A cytological study of the O5 chromosomal inversion of Drosophila subobscura (Diptera, Drosophilidae)

The O5 chromosomal inversion has been a cornerstone for understanding different aspects of the American colonization by Drosophila subobscura. To obtain more information of this evolutionary event it is important to know the pattern of bands of this inversion in detail. Comparing this pattern with that of D. melanogaster it is possible to predict which genes are located inside or close to the O5 inversion and use them as genetic markers. In this study, the complete band pattern of the O5 inversion is presented. Furthermore, the most important genes located inside it have been predicted. Finally, a constriction located close to the proximal breakage point of the O5 inversion has been observed many times and its possible genetic significance is discussed