CAJ | 학술논문

目的建立一种可信的单细胞全基因组扩增(whole genome amplification.WGA)技术,结合比较基因组杂交(comparative genomic hybridization,CGH)分析单细胞的染色体拷贝数变化,探讨其在胚胎植入前遗传学诊断(preimplantation genetic diagnosis,PGD)中的应用前景.方法采用引物延伸预扩增结合简并核苷酸引物PCR(primer extension preamplification with degenerate oligonucleotide primed-PCR,PEP-DOP-PCR)的方法,扩增12个已知核型的单细胞标本(包括5个绒毛标本、4个干细胞标本和3个淋巴细胞标本)和4个经PGD检测发现染色体异常的单卵裂球标本,将扩增产物标记红色荧光染料后,与标记绿色荧光染料的正常DNA等量混匀,与正常中期分裂相进行比较基因组杂交分析.同时,应用单纯的简并寡核苷酸引物-PCR(DOP-PCR)扩增10个单细胞DNA,标记后进行CGH分析.比较两种单细胞全基因组扩增方法的扩增效率及随后用于CGH分析染色体拷贝数时的准确性.结果所有的单细胞采用PEP-DOP-PCR扩增时,均能获得稳定均匀的PCR产物,片段大小范围在100～1000 bp之间,集中分布于400 bp左右的区域,CGH分析结果显示染色体拷贝数变化与其它技术检测的结果一致.而10个单纯的DOP-PCR扩增只有6个标本成功,扩增产物进行CGH分析时,杂交信号不均匀,有2个显示与其它技术分析的结果不一致.结论 PEP-DOP-PCR技术能有效地扩增单细胞的全基因组DNA,其扩增产物可应用CGH技术成功检测单个细胞的染色体拷贝数变化,而单纯的DOP-PCR技术易于出现扩增失败、扩增产物杂交后信号不均一的缺点.PEP-DOP-PCR全基因组扩增结合CGH技术在胚胎植入前遗传学诊断中有良好的应用前景.
목적 건립일충가신적단세포전기인조확증(whole genome amplification.WGA)기술,결합비교기인조잡교(comparative genomic hybridization,CGH)분석단세포적염색체고패수변화,탐토기재배태식입전유전학진단(preimplantation genetic diagnosis,PGD)중적응용전경.방법 채용인물연신예확증결합간병핵감산인물PCR(primer extension preamplification with degenerate oligonucleotide primed-PCR,PEP-DOP-PCR)적방법,확증12개이지핵형적단세포표본(포괄5개융모표본、4개간세포표본화3개림파세포표본)화4개경PGD검측발현염색체이상적단란렬구표본,장확증산물표기홍색형광염료후,여표기록색형광염료적정상DNA등량혼균,여정상중기분렬상진행비교기인조잡교분석.동시,응용단순적간병과핵감산인물-PCR(DOP-PCR)확증10개단세포DNA,표기후진행CGH분석.비교량충단세포전기인조확증방법적확증효솔급수후용우CGH분석염색체고패수시적준학성.결과 소유적단세포채용PEP-DOP-PCR확증시,균능획득은정균균적PCR산물,편단대소범위재100～1000 bp지간,집중분포우400 bp좌우적구역,CGH분석결과현시염색체고패수변화여기타기술검측적결과일치.이10개단순적DOP-PCR확증지유6개표본성공,확증산물진행CGH분석시,잡교신호불균균,유2개현시여기타기술분석적결과불일치.결론 PEP-DOP-PCR기술능유효지확증단세포적전기인조DNA,기확증산물가응용CGH기술성공검측단개세포적염색체고패수변화,이단순적DOP-PCR기술역우출현확증실패、확증산물잡교후신호불균일적결점.PEP-DOP-PCR전기인조확증결합CGH기술재배태식입전유전학진단중유량호적응용전경.
Objective To establish a single-cell whole genome amplification (WGA) technique, in combination with comparative genomic hybridization (CGH), for analyzing chromosomal copy number changes, and to explore its clinical application in preimplantation genetic diagnosis (PGD). Methods Twelve single cell samples with known karyotypes, including 5 chorionic villus samples, 4 human embryonic stem cell (hESC) samples and 3 peripheral lymphocyte samples, and 4 single blastomere samples carrying chromosomal abnormalities detected by PGD, were collected for whole genome amplification by combining primer extension preamplification (PEP) with degenerate oligonucleotide primed-PCR (DOP-PCR)amplification. The amplified products labeled by red fluorescence were mixed with control DNA labeled by green fluorescence, and then the mixture was analyzed by CGH. As a comparison, 10 single cell samples were amplified by DOP-PCR only and then CGH analysis was performed. Results The amplification using PEP-DOP-PCR was more stable than traditional DOP-PCR. The products of PEP-DOP-PCR range from 100 bp to 1000 bp, with the mean size being about 400 bp. The CGH results were consistent with analyses by other methods. However, only 6 out of 10 single cell samples were successfully amplified by DOP-PCR,and CGH analysis showed a high background and 2 samples showed inconsistent results from other methods. Conclusion PEP-DOP-PCR can effectively amplify the whole genome DNA of single cell.Combined with CGH, this WGA method can successfully detect single-cell chromosomal copy number changes, while DOP-PCR was easy to fail to amplify and amplify inhomogeneousty, and CGH analysis using this PCR product usually showed high background. These results suggest that PEP-DOP-CGH is a promising method for preimplantation genetic diagnosis.