Ovarian and Oviductal Morphology of Sexual and Parthenogenetic Geckos of the Heteronotia binoei Complex

Abstract

An examination of the morphological features of the ovaries and reproductive tract of sexual and parthenogenetic geckos of the Heteronotia binoei complex was conducted. The morphology of the ovaries and reproductive tract of both sexual and parthenogenetic females was similar to that found in other geckos. No significant differences were found in the maximum size of follicles nor in the height of the follicular wall in large, size-matched follicles of sexual and parthenogenetic females. There also was no significant difference in the area of the follicular wall comprised of large, intermediate, and small cells in these females. This suggests that the general mechanisms that govern ovarian development in the triploid parthenogenetic females are similar to that of their diploid ancestors. The morphology of the reproductive tract was examined with particular reference to the capacity for sperm storage. Sperm storage areas were found in the vaginal or infundibular regions of sexual females, most often during preovulatory stages of the ovarian cycle. Sperm were observed in two parthenogens, both in a late preovulatory stage: in one, sperm were in the vaginal region; whereas in the other, sperm were in the infundibular region. These observations suggest that both sexual and parthenogenetic H. binoei mate during the nuptial phase of their ovarian cycles and that sperm are stored for at least short-term periods during the same ovarian cycle. Sperm were found in the oviduct of parthenogenetic females less frequently than in sexual females; the frequency and outcome of sexual males mating with parthenogenetic females is presently unknown.