| dc.contributor.author | Wang, Chunde. | en_US |
| dc.date.accessioned | 2014-10-21T12:33:44Z | |
| dc.date.available | 2001 | |
| dc.date.issued | 2001 | en_US |
| dc.identifier.other | AAINQ66680 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55812 | |
| dc.description | Sex steroids, as well as their major metabolic enzymes and pathways, have been widely identified in molluscs. However, whether they are involved in molluscan reproductive control is generally not known. Thus, the aim of this study is to investigate the possible roles of sex steroids in the sea scallop. | en_US |
| dc.description | In these studies, injections of estradiol, testosterone, progesterone and dehydroepiandrosterone (DHEA) significantly promoted sexual differentiation and shifted sex ratios, resulting in more males than females, as well as other morphological changes. In vitro experiments demonstrated that estradiol and progesterone potentiated 5-HT-induced gamete release in both sexes while testosterone was only effective in males. Examinations of the time scales of these effects and pharmacological studies utilizing antisteroids or RNA or protein synthesis inhibitors suggested that these effects may be mainly mediated by intracellular sex steroid receptors. Similar effects were also obtained by in vivo injections of these steroids. Radioligand binding studies demonstrated that specific estrogen binding sites exist in the cytosolic and nuclear fractions of both female and male scallop gonads. Furthermore, translocation of these estrogen binding sites may be involved in the sexual maturation of scallops. Specific progesterone binding sites were also characterized in the nuclear fraction of gonads of both sexes. Using degenerate primers based upon nucleotide sequences of vertebrate estrogen receptors, a cDNA fragment was amplified from the scallop liver by RT-PCR. Similarity comparison suggested that it might be a partial sequence of the scallop estrogen receptor gene. With this identified sequence as a probe, Northern blotting revealed the expression of a 3.1 Kb mRNA in the scallop gonad and liver. | en_US |
| dc.description | The current studies suggested that sex steroids play important roles in the reproductive control of the scallops, possibly through the activation of sex steroid receptors. These findings may have potential applications in aquaculture and environmental issues. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 2001. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Oceanography. | en_US |
| dc.subject | Biology, Animal Physiology. | en_US |
| dc.title | Roles of sex steroids in reproduction of the sea scallop. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
