Paquis-Flucklinger V, Santucci-Darmanin S, Paul R, Saunières A, Turc-Carel C, Desnuelle C
Laboratoire de Neurobiologie Cellulaire, Laboratoire de Génétique Chromosomique des Tumeurs, UMR 6549 CNRS, Faculté de Médecine, Av. de Valombrose, Nice Cedex 2, 06107, France.
Genomics. 1997 Sep 1;44(2):188-94. doi: 10.1006/geno.1997.4857.
The Escherichia coli MutHLS system has been highly conserved throughout evolution. The eukaryotic pathway results in a specialization of MutS homologs that have evolved to play crucial roles in both DNA mismatch repair and meiotic recombination. So far, meiosis-specific genes belonging to this family have only been identified in yeast. In Saccharomyces cerevisiae, MSH4 (MutS homolog 4) is a meiosis-specific protein that is not involved in mismatch correction. This protein is required for reciprocal recombination and proper segregation of homologous chromosomes at meiosis I. We have identified the human MSH4 homolog gene. The predicted amino acid sequence shows 28.7% identity with the S. cerevisiae MSH4 protein. By Northern blot analysis, human MSH4 transcripts are only detectable in testis and in ovary with a lower level of expression. We have mapped MSH4 to human chromosome 1 at band p31 by fluorescence in situ hybridization. The identification of such a gene provides a powerful tool for clarifying the respective roles of MSH and MLH genes in mammalian meiosis.
大肠杆菌MutHLS系统在整个进化过程中高度保守。真核生物途径导致MutS同源物的特化，这些同源物已进化到在DNA错配修复和减数分裂重组中都发挥关键作用。到目前为止，属于这个家族的减数分裂特异性基因仅在酵母中被鉴定出来。在酿酒酵母中，MSH4（MutS同源物4）是一种减数分裂特异性蛋白，不参与错配校正。这种蛋白是减数分裂I时同源染色体相互重组和正确分离所必需的。我们已经鉴定出人类MSH4同源基因。预测的氨基酸序列与酿酒酵母MSH4蛋白有28.7%的同一性。通过Northern印迹分析，人类MSH4转录本仅在睾丸和卵巢中可检测到，且表达水平较低。我们通过荧光原位杂交将MSH4定位到人类染色体1的p31带。这样一个基因的鉴定为阐明MSH和MLH基因在哺乳动物减数分裂中的各自作用提供了一个有力的工具。
