F. Quan et al., A DROSOPHILA G-PROTEIN ALPHA-SUBUNIT, GF-ALPHA, EXPRESSED IN A SPATIALLY AND TEMPORALLY RESTRICTED PATTERN DURING DROSOPHILA DEVELOPMENT, Proceedings of the National Academy of Sciences of the United Statesof America, 90(9), 1993, pp. 4236-4240
Heterotrimeric guanine nucleotide binding proteins (G proteins) couple
receptors for extracellular signals to intracellular second messenger
-generating systems. Previous studies have shown that G-protein alpha
subunits (Galpha) are expressed in a spatially and temporally restrict
ed manner during Drosophila embryogenesis and, thus, may be responsibl
e for mediating developmental interactions. We have used the polymeras
e chain reaction to search for specific Galpha subunits that function
primarily during development and not in the adult fly. Using poly(A)RNA isolated from early pupae (day 1), we have isolated a cDNA coding
for a fly Galpha subunit, designated Gfalpha. This subunit is 30-38% i
dentical to previously described vertebrate and Drosophila Galpha subu
nits and appears to define an additional family of Galpha proteins. Gf
alpha transcripts are expressed primarily during embryonic, larval, an
d early pupal stages and only at low levels in adult flies. In situ hy
bridization studies indicate that Gfalpha transcripts are expressed ma
ternally and later during embryogenesis primarily in the developing mi
dgut and transiently in the amnioserosa. The Gfalpha gene has been cha
racterized and mapped to position 73B of the Drosophila genome.