Ovarian and Hemolymph Ecdysteroid Titers during Vitellogenesis in Macrobrachium rosenbergii

Young, N.J.; Webster, S. G.; Rees, Huw H.

doi:10.1006/gcen.1993.1073

Cited by 19 publications

(7 citation statements)

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“…Hemolymph HPP was not further identified in this study. However, the presence of 20‐hydroxyecdysonoic acid in the hemolymph of M. rosenbergii was reported using HPLC‐RIA and methylation studies 34 . Analysis using HPLC and enzymatic hydrolysis demonstrated that HPP in the ovaries and eggs of M. rosenbergii was a mixture of 20‐hydroxyecdysonoic acid, ecdysonoic acid, conjugated forms of ecdysteroids, and 20,26‐dihydroxyecdysone 18,19,35 .…”

Section: Discussionmentioning

confidence: 99%

Fluctuations in hemolymph ecdysteroid levels during the reproductive and non-reproductive molt cycles in the giant freshwater prawn Macrobrachium rosenbergii

Okumura

Aida

2000

Fisheries Sci

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SUMMARY: Hemolymph ecdysteroid levels were traced during the molt cycle in female giant freshwater prawn, Macrobrachium rosenbergii. Levels were compared between the reproductive molt cycle, accompanied by ovarian development and oviposition following ecdysis, and the non‐reproductive molt cycle, marked by the absence of ovarian development, to examine the involvement of ecdysteroids in ovarian development. Total ecdysteroid levels determined by radioimmunoassay (RIA) showed similar fluctuation patterns between both molt cycles. Levels were low during postmolt stages A–B and gradually decreased to low basal levels at intermolt stages C0–C1. Levels then increased during premolt stages D0–D2, reached a large peak at the early D3 stage, and declined sharply prior to ecdysis. In addition, ecdysteroids in the hemolymph were analyzed using high‐performance liquid chromatography combined with RIA in order to identify individual ecdysteroid species. During both molt cycles, 20‐hydroxyecdysone, ecdysone and high polarity immunoreactive products were detected, and 20‐hydroxyecdysone was the most predominant ecdysteroid. Fluctuations in all ecdysteroid species during each type of molt cycle paralleled those of total ecdysteroid levels, and did not show significant differences between the reproductive and non‐reproductive molt cycles. These results suggest that ecdysteroids are not involved in ovarian development but in the molting process only.

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Section: Discussionmentioning

confidence: 99%

Fluctuations in hemolymph ecdysteroid levels during the reproductive and non-reproductive molt cycles in the giant freshwater prawn Macrobrachium rosenbergii

Okumura

Aida

2000

Fisheries Sci

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“…In the anecdysic oxyrhynchan crab Acanthonyx lunulatus, the Y-organ degenerates at the pubertal molt, and there are then two more vitellogenic cycles that are completed in the absence of ecdysteroids [146]. In M. rosenbergii and P. monodon, both hemolymph and ovarian ecdysteroid levels declined from the immature to the late vitellogenic ovarian stages [147,148].…”

Section: Ecdysteroidsmentioning

confidence: 96%

Mechanisms and control of vitellogenesis in crustaceans

Subramoniam

2010

Fish Sci

159

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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.

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“…In some cases, the two processes are tightly linked [10] and can affect each others duration [64,65]. Therefore, it is believed that vitellogenesis and molting are controlled by the same regulatory factors, which include neuropeptides of the XO-SG complex [31,66,67], ecdysteroids [68][69][70], and juvenoid hormones [38,71]. Of great interest are the few species in which the molting cycle is halted upon puberty, the female blue crab being among them.…”

Section: Vitellogenesis In the Blue Crabmentioning

confidence: 99%

Vitellogenin and Its Messenger RNA During Ovarian Development in the Female Blue Crab, Callinectes sapidus: Gene Expression, Synthesis, Transport, and Cleavage1

Zmora

Trant

Chan

et al. 2007

Biology of Reproduction

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Blue crab vitellogenin (VTG) cDNA encodes a precursor that, together with two other Brachyuran VTGs, forms a distinctive cluster within a phylogenetic tree of crustacean VTGs. Using quantitative RT-PCR, we found that VTG was primarily expressed in the hepatopancreas of a vitellogenic female, with minor expression in the ovary. VTG expression in the hepatopancreas correlated with ovarian growth, with a remarkable 8000-fold increase in expression from stage 3 to 4 of ovarian development. In contrast, the VTG levels in the hepatopancreas and hemolymph decreased in stage 4. Western blot analysis and N-terminal sequencing revealed that vitellin is composed of three subunits of approximately 78.5 kDa, 119.42 kDa, and 87.9 kDa. The processing pathway for VTG includes an initial hepatopancreatic cleavage of the primary precursor into approximately 78.5-kDa and 207.3-kDa subunits, both of which are found in the hemolymph. A second cleavage in the ovary splits the approximately 207.3-kDa subunit into approximately 119.4-kDa and approximately 87.9-kDa subunits. The hemolymph VTG profiles of mated and unmated females during ovarian development indicate that early vitellogenesis and ovarian development do not require mating, which may be essential for later stages, as VTG decreased to the basal level at stage 4 in the unmated group but remained high in the mated females. Our results encompass comprehensive overall temporal and spatial aspects of vitellogenesis, which may reflect the reproductive physiology of the female blue crab, e.g., single mating and anecdysis in adulthood.

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Ovarian and Hemolymph Ecdysteroid Titers during Vitellogenesis in Macrobrachium rosenbergii

Cited by 19 publications

References 0 publications

Fluctuations in hemolymph ecdysteroid levels during the reproductive and non-reproductive molt cycles in the giant freshwater prawn Macrobrachium rosenbergii

Fluctuations in hemolymph ecdysteroid levels during the reproductive and non-reproductive molt cycles in the giant freshwater prawn Macrobrachium rosenbergii

Mechanisms and control of vitellogenesis in crustaceans

Vitellogenin and Its Messenger RNA During Ovarian Development in the Female Blue Crab, Callinectes sapidus: Gene Expression, Synthesis, Transport, and Cleavage1

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