. Rev. Genet. 2, 769-779 (2001).</li><li>Venken, K. J., He, Y., Hoskins, R. A., Bellen, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=P[acman]:+a+BAC+transgenic+platform+for+targeted+insertion+of+large+DNA+fragments+in+D.+melanogaster.">P[acman]: a BAC transgenic platform for targeted insertion of large DNA fragments in D. melanogaster.</a> Science. 314, 1747-1751 (2006).</li><li>Venken, K. J., 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=Versatile+P[acman]+BAC+libraries+for+transgenesis+studies+in+Drosophila+melanogaster.">Versatile P[acman] BAC libraries for transgenesis studies in Drosophila melanogaster.</a> Nat. Methods. 6, 431-434 (2009).</li><li>Groth, A. C., Fish, M., Nusse, R., Calos, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Construction+of+transgenic+Drosophila+by+using+the+site-specific+integrase+from+phage+phiC31.">Construction of transgenic Drosophila by using the site-specific integrase from phage phiC31.</a> Genetics. 166, 1775-1782 (2004).</li><li>Bischof, J., Maeda, R. K., Hediger, M., Karch, F., Basler, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+optimized+transgenesis+system+for+Drosophila+using+germ-line-specific+phiC31+integrases.">An optimized transgenesis system for Drosophila using germ-line-specific phiC31 integrases.</a> Proceedings of the National Academy of Sciences of the United States of America. 104, 3312-3317 (2007).</li><li>Chan, C. 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=Systematic+discovery+of+Rab+GTPases+with+synaptic+functions+in+Drosophila.">Systematic discovery of Rab GTPases with synaptic functions in Drosophila.</a> Current Biology: CB. 21, 1704-1715 (2011).</li><li>Chan, C. C., Scoggin, S., Hiesinger, P. R., Buszczak, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combining+recombineering+and+ends-out+homologous+recombination+to+systematically+characterize+Drosophila+gene+families:+Rab+GTPases+as+a+case+study.">Combining recombineering and ends-out homologous recombination to systematically characterize Drosophila gene families: Rab GTPases as a case study.</a> Commun. Integr. Biol. 5, 179-183 (2012).</li><li>Wu, N., Matand, K., Kebede, B., Acquaah, G., Williams, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancing+DNA+electrotransformation+efficiency+in+Escherichia+coli+DH10B+electrocompetent+cells.">Enhancing DNA electrotransformation efficiency in Escherichia coli DH10B electrocompetent cells.</a> Electronic Journal of Biotechnology. 13, (2010).</li><li>Wang, S., Zhao, Y., Leiby, M., Zhu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+positive/negative+selection+scheme+for+precise+BAC+recombineering.">A new positive/negative selection scheme for precise BAC recombineering.</a> Mol. Biotechnol. 42, 110-116 (2009).</li><li>Venken, K. J., Bellen, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transgenesis+upgrades+for+Drosophila+melanogaster.">Transgenesis upgrades for Drosophila melanogaster.</a> Development. 134, 3571-3584 (2007).</li><li>Dietzl, G., 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=A+genome-wide+transgenic+RNAi+library+for+conditional+gene+inactivation+in+Drosophila.">A genome-wide transgenic RNAi library for conditional gene inactivation in Drosophila.</a> Nature. 448, 151-156 (2007).</li></ol>

저자는 여기에 설명 된 기술에 관해서 어떤 경쟁 이익을 가지고 있지 않습니다.

생물 의학 연구에서 유전자 모델 생물의 힘은 크게 유전 조작을 위해 사용할 수있는 도구를 기반으로합니다. 작은 모델 C. 특히 엘레과 초파리는 다세포 개발이나 기능에 연루 전체 경로와 유전자 가족의 저렴하고 빠른 분자 유전 학적 분석을 허용합니다. 최근 몇 년 동안 초파리 14,15의 유전자를 조작하기위한 도구 개발에 상당한 진전을 보았다. 예를 들어, 널리 혈중 ...

