Abstract:
Theory predicts that organisms should diversify their offspring when faced with a stressful environment. This prediction has received empirical support across diverse groups of organisms and stressors. For example, when encountered by Caenorhabditis elegans during early development, food limitation (a common environmental stressor) induces the nematodes to arrest in a developmental stage called dauer and to increase their propensity to outcross when they are subsequently provided with food and enabled to develop to maturity. Here we tested whether food limitation first encountered during late development/early adulthood can also induce increased outcrossing propensity in C. elegans. Previously well-fed C. elegans increased their propensity to outcross when challenged with food limitation during the final larval stage of development and into early adulthood, relative to continuously well-fed (control) nematodes. Our results thus support previous research demonstrating that the stress of food limitation can induce increased outcrossing propensity in C. elegans. Furthermore, our results expand on previous work by showing that food limitation can still increase outcrossing propensity even when it is not encountered until late development, and this can occur independently of the developmental and gene expression changes associated with dauer.
摘要:
理论预测,面对压力环境时,生物体应该使其后代多样化。这一预测得到了不同生物和压力源群体的经验支持。例如,当在早期发育过程中遇到秀丽隐杆线虫时,食物限制(一种常见的环境压力源)会导致线虫在称为dauer的发育阶段停滞,并在随后为它们提供食物并使其发育成熟时增加其异交的倾向。在这里,我们测试了在发育后期/成年早期首次遇到的食物限制是否也可以诱导秀丽隐杆线虫的异交倾向增加。以前吃得很好的秀丽隐杆线虫在最后的幼虫发育阶段和成年早期受到食物限制的挑战时,增加了它们的杂交倾向,相对于连续饲喂良好的(对照)线虫。因此,我们的结果支持了先前的研究,表明食物限制的压力可以引起秀丽隐杆线虫的异交倾向增加。此外,我们的结果扩展了以前的工作,表明食物限制仍然可以增加异交倾向,即使它没有遇到,直到晚期发展,这可以独立于与dauer相关的发育和基因表达变化而发生。