Evidence for unequal crossing over within the mouse T/t complex.
Evidence for unequal crossing over within the mouse T/t complex.
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小鼠 T/t 复合体内不等交换的证据。
DOI：
10.1073/pnas.77.10.6077
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发表时间：
1980
影响因子：
11.1
通讯作者：
Artzt,K
中科院分区：
文献类型：
--
作者：
Silver,LM;White,M;Artzt,K
Tcp-1 基因位于小鼠 17 号染色体上的 T/t 复合体内，编码主要细胞表面相关蛋白 p63/6.9。之前，我们鉴定了该基因的两个结构等位基因，它们指定了 p63/6.9 蛋白的替代形式。 Tcp-1b 等位基因与所有野生型 17 号染色体相关； Tcp-1a 等位基因仅在携带完整 t 单倍型的 17 号染色体上发现。在任何完整 t 单倍型杂合的小鼠中，沿 17 号染色体主要长度的正常重组受到抑制。然而，抑制并不完全，野生型和 t 单倍型染色质之间确实会发生罕见的交叉。在本报告中，对 15 条稀有重组染色体的 Tcp-1 等位基因进行了分析。结果表明，在四个独立事件中，Tcp-1b 和 Tcp-1a 等位基因在单个 DNA 分子中的顺式位置上相关联。进一步的遗传分析为以下假设提供了支持：野生型和携带 t 的 17 号染色体上的 DNA 序列排列之间存在显着的非同源性。这可以解释沿 t 染色质延伸的正常重组的抑制以及罕见重组事件确实发生时频繁的不等交换。
The Tcp-1 gene located within the T/t complex on chromosome 17 of the mouse codes for a major cell surface-associated protein p63/6.9. Previously, we identified two structural alleles of this gene which specify alternate forms of the p63/6.9 protein. The Tcp-1b allele is associated with all wild-type chromosome 17; the Tcp-1a allele is found only with chromosome 17 carrying a complete t haplotype. Normal recombination along a major length of chromosome 17 is suppressed in mice that are heterozygous for any complete t haplotype. Suppression is not complete, however, and rare crossing over between wild-type and t haplotype chromatin does occur. In this report, 15 rare recombinant chromosomes have been analyzed for Tcp-1 alleles. The results indicate that in four independent events the Tcp-1b and Tcp-1a alleles have become associated in cis position in a single DNA molecule. Further genetic analysis provides support for the hypothesis that a significant nonhomology exists between the arrangement of DNA sequences on wild-type and t-carrying chromosome 17. This could account for both the suppression of normal recombination along the stretch of t chromatin and the frequent unequal crossing over when rare recombinational events do take place.