자신의 내생 유전자 좌에서 단일 유전자의 분자 정의 된 조작을 청소하는 진핵 세포 생물학 관련 질문 수많은 연구에 귀중한 도구를 제공합니다. 초파리는 기능 상실 대립 유전자를 생성하는 유전자 기법을 역 Golić 선수와 동료에 도입 될 때까지 도전 할 수 입증했다 생체 내 유전자는 초파리 1-3에 상동 재조합을 사용하여 대상. 그들은 특정 게놈 유전자 좌가 통합 된 형질 전환 구조에서 DNA의 선형 조각을 사용하여 대상이 될 수 있습니다 보여 주었다. 이 선형 &quot;기증자&quot;DNA는 meganuclease I-SCEI와 선형화 다음 FRT-매개 재조합 (소비세에 원형의 분자와 같은 염색체에서 DNA)를 통해 생체 내에서 생성됩니다. 이 방법이 성공적으로 정의 된 병변의 다양한 생성하는 데 사용되었습니다 있지만, 기술은 병렬로 다수의 유전자의 조작에 쉽게 확장되지 않았기 때문에 각 indivi이중 녹아웃 구조는 독특하고 사용자 정의 디자인을 필요로합니다. 예를 들어, 완벽하게 고전적인 제한 효소 / 결찰 복제 또는 PCR뿐만 아니라, 생체 내 변환 벡터 전통의 크기 제한을 사용하여 체외에서 DNA (&gt; 5 개 KB)의 큰 조각을 조작하는데 어려움은 종종 대상 상동 재조합의 신속한 생성을 방해 벡터. 이러한 한계를 극복하기 위해, 우리는 끝 아웃 유전자가 효율적이고 비교적 빠른 플랫폼을 구축하는 방법론을 대상으로, DNA의 최대 100KB의 하위 복제 및 transgenesis 수 있습니다 recombineering / transgenesis P [acman] 시스템을 결합하는 초파리 유전자 타겟팅 용이하게합니다. 재조합 - 중재 유전 공학 (recombineering)는 4,5 강력한 상동 재조합 기반의 복제 기술입니다. 기존의 제한 효소 / 리가 복제 대조적으로, recombineering는 순서 나 SIZ에 의해 제한되지 않는다조작 된 DNA의 전자. Recombineering는 특별한 E.를 사용 결함 λ prophage 4에서 제공하는 재조합 기계를 품고 대장균 균주. 이 기술은 최근 초파리 6.7에서 사용하기 위해 채택되었다. 초파리에 Recombineering은 P [acman] 6,7이라고 수정 조건부 증폭 세균 인공 염색체 (BAC) 벡터에 의존합니다. OriV, 시퀀싱 및 배아 주입 기저 상태에서 낮은 사본 번호를 유지 오리스에 필요한 DNA의 대량의 정화를위한 화학 유도에 높은 사본 번호가 생성이 벡터는 두 가지 복제 기원을 수행합니다. 또한, P [acman] 벡터는 세균 첨부 (attB) 사이트가 장착되어 있습니다. attB 사이트는 초파리 게놈 8,9에서 소정의 방문 사이트에 큰 DNA 조각의 설립을 허용 ΦC31 integrase-매개 transgenesis위한 기판 역할을합니다. 우리는 끝 아웃 상동 재조합 10,11에 대한 대상 벡터로 사용할 수있는 P [acman] 벡터 (P [acman]-KO 1.0라고도 함) 생성 한. 시스템에 타겟팅 기술을 통합하는 끝을 밖으로 유전자, 우리는 2 FRT와 두 개의 I-SCEI 사이트를 추가했습니다. 우리는 또한 P [acman]-KO 1.0에 상동 팔을 통합하는 프로세스를 간소화하기 위해이 수정 된 벡터 내의 게이트웨이 카세트를 포함했다. 이 대상 벡터에 관심 거의 모든 게놈 영역을 소개하는 신속하고 간단한 방법을 제공합니다. 이 프로토콜에서 우리는 P [acman]-KO 1.0 및 방법 내생 현장을 대상으로 생체 내에서이 벡터를 동원하는 방법을 사용하여 대상 벡터를 엔지니어링하는 방법을 설명합니다. 이 프로토콜의 목적을 위해 우리는 관심의 유전자를 대체하기 위해 RFP / 칸 카세트를 사용하지만 항생제 선택 마커를 포함하는 카세트의 다양한이 프로토콜을 사용할 수 있습니다. 우리는 카세트의 집합에 대한 설계하고 성공적으로 사용했습니다유전자 교체 및 태그 10,11.

