Androgens directly stimulate spermatogonial differentiation in juvenile Atlantic salmon (Salmo salar)
| Autor: | de Melo, Michelle, van Dijk, P, Andersson, Eva, Nilsen, Tom Ole, Fjelldal, Per Gunnar, Male, Rune, Nijenhuis, Wouter, Bogerd, Jan, de França, Luiz Renato, Taranger, Geir Lasse, Schulz, Rüdiger W, Developmental Biology, Sub Developmental Biology |
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| Přispěvatelé: | Developmental Biology, Sub Developmental Biology |
| Rok vydání: | 2015 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Transcription Genetic medicine.drug_class Salmo salar Stimulation Biology urologic and male genital diseases Androgen receptor binding chemistry.chemical_compound Endocrinology Internal medicine Testis medicine Animals Humans Testosterone RNA Messenger 14. Life underwater Spermatogenesis Cell Differentiation Androgen Spermatogonia Adrenosterone Androgen receptor HEK293 Cells Gene Expression Regulation chemistry Receptors Androgen Pituitary Gland Androgens Animal Science and Zoology Gene expression Gonadotropin Growth factors |
| Zdroj: | General and Comparative Endocrinology, 211C, 52. Academic Press Inc. |
| ISSN: | 0016-6480 |
| DOI: | 10.1016/j.ygcen.2014.11.015 |
| Popis: | We studied the effects of androgens on early stages of spermatogenesis along with androgen receptor binding characteristics and the expression of selected testicular and pituitary genes. To this end, immature Atlantic salmon postsmolts received testosterone (T), adrenosterone (OA, which is converted in vivo into 11-ketotestosterone, 11-KT) or a combination of the two androgens (T+OA). Treatment with OA and T elevated the plasma levels of 11-KT and T, respectively, and co-injection of OA with T lead to high 11-KT levels but prevented plasma T levels to reach the levels observed after injecting T alone. Clear stimulatory effects were recorded as regards pituitary lhb and gnrhr4 transcript levels in fish receiving T, and to a lesser extent in fish receiving OA (but for the lhb transcript only). The two androgen receptors (Ara1 and Ara2) we cloned bound T and 11-KT and responded to these androgens in a similar way. Both androgens down-regulated testicular amh and increased igf3 transcript levels after 1week of treatment, but effects on growth factor gene expression required sustained androgen stimulation and faded out in the groups with the decreasing T plasma levels. In fish exhibiting a sustained elevation of 11-KT plasma levels (OA and T+OA groups) for 2weeks, the number of differentiating spermatogonia had increased while the number of undifferentiated spermatogonia decreased. Previous work showed that circulating gonadotropin levels did not increase following androgen treatments of gonad-intact immature male salmonids. Taken together, androgen treatment of immature males modulated testicular growth factor expression that, when sustained for 2weeks, stimulated differentiation, but not self-renewal, of undifferentiated type A spermatogonia. |
| Databáze: | OpenAIRE |
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