Sarvetnick N, Fox H S, Mann E, Mains P E, Elliott R W, Silver L M
Genetics. 1986 Jul;113(3):723-34. doi: 10.1093/genetics/113.3.723.
We have investigated the structure and properties of a chromosomal product recovered from a rare recombination event between a t haplotype and a wild-type form of mouse chromosome 17. Our embryological and molecular studies indicate that this chromosome (twLub2) is characterized by both a deletion and duplication of adjacent genetic material. The deletion appears to be responsible for a dominant lethal maternal effect and a recessive embryonic lethality. The duplication provides an explanation for the twLub2 suppression of the dominant T locus phenotype. A reanalysis of previously described results with another chromosome 17 variant called TtOrl indicates a structure for this chromosome that is reciprocal to that observed for twLub2. We have postulated the existence of an inversion over the proximal portion of all complete t haplotypes in order to explain the generation of the partial t haplotypes twLub2 and TtOrl. This proximal inversion and the previously described distal inversion are sufficient to account for all of the recombination properties that are characteristic of complete t haplotypes. The structures determined for twLub2 and TtOrl indicate that rare recombination can occur between nonequivalent genomic sequences within the inverted proximal t region when wild-type and t chromosomes are paired in a linear, nonhomologous configuration.
我们研究了从t单倍型与野生型小鼠17号染色体之间罕见重组事件中回收的一种染色体产物的结构和特性。我们的胚胎学和分子研究表明，这条染色体（twLub2）的特征是相邻遗传物质的缺失和重复。这种缺失似乎导致了显性致死母本效应和隐性胚胎致死性。这种重复为twLub2对显性T位点表型的抑制提供了解释。对另一种名为TtOrl的17号染色体变体的先前描述结果进行重新分析，表明该染色体的结构与twLub2的结构相反。我们推测在所有完整的t单倍型近端部分存在一个倒位，以解释部分t单倍型twLub2和TtOrl的产生。这个近端倒位和先前描述的远端倒位足以解释完整t单倍型所特有的所有重组特性。twLub2和TtOrl的结构表明，当野生型和t染色体以线性、非同源构型配对时，在倒位近端t区域内的非等效基因组序列之间可能会发生罕见重组。
