Luke S, Verma R S, Conte R A, Mathews T
Division of Genetics, Long Island College Hospital-SUNY Health Science Center, Brooklyn, New York 11201.
J Cell Sci. 1992 Dec;103 ( Pt 4):919-23. doi: 10.1242/jcs.103.4.919.
Pericentric inversion of the secondary constriction region (qh) of human chromosome 9 is a frequent occurrence. This structural alteration is regarded as a normal familial variant, termed heteromorphism, and is inherited in a Mendelian fashion without any apparent phenotypic consequences. We characterized the qh region of chromosome 9 from five individuals using a series of molecular cytogenetic techniques. Four out of the five individuals have an additional area composed of alphoid DNA sequences on the inverted chromosome 9 while one case was found to have an apparently intact alphoid DNA sequence. Although the direct function(s) of alphoid DNA sequences remain unclear, the centromeric breakage involving these sequences in inverted chromosome 9 raises a series of questions pertaining to the monocentric, dicentric and pseudodicentric nature of pericentric inversions. Nevertheless, these findings have prompted us to suggest that the structural organization of alphoid DNA sequences of the centromeric region of chromosome 9 are apparently "breakage prone" and may be associated with a higher incidence of pericentric inversions. Furthermore, the hierarchical organization of various satellite DNA families (alpha-satellite, beta-satellite and satellite III) within the primary and secondary constriction regions of chromosomes 9 are elucidated here.
人类9号染色体次缢痕区（qh）的臂间倒位很常见。这种结构改变被视为一种正常的家族性变异，称为异态性，以孟德尔方式遗传，无明显表型后果。我们使用一系列分子细胞遗传学技术对5个人的9号染色体qh区域进行了特征分析。5个人中有4人在倒位的9号染色体上有一个由α卫星DNA序列组成的额外区域，而有1例被发现其α卫星DNA序列明显完整。尽管α卫星DNA序列的直接功能仍不清楚，但9号倒位染色体上涉及这些序列的着丝粒断裂引发了一系列与臂间倒位的单着丝粒、双着丝粒和假双着丝粒性质有关的问题。然而，这些发现促使我们提出，9号染色体着丝粒区域α卫星DNA序列的结构组织明显“易于断裂”，可能与臂间倒位的较高发生率有关。此外，本文还阐明了9号染色体主缢痕区和次缢痕区内各种卫星DNA家族（α卫星、β卫星和卫星III）的层次组织。
