Sequence and novel distribution of the chicken homologue of the mammalian gamma-aminobutyric acidA receptor gamma 1 subunit.
cDNAs have been cloned that encode the chicken (Gallus domesticus) gamma-aminobutyric acidA receptor gamma 1 subunit, the mature sequence of which shares 90, 79, and 69% identity with those of the rat gamma 1, gamma 2, and gamma 3 subunits, respectively. In situ hybridization reveals that there are pronounced differences in the regional and cellular localizations of the corresponding gamma-aminobutyric acidA receptor gamma-subunit mRNA compared with that of the gamma 2-subunit mRNA in 1-day-old chick brain. The absence of the gamma 1-subunit transcript in certain chick brain nuclei of visual and auditory pathways, in which gamma 2-subunit mRNA is present, points to differences in the functional roles of receptors containing one or other of these polypeptides. Certain cells in other brain regions appear to contain both gamma 1- and gamma 2-subunit mRNAs, suggesting that they either have two gamma-aminobutyric acidA receptor subtypes or possess receptors incorporating two different gamma subunits. We have also found contrasts in the distribution patterns, in homologous brain regions, of the chicken gamma 1-subunit mRNA and the rat gamma 1-subunit mRNA. These data may reflect different functional roles of the chicken and rat gamma 1 subunits.
Glencorse
T A
TA
MRC Molecular Neurobiology Unit, MRC Centre, Cambridge, England.
Darlison
M G
MG
Barnard
E A
EA
Bateson
A N
AN
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D017403:In Situ Hybridization; D046911:Macromolecular Substances; D008322:Mammals / Q000235:genetics; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis*; D051381:Rats / Q000235:genetics; D011963:Receptors, GABA-A / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D018076:DNA, Complementary; D046911:Macromolecular Substances; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D011963:Receptors, GABA-A