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Relations Between Hibernation and Ovarian Functions in a Temperate Zone Frog, Rana temporaria
Author(s) -
Jørgensen C. Barker
Publication year - 1984
Publication title -
acta zoologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.414
H-Index - 37
eISSN - 1463-6395
pISSN - 0001-7272
DOI - 10.1111/j.1463-6395.1984.tb01045.x
Subject(s) - hibernation (computing) , biology , vitellogenesis , torpor , ovulation , oogenesis , zoology , follicle , medicine , oocyte , endocrinology , andrology , embryo , microbiology and biotechnology , algorithm , computer science , hormone , thermoregulation , state (computer science)
Adult female frogs were exposed to artificial hibernation in a refrigerator, at about 1–3°C, 1–2 months earlier than in nature, isolated or together with males. Ovarian functional state at the beginning of hibernation was assessed from ovarian biopsies taken in mid‐September. All frogs ovulated during hibernation which was interrupted in mid‐May, but in seven out of 19 frogs ovulation was incomplete. The number of non‐ovulated oocytes varied from a minor fraction to about two thirds of the complement of vitellogenic oocytes, indicating that the follicle size reached at the time of induced hibernation was at the critical level for successful maturation. This critical size was about half the normal oocyte volume at the onset of natural hibernation. There was no vitellogenic growth during hibernation, which presumably constitutes the period of follicle maturation. In five of the frogs, oogenesis sensu stricto had occurred during the period of hibernation, some oogenic events being completely finished at autopsy in mid‐May and others still progressing.