Vitellogenesis in virgin and mated females of the mealworm beetle, Tenebrio molitor.

Abstract

A comparison between vitellogenesis in virgin and mated females of Tenebrio molitor showed significant differences at each investigated developmental stage. Yolk protein deposition in oocytes, measured as an increase in their size parameters (length, width, and volume), proceeded much faster and was more efficient in mated females as compared to virgins. In fertilized females the gonadotropic cycle showed a cyclicity with an eight-day period while virgin females finish their vitellogenic stage after the first cycle. These differences were reflected in changes in the rate of protein synthesis in the fat body of females completing vitellogenesis or entering the next oogenetic cycle. In the haemolymph, in addition to a large (158 kDa) and two small (56 kDa and 45 kDa) subunits of vitellogenin, there was an abundance of proteins of 80 kDa and 60 kDa.

A tapeworm molecule manipulates vitellogenin expression in the beetle Tenebrio molitor

“…1), although only two of these would be supported by published observations of cleavage products. Both Harnish & White (1982) and Webb & Hurd (1995) detected large subunits of 154 and 145 kDa and small subunits of 56 and 45 kDa, while Michalik et al . (1996) detected a single large subunit of 158 kDa and two small subunits of 56 and 45 kDa.…”

“…1), although only two of these would be supported by published observations of cleavage products. Both Harnish & White (1982) and Webb & Hurd (1995) detected large subunits of 154 and 145 kDa and small subunits of 56 and 45 kDa, while Michalik et al (1996) detected a single large subunit of 158 kDa and two small subunits of 56 and 45 kDa. We note that both T. molitor and A. grandis have recognizable R/KXXR motifs in almost identical locations (A. grandis, RRFR [359][360][361][362] or RFRR [360][361][362][363] ; T. molitor, KSSR [365][366][367][368] or RTKR [368][369][370][371] ).…”

Gonadoinhibitory effects of Neb‐colloostatin and Neb‐TMOF on ovarian development in the mealworm, Tenebrio molitor L.

“…The densitometric analysis revealed that two polypeptides with molecular masses of 150 and 180 kDa are nearly ab-sent in peptide-treated females while two other polypeptides with molecular masses of 47 and 130 kDa (Fig. 4) but also in regulating oviposition and ovulation (Michalik et al, 1996;Graham et al, 1996;Cole et al, 2003;Heming, 2003). Evidently, juvenile hormone is only one of the hormones controlling gonadal development in Tenebrio.…”

Research Progress on the Regulation of Autophagy and Apoptosis in Insects by Sterol Hormone 20-Hydroxyecdysone

“…Elevated JH concentrations typically suppress 20E synthesis [44]. In the captivating world of beetles, as part of the Coleoptera order, the JH takes center stage, driving vitellogenesis within the fat body [45,46]. Vitellogenesis involves the synthesis and accumulation of yolk proteins in maturing oocytes, which are crucial for nourishing the embryo post-fertilization [47].…”