Disease relevance of vtg1

• With E2, the most sensitive end points were feminization of offspring (at 0.1 nM) and increased VTG production in males (at 0.32 nM) [1].
• At 1 nM, decreased F, survival, increased F, body length and weight, VTG-related edema and kidney lesions, and inhibited spermatogenesis were observed [1].
• Results from this study demonstrate that reproduction in zebrafish is affected by waterborne exposure to B[a]P and that altered transcription of genes important in regulating reproduction (20beta-HSD, CYP19A2 and vitellogenin) may be one of the underlying mechanisms of B[a]P-induced reproductive toxicity [2].

High impact information on vtg1

• Ontogenetic expression of zp2 and zp3 mRNAs was first detected at 3 wk postfertilization, which was about 5 wk earlier than initial vtg1 expression, indicating that ovary development was earlier than vitellogenesis [3].
• The level of vtg1 mRNA was about 100x and 1000x higher than those of vtg2 and vtg3 mRNAs [4].
• Two Vg preparations, with apparent masses of 600 kDa (600 Vg) and 400 kDa (400 Vg), were isolated from the plasma of fish treated with estradiol-17beta (E(2)) by various chromatographic procedures [5].
• Full-length cDNAs encoding the 600 VgA, 600 VgB, and 400 Vg were isolated from a liver cDNA library of E(2) treated fish [5].
• Immunological analyses demonstrated that the 400 Vg underwent no change in native mass after being incorporated into oocytes [5].

Biological context of vtg1

• Further kinetics studies of the two fish models indicated that medaka was able to respond much faster to E2 treatment than zebrafish, while the zebrafish can attain a much higher level of vitellogenin mRNAs than medaka after a long-term E2 treatment [6].
• Continuous cDNAs of two zebrafish vitellogenin-like gene products (zfvg1 and zfvg3) were constructed by the help of expressed sequence tags of zebrafish and completely sequenced [7].
• A significant up-regulation of vtg1 expression was detected at 48 hpf for 1,000 and 2,000 ng/L EE2 [8].
• Abundance of vtg1 mRNA was detected using reverse transcription real-time polymerase chain reaction and normalized to beta-actin mRNA abundance [8].
• Blood vitellogenin levels and sex ratio changes were used as intermediate indicators of the reproduction failures [9].

Anatomical context of vtg1

• It is suggested that the changes in the hepatocytes, which coincide with special phases of ovarian activity, are related to vitellogenin synthesis [10].
• At 60dph, fish from each treatment were euthanized for histological examination of gonads, and whole body VTG and HSP70 levels [11].
• Several physiological endpoints that may be affected by endocrine disrupters were analysed, specifically vitellogenin (VTG) concentration, estradiol (E2), testosterone (T), and 11-ketotestosterone (KT) content, brain aromatase activity and gene expression of CYP19A1 and CYP19A2 in the testis [12].
• The egg yolk protein precursor vitellogenin was used as a biological indicator of estrogenicity [13].
• Effects of selected xenoestrogens on liver peroxisomes, vitellogenin levels and spermatogenic cell proliferation in male zebrafish [14].

Associations of vtg1 with chemical compounds

• In the present study, both zebrafish and medaka vitellogenin genes have been isolated and used as a biomarker to compare the two small aquarium fish in response to estrogen treatment and thus to evaluate the two fish models in development of a biomonitoring system for environmental estrogens [6].
• At 72, 96, and 120 hpf, vtg1 was significantly induced for all EE2 concentrations [8].
• Suppression of vg in female liver following exposure to 50 or 500 ng/L of the synthetic androgen 17beta-trenbolone occurs at similar magnitude for both vg1 and vg3 isoforms [15].
• Interestingly, the predicted vitellogenin has no polyserine phosvitin domain [16].
• In all EE10 exposure groups (EE10, EE10+NP10 and EE10+NP100), increasing NP concentration acted antagonistically to the action of EE in terms of VTG induction at 60dph [11].

Other interactions of vtg1

• LOECs for vitellogenin as well as estrogen receptor alpha expression were found to be 2.5 ng/l already after 4 d of exposure [7].

Analytical, diagnostic and therapeutic context of vtg1

• A real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay was developed for quantification of vitellogenin mRNA level in both control fish and E2-treated fish [6].
• Molecular cloning of zebrafish and medaka vitellogenin genes and comparison of their expression in response to 17beta-estradiol [6].
• Several histological methods were tested for their potential to detect the in vivo induction of vitellogenin in zebrafish, after exposure to 17beta-oestradiol (E2), and validated by correlating semi-quantitative measurements on digital images to vitellogenin plasma values measured by ELISA and morphological criteria [17].
• Vitellogenin expression in zebrafish Danio rerio: evaluation by histochemistry, immunohistochemistry, and in situ mRNA hybridisation [17].
• At 60 dph, 20 fish from each treatment were euthanized for histological examination of gonads and Western blotting for Vtg using pooled heart homogenates [18].

References