<table border="1">
	<tbody>
		<tr>
			<td>Name of the reagent</td>
			<td>Company</td>
			<td>Catalogue number</td>
			<td>Comments (optional)</td>
		</tr>
		<tr>
			<td>SW102 Recombination competent bacteria</td>
			<td>NCI-Frederick</td>
			<td>Recombination Bacteria (SW102, SW105 and SW106)</td>
			<td><a href="http://ncifrederick.cancer.gov/research/brb/logon.aspx" target="_blank">http://ncifrederick.cancer.gov/research/brb/logon.aspx</a></td>
		</tr>
		<tr>
			<td>TransforMax EPI300 electrocopmpetent E. coli</td>
			<td>Epicentre</td>
			<td>EC300110</td>
			<td>Includes CopyControl induction solution</td>
		</tr>
		<tr>
			<td>PfuUltra II Fusion HS DNA Polymerase</td>
			<td>Aligent Technology Inc.</td>
			<td>600670</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>BamHI-HF</td>
			<td>New England Biolabs</td>
			<td>R3136S</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Zymoclean Gel DNA Recovery Kit</td>
			<td>Zymo Research</td>
			<td>D4001</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Use Gateway BP ClonaseII Enzyme kit</td>
			<td>Invitrogen</td>
			<td>11789-020</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>P[acman]KO1.010</td>
			<td>Buszczak and Hiesinger Labs</td>
			<td>Upon request</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>pENTR RFP-Kan11</td>
			<td>Buszczak and Hiesinger Labs</td>
			<td>Upon request</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Flystocks</td>
			<td>Bloomington stock center</td>
			<td>Stock numbers: 25680, 25679</td>
			<td>y1 w*/Dp(2;Y)G, P{hs-hid}Y; P{70FLP}11 P{70I-SceI}2B snaSco/CyO, P{hs-hid}4 
			y1 w*/Dp(2;Y)G, P{hs-hid}Y; P{70FLP}23 P{70I-SceI}4A/TM3, P{hs-hid}14, Sb1</td>
		</tr>
		<tr>
			<td>Electroporation machine</td>
			<td>Biorad GenePulser Xcell with PC module</td>
			<td>165-2662</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Cuvettes</td>
			<td>Fisher Brand</td>
			<td>#FB101</td>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

recombineering homologous recombination constructs in drosophila

내생 유전자 좌위의 빠르고 대규모 조작 기술의 지속적인 발전은 인간의 질병 관련 연구를위한 유전자 모델 생물로 초파리의 사용을 확대 할 것이다. 최근 몇 년 동안 상동 재조합 recombineering 같은 기술 발전을 볼 수있다. 그러나 명백한 널 돌연변이 또는 태그 내생 단백질을 생성하는 것은 대부분의 유전자 상당한 노력이 남아있다. 여기, 우리는 생체 내에서 내생 궤적을 대상으로하고 조작하는 데 사용할 수있는 벡터를 생성하는 recombineering 기반 복제 방법을 사용하는 방법을 설명하고 보여 구체적으로, 우리는 세 가지 기술의 조합을 설립했습니다. (1) BAC의 transgenesis / recombineering ( 2) 끝 아웃 상동 재조합 (3) 게이트웨이 기술은 내생 게놈 유전자 좌를 조작하기위한 강력하고 효율적이며 유연한 방법을 제공합니다. 이 프로토콜에서는, 우리는 방법 (1) 디자인 individua에 대한 단계별 세부 사항을 제공L 벡터, (2) 간격 수리 (3) 방법 recombineering의 두 번째 라운드를 사용하여 이러한 벡터에서 관심의 유전자를 바꾸거나 태그를 사용하여 상동 재조합 벡터로 게놈 DNA의 큰 조각을 복제하는 방법에 대해 설명합니다. 마지막으로, 우리는 또한 녹아웃, 또는 노크의를 통해 태그 유전자를 생성하기 위해 생체 내에서 이러한 카세트를 동원하는 방법에 대한 프로토콜을 제공합니다. 이 방법은 쉽게 병렬로 여러 대상에 채택하고시의 적절하고 효율적인 방법으로 초파리의 게놈을 조작하기위한 수단을 제공 할 수 있습니다.

