Symbiont-Supplemented Maternal Investment Underpinning Host's Ecological Adaptation
Symbiont-Supplemented Maternal Investment Underpinning Host's Ecological Adaptation
复制标题
DOI：
10.1016/j.cub.2014.08.065
复制
发表时间：
2014-10-20
期刊：
影响因子：
9.2
通讯作者：
Fukatsu, Takema
中科院分区：
文献类型：
--
作者：
Kaiwa, Nahomi;Hosokawa, Takahiro;Fukatsu, Takema
母体对后代生长和生存的投资在不同的生物中广泛存在[1-3]。通过母体传递的垂直共生体传递对于许多生物体中后代的生长和存活也是关键的[4-6]。因此，它是预期的垂直共生体传输可能会与各种生物性状共同进化的母亲在后代的投资。在这里，我们报告了一种新的表型综合征，需要形态，组织学，行为和生态学专业化的母亲投资和垂直共生体传输的家庭Urostylididae [7-9]。成年雌性发育出巨大的卵巢，用于分泌多糖，具有新颖的产卵相关器官，用于细菌共生体的垂直传播（“Escheridatus Tachikawaea gelatinosa”），并产卵，卵上覆盖着大量的共生体补充果冻。新生幼虫在仲冬孵化，仅以水母为食，获得共生体，并在冬季生长。在春天，昆虫开始以植物汁液为食，其中共生体定位于专门的中肠区域并提供宿主饮食中缺乏的必需氨基酸。减少共生体基因组和主机共生物种表明其专性协会在进化时间。实验剥夺的果冻若虫死亡率的结果，而恢复的果冻导致恢复若虫的生长，确认果冻支持若虫生长在冬季。化学分析表明，半乳聚糖基果冻含有足够量的氨基酸，以维持若虫生长到第三龄。共生体的卵覆盖果冻的多才多艺的生物学角色突出了复杂的进化之间的相互作用，母体资源投资和垂直共生体的传输，这通常是重要的后代的生长，生存和生态适应。
Maternal investment for offspring's growth and survival is widespread among diverse organisms [1-3]. Vertical symbiont transmission via maternal passage is also pivotal for offspring's growth and survival in many organisms [4-6]. Hence, it is expected that vertical symbiont transmission may coevolve with various organismal traits concerning maternal investment in offspring. Here we report a novel phenotypic syndrome entailing morphological, histological, behavioral, and ecological specializations for maternal investment and vertical symbiont transmission in stinkbugs of the family Urostylididae [7-9]. Adult females develop huge ovaries exaggerated for polysaccharide excretion, possess novel ovipositor-associated organs for vertical transmission of a bacterial symbiont ("Candidatus Tachikawaea gelatinosa"), and lay eggs covered with voluminous symbiont-supplemented jelly. Newborns hatch in midwinter, feed solely on the jelly, acquire the symbiont, and grow during winter. In spring, the insects start feeding on plant sap, wherein the symbiont localizes to a specialized midgut region and supplies essential amino acids deficient in the host's diet. The reduced symbiont genome and host-symbiont co-speciation indicate their obligate association over evolutionary time. Experimental deprivation of the jelly results in nymphal mortality, whereas restoration of the jelly leads to recovered nymphal growth, confirming that the jelly supports nymphal growth in winter. Chemical analyses demonstrate that the galactan-based jelly contains a sufficient quantity of amino acids to sustain nymphal growth to the third instar. The versatile biological roles of the symbiont-containing egg-covering jelly highlight intricate evolutionary interactions between maternal resource investment and vertical symbiont transmission, which are commonly important for offspring's growth, survival, and ecological adaptation.