Developmental changes in the differential expression of two serotonin 5-HT3 receptor splice variants in the rat.
PCR was used to isolate identical partial cDNA clones encoding a serotonin 5-HT3 receptor subunit from rat nodose and superior cervical ganglia. The amino acid sequence predicted from these clones, extending from the putative transmembrane domain I to the stop codon, demonstrated a 93% homology with the 5-HT3 receptor A (R-A) subunit cloned from NCB 20 hybridoma mouse neuroblastoma/Chinese hamster embryonic brain cells. Comparison of the sequences of the rat gene and cDNA encoding this subunit revealed a five amino acid deletion, GSLLP, located within the putative second intracellular loop of the receptor subunit. This deletion was shown to occur at an intron/exon junction. Therefore, alternative splicing was probably responsible for the presence of short (5-HT3 R-As) and long (5-HT3 R-AL) forms of 5-HT3 R-A mRNA in these ganglia. PCR experiments, with specific primers located upstream and downstream of the GSLLP deletion, were used to detect reverse transcribed 5-HT3 R-A mRNAs. A short fragment (92 bp), corresponding to the deleted form, and a long fragment (107 bp), corresponding to the nondeleted form, were amplified from various regions of the CNS and peripheral ganglia of the rat, as well as from NG108-15 hybridoma cells. In the adult rat, the ratio of the two forms varied very little from one tissue to another, the long form corresponding to only approximately 10% of the total 5-HT3 R-A mRNA. Study of their respective distributions during ontogeny demonstrated a differential expression of the short and long forms in some tissues during late embryonic development, at embryonic day 17 (E17) or E20.(ABSTRACT TRUNCATED AT 250 WORDS)
Miquel
M C
MC
INSERM U288, Faculté de Médecine, Pitié-Salpêtrière, Paris, France.
Emerit
M B
MB
Gingrich
J A
JA
Nosjean
A
A
Hamon
M
M
el Mestikawy
S
S
D000375:Aging / Q000378:metabolism*; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D002490:Central Nervous System / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D004622:Embryo, Mammalian / Q000378:metabolism; D005314:Embryonic and Fetal Development; D014644:Genetic Variation; D051379:Mice; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D010525:Peripheral Nerves / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000235:genetics* / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D015335:Molecular Probes; D012333:RNA, Messenger; D011985:Receptors, Serotonin