去眼柄后中华绒螯蟹法呢酸甲基转移酶表达和卵巢发育

为了解甲基法呢酯(methyl farnesoate,MF)在中华绒螯蟹(Eriocheir sinensis)卵巢发育中的调控作用,采用离体方法研究了中华绒螯蟹大颚器(mandibular organ,MO)以及X-器官窦腺复合体(X-organ-sinus gland,XO-SG)对卵巢发育的作用。将MO与离体卵母细胞共培养作为实验组1,将MO和XO-SG与离体卵母细胞共培养作为实验组2,仅添加培养液的卵母细胞作为对照组。实验发现,蟹去眼柄(eyestalk ablation,ESA)后的第1、3、6、14天,同对照组相比,MO对其卵母细胞的发育均有极显著促进作用。ESA处理第6天,MO对卵母细胞发育的促进作用最强。XO-SG能逆转ESA处理后MO对卵巢发育的促进作用(P<0.01)。荧光定量PCR技术检测结果显示,ESA处理后,MO中法呢酸甲基转移酶(farnesoic acid O-methyltransferase,FAMeT)mRNA相对表达量上升。同未去眼柄的对照组相比,第1、3天FAMeT mRNA表达丰度无明显变化(P>0.05),第6、14天表达丰度提高至265%左右(P<0.01)。结果表明,中华绒螯蟹MO功能性物质能够促进卵母细胞发育,且ESA处理后第6天MO生物效应最强。MO中FAMeT mRNA的合成受XO-SG的抑制调节。在离体条件下,中华绒螯蟹XO-SG能够抑制卵母细胞的发育。

FAMeT expression and ovarian development following eyestalk ablation in Chinese mitten crab (Eriocheir sinensis)

We evaluated the role of methyl farnesoate(MF) during ovarian development in Eriocheir sinensis.We cultured oocytes with mandibular organ(MO)as group 1,and oocytes with MO and X-organ-sinus gland(XO-SG) as group 2 in vitro.Oocytes cultured with medium were set as control.MO excretion promoted oocyte maturation by increasing the oocyte diameter at the 1st,3rd,6th,and 14th day after eyestalk ablation,particularly on the 6th day(P<0.01).Incubation with XO-SG significantly inhibited oocyte development(P<0.05).We used fluorescent quantitative RT-PCR to quantify FAMeT expression.Levels were 265% higher than 6 and 14 days after eyestalk ablation,and were significantly higher than that in the control group(without MO)(P<0.01).FAMeT expression levels were lower on day 14 than that on day 6 and there was no change on day 1 and day 3 after eyestalk ablation(P>0.05).Our results suggest that the functional material in MO induces oocyte maturation,with the effect being strongest 6 days after eyestalk ablation.MO FAMeT mRNA was downregulated by the XO-SG causing inhibition of oocyte maturation in vitro.