Singh Avadhesh Kumar, Alam Chaudhary Mashhood, Sharfuddin Choudhary, Ali Safdar
Department of Biomedical Sciences, SRCASW, University of Delhi, Vasundhara Enclave, New Delhi 110096, India.
Department of Botany, Patna University, Bihar 800005, India.
Infect Genet Evol. 2014 Jun;24:92-8. doi: 10.1016/j.meegid.2014.03.010. Epub 2014 Mar 21.
Simple sequence repeats (SSRs) are tandem-repeated sequences ubiquitously present but differentially distributed across genomes. Present study is a systematic analysis for incidence, composition and complexity of different microsatellites in 48 representative Human papillomavirus (HPV) genomes. The analysis revealed a total of 1868 SSRs and 120 cSSRs. However, four genomes (HPV-60, HPV-92, HPV-112 and HPV-136) lacked any cSSR content; while HPV-31 accounted for a maximum of 10 cSSRs. An overall increase in cSSR% with higher dMAX was observed. The SSRs and cSSRs were prevalent in coding regions. Poly(A/T) repeats were significantly more abundant than poly(G/C) repeats possibly due to high (A/T) content of the HPV genomes. Further, higher prevalence of di-nucleotide repeats over tri-nucleotide repeats may be attributed to instability of former because of higher slippage rate. An in-depth study of the satellite sequences would provide an insight into the imperfections and evolution of microsatellites.
简单序列重复（SSRs）是串联重复序列，普遍存在于基因组中，但分布存在差异。本研究对48个代表性人乳头瘤病毒（HPV）基因组中不同微卫星的发生率、组成和复杂性进行了系统分析。分析共发现1868个SSR和120个cSSR。然而，四个基因组（HPV-60、HPV-92、HPV-112和HPV-136）没有任何cSSR；而HPV-31最多有10个cSSR。观察到随着dMAX升高，cSSR%总体增加。SSR和cSSR在编码区普遍存在。聚（A/T）重复序列比聚（G/C）重复序列明显更丰富，这可能是由于HPV基因组中（A/T）含量较高。此外，二核苷酸重复序列比三核苷酸重复序列的发生率更高，这可能归因于前者因较高的滑动率而具有不稳定性。对卫星序列的深入研究将有助于深入了解微卫星的缺陷和进化。