LA와 RA 상동 팔의 증폭은 500 bp의 제품을 생산해야하며, PCR-SOE 반응은 1.0 KB 제품 (섹션 2.1-2.4; 그림 2) 산출해야한다. 2.5 절에서 수행 BP 반응은 일반적으로 제품의 수율 평균 5-100 식민지의 매우 효율적이고 세균의 변형이다. 거의 PCR로 테스트 한 모든 식민지는 예상 PCR 제품 표시를 선택하십시오. recombineering의 첫 번째 라운드 (3 절) 동안 소화 P의 변환 후 20-40 식민?...

Watch this Scientific Journal Video about Recombineering Homologous Recombination Constructs in Drosophila at JoVE.com

Recombineering Homologous Recombination Constructs in Drosophila

상동 재조합 기술은 크게 발전<em&gt; 초파리</em&gt; 분자 정확한 돌연변이의 생성을 가능하게함으로써 유전학. recombineering의 최근 채용 한 DNA의 큰 조각을 조작으로 그들을 변환 할 수 있습니다<em&gt; 초파리</em<sup&gt; 6</sup&gt;. 방법은 신속하게 대규모 상동 재조합 벡터를 생성하기 위해 이러한 기술을 결합하여 여기에 제시 하였다.

에서 상동 재조합 구문을 Recombineering<em&gt; 초파리</em

The continued development of techniques for fast, large-scale manipulation of endogenous gene loci will broaden the use of Drosophila melanogaster as a ...

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Biology

Recombineering Homologous Recombination Constructs in Drosophila

19.1K 조회수.  University of Texas Southwestern Medical Center at Dallas. 상동 재조합 기술은 크게 발전 초파리 분자 정확한 돌연변이의 생성을 가능하게함으로써 유전학. recombineering의 최근 채용 한 DNA의 큰 조각을 조작으로 그들을 변환 할 수 있습니다 초파리

비디오: Recombineering Homologous Recombination Constructs in Drosophila

Wolbachia Bacterial Infection in Drosophila

Drosophila에서 Wolbachia 세균 감염

연구

생물학

Fabrication of Myogenic Engineered Tissue Constructs

Despite the fact that electronic pacemakers are life-saving medical devices, their long-term performance in pediatric patients can be problematic owing to the restrictions imposed by a child's small size and their inevitable growth. Consequently, there is a genuine need for innovative therapies designed specifically for pediatric patients with cardiac rhythm disorders. We propose that a conductive biological alternative consisting of a collagen-based matrix containing autologously-derived cells could better adapt to growth, reduce the need for recurrent surgeries, and greatly improve the quality of life for these patients. In the present study, we describe a procedure for incorporating primary skeletal myoblast cell cultures within a hydrogel matrix to fashion a surgically-implantable tissue construct that will serve as an electrical conduit between the upper and lower chambers of the heart. Ultimately, we anticipate using this type of engineered tissue to restore atrioventricular electrical conduction in children with complete heart block. In view of that, we isolate myoblasts from the skeletal muscles of neonatal Lewis rats and plate them onto laminin-coated tissue culture dishes using a modified version of established protocols[2, 3]. After one to two days, cultured cells are collected and mixed with antibiotics, type 1 collagen, Matrigel&trade;, and NaHCO3. The result is a viscous, uniform solution that can be cast into a mold of nearly any shape and size[1, 4, 5]. For our tissue constructs, we employ type 1 collagen isolated from fetal lamb skin using standard procedures[6]. Once the tissue has solidified at 37&deg;C, culture media is carefully added to the plate until the construct is submerged. The engineered tissue is then allowed to further condense through dehydration for 2 more days, at which point it is ready for in vitro assessment or surgical-implantation.

Here, we demonstrate fabrication of collagen-based, tissue constructs containing skeletal myoblasts. These 3-D engineered constructs may be used to replace or repair tissues in vivo. For our purposes, we have designed these as an atrioventricular electrical conduit for the repair of complete heart block[1].

Myogenic 엔지니어링된 조직 구조의 제작

Despite the fact that electronic pacemakers are life-saving medical devices, their long-term performance in pediatric patients can be problematic owing to ...

