Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695 USA.
Sci Rep. 2017 Mar 21;7:45071. doi: 10.1038/srep45071.
The methyl farnesoate receptor (MfR) orchestrates aspects of reproduction and development such as male sex determination in branchiopod crustaceans. Phenotypic endpoints regulated by the receptor have been well-documented, but molecular interactions involved in receptor activation remain elusive. We hypothesized that the MfR subunits, methoprene-tolerant transcription factor (Met) and steroid receptor coactivator (SRC), would be expressed coincident with the timing of sex programming of developing oocytes by methyl farnesoate in daphnids. We also hypothesized that methyl farnesoate activates MfR assembly. Met mRNA was expressed rhythmically during the reproductive cycle, with peak mRNA accumulation just prior period of oocytes programming of sex. Further, we revealed evidence that Met proteins self-associate in the absence of methyl farnesoate, and that the presence of methyl farnesoate stimulates dissociation of Met multimers with subsequent association with SRC. Results demonstrated that the Met subunit is highly dynamic in controlling the action of methyl farnesoate through temporal variation in its expression and availability for receptor assembly.
甲呋酰胺受体（MfR）在甲壳纲动物中协调生殖和发育的各个方面，例如雄性性别决定。受受体调节的表型终点已有很好的记录，但参与受体激活的分子相互作用仍不清楚。我们假设 MfR 亚基，即法呢醇耐受转录因子（Met）和类固醇受体共激活因子（SRC），将与甲基法呢醇在溞类中发育卵母细胞的性别编程时间一致表达。我们还假设甲基法呢醇激活 MfR 组装。Met mRNA 在生殖周期中呈节律性表达，在卵母细胞编程性别之前的高峰期 mRNA 积累。此外，我们还揭示了证据表明，Met 蛋白在没有甲基法呢醇的情况下会自我缔合，并且甲基法呢醇的存在会刺激 Met 多聚体的解离，随后与 SRC 结合。结果表明，Met 亚基通过其表达的时间变化及其用于受体组装的可用性来高度动态地控制甲基法呢醇的作用。
