Mechanisms and control of vitellogenesis in crustaceans

Abstract

Crustaceans produce complex yolk proteins to meet the substrate and energy requirements of embryonic development. Early electron microscopic investigations point to a biphasic yolk synthesis, first within the ovary, followed by heterosynthesis at extra-ovarian sites. Recent advances in molecular techniques have enhanced our understanding of the genetic control of yolk synthesis in crustaceans. Amino acid sequencing of crustacean vitellogenin (Vg) has enabled the elucidation of the cDNA sequence associated with it, the identification of genes, and the examination of their expression patterns in different tissues. Yolk processing in crustaeans involves cleavage of the pro-Vg at consensus sites by subtilisin-like endoproteases within the hepatopancreas, hemolymph and oocytes. The structural elucidation of crustacean yolk proteins, as well as the comparison of amino acid sequences of vitellogenins from various crustacean species, has revealed molecular phylogenetic relationships not only among them but also with other large lipid transfer lipoproteins of disparate function. The combinatorial effects of eyestalk neuropeptides and a variety of trophic hormones achieve the hormonal coordination of molting and reproduction. Biogenic amines secreted by the central nervous system may also play an integrative role by stimulating neuropeptide secretion.

Effects of different dietary lipids concentrations on the egg production and egg quality produced by Macrobrachium acanthurus females

“…Interestingly, the protein content in the hepatopancreas and ovaries, decreased as the lipid increased in the diet, showing the mobilization from hepatopancreas to the ovaries, and then deposited in the eggs. Subramoniam (2011), reported that the egg yolk of crustaceans is composed of large quantities of the protein vitellogenin linked to lipids, forming a complex referred to as lipovitellin. Dietary protein was the same in all the diets, so with the increment of egg production in the females with higher lipid inclusions, protein must be mobilized at a higher rate than the lipid.…”

Vitellogenin2: spermatozoon specificity and immunoprotection in mud crabs

“…Vg is usually produced in an extraovarian tissue and then transported by the circulation system into ovary, where it is internalized into growing oocytes via receptormediated endocytosis (Arukwe & Goksory 2003, Finn & Fyhn 2010. Thereafter Vg undergoes several modifications, such as specific proteolytic cleavage, to become Vn providing nutrients and energy to the embryos development (Avarre et al 2003, Subramoniam 2011, Zhang et al 2016. It is well known that the sites of Vg synthesis include the liver of vertebrate species (Gerber-Huber et al 1987, Pousis et al 2011, the intestine of nematode (Sharrock 1983), the fat body of insects (Chen & Hillen 1983, Giorgi et al 1989, and the hepatopancreas and ovary of crustaceans (Tsutsui et al 2000, Jia et al 2013.…”

“…Most studies have been focused on the mechanism of Vg/Vn involved in the vitellogenesis and its hormonal control (Subramoniam 2011). On the other hand, partial Vg genes are detected in male marine shrimp Penaeus semisulcatus and Chinese mitten crab Eriocheir sinensis (Avarre et al 2003, Liu et al 2015 without any induction or treatment.…”

Vertebrate-Type Steroid Profile in Different Tissues of Wild and Endocrinologically Manipulated Female Brood Stocks of <i>Penaeus monodon</i>

“…The domestication and breeding of P. monodon is severely hindered owing to the reproductive dysfunction of pond-reared broodstock. The eyestalk neuroendocrine system has long been known to play an important role in the vitellogenesis of crustaceans 11,12 . Therefore, most researchers focused attention on eyestalk neurohormones and their role in maturation.…”