Methyl farnesoate synthesis is necessary for the environmental sex determination in the water flea Daphnia pulex.
Methyl farnesoate synthesis is necessary for the environmental sex determination in the water flea Daphnia pulex.
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DOI：
10.1016/j.jinsphys.2015.02.002
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发表时间：
2015-09
影响因子：
2.2
通讯作者：
K. Toyota;H. Miyakawa;Chizue Hiruta;Kenjiro Furuta;Y. Ogino;T. Shinoda;N. Tatarazako;S. Miyagawa
中科院分区：
文献类型：
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作者：
K. Toyota;H. Miyakawa;Chizue Hiruta;Kenjiro Furuta;Y. Ogino;T. Shinoda;N. Tatarazako;S. Miyagawa
性别决定系统可分为两组：遗传型性别决定(GSD)和环境性别决定(ESD)。ESD是一种适应性生活史策略，它允许根据环境线索进行性行为控制，以优化健康。然而，ESD的分子基础在很大程度上仍不清楚。微小甲壳动物长尾水蚤对各种外界刺激表现出ESD反应。尽管金合欢酸甲酯(MF：在丝虫中被认为是保幼激素，JH)已被报道在丝虫中诱导雄性产生，但由于缺乏合适的模型系统来研究，作为性别决定因素的MF的作用仍然是未知的。在这里，我们建立了这样一个可持续发展研究的体系。普雷克斯。WTN6品系在白昼缩短的情况下从产雌变雄，而MFP品系只产雌，与日长无关。为了阐明MF是否具有作为性别决定因子Ind的新的生理作用。Pulex，我们证明了MF/JH生物合成抑制剂抑制了在雄性诱导条件下饲养的WTN6菌株的雄性产量，缩短了日长。此外，我们还发现保幼激素酸性O-甲基转移酶(JHAMT)是MF/JH生物合成的关键酶，它通过催化法尼酸显示出产MF的活性。JHAMT基因的表达在WTN6品系的雄性生殖敏感期之前显著增加，但在MFP品系中没有，当维持在雄性诱导的条件下时。这些结果表明，JHAMT调控的MF合成对于雄性后代的生产是必要的。普雷克斯。我们的发现为ESD的遗传基础提供了新的见解，并开始阐明MF作为男性命运决定因素IND的生理功能。普雷克斯。
Sex-determination systems can be divided into two groups: genotypic sex determination (GSD) and environmental sex determination (ESD). ESD is an adaptive life-history strategy that allows control of sex in response to environmental cues in order to optimize fitness. However, the molecular basis of ESD remains largely unknown. The micro crustaceanDaphnia pulexexhibits ESD in response to various external stimuli. Although methyl farnesoate (MF: putative juvenile hormone, JH, in daphnids) has been reported to induce male production in daphnids, the role of MF as a sex-determining factor remains elusive due to the lack of a suitable model system for its study. Here, we establish such a system for ESD studies inD. pulex. The WTN6 strain switches from producing females to producing males in response to the shortened day condition, while the MFP strain only produces females, irrespective of day-length. To clarify whether MF has a novel physiological role as a sex-determining factor inD. pulex, we demonstrate that a MF/JH biosynthesis inhibitor suppressed male production in WTN6 strain reared under the male-inducible condition, shortened day-length. Moreover, we show that juvenile hormone acidO-methyltransferase (JHAMT), a critical enzyme of MF/JH biosynthesis, displays MF-generating activity by catalyzing farnesoic acid. Expression of theJHAMTgene increased significantly just before the MF-sensitive period for male production in the WTN6 strain, but not in the MFP strain, when maintained under male-inducible conditions. These results suggest that MF synthesis regulated by JHAMT is necessary for male offspring production inD. pulex. Our findings provide novel insights into the genetic underpinnings of ESD and they begin to shed light on the physiological function of MF as a male-fate determiner inD. pulex.