Single-locus complementary sex determination absent in Heterospilus prosopidis (Hymenoptera: Braconidae)
Single-locus complementary sex determination absent in Heterospilus prosopidis (Hymenoptera: Braconidae)
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DOI：
10.1038/sj.hdy.6800720
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发表时间：
2005-09-01
期刊：
影响因子：
3.8
通讯作者：
Heimpel, GE
中科院分区：
文献类型：
--
作者：
Wu, Z;Hopper, KR;Heimpel, GE
在单倍二倍体的Hyattera中，单倍体雄性来自未受精的卵，接受一组母本染色体，而二倍体雌性来自受精卵，接受母本和父本染色体。在单基因座互补性别决定（sl-CSD）下，性别由单个基因座上的多个等位基因决定。性位点杂合子发育为雌性，而半合子和纯合子卵分别发育为单倍体和二倍体雄性。二倍体男性，这是在几乎所有的情况下，不育或不育的研究，因此产生的高频率下近亲繁殖或低性别等位基因多样性的人口。CSD被认为是Hytera内性别决定的祖先形式，因为大多数基础类群的成员具有CSD，而一些更衍生的类群具有产生单倍-二倍体模式而不惩罚近亲繁殖的其他性别决定机制。在这项研究中，我们调查了性别决定Heterospilus prosoppellus Viereck，寄生蜂从一个相对原始的亚科茧蜂，一个hyperteran家庭有种和没有CSD。通过比较性比和死亡率模式产生的近交和远交的女性，我们能够排除在这个物种中的性别决定机制的sl-CSD。在H.考虑到它在茧蜂科中的基本系统发育位置，前茧蜂是出乎意料的。这项研究和其他最近的研究表明，在Hyattera的性别决定系统可能是进化不稳定的。
In the haplodiploid Hymenoptera, haploid males arise from unfertilized eggs, receiving a single set of maternal chromosomes while diploid females arise from fertilized eggs and receive both maternal and paternal chromosomes. Under single-locus complementary sex determination (sl-CSD), sex is determined by multiple alleles at a single locus. Sex locus heterozygotes develop as females, while hemizygous and homozygous eggs develop as haploid and diploid males, respectively. Diploid males, which are inviable or sterile in almost all cases studied, are therefore produced in high frequency under inbreeding or in populations with low sex allele diversity. CSD is considered to be the ancestral form of sex determination within the Hymenoptera because members of the most basal taxa have CSD while some of the more derived groups have other mechanisms of sex determination that produce the haplo-diploid pattern without penalizing inbreeding. In this study, we investigated sex determination in Heterospilus prosopidis Viereck, a parasitoid from a relatively primitive subfamily of the Braconidae, a hymenopteran family having species with and without CSD. By comparing sex ratio and mortality patterns produced by inbred and outbred females, we were able to rule out sl-CSD as a sex determination mechanism in this species. The absence of sl-CSD in H. prosopidis was unexpected given its basal phylogenetic position in the Braconidae. This and other recent studies suggest that sex determination systems in the Hymenoptera may be evolutionary labile.