Ac. Piedrafita et al., A GENETIC-ANALYSIS OF AROMATIC AMINO-ACID HYDROXYLASES INVOLVEMENT INDOPA SYNTHESIS DURING DROSOPHILA ADULT DEVELOPMENT, Insect biochemistry and molecular biology, 24(6), 1994, pp. 581-588
Around 50 min after adult ecdysis, a significant increase in DOPA cont
ent is observed in Drosophila melanogaster. This increase, which is fo
llowed by increases of other catecholamine sclerotizing precursors, pa
rallels the visually observable pigmentation and hardening of the adul
t cuticle. Since this DOPA concentration developmental profile is corr
elated with cuticle formation, we have analyzed the involvement of aro
matic amino acid hydroxylases in this process by determining the same
profile in mutant strains affecting these hydroxylations, either direc
tly (defects in the genes coding for these hydroxylases), or indirectl
y (defects in genes involved in the biosynthesis of the essential pter
in cofactor, tetrahydrobiopterin). The altered profiles of the pterin
biosynthesis defective strains Pu-2/SM1 and cn pr(c4)/cn pr(m2b) showe
d that some pterin is required for these metabolic changes. Meanwhile
the altered profiles of the Hn(r3) and ple/TM3 strains directly implic
ate the phenylalanine and tyrosine hydroxylase enzymes. An analysis of
the phenylalanine hydroxylase protein presence during the period of t
he first 3 h post adult ecdysis in thorax plus abdomen extracts has sh
own that although the protein is present during the complete developme
ntal period, no changes in the cross reacting material amounts are obs
erved.