Abstract
The seasonal variations of chiasma frequency and distribution have been studied in the lizard: Podareis sicula. In this species, as in Phyllodactylus (King & Hayman, Chromosoma 69: 131–154, 1978), chiasma frequencies vary following a definite annual cycle, and clearly different trends are shown by interstitial and terminal chiasmata.
A comparison between these seasonal chiasma frequency variations and those of environmental temperature shows the existence of a clear correlation between these two parameters. However, this correlation is different in the two types of chiasmata, and may be different within the same type of chiasma depending on the period of the year.
A more significant correlation is observed between chiasma cycles and annual variations of the haematic levels of sexual steroid hormones. In particular we observe a highly significant correlation between interstitial chiasma frequencies and testosterone concentration. A less precise correlation between terminal chiasma frequencies and estradiol concentration is also observed.
In Podarcis, as in Phyllodactylus, the sperm that will be used for fertilization derive from the spermatocytes showing the highest rate of interstitial chiasmata. This supports the hypothesis that the cyclic variations in interstitial chiasma frequencies represent a mechanism to ensure an adequate level of variability in a given population. The above mentioned correlation between chiasma frequencies and steroia hormone concentrations suggests that the seasonal chiasma cycles are controlled by the same environmental and hormonal factors regulating the spermatogenetic cycle.
Similar content being viewed by others
References
Angelini, F., Botte, V. & Boschi, R., 1980. The origin of the reproductive cycle in Podarcis s. sicula Raf. (Reptilia, Lacertidae): Influence of the refractory period on the springtime testicular activity. Monit. zool. Ital. 14: 27–39.
Angelini, F. & Ghiara, G., 1984. Reproductive modes and strategies in vertebrate evolution. Boll. zool. 51: 121–203.
Botte, V. & Angelini, F., 1980. Endocrine control of reproduction in reptiles: the refractory period. In: Steroids and their mechanism of action in nonmammalian vertebrates. (G. Delrio, & J. Brachet, eds) pp. 201–211. Raven press, New York.
Ciarcia, G., Angelini, F., Polzonetti, A., Zerani, M. & Botte, V., 1986. Hormones and reproduction in the lizard Podareis sicula Raf. Int. Colloquium CNRS. ‘Congress of endocrine regulation as adaptive mechanism to the environment’. Forêt de Clizé, July 1–5, 1985 (in press).
Elliott, C. G., 1955. The effect of temperature on chiasma frequency. Heredity 9: 385–398.
Estes, R., 1983. The fossil record and early distribution of lizards. In: Advances in herpetology and evolutionary biology (A. J. Rhodin, & K. Miyata, eds) pp. 365–398. Mus. Comp. Zool., Harvard Univ. Cambridge, Massachusetts.
Gorman, G. C., 1973. The chromosomes of the Reptilia, a cytotaxonomic interpretation. In: Cytotaxonomy and vertebrate evolution (A. B. Chiarelli & E. Capanna, eds) pp. 349–424. Academic Press, London-New York.
Hillel, J., Feldman, M. W. & Simchen, G., 1973. Mating systems and population structure in two closely related species of the wheat group. Heredity 1: 1–9.
King, M., 1977, Reproduction in the Australian gekko Phyllodactylus marmoratus (Gray). Herpetologica 33: 7–13.
King, M. & Hayman, D., 1978. Seasonal variation of chiasma frequency in Phyllodactylus marmoratus (Gray) (Gekkonidae-Reptilia). Chromosoma 69: 131–154.
Licht, P., Hoyer, H. E. & Van Oordt, P. G. W. J., 1969. Influence of photoperiod and temperature on testicular recrudescence and body growth in the lizards Lacerta sicula and Lacerta muralis. J. Zool. Lond. 157: 469–501.
Lin, Y. J., 1982. Temperature and chiasma formation in Rhoeo spatacea var. variegata. Genetica 60: 25–30.
Shaw, D. D., 1971. Genetic and environmental components of chiasma control. I. Spatial and temporal variation in Schistocerca and Stethophyma. Chromosoma 34: 281–301.
Zarchi, Y., Simchen, G., Hillel, J. & Schaap, T., 1972. Chiasmata and the breeding system in wild populations of diploid wheats. Chromosoma 38: 77–94.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Cobror, O., Olmo, E., Odierna, G. et al. Cyclic variation of chiasma frequency and distribution in Podarcis sicula (Reptilia: Lacertidae). Genetica 71, 31–37 (1986). https://doi.org/10.1007/BF00123230
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00123230