GENOMIC IMPRINTING OF CHROMATIN IN DROSOPHILA-MELANOGASTER

During gametogenesis, chromosomes may become imprinted with informatio n which facilitates proper expression of the DNA in offspring. We have used a position effect variegation mutant as a reporter system to inv estigate the possibility of imprinting in Drosophila melanogaster. Gen etic crosses were performed in which the variegating gene and a strong modifier of variegation were present either within the same parental genome or in opposite parental genomes in all possible combinations. O ur results indicate that the presence of the variegating chromosome an d a modifier chromosome in the same parental genome can alter the amou nt of variegation formed in progeny. The genomic imprinting we observe d is not determined by the parental origin of the variegating chromoso me but is instead determined by the genetic background the variegating chromosome is subjected to during gametogenesis.