Photomap of the polythenic chromosomes of Drosophila malerkotliana and in situ mapping of the Hsp83 locus

Abstract

A photomap of the polythenic chromosomes of D. malerkotliana was constructed to facilitate the identification of the chromosomal arms and their sections, in order to allow the identification of the breaking points of inversions and the location of the bands marked by in situ hybridization. The photomap included the six chromosome arms corresponding to pairs I (chromosome X), II and III, excluding pair IV and Y chromosome, because they were not visualized in the material examined, probably due to their small size. Through the in situ hybridization technique with the use of a biotined probe of a fragment of the D. melanogaster gene, the Hsp83 locus of D. malerkotliana was mapped. The probe hybridized with a frequency of 70% in section 98 of the IIIR chromosome. This is the first mapped gene in the species, and indicates that possibly the IIIR arm of D. malerkotliana corresponds to the IIIL arm of D. melanogaster, where the Hsp83 gene was located.