... of vitellogenin (a longevity-, nutrition- and immune-related gene), and large provisioning glands in their head. The environmental factors (both within the colony and within the surrounding environment) that trigger this transition to long-lived winter bees are poorly understood. One theory is that winter bees...

.... ( 2011 ). Role of the Halloween genes, Spook and Phantom in ecdysteroidogenesis in the desert locust, Schistocerca gregaria . J. Insect Physiol. 57 , 1240 - 1248 . 10.1016/j.jinsphys.2011.05.009 Martín , D. , Wang , S. F. and Raikhel , A. S. ( 2001 ). The vitellogenin...

... affect protein storage and development are possible in arthropods, which store proteins in the hemolymph. We hypothesized that diets with a composition of amino acids that matches the precursor of egg yolk protein (vitellogenin, Vg) will be high quality and support both egg production and accumulation...

...Heli Havukainen; Jarl Underhaug; Florian Wolschin; Gro Amdam; Øyvind Halskau SUMMARY Vitellogenin (Vg) is an egg-yolk precursor protein in most oviparous species. In honeybee ( Apis mellifera ), the protein (AmVg) also affects social behavior and life-span plasticity. Despite its manifold functions...

... expressed in the absence of significant amounts of vitellogenin. We conclude that drones – like worker bees – have the potential to activate multiple elements of the innate immune response. Furthermore, several haemolymph proteins were resolved by two-dimensional gel electrophoresis that were...

... by secreting the yolk protein precursor vitellogenin (Vg), which suppresses lipophilic juvenile hormone and social foraging behavior. In a two-factorial experiment, we used RNA interference (RNAi)-mediated vg gene knockdown and amino acid nutrient enrichment of hemolymph (blood) to perturb this regulatory...

...Heli Havukainen; Øyvind Halskau; Lars Skjaerven; Bente Smedal; Gro V. Amdam SUMMARY Vitellogenin, an egg-yolk protein precursor common to oviparous animals, is found abundantly in honeybee workers – a caste of helpers that do not usually lay eggs. Instead, honeybee vitellogenin (180 kDa...

... sisters (brood), workers survive for 3-6 weeks. When brood rearing declines, worker lifespan is 20 weeks or longer. Insects can survive unfavorable periods on endogenous stores of protein and lipid. The glyco-lipoprotein vitellogenin extends worker bee lifespan by functioning in free radical defense...

...) and that the maintenance and activity costs of the oviduct are responsible for 18% of the variation in elevated laying RMR. Therefore, other energy-consuming physiological mechanisms must be responsible for the remaining unexplained variation in elevated laying RMR. Yolk precursor[vitellogenin (VTG) and very-low-density...

... protein. E 2 also increased concentrations of zinc in the plasma. The changes in zinc concentration in the bloodstream followed the same time course as vitellogenin(VTG) transport from the liver. However, the high ratio of molar concentrations of zinc to VTG in the bloodstream suggest that VTG may...

...Karin Kinnberg; Bodil Korsgaard; Poul Bjerregaard; Åse Jespersen ABSTRACT Nonylphenol has been found to exert estrogenic effects in fish and may influence the fertility of male fish. In the present study, the effects of nonylphenol and 17β-estradiol on vitellogenin synthesis and testis morphology...

... of yolk precursors (vitellogenin and very-low density lipoprotein, VLDL) by the liver, and of albumen by the oviduct. We gave European starlings ( Sturnus vulgaris ) silastic implants containing estradiol prior to egg formation, which we predicted would increase egg mass. As expected, exogenous estradiol...

... on the synthesis of vitellogenin and on testicular structure and cytology were investigated in male eelpout Zoarces viviparus during active spermatogenesis (May) and late spermatogenesis (June). Twenty-five days after injection, a significant dose-dependent increase in the plasma vitellogenin concentration...

... females, but not in earlier stages, in immature females or in males, indicated the presence of vitellogenin in pregnant females and, thus, the potential for matrotrophic supplementation to yolk sequestered before fertilization. The retention of higher molecular mass proteins and highly phosphorylated...

... into two fractions. One fraction included vitellogenin, the precursor of egg yolk proteins, and the other contained some plasma proteins other than vitellogenin. Retinals were detected in the former and retinols in the latter. It is suggested that retinals are bound to vitellogenin and are taken up...