The Production of C. elegans Transgenes via Recombineering with the galK Selectable Marker

The creation of transgenic animals is widely utilized in C. elegans research including the use of GFP fusion proteins to study the regulation and expression pattern of genes of interest or generation of tandem affinity purification (TAP) tagged versions of specific genes to facilitate their purification. Typically transgenes are generated by placing a promoter upstream of a GFP reporter gene or cDNA of interest, and this often produces a representative expression pattern. However, critical elements of gene regulation, such as control elements in the 3' untranslated region or alternative promoters, could be missed by this approach. Further only a single splice variant can be usually studied by this means. In contrast, the use of worm genomic DNA carried by fosmid DNA clones likely includes most if not all elements involved in gene regulation in vivo which permits the greater ability to capture the genuine expression pattern and timing. To facilitate the generation of transgenes using fosmid DNA, we describe an E. coli based recombineering procedure to insert GFP, a TAP-tag, or other sequences of interest into any location in the gene. The procedure uses the galK gene as the selection marker for both the positive and negative selection steps in recombineering which results in obtaining the desired modification with high efficiency. Further, plasmids containing the galK gene flanked by homology arms to commonly used GFP and TAP fusion genes are available which reduce the cost of oligos by 50% when generating a GFP or TAP fusion protein. These plasmids use the R6K replication origin which precludes the need for extensive PCR product purification. Finally, we also demonstrate a technique to integrate the unc-119 marker on to the fosmid backbone which allows the fosmid to be directly injected or bombarded into worms to generate transgenic animals. This video demonstrates the procedures involved in generating a transgene via recombineering using this method.

The Production of C. elegans Transgenes via Recombineering with the galK Selectable Marker

The ability to produce transgenes for Caenorhabditis elegans using genomic DNA carried by fosmids is particularly attractive as all of the native regulatory elements are retained. Described is a simple and robust procedure for the production of transgenes via recombineering with the galK selectable marker.

생산 C. 엘레간스</em함께 Recombineering 통해> Transgenes galK 선택 마커

The creation of transgenic animals is widely utilized in C. elegans research including the use of GFP fusion proteins to study the regulation and ...

Identifying the Effects of BRCA1 Mutations on Homologous Recombination using Cells that Express Endogenous Wild-type BRCA1

The functional analysis of missense mutations can be complicated by the presence in the cell of the endogenous protein. Structure-function analyses of the BRCA1 have been complicated by the lack of a robust assay for the full length BRCA1 protein and the difficulties inherent in working with cell lines that express hypomorphic BRCA1 protein1,2,3,4,5. We developed a system whereby the endogenous BRCA1 protein in a cell was acutely depleted by RNAi targeting the 3'-UTR of the BRCA1 mRNA and replaced by co-transfecting a plasmid expressing a BRCA1 variant. One advantage of this procedure is that the acute silencing of BRCA1 and simultaneous replacement allow the cells to grow without secondary mutations or adaptations that might arise over time to compensate for the loss of BRCA1 function. This depletion and add-back procedure was done in a HeLa-derived cell line that was readily assayed for homologous recombination activity. The homologous recombination assay is based on a previously published method whereby a recombination substrate is integrated into the genome (Figure 1)6,7,8,9. This recombination substrate has the rare-cutting I-SceI restriction enzyme site inside an inactive GFP allele, and downstream is a second inactive GFP allele. Transfection of the plasmid that expresses I-SceI results in a double-stranded break, which may be repaired by homologous recombination, and if homologous recombination does repair the break it creates an active GFP allele that is readily scored by flow cytometry for GFP protein expression. Depletion of endogenous BRCA1 resulted in an 8-10-fold reduction in homologous recombination activity, and add-back of wild-type plasmid fully restored homologous recombination function. When specific point mutants of full length BRCA1 were expressed from co-transfected plasmids, the effect of the specific missense mutant could be scored. As an example, the expression of the BRCA1(M18T) protein, a variant of unknown clinical significance10, was expressed in these cells, it failed to restore BRCA1-dependent homologous recombination. By contrast, expression of another variant, also of unknown significance, BRCA1(I21V) fully restored BRCA1-dependent homologous recombination function. This strategy of testing the function of BRCA1 missense mutations has been applied to another biological system assaying for centrosome function (Kais et al, unpublished observations). Overall, this approach is suitable for the analysis of missense mutants in any gene that must be analyzed recessively.

We provide a method for testing BRCA1 variants in a tissue culture based assay for homologous recombination repair of DNA damage by depleting endogenous BRCA1 protein from a cell using RNAi and replacing it with a BRCA1 point mutant that contains a coding change.

