Abstract:
Seasonal plasticity in male courtship in Bicyclus anynana butterflies is due to variation in levels of the steroid hormone 20E (20-hydroxyecdysone) during pupation. Wet season (WS) males have high levels of 20E and become active courters. Dry season (DS) males have lower levels of 20E and reduced courtship rates. However, WS courtship rates can be achieved if DS male pupae are injected with 20E at 30% of pupation. Here, we investigated the genes involved in male courtship plasticity and examined whether 20E plays an organizational role in the pupal brain that later influences the sexual behaviour of adults. We show that DS pupal brains have a sevenfold upregulation of the yellow gene relative to the WS brains, and that knocking out yellow leads to increased male courtship. We find that injecting 20E into DS pupa reduced yellow expression although not significantly. Our results show that yellow is a repressor of the neural circuity for male courtship behaviour in B. anynana. 20E levels experienced during pupation could play an organizational role during pupal brain development by regulating yellow expression, however, other factors might also be involved. Our findings are in striking contrast to Drosophila where yellow is required for male courtship.
摘要:
Bicyclusanynana蝴蝶的雄性求爱的季节性可塑性是由于化page过程中类固醇激素20E(20-羟基蜕皮激素)水平的变化。湿季(WS)男性的20E水平很高,并成为活跃的运动员。旱季(DS)男性的20E水平较低,求爱率降低。然而,如果以30%的化up注射20E,则可以实现WS求偶率。这里,我们调查了与男性求偶可塑性有关的基因,并检查了20E是否在the中发挥组织作用,后来影响成年人的性行为。我们显示DSp的大脑相对于WS的大脑有7倍的黄色基因上调,剔除黄色会导致男性求爱增加。我们发现将20E注射到DSthe中降低了黄色表达,尽管没有显着。我们的结果表明,黄色是B.anynana男性求偶行为的神经回路的阻遏物。化蛹过程中经历的20E水平可以通过调节黄色表达在蛹大脑发育过程中发挥组织作用,然而,也可能涉及其他因素。我们的发现与果蝇形成鲜明对比,果蝇需要黄色才能进行男性求爱。