Glycerol-3-phosphate dehydrogenase isozyme variation in adult meliponids (Hymenoptera: Apidae)

alpha-glycerophosphate dehydrogenase activity in flight muscles of triatomine bugs Panstrongylus megistus and Triatoma sordida

The alpha-glycerophosphate dehydrogenase (alpha-GPDH) activity in flight muscles of Panstrongylus megistus and Triatoma sordida, vectors of Chagas disease in Brazil, was studied. Both species showed higher enzymatic activities in fliers than in non-fliers insects. T. sordida exhibited a higher proportion of flier insects than P. megistus. A possible role of alpha-GPDH on triatomines flight is discussed.

sn-Glycerol-3-phosphate dehydrogenase in the honey bee Apis mellifera -an unusual phenotype associated with the loss of introns

In comparison with the numerous Drosophila species and the mouse, the Gpdh gene in the honey bee Apis mellifera lacks most introns. This prevents the gene from producing different GPDH isoforms by alternative splicing, which occurs in Drosophila melanogaster. The sequences of the cDNA and genomic Gpdh of A. mellifera are described and show that at the amino acid level they share 84% similarity and 71% identity with D. melanogaster. The identity at the nucleotide level is 62% in the coding region, but no significant similarities were detected in the UTRs. Northern analyses revealed an accumulation of unspliced Gpdh pre-mRNA in the honey bee, probably reflecting splicing inefficiency, although it is also possible that splicing is a regulated step in Gpdh expression in A. mellifera. It is suggested that the intron loss occurred via reverse transcription of a mature Gpdh transcript.

Isoenzymes related to flight activity in Tetragonisca angustula (Hymenoptera:Apidae:Meliponinae): evidence of postranslational modification of the hexokinase and detection of new glycerol-3-phosphate dehydrogenase variants

To detect genetic markers, electrophoretic analyses were carried out on Tetragonisca angustula, a stingless bee well adapted to its wide area of occurrence, which is becoming economically important because of the quality of its honey. Polymorphism of the enzyme hexokinase was detected and it was demonstrated that, although it presents two bands in meliponines, this enzyme is under the control of a single locus whose product probably undergoes postranslational modification. The more common allele occurs in the two Tetragonisca subspecies studied here, but the other seems to be characteristic of only one subspecies. Four variants involving the two glycerol-3-phosphate dehydrogenase loci are also described. These two enzymes share the property of presenting two electrophoretic bands, one of which is characteristic of actively flying adult thoraces.