Position-effect variegation and z1 mediated white repression in the In(1)wis system in Drosophila melanogaster.

We have characterized a new X-chromosomal inversion in Drosophila melanogaster, extending from just distal of white to just proximal of the bb locus. The inversion places the w-isoxanthopterinless (wis) allele close to heterochromatin and under the influence of position-effect variegation (PEV). The wis gene activity is also regulated by chromosome pairing-dependent z1-mediated repression.

Uptake and incorporation in pteridines of externally supplied GTP in normal and pigment-deficient eyes of Drosophila melanogaster.

Some aspects of the synthesis of drosopterins in the eyes of Drosophila melanogaster have been studied in flies with different levels of white gene expression. The activity of GTP cyclohydrolase was found to differ between wild-type and yellow-eyed mutants in vivo but not in vitro. To elucidate the uptake of substrate, we measured the removal of labeled GTP from the incubation medium by excised pupal eyes and followed the subsequent fate of this label.

Biological effects of high-frequency electromagnetic fields on Salmonella typhimurium and Drosophila melanogaster.

Salmonella typhimurium and Drosophila melanogaster were exposed to continuous wave (CW) 2.45-GHz electromagnetic radiation, pulsed 3.10-GHz electromagnetic radiation, CW 27.

Content of histone H1 and histone phosphorylation in relation to the higher order structures of chromatin in Drosophila.

The amount of histone H1 relative to core histones has been determined in three Drosophila species (D. melanogaster, D. texana and D.

Enhanced susceptibility of a transposable-element-bearing strain of Drosophila melanogaster to somatic eye-color mutations by ethyl nitrosourea, methyl nitrosourea, and X-rays.

A strain of Drosophila with the genes z and w+ plus a transposable element (TE) is about 3 times more sensitive than a strain without TE toward somatic eye-color mutations after larval exposure to ethyl nitrosourea, methyl nitrosourea and X-rays. The assay system with TE is simple, reliable, and sensitive for detecting somatic mutations induced in vivo by mutagens.