Department of Biotechnology, Sri Venkateswara University, Tirupati 517502, India; Department of Zoology, Sri Venkateswara University, Tirupati 517502, India.
Department of Zoology, Sri Venkateswara University, Tirupati 517502, India.
Biochem Biophys Res Commun. 2014 May 2;447(2):323-7. doi: 10.1016/j.bbrc.2014.03.148. Epub 2014 Apr 5.
The objective of the present study was to explore the site of synthesis of vitellogenin (Vtg) in fresh water edible crab, Oziothelphusa senex senex. Vtg cDNA fragments were isolated from the hepatopancreas of female crabs using RT-PCR method, and the deduced amino acid sequence of O. senex senex showed more than 60% identity with other brachyuran Vtg sequences. RT-PCR analysis showed that Vtg mRNA can be detected only in hepatopancreas of female Oziothelphusa but not in other tissues including eyestalks, Y-organs, mandibular organs, thoracic ganglion, hypodermis and ovary. Antibodies were raised against vitellin purified from the ovary of O. senex senex. Immunoprecipitation analysis revealed the presence of Vtg in the hepatopancreas of vitellogenic stage I females and in the hemolymph, hepatopancreas and ovary extracts from vitellogenic stage II females but absent in hemolymph and hepatopancreas extract of males. These results suggest that Vtg is synthesized only in hepatopancreas but not in the ovaries of O. senex senex. In addition, Vtg synthesized in hepatopancreas is transported to ovary through hemolymph.
本研究旨在探索淡水食用蟹 Oziothelphusa senex senex 卵黄蛋白原 (Vtg) 的合成部位。采用 RT-PCR 法从雌蟹的肝胰腺中分离出 Vtg cDNA 片段，O. senex senex 的推导氨基酸序列与其他短尾类 Vtg 序列的相似度超过 60%。RT-PCR 分析表明，Vtg mRNA 仅可在 Oziothelphusa 的肝胰腺中检测到，而在其他组织（包括触角、Y 器官、下颌器官、胸神经节、真皮和卵巢）中均无法检测到。针对从 O. senex senex 卵巢中纯化的卵黄蛋白制备了抗体。免疫沉淀分析显示，在卵黄发生期 I 期雌性的肝胰腺中以及卵黄发生期 II 期雌性的血淋巴、肝胰腺和卵巢提取物中存在 Vtg，但在雄性的血淋巴和肝胰腺提取物中不存在。这些结果表明，Vtg 仅在 O. senex senex 的肝胰腺中合成，而不在卵巢中合成。此外，肝胰腺中合成的 Vtg 通过血淋巴转运至卵巢。
