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Multiple signal transduction pathways mediating gonadotropin-induced testosterone and 17b-estradiol (E 2 ) production were identified in carp ovarian theca and granulosa cells in short-term co-incubation. Inhibitors of voltage-sensitive calcium channels (VSCCs) and calmodulin attenuated human chorionic gonadotropin (HCG)-induced steroid production, whereas modulators of adenylate cyclase and protein kinase A (PKA) increased their production, indicating that both calcium-and PKA-dependent pathways are involved in the regulation of gonadotropin-induced steroidogenesis in carp ovary. Interactions between these two pathways are evident from the positive effect of elevated intracellular calcium on HCG-induced steroid production and the reduction of forskolin (FK)-and dibutyryl cAMP (dbcAMP)-induced steroidogenesis by inhibitors of VSCCs and calmodulin. In this study, we found the involvement of a third signaling pathway, a mitogen-activated protein kinase (MAP kinase), in the regulation of gonadal steroidogenesis in this fish. An antagonist of mitogen-activated protein kinase kinases 1/2 (MEK1/2; also known as MAP2K1/MAP2K2) markedly attenuated HCG-induced steroid production. Cells treated with HCG stimulated MEK1/2-dependent phosphorylation of extracellular signal-regulated protein kinases 1/2 (ERKs1/2) in a concentration and time-dependent manner. Moreover, ERK1/2 activation in cells was mimicked by FK and dbcAMP suggesting that ERK1/2 transduce signal downstream of PKA in HCG-induced ovarian steroidogenesis. Evidence for presence of cross talk between calcium-dependent pathways and this MAP kinase cascade has been shown by demonstrating the inhibitory effects of verapamil and calmodulin on ERK1/2 activation after HCG stimulation. Our results suggest that activation of ERK1/2 by HCG as well as other agents may be a key mechanism for the modulation of gonadotropin-induced steroidogenesis in carp ovary.

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The effects of salmon calcitonin (sCT) on the secretion of 17b-estradiol (E 2 ) were examined in female common carp, Cyprinus carpio. Vitellogenic stage fish adapted to high-Ca water were i.p. injected with vehicle, sCT, human chorionic gonadotropin (hCG), or hCG plus sCT. To determine whether ovarian follicles are equipped with CT receptors, a CT binding assay was conducted. In the in vitro experiments, vitellogenic follicles were incubated with stimulators and inhibitors. Administration of sCT increased the basal and hCG-stimulated E 2 release in vivo and in vitro. Binding characteristics of [ 125 I]sCT to plasma membrane preparation of carp ovarian follicles showed saturability with high-affinity (K d Z48 . 48 pmol/l and B max Z1 . 2 pmol/mg protein). To clarify the mechanism of E 2 production by sCT, in vitro effect of sCT and hCG on aromatase activity (conversion of testosterone to E 2 ) and cytochrome P450 aromatase (P450arom) gene expression in carp ovarian follicles were investigated. Salmon CT-stimulated both aromatase activity and P450arom gene expression in ovarian follicles of carp. sCT-stimulated E 2 release by the ovarian follicles in vitro was augmented in the presence of dibutyryl cAMP. Inhibitor of protein kinase A (PKA), SQ 22536 inhibited sCT-stimulated steroid production in a dose-dependent manner. Specific inhibitor of protein kinase C (PKC), NPC-15437 dihydrochloride had no inhibitory effects on sCT-induced E 2 release. The present study indicates that sCT binds specifically to carp ovary and stimulates E 2 production by increasing the activity of cytochrome P450 aromatase and P450arom gene expression. The results further suggest that stimulatory action of sCTon E 2 production is mediated through cAMP pathway.

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Differential privacy(DP) has now become a standard in case of sensitive statistical data analysis. The two main approaches in DP is local and central. Both the approaches have a clear gap in terms of data storing,amount of data to be analyzed, analysis, speed etc. Local wins on the speed. We have tested the state of the art standard RAPPOR which is a local approach and supported this gap. Our work completely focuses on that part too. Here, we propose a model which initially collects RAPPOR reports from multiple clients which are then pushed to a Tf-Idf estimation model. The Tf-Idf estimation model then estimates the reports on the basis of the occurrence of "on bit" in a particular position and its contribution to that position. Thus it generates a centralized differential privacy analysis from multiple clients. Our model successfully and efficiently analyzed the major truth value every time.

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