Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Brazil; Department of Biological Sciences, Binghamton University, USA.
Department of Biological Sciences, Binghamton University, USA.
Insect Biochem Mol Biol. 2021 Jun;133:103569. doi: 10.1016/j.ibmb.2021.103569. Epub 2021 Mar 20.
The fly genome contains a single ortholog of the evolutionarily conserved transcription factor hepatocyte nuclear factor 4 (HNF4), a broadly and constitutively expressed member of the nuclear receptor superfamily. Like its mammalian orthologs, Drosophila HNF4 (dHNF4) acts as a critical regulator of fatty acid and glucose homeostasis. Because of its role in energy storage and catabolism, the insect fat body controls non-autonomous organs including the ovaries, where lipid metabolism is essential for oogenesis. The present paper used dHNF4 overexpression (OE) in the fat bodies and ovaries to investigate its potential roles in lipid homeostasis and oogenesis. When the developing fat body overexpressed dHNF4, animals exhibited reduced size and failed to pupariate, but no changes in body composition were observed. Conditional OE of dHNF4 in the adult fat body produced a reduction in triacylglycerol content and reduced oogenesis. Ovary-specific dHNF4 OE increased oogenesis and egg-laying, but reduced the number of adult offspring. The phenotypic effects on oogenesis that arise upon dHNF4 OE in the fat body or ovary may be due to its function in controlling lipid utilization.
果蝇基因组中包含一个与进化上保守的转录因子肝细胞核因子 4（HNF4）的单一直系同源物，HNF4 是核受体超家族中广泛且组成性表达的成员。与哺乳动物直系同源物一样，果蝇 HNF4（dHNF4）是脂肪酸和葡萄糖稳态的关键调节因子。由于其在能量储存和分解代谢中的作用，昆虫脂肪体控制着非自主器官，包括卵巢，其中脂质代谢对于卵子发生至关重要。本文通过在脂肪体和卵巢中过度表达 dHNF4 来研究其在脂质稳态和卵子发生中的潜在作用。当发育中的脂肪体过度表达 dHNF4 时，动物体型减小，无法化蛹，但身体成分没有变化。在成年脂肪体中条件性过表达 dHNF4 会导致三酰基甘油含量降低和卵子发生减少。卵巢特异性 dHNF4 OE 增加卵子发生和产卵，但减少了成年后代的数量。在脂肪体或卵巢中过度表达 dHNF4 对卵子发生产生的表型影响可能与其控制脂质利用的功能有关。
