Sillam-Dussès David, Hanus Robert, Poulsen Michael, Roy Virginie, Favier Maryline, Vasseur-Cognet Mireille
Laboratoire d'Ethologie Expérimentale et Comparée, Université Paris 13, EA4443, 93430 Villetaneuse, France UMR IRD 242, UPEC, CNRS 7618, UPMC 113, INRA 1392, PARIS 7 113, Institut d'Ecologie et des Sciences de l'Environnement de Paris, 93140 Bondy, France Sorbonne Paris Cité, Paris, France Sorbonne Universités, Paris, France.
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 16610 Prague, Czech Republic.
Open Biol. 2016 May;6(5). doi: 10.1098/rsob.160080. Epub 2016 May 18.
Termites are among the few animals that themselves can digest the most abundant organic polymer, cellulose, into glucose. In mice and Drosophila, glucose can activate genes via the transcription factor carbohydrate-responsive element-binding protein (ChREBP) to induce glucose utilization and de novo lipogenesis. Here, we identify a termite orthologue of ChREBP and its downstream lipogenic targets, including acetyl-CoA carboxylase and fatty acid synthase. We show that all of these genes, including ChREBP, are upregulated in mature queens compared with kings, sterile workers and soldiers in eight different termite species. ChREBP is expressed in several tissues, including ovaries and fat bodies, and increases in expression in totipotent workers during their differentiation into neotenic mature queens. We further show that ChREBP is regulated by a carbohydrate diet in termite queens. Suppression of the lipogenic pathway by a pharmacological agent in queens elicits the same behavioural alterations in sterile workers as observed in queenless colonies, supporting that the ChREBP pathway partakes in the biosynthesis of semiochemicals that convey the signal of the presence of a fertile queen. Our results highlight ChREBP as a likely key factor for the regulation and signalling of queen fertility.
白蚁是少数能够自行将最丰富的有机聚合物纤维素消化为葡萄糖的动物之一。在小鼠和果蝇中，葡萄糖可通过转录因子碳水化合物反应元件结合蛋白（ChREBP）激活基因，以诱导葡萄糖利用和从头脂肪生成。在此，我们鉴定出ChREBP的白蚁直系同源物及其下游脂肪生成靶点，包括乙酰辅酶A羧化酶和脂肪酸合酶。我们发现，在八种不同白蚁物种中，与雄蚁、不育工蚁和兵蚁相比，所有这些基因（包括ChREBP）在成熟蚁后中均上调。ChREBP在包括卵巢和脂肪体在内的多个组织中表达，并且在全能工蚁分化为幼态成熟蚁后的过程中表达增加。我们进一步表明，ChREBP受蚁后碳水化合物饮食的调节。用药物抑制蚁后的脂肪生成途径会在不育工蚁中引发与无蚁后蚁群中观察到的相同行为改变，这支持ChREBP途径参与了传递可育蚁后存在信号的信息素的生物合成。我们的结果突出了ChREBP作为蚁后生育力调节和信号传导的一个可能关键因素。
