Studies on the chromosomes of the rainbow lizard Agama agama agama (L.) with notes on polypoidy in the spermatocytes.

Abstract

The chromosomes of the Rainbow lizard, A. agama agama have been studied from bone marrow and testis preparations. The animal has a diploid chromosome complement of 44 with a fundamental number of 46. The karyotype bears very close relationship to that of A. atra from South Aftrica. Several spermatocytes in diakinesis and metaphase I show polyploidy which may be regular or apparent. The incidence of the regular polyploids varies from one animal to the other, although averagely about 4.8% of all cells in diakinesis are of the tetraploid origin while other ploidy levels account for 0.4%. Quadrivalents were not found in these polyploid cells and a process of endoreduplication of chromosomes without separation of sister chromatids is suggested for their origin.