Abstract
The European beaver (Castor fiber) is the largest free-living rodent in Eurasia which belongs to the group of long-day breeders. A seasonally changing photoperiod may be related to cyclic changes in the secretion of gonadotropins and sex steroids. The goal of our study was to determine sex- and seasonally dependent changes in the concentration of gonadotropins (LH—luteinizing hormone and FSH—follicle-stimulating hormone) and steroids (T—testosterone, E2—estradiol, and P4—progesterone) in the blood plasma of free-living male and female beavers. Blood samples were collected in April—pregnancy in females; July—the end of lactation, raising of offspring; and November—sexual silence. Our results indicate that in females, a higher FSH concentration was noted in July and November than in April. Plasma T content did not differ between males and females, but in females, it was higher in April as compared with July or November. Plasma P4 concentration was the highest in females in April. In summary, our findings indicate, for the first time, that in the European beaver occur sex- and/or seasonally related changes in the concentration of plasma FSH and sex steroids (T and P4). Seasonal differences in the tested hormones can be associated with the differential activity of the hypothalamo-pituitary-gonadal axis during various reproductive stages of the beaver.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bronson FH (1990) Mammalian reproductive biology. University of Chicago Press, Chicago
Bronson FH (2009) Climate change and seasonal reproduction in mammals. Philos Trans R Soc B 364:3331–3340
Bronson FH, Heideman PD (1994) Seasonal regulation of reproduction in mammals. In: Knobil E, Neil JD (eds) The physiology of reproduction, 2nd edn. Raven, New York, pp 541–583
Caillol M, Martinet L (1976) Preliminary results on plasmaprogesterone levels during pregnancy and superfetation in the hare, Lepus europaeus. J Reprod Fertil 46:61–64
Ciereszko R, Opalka M, Kaminska B, Wojtczak M, Okrasa S, Dusza L (2001) Luteotrophic action of prolactin during the early luteal phase in pigs: the involvement of protein kinases and phosphatases. Reprod Biol 1(2):62–83
Feoktistova NY, Kropotkina MV, Naidenko SV (2010) Seasonal changes of steroid levels in blood plasma of three Phodopus species (Mamalia, Cricetinae). Biol Bull 37(6):659–664
Hoffman B, Wagner WC, Hixon JE, Bahr J (1979) Observations concerning the functional status of the corpus luteum and the placenta around parturition in the cow. Anim Reprod Sci 2:252–266
Kerbeshian MC, Bronson FH, Bellis ED (1994) Variation in reproductive photoresponsiveness in a wild population of meadow voles. Biol Reprod 50:745–750
Larsson K, Wagner WC, Sachs M (1981) Oestrogen synthesis by foetal placenta at normal parturition. Acta Endocrinol (Copenh) 98:112–118
Li B, Sheng X, Bao L, Huang S, Li Q, Liu Y, Han Y, Watanabe G, Taya K, Weng Q (2014) Seasonal changes in expression of nerve growth factor and its receptors TrkA and p75 in the ovary of wild ground squirrel (Citellus dauricus Brandt). J Ovarian Res 7:3
Lincoln GA, MacKinnon PCB (1976) A study of seasonally delayed puberty in the male hare, Lepus europaeus. J Reprod Fertil 46:123–128
Lv XH, Shi DZ (2010) Variations of serum estradiol and progesterone levels during consecutive reproductive states in Mongolian gerbils (Merione sunguiculatus). Exp Anim 59(2):231–237
Meyer HHD, Flackenberg D, Janowski T, Rapp M, Rösel EF, Von Look L, Karg H (1992) Evidence for the presence of endogenous 19-nor-testosterone in the cow peripartum and in the neonatal calf. Acta Endocrinol (Copenh) 126:369–373
Müler-Schwarze D (2011) The beaver: its life and impact, 2nd edn. Cornell University Press, Ithaca NY
Nelson RJ (1985) Photoperiod influences reproduction in the Prairie vole (Microtus ochrogaster). Biol Reprod 33:596–602
Nolet BA (1997) Management of the beaver (Castor fiber): towards restoration of its former distribution and ecological function in Europe. Nature and Environmental No. 86. Council of Europe, Strasbourg
Nolet BA, Rosell F (1998) Comeback of the beaver Castor fiber: an overview of old and new conservation problems. Conserv Biol 83(2):165–173
Novikov EA (2007) Economy of resources as a basic of adaptation of the Northern Mole vole (Ellobius talpinus: Rodentia) to subterranean life style. Zh Obshch Biol 67(4):268–277
Place NJ, Kenagy GJ (2000) Seasonal changes in plasma testosterone and glucocorticosteroids in free-living male yellow-pine chipmunks and the response to capture and handling. J Comp Physiol B 170:245–251
Schlatt S, Niklovitz P, Hoffman K, Nieschlag E (1993) Influence of short photoperiods on reproductive organs and estrus cycles of normal and pinealectomized female Djungarian hamsters, Phodopus sungorus. Biol Reprod 49:243–250
Stavy M, Terkel J, Kohen F (1978) Plasma progesterone levels during pregnancy and pseudo- pregnancy in the hare (Lepus europaeus syriacus). J Reprod Fertil 54:9–14
Szafranska B, Ziecik A, Okrasa S (2002) Primary antisera against selected steroids or proteins and secondary antisera against γ-globulins—as available tool for studies of reproductive processes. Reprod Biol 2:187–204
Thimonier J (1981) Control of seasonal reproduction in sheep and goats by light and hormones. J Reprod Fertil 30:33–45
Wade GN, Bartness TJ, Alexander JR (1986) Photoperiod and body weight in female Syrian hamsters: skeleton photoperiods, response magnitude, and development of photorefractoriness. Physiol Behav 37(6):863–868
Zurowski W (1992) Building activity of beavers. Acta Theriol 37:403–411
Acknowledgments
This study was supported by the National Science Centre (project No. 2012/07/B/NZ9/01335), the Ministry of Higher Education (project No. 528/0206/882), and individual scholarships from PhD students programs (1. Author Katarzyna Chojnowska is a beneficiary of the project “Scholarships for PhD students of Podlaskie Voivodeship.” The project is co-financed by the European Social Fund, Polish Government, and Podlaskie Voivodeship, project No. POKL.08.02.02-20-002/12; 2. Author Joanna Czerwinska is a beneficiary of the project co-financed by the European Social Fund, project No. CIiTT/RIM WiM/2014/59). The authors would like to thank Jan Gozdziewski from the Polish Hunting Association in Suwalki for capturing and delivery of animals; Grzegorz Belzecki, Ph.D. from The Kielanowski Institute of Animal Physiology and Nutrition of Polish Academy of Sciences in Jabłonna and Zygmunt Gizejewski, Prof. from Research Station of Ecological Agriculture and Preservation Animal Breeding of the Polish Academy of Sciences in Popielno for cooperation and sharing of materials to research.
Ethical approval
All experimental procedures were conducted in accordance with ethical standards of the institutional Animal Ethical Committees (ministerial approval: RDOS-28-OOP-6631-0007-638/09/10/pj and local approvals: SGGW/11/2010 and UWM/87/2012/DTN).
Conflict of interest
The authors declare that they have no competing interests.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Chojnowska, K., Czerwinska, J., Kaminski, T. et al. Sex- and seasonally related changes in plasma gonadotropins and sex steroids concentration in the European beaver (Castor fiber). Eur J Wildl Res 61, 807–811 (2015). https://doi.org/10.1007/s10344-015-0955-z
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10344-015-0955-z