Jeyalectumie C, Subramoniam T
Department of Zoology, University of Madras, India.
Mol Reprod Dev. 1991 Sep;30(1):44-55. doi: 10.1002/mrd.1080300107.
Biochemical studies on the male reproductive tissues and seminal secretions have been made with reference to sperm metabolism and different stages of maturity in the crab Scylla serrata. The results reveal that the seminal plasma and spermatophores are rich in protein, carbohydrate, and lipid. In general, organic components of spermatophores are considerably higher than those of seminal plasma. Enzyme studies show that the succinate dehydrogenase (SDH) activity is very low, whereas fumarate reductase (FR) and lactate dehydrogenase (LDH) exhibit high activity. Electrophoretic studies on LDH show that, in addition to the occurrence of a sperm-specific fraction, LDHx, the M-type subunits are predominant in the mature spermatophores. These results from enzyme studies suggest that sperm metabolism is mainly anaerobic, utilizing the carbohydrates as substrates. The results for maturational changes reveal that the male reproductive tissues and their secretions contain lesser quantity of organic components in the immature crabs; as the maturity proceeds, there is not only concentration of organic substances but also an increase in the size of spermatophores. The concentration of biochemical constituents is highest in the proximal vas deferens (PVD), suggesting that the granular seminal plasma as well as the sperm-agglutinating substance and spermatophoric wall are secreted in this region. The spermatheca of the unmated female crabs are poor in organic constituents. After mating, their contents are enriched by organic substances derived from contributions of the seminal substances. During sperm storage in the spermatheca, only the carbohydrates decline steeply. A low activity of SDH, but a moderate level of LDH and a high level of FR activity, is recorded in the spermathecal content of mated crabs, providing further evidence for anaerobic metabolism of sperm during storage in female. A sharp fall in the stored carbohydrates constitutes further evidence in this regard.
针对锯缘青蟹精子代谢及不同成熟阶段，对其雄性生殖组织和精液分泌物进行了生化研究。结果显示，精浆和精荚富含蛋白质、碳水化合物和脂质。总体而言，精荚的有机成分显著高于精浆。酶学研究表明，琥珀酸脱氢酶（SDH）活性极低，而延胡索酸还原酶（FR）和乳酸脱氢酶（LDH）活性较高。对LDH的电泳研究表明，除了出现精子特异性组分LDHx外，M型亚基在成熟精荚中占主导地位。这些酶学研究结果表明，精子代谢主要为无氧代谢，以碳水化合物为底物。成熟变化的结果显示，未成熟青蟹的雄性生殖组织及其分泌物中有机成分含量较少；随着成熟进程，不仅有机物质浓度增加，精荚尺寸也增大。近端输精管（PVD）中生化成分浓度最高，表明颗粒状精浆以及精子凝集物质和精荚壁均在此区域分泌。未交配雌蟹的受精囊有机成分较少。交配后，其内容物因精液物质的贡献而富含有机物质。在精子储存在受精囊期间，只有碳水化合物急剧下降。在交配雌蟹的受精囊内容物中，记录到SDH活性较低，但LDH水平适中，FR活性较高，这为精子在雌蟹体内储存期间的无氧代谢提供了进一步证据。储存的碳水化合物急剧下降在这方面构成了进一步证据。
