In situ hybridization of human chromosomes appears as one of the most attractive methods of gene mapping since it enables the locus being looked for to be directly visualized. This technique however includes a critical step which is the denaturation of chromosomal DNA by different procedures such as heat, alkali or acid treatment (1). These affect the chromosome structure and decrease the good ...

Resistance in wheat (Triticum aestivum) to the Hessian fly (Mayetiola destructor), a major insect pest of wheat, is based on a gene-for-gene interaction. Close linkage (3 +/- 2 cM) was discovered between Hessian fly avirulence genes vH3 and vH5. Bulked segregant analysis revealed two DNA markers (28-178 and 23-201) within 10 cM of these loci and only 3 +/- 2 cM apart. However, 28-178 was locate...

Drosophila melanogaster bearing the Passover mutation fail to jump in response to a light-off stimulus. Pas also disrupts some of the synapses between the neurons of the giant fiber system which mediate this escape behavior. We have mapped Pas to the 19E subdivision of the polytene X chromosome. Our genetic analyses reveal that deletions of either of two nonoverlapping regions fail to fully com...

We report studies using an enhanced experimental system to investigate organization of nuclear pre-mRNA metabolism. It is based on the powerful genetic system and polytene nuclei of Drosophila. We observe (at steady state) movement of a specific pre-mRNA between its gene and the nuclear surface. This movement is isotropic, at rates consistent with diffusion and is restricted to a small nuclear ...

The Drosophila melanogaster suppressor of sable gene, su(s), encodes a novel, 150-kDa nuclear RNA binding protein, SU(S), that negatively regulates RNA accumulation from mutant alleles of other genes that have transposon insertions in the 5' transcribed region. In this study, we delineated the RNA binding domain of SU(S) and evaluated its relevance to SU(S) function in vivo. As a result, we hav...

The DHR3 orphan receptor gene is induced directly by the steroid hormone ecdysone at the onset of Drosophila metamorphosis. DHR3 expression peaks in early prepupae, as the early puff genes are repressed and betaFTZ-F1 is induced. Here we provide evidence that DHR3 directly contributes to both of these regulatory responses. DHR3 protein is bound to many ecdysone-induced puffs in the polytene chr...

Despite having no mammary glands, Drosophila is a very useful model for conducting research on molecular mechanisms as well as the regulation of transcription including epigenetic changes associated with breast cancer development. Drosophila has been used as one of the model systems since it was first introduced by Thomas Morgan, a pioneer in genetics for the study of heredity, in the early 20t...