The Presence of Estradiol-17β and Its Specific Binding Sites in Posterior Silk Gland of Bombyx mori

Estradiol-17β: Tracing its metabolic significance in female fatbody of fifth instar larvae of silkworm, Bombyx mori L (race: Nistari)

“…However, higher dissociation constant has also been reported in Atlantic salmon liver (13 K d , Lazier et al, 1985) along with a much lower affinity-binding site. A similar high affinity binding had been reported in the cytosol of posterior silkgland of B. mori (8.98 ± 0.744 nM) by Keshan and Ray (2001a). The B max obtained in our study is 0.718 nmol/mg DNA (Fig.…”

“…In a detailed investigation in our laboratory, Keshan and Ray (1998) demonstrated that E 2 exerts a dose-dependent effect on silk protein synthesis in Bombyx mori. All these effects of E 2 on silkgland could be counteracted by simultaneous application of ICI-182780 (an anti-estrogenic compound); the presence of estradiol-17β-specific binding proteins i.e., putative receptors has been identified in the posterior silkgland cytosol (Keshan and Ray, 2001a). These findings strengthen the view that this steroid ligand might have a very prominent role in the normal metabolic processes of the silkworm, B. mori.…”

Sex steroids and potential mechanisms of non-genomic endocrine disruption in invertebrates

“…Despite the limited genetic evidence for steroid receptors in invertebrates, binding proteins for vertebrate steroids have been described in several species, including nematodes, echinoderms, crustaceans, and molluscs (de Waal et al 1982;Kiser et al 1986;Paesen and De Loof 1989;Di Cosmo et al 1998, 2002Keshan and Ray 2001). However, the presence of these binding proteins has not been coupled to a biological response.…”

Vertebrate hormones in insects: the role of estrogen in silkworm – a review

“…Detections of estrogen-and androgen-like substances in S. bullata, Periplaneta americana Linnaeus, 1758 (Blattodae: Blattidae), M. sexta, Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae), and Oncopeltus fasciatus Dallas, 1852 (Hemiptera: Lygaeidae) led to further investigations of this aspect (Mechoulam et al, 1984). The presence of estradiol was demonstrated in the ovary (Ohnishi et al, 1985), in hemolymph (Das and Ray, 2007), in the posterior silk gland (Keshan and Ray, 2001), and in the larval and pupal fat body of B. mori (De, 2007;Roy, 2007).…”