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通过对三疣梭子蟹胚胎进行连续采样和组织切片,系统研究了三疣梭子蟹胚胎发育过程中卵黄囊和肝胰腺的发生与卵黄物质利用的关系。结果表明:(1)三疣梭子蟹胚胎的卵黄岛和卵黄囊结构分别出现在原肠期和无节幼体期,胚胎从原肠期至卵内第一期溞状幼体期,始终存在卵黄岛结构,且卵黄岛中的卵黄物质不断被分解和利用.(2)卵内第二期溞状幼体后,卵黄囊分为两个区域,卵黄囊壁中出现肝胰腺细胞(柱状上皮细胞),此时肝胰腺前体已开始形成,卵黄岛开始融合.(3)卵内第三期溞状幼体阶段,卵黄囊发育成一双肝胰腺,由于肝胰腺中的卵黄物质互相融合,卵黄岛结构消失。此阶段胚胎对卵黄物质的利用加快,卵黄物质中存在许多空泡状结构;(4)胚胎发育进入孵化前期后,肝胰腺腔内的卵黄物质极少,而初孵溞状幼体肝胰腺腔内卵黄物质已完全消失,肝胰腺为一对囊状结构。这些结果表明在三疣梭子蟹胚胎发育从原肠期到孵化前的过程中,卵黄岛和肝胰腺细胞对于卵黄物质分解和利用起着十分重要的作用。
Through the continuous sampling and histological sectioning of B. portunus embryos, the relationship between yolk sac, hepatopancreas and yolk utilization during the embryonic development of B. portunus was systematically studied. The results showed that: (1) The structure of yolk island and yolk sac of Portunus trituberculatus embryos appeared in gastrula stage and nauplius stage. The embryo had yolk island structure, And the yolk material in the yolk island was continuously decomposed and utilized. (2) After the second stage ova in the egg, the yolk sac was divided into two regions, hepatopancreas cells (columnar epithelial cells) appeared in the yolk sac wall, The precursor of hepatopancreas has started to form, and the yolk island begins to fuse. (3) In the third stage of the egg, the yolk sac develops into a pair of hepatopancreas. Due to the fusion of the yolk substances in the hepatopancreas, the structure of the yolk island disappears. In this stage, the utilization of yolk substance in the embryo is accelerated, and there are many vacuole-like structures in the yolk substance. (4) After embryo development enters the early stage of hatching, the yolk substance in the hepatopancreas cavity is extremely rare. Yolk material has completely disappeared, hepatopancreas is a pair of cystic structure. These results indicate that the yolk island and hepatopancreas cells play a very important role in the decomposition and utilization of yolk during the embryonic development of Portunus trituberculatus from the gut phase to hatching.