The nucleotide sequence of glutamate tRNA4 of Drosophila melanogaster.

The nucleotide sequence of Drosophila melanogaster glutamate tRNA4 was determined to be: pU-C-C-C-A-U-A-U-G-G-U-C-psi-A-G-D-G-G-C-D-A-G-G-A-U-A-U-C-U-G-G-C (m) -U-U-U-C-A-C-C-A-G-A-A-G-G-C-C-C-G-G-G-T-psi-U-C-G-A-U-U-C-C-C-G-G-U-A-U-G-G-G-A-A-C-C-AOH. A partial modified C is found at position 32 in the anticodon loop.     

The nucleotide sequence of the initiator tRNA from Drosophila melanogaster.

The nucleotide sequence of Drosophila melanogaster methionine tRNAi was determined to be: pA-G-C-A-G-A-G-U-m1G-m2G-C-G-C-A-G-U-G-G-A-A-G-C-G-U-m2G-C-U-G-G-G-C-C-C-A-U-t6A-A-C-C-C-A-G-A-G-m7G-D-m5C-C-C-G-A-G-G-A-U-C-G-m1A-A-A-C-C-U-U-G-C-U-C-U-G-C-U-A-C-C-A(OH). It differs from vertebrate initiator tRNAs in only 6 out of 75 positions.     

The nucleotide sequence of histidine tRNA gamma of Drosophila melanogaster.

The nucleotide sequence of D. melanogaster histidine tRNA gamma was determined to be: pG-G-C-C-G-U-G-A-U-C-G-U-C-psi-A-G-D-G-G-D-D-A-G-G-A-C-C-C-C-A-C-G-psi-U-G-U-G- m1G-C-C-G-U-G-G-U-A-A-C-C-m5C-A-G-G-U-psi-C-G-m1A-A-U-C-C-U-G-G-U-C-A-C-G-G-m5C -A-C-C-AOH. An additional unpaired G is found at the 5' end, and the T in the TpsiC loop is replaced by a U.     

The nucleotide sequence of the gene coding for Drosophila melanogaster yolk protein 3

The entire sequence of the Drosophila melanogaster yolk protein 3 (YP3) gene (yp3), including 1822 nucleotides (nt) of 5'- and 834 nt of 3'-flanking DNA, has been determined. In addition, the 5' and 3' ends of the mRNA and the two introns have been mapped. The predicted amino acid sequence of YP3 has considerable homology (43%) to the other two yolk proteins of D. melanogaster. The nucleotide sequence of yp3 was compared to the other two yolk protein genes which have the same developmental pattern of expression. In addition to extensive homology between the protein coding regions, we found two small regions of homology between yp3 flanking sequences and a segment of DNA required for normal expression of the yolk protein 1 gene in adult female fat bodies.     

Tissue-specific and dietary control of alpha-amylase gene expression in the adult midgut of Drosophila melanogaster.

The regulatory effects of allelic substitution at the trans-acting mapP locus and of dietary glucose on the expression of the duplicate genes for alpha-amylase (Amy) in Drosophila melanogaster were examined in the anterior midgut and posterior midgut regions of mature flies. The levels of amylase activity and amylase protein, as well as the abundance of amylase-specific RNA, were quantified. All 3 parameters of Amy expression were concordant. Results indicate that the effects of both mapP and dietary glucose are exerted at the level of amylase RNA. However, the tissue-specific effects of mapP are restricted to the posterior midgut and can therefore be distinguished from the effects of glucose in food medium, which influences amylase RNA levels in both the anterior and posterior midgut regions. Our data suggest that, in large part, strain-specific effects of dietary glucose can be explained on the basis of alternate alleles at the mapP locus in different homozygous strains of flies. Levels of amylase RNA in tissue extracts of flies from an amylase-null strain were also measured. Low levels were observed in both anterior and posterior midgut extracts. These were unresponsive to dietary conditions.     

Primary sequence and developmental expression of a novel Drosophila melanogaster src gene.

We have sequenced a cDNA clone for the Drosophila melanogaster gene Dsrc28C, a homolog of the vertebrate gene c-src. The cDNA contains a single open reading frame encoding a protein of 66 kilodaltons which contains features highly conserved within the src family of tyrosine protein kinases. Novel structural features of the Dsrc28C protein include a basic pI and a polyglycine domain near the amino terminus. Cell-free translation of in vitro-transcribed RNA yielded a protein of the predicted size which could be immunoprecipitated by anti-v-src antisera. RNA blot hybridization revealed that the gene is expressed predominantly during embryogenesis, in imaginal disks of third-instar larvae, and in adult females. In situ hybridization showed that expression in adult females is largely confined to nurse cells and developing oocytes.     

Conservation of gene order, structure and sequence between three closely linked genes in Drosophila melanogaster and Drosophila virilis

In Drosophila melanogaster, the apparently unrelated genes anon-66Da, RpL14, and anon-66Db (from telomere to centromere) are located on a 5547 bp genomic fragment on chromosome arm 3L at cytological position 66D8. The three genes are tightly linked, and flanked by two relatively large genes with unknown function. We have taken a comparative genomic approach to investigate the evolutionary history of the three genes. To this end we isolated a Drosophila virilis 7.3 kb genomic fragment which is homologous to a 5.5 kb genomic region of D. melanogaster. Both fragments map to Muller's element D, namely to section 66D in D. melanogaster and to section 32E in D. virilis, and harbor the genes anon-66Da, RpL14, and anon-66Db. We demonstrate that the three genes exhibit a high conservation of gene topography in general and in detail. While most introns and intergenic regions reveal sequence divergences, there are, however, a number of interspersed conserved sequence motifs. In particular, two introns of the RpL14 gene contain a short, highly conserved 60 nt long sequence located at corresponding positions. This sequence represents a novel Drosophila small nucleolar RNA, which is homologous to human U49. Whereas DNA flanking the three genes shows no significant interspecies homologies, the 3'-flanking region in D. virilis contains sequences from the transposable element Penelope. The Penelope family of transposable elements has been shown to promote chromosomal rearrangements in the D. virilis species group. The presence of Penelope sequences in the D. virilis 7.3 kb genomic fragment may be indicative for a transposon-induced event of transposition which did not yet scramble the order of the three genes but led to the breakdown of sequence identity of the flanking DNA.     

The heat shock consensus sequence is not sufficient for hsp70 gene expression in Drosophila melanogaster.

A hybrid gene in which the expression of an Escherichia coli beta-galactosidase gene was placed under the control of a Drosophila melanogaster 70,000-dalton heat shock protein (hsp70) gene promoter was constructed. Mutant derivatives of this hybrid gene which contained promoter sequences of different lengths were prepared, and their heat-induced expression was examined in D. melanogaster and COS-1 (African green monkey kidney) cells. Mutants with 5' nontranscribed sequences of at least 90 and up to 1,140 base pairs were expressed strongly in both cell types. Mutants with shorter 5' extensions (of at least 63 base pairs) were transcribed and translated efficiently in COS-1 but not at all in D. melanogaster cells. Thus, in contrast to the situation in COS-1 cells, the previously defined heat shock consensus sequence which is located between nucleotides 62 and 48 of the hsp70 gene 5' nontranscribed DNA segment is not sufficient for the expression of the D. melanogaster gene in homologous cells. A second consensus-like element 69 to 85 nucleotides upstream from the cap site is postulated to be also involved in the heat-induced expression of the hsp70 gene in D. melanogaster cells.