내생 와일드 타입 BRCA1을 표현 세포를 사용하는 동종 재조합에 BRCA1 변이의 효과를 확인

The functional analysis of missense mutations can be complicated by the presence in the cell of the endogenous protein. Structure-function analyses of the ...

Imaging Cell Shape Change in Living Drosophila Embryos

The developing Drosophila melanogaster embryo undergoes a number of cell shape changes that are highly amenable to live confocal imaging. Cell shape changes in the fly are analogous to those in higher organisms, and they drive tissue morphogenesis. So, in many cases, their study has direct implications for understanding human disease (Table 1)1-5. On the sub-cellular scale, these cell shape changes are the product of activities ranging from gene expression to signal transduction, cell polarity, cytoskeletal remodeling and membrane trafficking. Thus, the Drosophila embryo provides not only the context to evaluate cell shape changes as they relate to tissue morphogenesis, but also offers a completely physiological environment to study the sub-cellular activities that shape cells.
The protocol described here is designed to image a specific cell shape change called cellularization. Cellularization is a process of dramatic plasma membrane growth, and it ultimately converts the syncytial embryo into the cellular blastoderm. That is, at interphase of mitotic cycle 14, the plasma membrane simultaneously invaginates around each of ~6000 cortically anchored nuclei to generate a sheet of primary epithelial cells. Counter to previous suggestions, cellularization is not driven by Myosin-2 contractility6, but is instead fueled largely by exocytosis of membrane from internal stores7. Thus, cellularization is an excellent system for studying membrane trafficking during cell shape changes that require plasma membrane invagination or expansion, such as cytokinesis or transverse-tubule (T-tubule) morphogenesis in muscle.
Note that this protocol is easily applied to the imaging of other cell shape changes in the fly embryo, and only requires slight adaptations such as changing the stage of embryo collection, or using "embryo glue" to mount the embryo in a specific orientation (Table 1)8-19. In all cases, the workflow is basically the same (Figure 1). Standard methods for cloning and Drosophila transgenesis are used to prepare stable fly stocks that express a protein of interest, fused to Green Fluorescent Protein (GFP) or its variants, and these flies provide a renewable source of embryos. Alternatively, fluorescent proteins/probes are directly introduced into fly embryos via straightforward micro-injection techniques9-10. Then, depending on the developmental event and cell shape change to be imaged, embryos are collected and staged by morphology on a dissecting microscope, and finally positioned and mounted for time-lapse imaging on a confocal microscope.

Imaging Cell Shape Change in Living Drosophila Embryos

Early development of the fruit fly, Drosophila melanogaster, is characterized by a number of cell shape changes that are well suited for imaging approaches. This article will describe basic tools and methods required for live confocal imaging of Drosophila embryos, and will focus on a cell shape change called cellularization.

생활의 이미징 셀 모양 변경 Drosophila 태아

The developing Drosophila melanogaster embryo undergoes a number of cell shape changes that are highly amenable to live confocal imaging.  Cell shape ...

Genetic Modification and Recombination of Salivary Gland Organ Cultures

Branching morphogenesis occurs during the development of many organs, and the embryonic mouse submandibular gland (SMG) is a classical model for the study of branching morphogenesis. In the developing SMG, this process involves iterative steps of epithelial bud and duct formation, to ultimately give rise to a complex branched network of acini and ducts, which serve to produce and modify/transport the saliva, respectively, into the oral cavity1-3. The epithelial-associated basement membrane and aspects of the mesenchymal compartment, including the mesenchyme cells, growth factors and the extracellular matrix, produced by these cells, are critical to the branching mechanism, although how the cellular and molecular events are coordinated remains poorly understood 4. The study of the molecular mechanisms driving epithelial morphogenesis advances our understanding of developmental mechanisms and provides insight into possible regenerative medicine approaches. Such studies have been hampered due to the lack of effective methods for genetic manipulation of the salivary epithelium. Currently, adenoviral transduction represents the most effective method for targeting epithelial cells in adult glands in vivo5. However, in embryonic explants, dense mesenchyme and the basement membrane surrounding the epithelial cells impedes viral access to the epithelial cells. If the mesenchyme is removed, the epithelium can be transfected using adenoviruses, and epithelial rudiments can resume branching morphogenesis in the presence of Matrigel or laminin-1116,7. Mesenchyme-free epithelial rudiment growth also requires additional supplementation with soluble growth factors and does not fully recapitulate branching morphogenesis as it occurs in intact glands8. Here we describe a technique which facilitates adenoviral transduction of epithelial cells and culture of the transfected epithelium with associated mesenchyme. Following microdissection of the embryonic SMGs, removal of the mesenchyme, and viral infection of the epithelium with a GFP-containing adenovirus, we show that the epithelium spontaneously recombines with uninfected mesenchyme, recapitulating intact SMG glandular structure and branching morphogenesis. The genetically modified epithelial cell population can be easily monitored using standard fluorescence microscopy methods, if fluorescently-tagged adenoviral constructs are used. The tissue recombination method described here is currently the most effective and accessible method for transfection of epithelial cells with a wild-type or mutant vector within a complex 3D tissue construct that does not require generation of transgenic animals.

