Variation in the pteridine content in the heads of tsetse flies (Diptera: Glossinidae:GlossinaWiedemann): evidence for genetic control

Abstract

The pteridine content of the head capsule of teneral flies from 11 genetically selected lines (including eye-color mutants) of Glossina morsitans morsitans Westwood and Glossina palpalis palpalis Robineau-Desvoidy was examined using fluorescence spectroscopy. Wild-type G. p. palpalis had a greater pteridine content than did wild-type G. m. morsitans. Within G. m. morsitans there was a 25% variation in fluorescence values between genetic lines. Wild-type G. p. palpalis had the same pteridine content as brick mutants but more than tan mutants; in G. m. morsitans the salmon mutants had a higher pteridine content than did wild-type flies. Pteridine content did not account for the difference in eye color between male and female brick mutants. Accumulation of pteridines was not influenced by genotype in young flies, but in older flies salmon mutants accumulated pteridines more rapidly than did wild-type flies. Young flies, both wild type and salmon, accumulated pteridines more rapidly than did old flies. The results of the analysis of head capsule fluorescence in males from the parental lines and F1and F2generations of reciprocal crosses of the G. m. morsitans lines with the highest and lowest pteridine contents revealed that genetic control of pteridine content lies on the X chromosome and on one autosome.