Studies of esterase 6 in Drosophila melanogaster. III. The developmental pattern and tissue distribution

High resolution electrophoretic variation at the esterase-6 locus in a natural population of Drosophila melanogaster

“…Thirteen lines representing six of the seven Est6 alleles which Cochrane (1976) and Cochrane and Richmond (1979) isolated by thermostability criteria were also electrophoresed. Two of these classes were slow variants designated Si and S2 by the authors above, while four were fast variants designated Fl, F2, F3 and F4.…”

“…Est6 is produced in the anterior ejaculatory duct of adult males, from where it is transferred to the female during copulation (Sheehan et a!., 1979;Richmond and Senior 1981). The presence of transferred Est6 in the females stimulates sperm utilisation and oviposition and affects her latency to remating (Gilbert, 1981;Scott, 1986).…”

“…EstO variants were also tested for gametic disequilibrium with third chromosome viability modifiers and inversion polymorphism. Finally, lines from another D. melanogaster population representing six Est6 alleles differentiated by thermostability criteria (Cochrane, 1976;Cochrane and Richmond, 1979) were analysed with the cellulose acetate system to determine whether the two criteria resolve the same variation.…”

Regulatory aspects of esterase 6 activity variation in sibling Drosophila species

“…Strains of D. me!anogaster used in germ line transformation experiments were w; A2-3(99B), w; TM3/ TM6B and w; EST6' (Sheehan et al, 1979;Robertson et a!., 1988). All stocks were maintained at 18°C on standard yeast-treacle-cornmeal media (Healy etal., 1991).…”

“…(1991), divided into aliquots and stored at -20°C. Two replicates of each homogenate were assayed spectrophotometrically for -naphthyl acetate hydrolysing activity in the presence of eserine sulfate and pchloromercuribenzoate acid (Healy et al, 1991), an assay shown to be specific for EST6 in these species (Sheehan et a!., 1979; Healy et a!., 1991; J. K., M. J. Healy & J. G. 0., unpublished data). Replicate determinations of the protein concentration of each homogenate were obtained by the method of Bradford (1976) using the BioRad protein assay kit II.…”