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
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.