早熟中华绒螯蟹眼柄视神经节对卵巢发育的生殖调控作用

Effect and regulation of eyestalk optic ganglia on ovarian development in precocious Chinese mitten crab,Eriocheir sinensis

采用组织切片技术于光镜下观察了早熟中华绒螯蟹(Eriocheir sinensis)眼柄视神经节的组织形态结构,以体外培养法研究早熟蟹眼柄视神经节对同种甲壳动物中华绒螯蟹和异种甲壳动物克氏原螯虾卵巢发育的影响,并以放射化学测定法测定早熟蟹眼柄粗提物及单侧或双侧眼柄镊烫后对大颚器生物合成甲基法尼酯(MF)的影响.结果表明,早熟蟹眼柄视神经节呈乳白色,椭圆柱形,外包一层黑色视网膜,由外髓、内髓、端髓3部分构成;端髓区域可明显区分3种类型的神经分泌细胞;早熟蟹眼柄视神经节对同种和异种甲壳动物的卵巢发育均有抑制作用;早熟蟹眼柄粗提物对MF生物合成的抑制作用随浓度的增加而增强.研究证实早熟蟹眼柄视神经节对卵巢的抑制作用较正常发育蟹弱,且对同种甲壳动物卵巢发育的抑制作用强于对异种动物.

The tectological structures of eyestalk optic ganglia in precocious Chinese mitten crab,Eriocheir sinensis, were observed under microscopes with microtome section. The effect of eyestalk optic ganglia of precocious E. sinensis on ovarian development from homogeneous or heterogeneous crustacean was studied with in vitro culture. The red swamp crayfish,Procambarus clarkii was chosen as heterogeneous crustacean. The effect of crude eyestalk extracts of precocious E. sinensis and unilateral or bilateral eyestalks ablated with the burning tweezers on methyl farnesoate （MF） biosynthesis were investigated with in vitro radiochemical method. The results are as follows：The eyestalk optic ganglia of precocious E. sinensis was milk white, oval columniform and wrapped around by a black layer of retina,consists of medulla externa （ME）, medulla interna （MI） and medulla terminalis （MT） ;Three types of neurosecretory cells were observed distinctively and located mostly on the part of MT; There existed significant inhibitive effect imposed by the eyestalk optic ganglia homogeneous crustacean as well as the heterogeneous of precocious E. sinensis on the ovarian development of the crustacean. There also existed significant inhibitive effect strengthened with the increasing concentration or different gradient of the crude eyestalk extracts of precocious E. sinensis on MF biosynthesis. It proves that the inhibitive effect of the eyestalk optic ganglia of precocious crab on the ovarian development was weaker than that of normal crab. The result also indicated that the effect of the eyestalk optic ganglia of precocious crab on the ovarian development from homogeneous crustacean was significantly stronger than that from heterogeneous crustacean.