A technique to genetically manipulate epithelial cells within whole ex vivo cultured embryonic mouse submandibular glands (SMGs) using viral gene transfer is described. This method takes advantage of the innate ability of SMG epithelium and mesenchyme to spontaneously recombine after separation and infection of epithelial rudiments with adenoviral vectors.

침샘 조직 문화의 유전자 변형과 재결합

Branching  morphogenesis occurs during the development of many organs, and the embryonic  mouse submandibular gland (SMG) is a classical model for the ...

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

The proper elimination of unwanted or aberrant cells through apoptosis and subsequent phagocytosis (apoptotic cell clearance) is crucial for normal development in all metazoan organisms. Apoptotic cell clearance is a highly dynamic process intimately associated with cell death; unengulfed apoptotic cells are barely seen in vivo under normal conditions. In order to understand the different steps of apoptotic cell clearance and to compare 'professional' phagocytes - macrophages and dendritic cells to 'non-professional' - tissue-resident neighboring cells, in vivo live imaging of the process is extremely valuable. Here we describe a protocol for studying apoptotic cell clearance in live Drosophila embryos. To follow the dynamics of different steps in phagocytosis we use specific markers for apoptotic cells and phagocytes. In addition, we can monitor two phagocyte systems in parallel: 'professional' macrophages and 'semi-professional' glia in the developing central nervous system (CNS). The method described here employs the Drosophila embryo as an excellent model for real time studies of apoptotic cell clearance.

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

Here we describe an effective method for studying dynamics of apoptotic cell clearance in vivo. This method employs live Drosophila embryos as a powerful model for monitoring phagocytosis of apoptotic cells using specific labeling of apoptotic cells and phagocytes.

사멸 세포 간극의 이미지를하는 동안 라이브<em&gt; 초파리</em&gt; 배아

The  proper elimination of unwanted or aberrant cells through apoptosis and  subsequent phagocytosis (apoptotic cell clearance) is crucial for normal  ...

Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy

The MGM101 gene was identified 20 years ago for its role in the maintenance of mitochondrial DNA. Studies from several groups have suggested that the Mgm101 protein is involved in the recombinational repair of mitochondrial DNA. Recent investigations have indicated that Mgm101 is related to the Rad52-type recombination protein family. These proteins form large oligomeric rings and promote the annealing of homologous single stranded DNA molecules. However, the characterization of Mgm101 has been hindered by the difficulty in producing the recombinant protein. Here, a reliable procedure for the preparation of recombinant Mgm101 is described. Maltose Binding Protein (MBP)-tagged Mgm101 is first expressed in Escherichia coli. The fusion protein is initially purified by amylose affinity chromatography. After being released by proteolytic cleavage, Mgm101 is separated from MBP by cationic exchange chromatography. Monodispersed Mgm101 is then obtained by size exclusion chromatography. A yield of ~0.87 mg of Mgm101 per liter of bacterial culture can be routinely obtained. The recombinant Mgm101 has minimal contamination of DNA. The prepared samples are successfully used for biochemical, structural and single particle image analyses of Mgm101. This protocol may also be used for the preparation of other large oligomeric DNA-binding proteins that may be misfolded and toxic to bacterial cells.

The yeast mitochondrial nucleoid protein, Mgm101, is a Rad52-type recombination protein that forms large oligomeric rings. A protocol is described to prepare soluble recombinant Mgm101 using the Maltose Binding Protein (MBP)-tagging strategy coupled with cation exchange and size exclusion chromatography.

