دورية أكاديمية
Winter profile of plasma sex steroid levels in free-living male western diamond-backed rattlesnakes, Crotalus atrox (Serpentes: Viperidae).
| العنوان: | Winter profile of plasma sex steroid levels in free-living male western diamond-backed rattlesnakes, Crotalus atrox (Serpentes: Viperidae). |
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| المؤلفون: | Schuett GW; Department of Biology, Center for Behavioral Neuroscience, Georgia State University, 33 Gilmer Street, S. E., Atlanta, GA 30303-3088, USA. biogws@langate.gsu.edu, Repp RA, Taylor EN, DeNardo DF, Earley RL, Van Kirk EA, Murdoch WJ |
| المصدر: | General and comparative endocrinology [Gen Comp Endocrinol] 2006 Oct; Vol. 149 (1), pp. 72-80. Date of Electronic Publication: 2006 Jul 07. |
| نوع المنشور: | Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S. |
| اللغة: | English |
| بيانات الدورية: | Publisher: Academic Press Country of Publication: United States NLM ID: 0370735 Publication Model: Print-Electronic Cited Medium: Print ISSN: 0016-6480 (Print) Linking ISSN: 00166480 NLM ISO Abbreviation: Gen Comp Endocrinol Subsets: MEDLINE |
| أسماء مطبوعة: | Publication: New York, NY : Academic Press Original Publication: New York. |
| مواضيع طبية MeSH: | Seasons*, Crotalus/*physiology , Estradiol/*blood , Testosterone/*analogs & derivatives , Testosterone/*blood, Animals ; Body Temperature ; Estradiol/metabolism ; Estrone ; Male ; Reproduction/physiology ; Sexual Behavior, Animal ; Testosterone/metabolism |
| مستخلص: | Recent field studies on the reproductive ecology of western diamond-backed rattlesnakes (Crotalus atrox) from populations in southern Arizona showed significant differences in the concentration of plasma sex steroids (testosterone, T; 5alpha-dihydrotestosterone, DHT; and 17beta-estradiol, E2) throughout the active season (March-October), and peak levels were coincident with the two mating periods (late summer and early spring). There is, however, no information on levels of sex steroids during winter. Similar to most snakes, hibernating individuals of C. atrox are typically inaccessible, but in southern Arizona, where environmental conditions are typically mild during winter, adult males frequently bask at or near the entrances of communal dens. Basking activity, therefore, offers a unique logistical opportunity to assess the complete annual profile of plasma sex steroid levels in males of a temperate reptile in nature. From November to February, we measured levels of plasma T, DHT, and E2 in adult male C. atrox that were located basking at communal dens. Additionally, cloacal, core body, and ambient air temperatures were obtained to investigate potential relationships between body temperatures and levels of sex steroids. Mean levels of T, DHT, and E2 were relatively high, and the concentration hierarchy was T>DHT>E2. Mean levels of T, DHT, and E2 showed no significant variation across the four months of sampling; however, E2 levels decreased progressively. In the annul cycle, sex steroid levels during winter were not basal when compared to values obtained during the active season. Mean cloacal temperatures of basking males were significantly higher than core body temperatures of non-basking males (inside dens) from November-December, and in February, which suggests that one function of winter basking is to elevate body temperatures. Steroid levels, nonetheless, were not significantly correlated with cloacal temperatures. We suggest that future field studies of male C. atrox should: (a) investigate sex steroid levels in non-basking individuals and (b) test whether elevated levels of sex steroids during winter facilitate the large increases that occur in early spring, which are coincident with the second mating season. Our findings on the reproductive biology of C. atrox and other viperids are discussed in the context of the associated-dissociated model of reproduction. |
| المشرفين على المادة: | 2DI9HA706A (Estrone) 3XMK78S47O (Testosterone) 4TI98Z838E (Estradiol) 5H7I2IP58X (boldenone) |
| تواريخ الأحداث: | Date Created: 20060711 Date Completed: 20070206 Latest Revision: 20131121 |
| رمز التحديث: | 20221213 |
| DOI: | 10.1016/j.ygcen.2006.05.005 |
| PMID: | 16828091 |
| قاعدة البيانات: | MEDLINE |
Full Text Finder | تدمد: | 0016-6480 |
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| DOI: | 10.1016/j.ygcen.2006.05.005 |