| Popis: |
The first description of the mitotic chromosomes of Drosophila was made in 1912 by Stevens. She observed four pairs of chromosomes in spermatogonia and oogonia of Drosophila ampelophila (synonym of Drosophila melanogaster). Nevertheless, the first comparative studies of Drosophila karyotypes were performed by Metz (1914, 1916a, b). He understood that the cytological data are of interest for evolutionary biologists. The karyotype of Drosophila melanogaster (2n = 8) (Figure VI. 1) consists of three pairs of autosomes (pairs n°2, 3 and 4) and one pair of sex chromosomes (pair n°1). Chromosomes 2 and 3 are large metacentric, the chromosomes 4 are dot chromosomes, the X chromosome is a large acrocentric. The Y chromosome is submetacentric. The different banding techniques of mammals chromosomes may be used for the mitotic chromosomes of Drosophila. |
