PDF(Pubmed)
Abstract：
Methyl farnesoate epoxidase (MFE) is a gene encoding an enzyme related to the last step of juvenile hormone biosynthesis. Mn-MFE cDNA has a total length of 1695 bp and an open reading frame (ORF) length of 1482 bp, encoding 493 amino acids. Sequence analysis showed that its amino acid sequence has a PPGP hinge, an FGCG structural domain, and other structural domains specific to the P450 family of enzymes. Mn-MFE was most highly expressed in the hepatopancreas, followed by the ovary and gill, weakly expressed in heart and muscle tissue, and barely expressed in the eyestalk and cranial ganglion. Mn-MFE expression remained stable during the larval period, during which it mainly played a critical role in gonadal differentiation. Expression in the ovary was positively correlated and expression in the hepatopancreas was negatively correlated with ovarian development. In situ hybridization (ISH) showed that the signal was expressed in the oocyte, nucleus, cell membrane and follicular cells, and the intensity of expression was strongest at stage O-IV. The knockdown of Mn-MFE resulted in a significantly lower gonadosomatic index and percentage of ovaries past stage O-III compared to the control group. However, no differences were found in the cumulative frequency of molting between the experimental and control groups. Moreover, the analysis of ovarian tissue sections at the end of the experiment showed differences between groups in development speed but not in subcellular structure. These results demonstrate that Mn-MFE promotes the ovarian development of Macrobrachium nipponense adults but has no effect on molting.
摘要：
法尼酸甲酯环氧酶（MFE）是编码与少年激素生物合成的最后一步相关的酶的基因。Mn-MFEcDNA的总长度为1695bp，开放阅读框（ORF）长度为1482bp，编码493个氨基酸。序列分析表明，其氨基酸序列具有PPGP铰链，FGCG结构域,和其他对P450家族酶特异的结构域。Mn-MFE在肝胰腺中表达最高，其次是卵巢和ill，在心脏和肌肉组织中弱表达，在眼柄和颅骨神经节中几乎没有表达。Mn-MFE表达在幼虫期保持稳定,在此期间，它主要在性腺分化中起关键作用。卵巢中的表达与卵巢发育呈正相关，肝胰腺中的表达与卵巢发育呈负相关。原位杂交(ISH)显示该信号在卵母细胞中表达,核，细胞膜和滤泡细胞，在O-IV期表达强度最强。与对照组相比，Mn-MFE的击倒导致性腺指数和O-III期卵巢百分比显着降低。然而,实验组和对照组之间的蜕皮累积频率没有差异。此外，实验结束时对卵巢组织切片的分析显示，各组之间的发育速度存在差异，但亚细胞结构没有差异。这些结果表明，Mn-MFE促进了日本沼虾成虫的卵巢发育，但对蜕皮没有影响。
