Genetic interaction between male mating strategy and sex ratio in a marine isopod
Genetic interaction between male mating strategy and sex ratio in a marine isopod
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DOI：
10.1038/41089
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发表时间：
1997-07-24
期刊：
影响因子：
64.8
通讯作者：
Sassaman, C
中科院分区：
文献类型：
--
作者：
Shuster, SM;Sassaman, C
许多动物物种中的雄性个体表现出不同的行为模式(1-3)，但人们对这些差异背后的遗传机制知之甚少。在这里，我们研究了等足类甲壳类动物 Paracerceis sculpta 的遗传学，其中三种不同类型的雄性共存，每种雄性都通过其行为和形态表型与其他雄性区分开来 (4,5)。在家族中，编码磷酸葡萄糖变位酶的基因（Pgm 基因）的等位基因与特定的雄性表型相关，尽管这些特征之间在整个群体中不存在显着关联。这表明 Pgm 与控制男性表型的单个遗传位点密切相关。我们称之为替代交配策略 (Ams) 基因座。我们提出的证据表明，另外两个因素——常染色体基因变压器（Tfr）和染色体外因素——与主要性别决定位点和 Ams 等位基因相互作用，导致某些个体改变性别，从而使家庭性别比例产生偏差。基于我们的遗传分析的模型表明：首先，男性行为的多态性是由 Ams 基因座的三个等位基因的孟德尔分离控制的；其次，家庭性别比受到 TFr 位点的替代等位基因的影响，而 TFr 基因座的表达受染色体外因子的影响；第三，TFr 和 Ams 相互作用来确定个体的性别，如果是男性，则确定其行为和外部形态。
Individual males in many animal species exhibit discrete modes of behaviour(1-3), but the genetic mechanisms underlying these differences are poorly understood. Here we investigate the genetics of the isopod crustacean Paracerceis sculpta, in which three different types of males coexist, each distinguishable from the others by their behavioural and morphological phenotypes(4,5). Within families, alleles of the gene encoding the enzyme phosphoglucomutase (Pgm gene) are associated with particular male phenotypes, although no significant association between these characters exists population-wide. This suggests that Pgm is closely linked to a single genetic locus which controls male phenotype. We call this the alternative mating strategy (Ams) locus. We present evidence that two other factors-an autosomal gene, transformer(Tfr), and an extrachromosomal factor-interact with primary sex determination loci and with alleles at Ams, causing certain individuals to change sex, thereby biasing family sex ratios. A model based on our genetic analysis suggests that: first, polymorphism in male behaviour is controlled by the mendelian segregation of three alleles at the Ams locus; second, that family sex ratio is influenced by alternative alleles at the TFr locus whose expression is influenced by the extrachromosomal factor; and third, that TFr and Ams interact epistatically to determine the sex of the individual and, if male, its behaviour and external morphology.