Insulin and gender: an insulin-like gene expressed exclusively in the androgenic gland of the male crayfish
Autor: | Vered Chalifa-Caspi, Miri Lapidot, Rivka Manor, Eliahu D. Aflalo, Simy Weil, Amir Sagi, Shirley Oren, Lilah Glazer, Tomer Ventura |
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Rok vydání: | 2006 |
Předmět: |
Male
Models Molecular DNA Complementary Sex Differentiation medicine.medical_treatment Molecular Sequence Data Astacoidea Biology Endocrinology Cherax quadricarinatus Complementary DNA medicine Animals Insulin Amino Acid Sequence Gonads Gene In Situ Hybridization Phylogeny Genetics Expressed Sequence Tags Sexual differentiation Base Sequence cDNA library Reverse Transcriptase Polymerase Chain Reaction biology.organism_classification Blotting Northern Molecular biology Suppression subtractive hybridization Animal Science and Zoology Sequence Alignment Endocrine gland |
Zdroj: | General and comparative endocrinology. 150(2) |
ISSN: | 0016-6480 |
Popis: | Members of the insulin family of hormones are generally not regarded as gender-specific, although there is sporadic evidence for the possible involvement of insulin pathways in sexual differentiation. In crustaceans, sexual differentiation is controlled by the androgenic gland (AG), an organ unique to males. To date, attempts to identify active AG factors in decapods through either classical purification methods or sequence similarity with isopod AG hormones have proven unsuccessful. In the present study, the first subtractive cDNA library from a decapod AG was constructed from the red-claw crayfish Cherax quadricarinatus. During library screening, an AG-specific gene, expressed exclusively in males even at early stages of maturation and termed Cq-IAG (C. quadricarinatus insulin-like AG factor), was discovered. In situ hybridization of Cq-IAG confirmed the exclusive localization of its expression to the AG. Following cloning and complete sequencing of the gene, its cDNA was found to contain 1445 nucleotides encoding a deduced translation product of 176 amino acids. The proposed protein sequence encompasses Cys residue and putative cleaved peptide patterns whose linear and 3D organization are similar to those of members of the insulin/insulin-like growth factor/relaxin family and their receptor recognition surface. The identification of Cq-IAG is the first report of a pro-insulin-like gene expressed in a decapod crustacean in a gender-specific manner. Its expression in a male-specific endocrine gland controlling sex differentiation supports the notion that insulin may have evolved in the context of regulating sexual differentiation. |
Databáze: | OpenAIRE |
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