کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5901028 | 1568894 | 2015 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Androgens directly stimulate spermatogonial differentiation in juvenile Atlantic salmon (Salmo salar)
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کلمات کلیدی
11-KT11-ketotestosterone - 11-کتواستاسترونandrogens - آندروژنspermatogonia - اسپرماتوگونیاAMH - اوGene expression - بیان ژنTestis - بیضهtestosterone - تستوسترونGrowth factors - فاکتور رشدAnti-Müllerian hormone - هورمون Anti-Mellerianfollicle stimulating hormone - هورمون تحریک کننده فولیکولluteinizing hormone - هورمون جسم زردFSH - هورمون محرکه فولیکولی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
علوم غدد
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
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 (TÂ +Â 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 1Â week 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 TÂ +Â OA groups) for 2Â weeks, 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 2Â weeks, stimulated differentiation, but not self-renewal, of undifferentiated type A spermatogonia.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: General and Comparative Endocrinology - Volume 211, 15 January 2015, Pages 52-61
Journal: General and Comparative Endocrinology - Volume 211, 15 January 2015, Pages 52-61
نویسندگان
Michelle C. Melo, Petra van Dijk, Eva Andersson, Tom Ole Nilsen, Per Gunnar Fjelldal, Rune Male, Wouter Nijenhuis, Jan Bogerd, Luiz Renato de França, Geir Lasse Taranger, Rüdiger W. Schulz,