Ne. Gruntenko et al., Prolonged negative selection of Drosophila melanogaster for a character ofadaptive significance disturbs stress reactivity, INSEC BIO M, 29(5), 1999, pp. 445-452
The metabolism of juvenile hormone by JH-esterase and JH-epoxide hydrolase,
and octopamine by tyrosine decarboxylase were studied under normal and str
ess conditions in flies of two related lines of D. melanogaster. One was se
lected for high (HA line) and another for low (LA line) male sexual activit
y for more than 700 generations. It was demonstrated that prolonged selecti
on for low male sexual activity results in considerable changes in both sys
tems. Tyrosine decarboxylase activity in males and females of the LA line w
as sharply reduced as compared with those of the HA and controle Canton-S l
ines; JH-esterase and JH-epoxide hydrolase activities were decreased in fem
ales, and not in males, of the LA line. It was demonstrated that the respon
se of both metabolic systems to heat stress is impaired in individuals of t
he LA line: the system of juvenile hormone metabolism does not respond to s
tress, and that of octopamine metabolism is decelerated. The role of juveni
le hormone metabolism in male reproductive function is discussed. (C) 1999
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