Egg (Ovalbumin) ELISA Kit

This study of the fish blood flukeAporocotyle simplexrepresents the first detailed transmission electron microscopical (TEM) investigation of the vitellarium of an aporocotylid digenean blood fluke. It revealed some unusual characteristics in the cytoarchitecture of the vitelline follicles and demonstrated modifications of the vitelline granules for eggshell formation. The vitelline follicles consist of vitellocytes at different developmental stages surrounded by sarcoplasmic processes of myocytes which occur throughout each follicle. Sites of intimate contact occur between the vitellocytes and the myocytes. Individual vitelline globules (0.1-0.2 mu m in diameter) accumulate in quite small clusters of 10-20 and have a dense, heterogeneous matrix possessing central and peripheral regions with a greater density. Modifications of the vitelline globules take place within the clusters and are first apparent when the vitellocytes reach the lumen of the vitelline duct and vitelline reservoir. Globules within the clusters become confluent, and, when the vitellocytes reach the lumen of the oviduct and proximal ootype, these consolidated clusters contain a shapeless, loosely packed, dense material which is released from the vitellocytes by exocytosis. This investigation has provided morphological evidence for shell formation from modified vitelline globules in the form of a discontinuous, thin layer (similar to 0.07 mu m in thickness) of electron-dense shell material around the fertilized ovum and associated vitellocytes in the proximal ootype. The eggshell of intra-uterine eggs acquires an additional thin, heterogeneous outer layer, increasing its thickness to similar to 0.1 mu m. The cytoarchitecture of the vitellarium, modifications of the vitelline globules within the clusters and the structure of the eggshell ofA. simplexmay prove to be of value in studies examining relationships between the three distinct lineages of aporocotylid digeneans.

Information on the effects of bet-hedging strategies on ova lipid profiles in serial spawning fishes remain sparse. We ascertained the total concentration (mg/mg(-1)) and relative composition (%) of triglycerides (TAGs) in individual ova of New Zealand snapper Chrysophrys auratus during three consecutive spawning events in one season. Total TAG concentrations were significantly higher in the second, when compared to the first or third spawning batch. In terms of relative composition, TAG ova profiles were dominated by C56:7, C60:12, and C54:7, and also temporally variable. The observed temporal variability in total TAG concentrations may be explained by C. auratus adopting a diversified bet-hedging strategy, whereas variations in TAG profiles hint towards a physiological shift along the capital-income breeding continuum.