Caste determination in a polyembryonic wasp involves inheritance of germ cells
Caste determination in a polyembryonic wasp involves inheritance of germ cells
复制标题
DOI：
10.1073/pnas.0403625101
复制
发表时间：
2004-07-06
影响因子：
11.1
通讯作者：
Strand, MR
中科院分区：
文献类型：
--
作者：
Donnell, DM;Corley, LS;Strand, MR
社会性昆虫的特点是等级的发展，其中一些群体成员繁殖，而另一些则是利他主义的帮手。控制种姓形成的条件开关通常涉及环境刺激，这些刺激作用于调节个体发展的过程。与其他社会物种不同，多胚蜂的胚胎克隆发育，产生大量遗传上相同的后代和两个形态上不同的种姓。克隆中的所有胚胎都存在于同一个环境中，即宿主，但发育成生殖幼虫，成熟为成年黄蜂，或者发育成具有防御功能的士兵幼虫。在这里，我们报告说，种性决定在Copidosoma floridanum涉及遗传的生殖细胞。表达了一个C.生殖细胞标记Vasa的floridanum同源物（Cf-vas）表明四细胞期胚胎中的B-4卵裂球被指定为原始生殖细胞。Vas在发育后期的表达进一步表明，发育成生殖幼虫的胚胎具有原始生殖细胞，而发育成兵蚁幼虫的胚胎则没有。消融的B-4卵裂球导致大多数育雏只包含士兵，而消融其他卵裂球产生育雏包含两个种姓。这些结果表明，士兵幼虫是专性不育，并揭示了一个以前未知的作用，生殖细胞在种姓形成。
Social insects are characterized by the development of castes in which some colony members reproduce whereas others function as altruistic helpers. The conditional switch controlling caste formation usually involves environmental stimuli that act on processes that regulate development of individuals. Unlike other social species, embryos of polyembryonic wasps develop clonally to produce large numbers of genetically identical offspring and two morphologically distinct castes. All embryos in a clone exist in an identical environment, the host, yet develop into either reproductive larvae that mature into adult wasps or soldier larvae whose function is defense. Here, we report that caste determination in Copidosoma floridanum involves inheritance of germ cells. Expression of a C. floridanum homolog (Cf-vas) of the germ cell marker Vasa indicated that the B-4 blastomere in four cell-stage embryos is specified as a primordial germ cell. Vas expression later in development further indicated that embryos developing into reproductive larvae possess primordial germ cells whereas embryos developing into soldier larvae do not. Ablation of the B-4 blastomere resulted in most broods containing only soldiers whereas ablation of other blastomeres produced broods containing both castes. These results indicate that soldier larvae are obligately sterile and reveal a previously unknown role for germ cells in caste formation.