Disease relevance of Vg

• Despite extensive screening of a phage library prepared from E. pergandiella genomic DNA, a Vg gene was not detected in this species [1].
• The show that the expression of vitellogenin and transferrin is correlated with ovary activation in workers, and may therefore be part of the gene network involved in the regulatory control of functional sterility in honeybees [2].

Psychiatry related information on Vg

• This role of vitellogenin in the tuning of the endocrine system is uncommon and may elucidate how an ancestral pathway of fertility regulation has been remodeled into a novel circuit controlling social behavior [3].
• Honeybee workers are functionally sterile, and via the expression of juvenile hormone, a key gonotrophic hormone in adult insects, their vitellogenin levels are influenced by social interactions with other bees [4].

High impact information on Vg

• We establish that vitellogenin gene activity protects worker bees from oxidative stress [5].
• Vitellogenin is a female-specific glucolipoprotein yolk precursor produced by all oviparous animals [6].
• JH is a principal controller of vitellogenin expression and behavioral development [3].
• Recent research, however, has shown that JH is controlled by the hemolymph vitellogenin level, which implies that the fat body specific vitellogenin gene can be a key regulator of behavioral change [7].
• Downregulation of vitellogenin gene activity increases the gustatory responsiveness of honey bee workers (Apis mellifera) [7].

Biological context of Vg

• Vitellogenin mRNA was also observed in drones, although it was first detected not in pupae but in freshly molted adults [8].
• The deduced amino acid sequence of the E. formosa Vg gene most closely resembles that of the ichneumonid parasitoid, Pimpla nipponica (38% identity) [1].
• The position of two introns in the hymenopteran sequences are shared with every full-length insect Vg gene characterized to date [1].
• Southern analysis indicates that the Vg gene is present as a single copy in the honeybee genome [9].
• In addition, larvae of both sexes produce Vg in significant amounts, which suggest that Vg serves for functions additional to oocyte growth and energy supply to the embryo [9].

Anatomical context of Vg

• This recovery, which is triggered by a social manipulation, is accompanied by a drop in the endogenous JH titer and an increase in the hemolymph vitellogenin level [10].
• We suggest that the transition is under regulatory control by an internal and an external repressor of the allatoregulatory central nervous system, where these two repressors modulate a positive regulatory feedback loop involving juvenile hormone (JH) and the lipoprotein vitellogenin [11].
• Vitellogenin, an egg yolk precursor, and transferrin, an iron transporter, were two transcripts found to be significantly down-regulated as a function of the ovary-inhibiting treatment [2].

Associations of Vg with chemical compounds

• In vivo hormone treatment experiments suggest that the decrease of 20-hydroxyecdysone concentration occurring in previtellogenic phases allows Vg production [9].
• The gene also codes for the highest level of lysine (9.5%), and lowest levels of phenylalanine (2.6%) and tyrosine (2.3%), observed in any insect Vg characterized to date [1].
• When analyzed by sodium dodecyl sulfate (SDS)-gel electrophoresis, A. mellifera vitellogenin resolved into a single band with an apparent Mr of 180,000 [12].
• We sequenced their N-terminal ends and one internal cyanogen bromide fragment of the large vitellin and compared these sequences with the deduced amino acid sequence from the vitellogenin gene [13].

Analytical, diagnostic and therapeutic context of Vg

• Using two fragments of the vitellogenin cDNA as probes, we analyzed by Northern blot the sex- and caste-specific patterns of vitellogenin expression in pupae and adults of A. mellifera [8].
• The honey bee vitellogenin was isolated from hemolymph of honey bee queens by a combination of density gradient ultracentrifugation, ion-exchange chromatography, and affinity chromatography [12].
• Vitellogenin levels were measured in hemolymph using immunological techniques [14].

References