Hormonal regulation and characterization of MHG30 gene, a desaturase-like gene of hamster harderian gland.
The harderian gland (HG) is an orbital gland of the vast majority of land vertebrates. In the Syrian hamster these glands display a marked sexual dimorphism. Here we present data on a male specific clone named MHG30. The MHG30 cDNA (1470 bp) has significant sequence homologies with human #15μ10#Δ6-desaturase enzymes. The expression of MHG30 has been found in male HG and in the liver of both sexes, no other tissue showing the presence of MHG30 mRNA. Castration brings the MHG30 levels below detectable level in about 7 days. In in vitro cultures of male hamster HG cells, androgens (A) determine an enhancement of MHG30 expression in a time-dependent manner. Conversely, a continuous decrement has been observed in control cells and in cells treated with A plus flutamide (F) or with A and cycloheximide (Cy). Incubation of cells in cultures supplemented with desamethason (Dex) or thyroid hormone (T3) also increases MHG30 expression while 17β-estradiol prevents the stimulatory effect exerted by A, Dex and T3. Findings strongly suggest that the MHG30 gene could be involved in supporting the sexual dimorphism and its expression is likely triggered by a series of hormonal interactions.
Department of Experimental Medicine School of Medicine, II University of Naples, Via Costantinopoli 16, 80138 Naples, Italy.
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Esposito
Department of Experimental Medicine School of Medicine, II University of Naples, Via Costantinopoli 16, 80138 Naples, Italy.
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Tammaro
Department of Scienze Mediche, Chirurgiche, Neurologiche, Metaboliche e dell'Invecchiamento, Second University of Naples, Naples, Italy.
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Paolisso
Department of Experimental Medicine School of Medicine, II University of Naples, Via Costantinopoli 16, 80138 Naples, Italy. Electronic address: bruno.varriale@unina2.it.
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Varriale
D000818:Animals; D001483:Base Sequence; D002369:Castration; D006224:Cricetinae; D018076:DNA, Complementary; D044943:Fatty Acid Desaturases / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006243:Harderian Gland / Q000201:enzymology*; D006728:Hormones / Q000502:physiology*; D008297:Male; D008647:Mesocricetus; D008969:Molecular Sequence Data
D018076:DNA, Complementary; D006728:Hormones; D044943:Fatty Acid Desaturases
#15μ10#Δ6-Desaturase; MHG30; Sequence analysis; Sexual dimorphism; Steroid regulation