Histological changes in the ovary during the annual breeding cycle in Agama impalearis Boettger, 1874 (Reptilia : Agamidae)

Citation
E. El Mouden et al., Histological changes in the ovary during the annual breeding cycle in Agama impalearis Boettger, 1874 (Reptilia : Agamidae), BELG J ZOOL, 131(1), 2001, pp. 17-30
Citations number
81
Categorie Soggetti
Animal Sciences
Journal title
BELGIAN JOURNAL OF ZOOLOGY
ISSN journal
07776276 → ACNP
Volume
131
Issue
1
Year of publication
2001
Pages
17 - 30
Database
ISI
SICI code
0777-6276(200101)131:1<17:HCITOD>2.0.ZU;2-A
Abstract
The aim of the present work is to investigate the female reproductive cycle of the North African agamid, Agama impalcaris. Histological changes of the whole ovarian cycle were described. Folliculogenesis and oocyte growth wer e comparable to the general lizard pattern. A single germinal bed per ovary was found. Only previtellogenic follicles were present during the non repr oductive period and the onset of vitellogenesis was observed just after eme rgence from winter dormancy. Two vitellogenic cycles which probably produce two successive clutches per breeding season were observed. The number of v itellogenic follicles can reach 12 per ovarian vitellogenic cycle. The oocy te growth was accompagnied by changes in the theca, granulosa, zona pelluci da and zona radiata layers. The postovulatory follicles (corpora lutea) wer e observed until the onset of the second vitellogenic cycle and disappeared rapidly after them. Two kinds of atretic follicles, hydratation stage and vitellogenic stage atretic follicles, were described. Atresia was less freq uent in Agama impalearis and particularly concerned with larger vitellogeni c follicles.