MBP 기반 태깅 전략에 의해 Mgm101 재조합 단백질의 제조

The MGM101 gene was identified 20 years ago for its role in the maintenance of mitochondrial DNA. Studies from several groups have suggested that the ...

Subcloning Plus Insertion (SPI) - A Novel Recombineering Method for the Rapid Construction of Gene Targeting Vectors

Gene targeting refers to the precise modification of a genetic locus using homologous recombination. The generation of novel cell lines and transgenic mouse models using this method necessitates the construction of a &#8216;targeting&#8217; vector, which contains homologous DNA sequences to the target gene, and has for many years been a limiting step in the process. Vector construction can be performed in vivo in Escherichia coli cells using homologous recombination mediated by phage recombinases using a technique termed recombineering. Recombineering is the preferred technique to subclone the long homology sequences (>4kb) and various targeting elements including selection markers that are required to mediate efficient allelic exchange between a targeting vector and its cognate genomic locus. Typical recombineering protocols follow an iterative scheme of step-wise integration of the targeting elements and require intermediate purification and transformation steps. Here, we present a novel recombineering methodology of vector assembly using a multiplex approach. Plasmid gap repair is performed by the simultaneous capture of genomic sequence from mouse Bacterial Artificial Chromosome libraries and the insertion of dual bacterial and mammalian selection markers. This subcloning plus insertion method is highly efficient and yields a majority of correct recombinants. We present data for the construction of different types of conditional gene knockout, or knock-in, vectors and BAC reporter vectors that have been constructed using this method. SPI vector construction greatly extends the repertoire of the recombineering toolbox and provides a simple, rapid and cost-effective method of constructing these highly complex vectors.

Subcloning Plus Insertion SPI - A Novel Recombineering Method for the Rapid Construction of Gene Targeting Vectors

Gene targeting methodologies can be used to generate transgenic mice with knockout, knock-in and tagged alleles. Here, we describe an improved method of recombineering in E. coli, that we term &#8216;subcloning plus insertion&#8217;, which can be used to generate custom gene targeting vectors rapidly.

서브 클로닝 플러스 삽입 (SPI) - 유전자 타겟팅 벡터의 신속한 건설 소설 Recombineering 방법

Gene targeting refers to the precise modification of a genetic locus using homologous recombination. The generation of novel cell lines and transgenic ...

Phage-mediated Delivery of Targeted sRNA Constructs to Knock Down Gene Expression in E. coli

RNA-mediated knockdowns are widely used to control gene expression. This versatile family of techniques makes use of short RNA (sRNA) that can be synthesized with any sequence and designed to complement any gene targeted for silencing. Because sRNA constructs can be introduced to many cell types directly or using a variety of vectors, gene expression can be repressed in living cells without laborious genetic modification. The most common RNA knockdown technology, RNA interference (RNAi), makes use of the endogenous RNA-induced silencing complex (RISC) to mediate sequence recognition and cleavage of the target mRNA. Applications of this technique are therefore limited to RISC-expressing organisms, primarily eukaryotes. Recently, a new generation of RNA biotechnologists have developed alternative mechanisms for controlling gene expression through RNA, and so made possible RNA-mediated gene knockdowns in bacteria. Here we describe a method for silencing gene expression in E. coli that functionally resembles RNAi. In this system a synthetic phagemid is designed to express sRNA, which may designed to target any sequence. The expression construct is delivered to a population of E. coli cells with non-lytic M13 phage, after which it is able to stably replicate as a plasmid. Antisense recognition and silencing of the target mRNA is mediated by the Hfq protein, endogenous to E. coli. This protocol includes methods for designing the antisense sRNA, constructing the phagemid vector, packaging the phagemid into M13 bacteriophage, preparing a live cell population for infection, and performing the infection itself. The fluorescent protein mKate2 and the antibiotic resistance gene chloramphenicol acetyltransferase (CAT) are targeted to generate representative data and to quantify knockdown effectiveness.

Phage-mediated Delivery of Targeted sRNA Constructs to Knock Down Gene Expression in E. coli

We describe a method to knock down gene expression in a growing population of E. coli cells using sequence-targeted sRNA expression cassettes delivered by an M13 phagemid vector.