Psychiatry related information on Est-6

• Our observations agree with previous results for D. melanogaster and provide additional support to our hypothesis that after the duplication event Est-6 retained the esterase-coding function and its role during copulation, while psiEst-6 lost that function but now operates in conjunction with Est-6 as an intergene [1].

High impact information on Est-6

• The regulatory regions of homologous genes encoding esterase 6 (Est-6) of Drosophila melanogaster and esterase 5B (Est-5B) of Drosophila pseudoobscura show very little similarity [2].
• The expression patterns of the Est-5B/lacZ construct are different from those of a fusion gene containing the upstream region of Est-6 [2].
• We have begun to determine the location of the regulatory regions of Est-6 by constructing deletion mutants of the 5' regions of the gene and transforming them back into flies [3].
• Deletion mutants of the putative 5' promoter regions of Est-6 were fused to the bacterial beta-galactosidase gene (lacZ) and assayed for their ability to direct tissue-specific expression in transformed D. melanogaster adults [3].
• We also found a region near the start of transcription that directed expression of Est-6 in the cardia or proventriculus in some transformed lines [3].

Biological context of Est-6

• Comparison of the genomic and cDNA sequences revealed that the Est-6 gene comprises two exons, one of 1,387 bp and one of 248 bp, separated by a short intron of 51 bp [4].
• The consistent Est-6 clines are attributed to latitudinal selection gradients but not consistent correlations are found between Est-6 gene frequencies and maximum or minimum temperature or rainfall which might be associated with these gradients [5].
• Comparisons of the 5'-flanking DNA of Est-5B and Est-6 reveal four short conserved sequence elements, but the remaining upstream sequences show no significant similarity [6].
• The patterns of nucleotide substitutions and amino acid replacements between Est-5B and Est-6 are consistent with the hypothesis that mutation and genetic drift are responsible for the differences between these two genes [6].
• Conservation in the 3'-flanking DNA is limited to the presence of two polyadenylation sites that may correlate with the existence of two transcripts from both Est-5B and Est-6 [6].

Anatomical context of Est-6

• We have identified four independently acting Est-6 regulatory regions that direct the expression of lacZ in (i) the ejaculatory duct; (ii) the adult salivary glands; (iii) the respiratory system, prefrons, antennae, and maxillary palps; and (iv) the ejaculatory bulb and prefrons [3].
• The genetic bases of the differences between D. melanogaster and the other species are investigated through germ line transfer of the D. simulans and D. mauritiana Est-6 genes plus 1.2 kb of 5' and 0.2 kb of their 3' flanking sequences into D. melanogaster [7].
• EST 5 is expressed in the eyes and hemolymph of transformed D. melanogaster just as it is in D. pseudoobscura, but it is not detectable in the ejaculatory duct, where the homologous enzyme, EST 6, is most abundant [8].
• Hemolymph is a conserved ancestral site of EST6 activity in Drosophila and the primary sequences regulating its activity lie between -171 and -25 bp relative to the translation initiation site: deletion of these sequences decrease activity approximately 20-fold [9].

Associations of Est-6 with chemical compounds

• At the protein level, Gramoxone had detectable mutagenic effects on the genetic background of two enzymes, Adh and Est-6 [10].
• Molecular cloning and characterization of esterase-6, a serine hydrolase of Drosophila [11].
• Physiological studies of the control of EST 6 levels reveal that both juvenile hormone and 20 hydroxyecdysone stimulate the production of EST 6 activity in adult males [12].
• Reexamination of the electrophoretic mobilities of esterases encoded by the Est-alpha and the Est-beta alleles of Drosophila virilis was carried out in detail using both thin-layer agar gel and polyacrylamide slab gel electrophoresis [13].

Other interactions of Est-6

• Further sequencing revealed the presence of a tandem duplication of the Est-6 gene (denoted Est-P) which also has an exon of 1,387 bp and an exon of 248 bp, separated by a short intron of 56 bp [4].
• Latitudinal relationships of esterase-6 and phosphoglucomutase gene frequencies in Drosophila melanogaster [5].
• The transversion/transition ratio is more than five times larger in Sod than in Est-6 [14].
• Idh is ten map units to the left of Est-6, Odh twelve map units to the right and Ao is seven units beyond Odh [15].
• A clone of the esterase-5 (Est-5) gene from Drosophila pseudoobscura has been isolated by hybridization to the cloned Est-6 gene of D. melanogaster [6].

Analytical, diagnostic and therapeutic context of Est-6

• Sequence analysis indicates that Est-5B encodes a 545-amino-acid protein and is composed of two exons separated by a 55-bp intron in the same position as the 51-bp intron in Est-6 [6].
• Radial immunodiffusion assays with polyclonal anti-EST6 antibody established that differences among lines in male EST6 activity were largely due to differences in the number of EST6 protein molecules, with negligible differences in their specific activities [16].

References