家蚕的杀雌染色体是由Z染色体和W染色体之间的易位产生的。

The female-killing chromosome of the silkworm, Bombyx mori, was generated by translocation between the Z and W chromosomes.

作者信息

Fujii T, Tanaka N, Yokoyama T, Ninaki O, Oshiki T, Ohnuma A, Tazima Y, Banno Y, Ajimura M, Mita K, Seki M, Ohbayashi F, Shimada T, Abe H

机构信息

Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, 183-8509, Fuchu, Tokyo, Japan.

出版信息

Genetica. 2006 May;127(1-3):253-65. doi: 10.1007/s10709-005-4147-8.

DOI:10.1007/s10709-005-4147-8

PMID:16850229

Abstract

Bombyx mori is a female-heterogametic organism (female, ZW; male, ZZ) that appears to have a putative feminizing gene (Fem) on the W chromosome. The paternally transmitted mutant W chromosome, Df(p ( Sa ) + ( p )W + ( od ))Fem, derived from the translocation-carrying W chromosome (p ( Sa ) + ( p )W + ( od )), is inert as femaleness determinant. Moreover, this Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome has been thought to have a female-killing factor because no female larvae having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome are produced. Initially, to investigate whether the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains any region of the W chromosome or not, we analyzed the presence or absence of 12 W-specific RAPD markers. The Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contained 3 of 12 W-specific RAPD markers. These results strongly indicate that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains the region of the W chromosome. Moreover, by using phenotypic and molecular markers, we confirmed that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is connected with a partially deleted Z chromosome and that this fused chromosome behaves as a Z chromosome during male meiosis. Furthermore, we demonstrated that the ZZW-type triploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is viable. Therefore, we concluded that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome does not have a female-killing factor but that partial deletion of the Z chromosome causes the death of the ZW-type diploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome. Additionally, our results of detailed genetic analyses strongly indicate that the female-killing chromosome composed of the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome and deleted Z chromosome was generated by translocation between the Z chromosome and the translocation-carrying W chromosome, p ( Sa ) + ( p )W + ( od ).

摘要

家蚕是一种雌性异配生物（雌性为ZW，雄性为ZZ），其W染色体上似乎存在一个假定的雌性化基因（Fem）。源自携带易位的W染色体（p(Sa)+(p)W+(od)）的父系遗传突变W染色体Df(p(Sa)+(p)W+(od))Fem，作为雌性决定因子是无活性的。此外，由于没有产生具有Df(p(Sa)+(p)W+(od))Fem染色体的雌性幼虫，所以该Df(p(Sa)+(p)W+(od))Fem染色体被认为具有雌性致死因子。最初，为了研究Df(p(Sa)+(p)W+(od))Fem染色体是否包含W染色体的任何区域，我们分析了12个W特异性RAPD标记的有无。Df(p(Sa)+(p)W+(od))Fem染色体包含12个W特异性RAPD标记中的3个。这些结果有力地表明Df(p(Sa)+(p)W+(od))Fem染色体包含W染色体的区域。此外，通过使用表型和分子标记，我们证实Df(p(Sa)+(p)W+(od))Fem染色体与部分缺失的Z染色体相连，并且这种融合染色体在雄性减数分裂过程中表现为Z染色体。此外，我们证明具有Df(p(Sa)+(p)W+(od))Fem染色体的ZZW型三倍体雌性是可存活的。因此，我们得出结论，Df(p(Sa)+(p)W+(od))Fem染色体没有雌性致死因子，而是Z染色体的部分缺失导致具有Df(p(Sa)+(p)W+(od))Fem染色体的ZW型二倍体雌性死亡。此外，我们详细的遗传分析结果有力地表明，由Df(p(Sa)+(p)W+(od))Fem染色体和缺失的Z染色体组成的雌性致死染色体是由Z染色体与携带易位的W染色体p(Sa)+(p)W+(od)之间的易位产生的。