Ewis Ashraf A, Lee Juwon W, Kuroki Yoko, Shinka Toshikatsu, Nakahori Yutaka
Department of Human Genetics and Public Health, Graduate School of Proteomics, Faculty of Medicine, The University of Tokushima, Japan.
J Hum Genet. 2002;47(10):523-8. doi: 10.1007/s100380200078.
A recently developed microsatellite marker on the Y chromosome, Yfm1, which was originally cloned from a cosmid clone mapped near the DAZ (Deleted in AZoospermia) genes, was used to classify Y chromosomes using an automatic sequencer. Yfm1 could detect multicopies on Y chromosomes in a single polymerase chain reaction, showing four main classes, A, A*, B, and C, according to the number of copies and peak patterns. Compound haplotype analysis of the Y chromosome using the Yfm1 marker with three other biallelic markers on the Y chromosome, SRY, DXYS5Y, and YAP, resulted in nine different haplotypes among different populations, including Japanese. Haplotype II (defined by YAP insertion) observed in the Japanese population was consistently associated with Yfm1 class A or A*, which showed the lowest number of copies of Yfm1. Haplotypes III and IV were consistently associated with Yfm1 class B. On the other hand, haplotype I showed a variety of Yfm1 patterns that were dubbed class C when not appropriately classified as A, A*, or B. These relationships among Yfm1 microsatellite and Y-specific biallelic markers could supply useful population genetic information. Moreover, because we have already shown that men with haplotype II have significantly lower spermatogenic ability than those with other haplotypes, Yfm1 class A or A* with the least number of copies may be related to the haplotype II-specific structure of the Y chromosome, such as deletion of DAZ or DAZ repeats, reflecting the lower spermatogenic abilities of Japanese haplotype II men. Thus, Yfm1 represents a very useful marker for analysis of genetic structure in different populations and studies on Y chromosome lineage-specific genotype-phenotype correlations.
最近在Y染色体上开发的一个微卫星标记Yfm1，最初是从定位在无精子症缺失（DAZ）基因附近的一个黏粒克隆中克隆出来的，被用于通过自动测序仪对Y染色体进行分类。Yfm1在一次聚合酶链反应中就能检测到Y染色体上的多拷贝，根据拷贝数和峰型显示出四个主要类别，即A、A*、B和C。使用Yfm1标记与Y染色体上的其他三个双等位基因标记SRY、DXYS5Y和YAP对Y染色体进行复合单倍型分析，在包括日本人在内的不同人群中产生了九种不同的单倍型。在日本人群中观察到的单倍型II（由YAP插入定义）始终与Yfm1类别A或A相关，这两类显示出Yfm1的拷贝数最少。单倍型III和IV始终与Yfm1类别B相关。另一方面，单倍型I显示出多种Yfm1模式，在未被适当地归类为A、A或B时被称为C类。Yfm1微卫星与Y特异性双等位基因标记之间的这些关系可以提供有用的群体遗传信息。此外，因为我们已经表明，具有单倍型II的男性的生精能力明显低于具有其他单倍型的男性，拷贝数最少的Yfm1类别A或A*可能与Y染色体的单倍型II特异性结构有关，比如DAZ缺失或DAZ重复，这反映了日本单倍型II男性较低的生精能力。因此，Yfm1是分析不同人群遗传结构以及研究Y染色体谱系特异性基因型-表型相关性的一个非常有用的标记。
