Knebel S, Pasantes J J, Thi D A D, Schaller F, Schempp W
Institute of Human Genetics, University Clinic Freiburg, Germany.
Cytogenet Genome Res. 2011;132(4):219-26. doi: 10.1159/000322080. Epub 2011 Feb 1.
Pericentric inversions of the human Y chromosome (inv(Y)) are the result of breakpoints in Yp and Yq. Whether these breakpoints occur recurrently on specific hotspots or appear at different locations along the repeat structure of the human Y chromosome is an open question. Employing FISH for a better definition and refinement of the inversion breakpoints in 9 cases of inv(Y) chromosomes, with seemingly unvarying metacentric appearance after banding analysis, unequivocally resulted in heterogeneity of the pericentric inversions of the human Y chromosome. While in all 9 inv(Y) cases the inversion breakpoints in the short arm fall in a gene-poor region of X-transposed sequences proximal to PAR1 and SRY in Yp11.2, there are clearly 3 different inversion breakpoints in the long arm. Inv(Y)-types I and II are familial cases showing inversion breakpoints that map in Yq11.23 or in Yq11.223, outside the ampliconic fertility gene cluster of DAZ and CDY in AZFc. Inv(Y)-type III shows an inversion breakpoint in Yq11.223 that splits the DAZ and CDY fertility gene-cluster in AZFc. This inversion type is representative of both familial cases and cases with spermatogenetic impairment. In a further familial case of inv(Y), with almost acrocentric morphology, the breakpoints are within the TSPY and RBMY repeat in Yp and within the heterochromatin in Yq. Therefore, the presence of specific inversion breakpoints leading to impaired fertility in certain inv(Y) cases remains an open question.
人类Y染色体的臂间倒位（inv(Y)）是Yp和Yq上断点的结果。这些断点是在特定热点区域反复出现，还是沿着人类Y染色体的重复结构出现在不同位置，仍是一个悬而未决的问题。对9例inv(Y)染色体进行荧光原位杂交（FISH），以更好地定义和细化倒位断点，这些inv(Y)染色体在显带分析后看似具有不变的中着丝粒外观，结果明确显示人类Y染色体臂间倒位具有异质性。在所有9例inv(Y)病例中，短臂上的倒位断点位于Yp11.2中靠近PAR1和SRY的X易位序列的基因贫乏区域，而长臂上显然有3个不同的倒位断点。I型和II型inv(Y)是家族性病例，其倒位断点位于Yq11.23或Yq11.223，在AZFc中DAZ和CDY的扩增性生育基因簇之外。III型inv(Y)在Yq11.223处有一个倒位断点，该断点将AZFc中的DAZ和CDY生育基因簇分开。这种倒位类型在家族性病例和精子发生受损的病例中均有代表性。在另一例几乎为近端着丝粒形态的inv(Y)家族性病例中，断点位于Yp的TSPY和RBMY重复序列内以及Yq的异染色质内。因此，在某些inv(Y)病例中导致生育力受损的特定倒位断点的存在仍然是一个悬而未决的问题。
