Materials and methods Directory UMM :Data Elmu:jurnal:I:Insect Biochemistry and Molecular Biology:Vol30.Issue8-9.Sept2000:
776 N.E. Gruntenko et al. Insect Biochemistry and Molecular Biology 30 2000 775–783
In this work, we analysed the mutations ts403, Met, T
bh and ebony e with respect to the response of JH- degradation system to stress. The recessive temperature
sensitive lethal mutation llts403 results in the failure of heat shock protein HSP83 and HSP35 to be
expressed, and a number of HSP70 proteins are only par- tially expressed Evgen’ev and Denisenko, 1990. Met
27
is a null allele of the Methoprene-tolerant gene that shows resistance to the toxic effects of both JH and a
JH analog, methoprene. The mechanism of the resistance appears to be altered JH receptionWilson and Fabian,
1986; Shemshedini and Wilson, 1990. Met
27
completely lacks Met transcript and is clearly a null allele Wilson
and Ashok, 1998. T bh
nM18
is a null mutation at the Tyr- amine
b-hydroxylase locus, which results in complete absence of the tyramine
β -hydroxylase protein and
blockage of octopamine biosynthesis Monastirioti et al., 1996. e is postulated to be the mutation of N-
b-alanyl dopamine synthetase
gene, based on the fact that e has twice as much DA as normal Hodgetts, 1972; Hodgetts
and Konopka, 1973; Ramadan et al., 1993. Here we asked whether these mutations would affect
the decrease in JH degradation occurring in D. mel- anogaster
when stressed. In order to answer this ques- tion, we studied the JH degradation in individuals of
ts403, n Met
27
, T bh
nM18
and Ste strains carring llts403, Met
27
, T bh and e mutations, respectively, under normal
and stress conditions, and compared their stress-reac- tivity calculated as percent change in JH hydrolysis
under stress compared to hydrolysis under normal conditions with that in a number of wild type and lab-
oratory strains.
We demonstrated 1 that ts403 females respond to stress by a decrease in JH degradation, as occurs in wild
type females, but that their stress-reactivity significantly differs from that of wild type; 2 that in young v Met
27
females, similar to wild type flies, JH hydrolysis is decreased upon stress, but their stress-reactivity is sig-
nificantly lower than in wild type; 3 that JH degra- dation is unaffected in older v Met
27
females under stress; 4 that T
bh
nM18
females show a significantly higher JH-hydrolysis level and different stress-reactivity
than does the wild type; and 5 that young Ste females demonstrate significantly lower JH-hydrolysis and
stress-reactivity, compared to the wild type.