Abstract:
In social insect colonies, selfish behaviour due to intracolonial conflict among members can result in colony-level costs despite close relatedness. In certain termite species, queens use asexual reproduction for within-colony queen succession but rely on sexual reproduction for worker and alate production, resulting in multiple half-clones of a single primary queen competing for personal reproduction. Our study demonstrates that competition over asexual queen succession among different clone types leads to the overproduction of parthenogenetic offspring, resulting in the production of dysfunctional parthenogenetic alates. By genotyping the queens of 23 field colonies of Reticulitermes speratus, we found that clone variation in the queen population reduces as colonies develop. Field sampling of alates and primary reproductives of incipient colonies showed that overproduced parthenogenetic offspring develop into alates that have significantly smaller body sizes and much lower survivorship than sexually produced alates. Our results indicate that while the production of earlier and more parthenogenetic eggs is advantageous for winning the competition for personal reproduction, it comes at a great cost to the colony. Thus, this study highlights the evolutionary interplay between individual-level and colony-level selection on parthenogenesis by queens.
摘要:
在社会昆虫殖民地,尽管存在密切关系,但由于成员之间的殖民地冲突而导致的自私行为会导致殖民地水平的成本。在某些白蚁物种中,女王使用无性繁殖进行殖民地女王继承,但依靠有性生殖进行工人和alate生产,导致单个主要女王的多个半克隆竞争个人繁殖。我们的研究表明,不同克隆类型之间对无性女王继承的竞争导致了孤雌生殖后代的过度生产,导致产生功能失调的孤雌生殖。通过对23个精细细胞野外殖民地的皇后进行基因分型,我们发现,随着殖民地的发展,女王种群中的克隆变异减少。对初期殖民地的母鸡和主要繁殖体的实地采样表明,过度繁殖的孤雌生殖后代发育成母鸡,其体型明显小于有性繁殖的母鸡,存活率低得多。我们的结果表明,虽然更早和更多的孤雌生殖卵的生产有利于赢得个人繁殖的竞争,这给殖民地带来了巨大的代价。因此,这项研究强调了个体水平和群体水平选择对皇后孤雌生殖的进化相互作用。