We report the development of a quantifiable exposure indicator for measuring the presence of environmental estrogens in aquatic systems. Synthetic oligonucleotides, designed specifically for the vitellogenin gene (Vg) transcription product, were used in a reverse transcription-polymerase chain reaction (RT-PCR) protocol. This extremely sensitive and rapid method was able to detect vitellogenin ...

In Xenopus, estrogen induces the stabilization of vitellogenin mRNA and the destabilization of albumin mRNA. These processes correlate with increased polysomal activity of a sequence-selective mRNA endonuclease, PMR-1, and a hnRNP K homology-domain RNA-binding protein, vigilin. Vigilin binds to a region of the vitellogenin mRNA 3'-untranslated region (3'-UTR) implicated in estrogen-mediated sta...

0379 Students of the evolution of social behavior got a big boost with the publication of the newly sequenced honeybee genome in October 2006. The honeybee (Apis mellifera) belongs to the rarifi ed cadre of insects that pool resources, divide tasks, and communicate with each other in highly structured colonies. Understanding how this advanced state of organization evolved from a solitary lifest...

The cDNA of Apis mellifera vitellogenin was cloned and sequenced. It is 5440 bp long and contains an ORF of 1770 amino acids (including a putative signal peptide of 16 residues). The deduced amino acid sequence shows significant similarity with other hymenopteran vitellogenins (58% with Pimpla nipponica and 54% with Athalia rosae). The alignment with 19 insect vitellogenins shows a high number ...

Honeybee (Apis mellifera) society is characterized by a helper caste of essentially sterile female bees called workers. Workers show striking changes in lifespan that correlate with changes in colony demography. When rearing sibling 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 endog...

The response of male Fundulus heteroclitus to estrogenic compounds was assessed in anticipation of using this species in endocrine disrupter field studies in the Chesapeake Bay. Measurements of plasma vitellogenin, gonadosomatic (GSI) and hepatosomatic (HSI) indices, and an assessment of changes in gonadal histology were made. Of the parameters assessed, vitellogenin was found to be the most se...

DNA-cDNA titrations suggest that the Xenopus genome comprises two albumin genes, whereas there are 12 to 16 vitellogenin-like genes. Both sets of genes are expressed in liver, those coding for albumin constitutively, but vitellogenin only when induced by estrogen in both male and female frogs. Mild micrococcal nuclease digestion of liver nuclei to separate “expressed” from “unexpressed” gene fr...

Vitellogenin (VTG) is known to be a female-specific protein and a precursor form of egg yolk. Threevitellogenin,Vtg I,Vtg II and Vtg III have been identified in chicken.Vitellinogen precursors supply the major egg yolk proteins which are a source of nutrients during early development of egg-laying (oviparous) vertebrates and invertebrates. A complete structural analysis and 3-D modelling of Vit...

Avian vitellogenin-cauliflower mosaic virus hybrid gene is effectively transcribed in vitro in the homologous embryonic liver nuclei system. The transcription of the hybrid gene is modulated by the addition of an estradiol-receptor preparation that has been shown to bind selectively to an upstream region of cloned vitellogenin gene. Stimulation of the transcription of cloned vitellogenin hybrid...

A series of overlapping recombinant clones, which cover the vitellogenin gene, has been isolated from a phage-lambda linked chicken gene library. The DNA of the overlapping clones spans 28 kb of contiguous DNA sequences in the chicken genome. Electron microscopic analysis of hybrids between vitellogenin mRNA and the genomic clones indicates that the chicken vitellogenin gene has a length of app...