Mosaicism induced by the loss of chromosome X and/or IV in cand mutants of Drosophila melanogaster

A pattern of cuticular mosaicism for X-chromosome markers and for haplo-4 Minute phenotype was studied. Losses of either X- or IV-chromosomes were found to occur mainly in the first two cleavage divisions, being several times higher in the 1st one. X- or IV-chromosomes may be lost either separately or together, the nonrandom coincidence of joint losses in the successive divisions being observed in the latter case. No proliferation delay was found due to Minute (4) gene hemizygosity while this condition caused some enhancement in ssak expression (intersegmental fusions in tarsi) and pronounced suppression of the Hw effect.