Developmental changes in the differential expression of two serotonin 5-HT3 receptor splice variants in the rat

• Published in: Journal of neurochemistry Vol. 65; no. 2; p. 475
• Main Authors: Miquel, M C, Emerit, M B, Gingrich, J A, Nosjean, A, Hamon, M, el Mestikawy, S
• Format: Journal Article
• Language: English
• Published: England 01-08-1995
• Subjects: Aging - metabolism; Alternative Splicing; Amino Acid Sequence; Animals; Animals, Newborn; Base Sequence; Central Nervous System - embryology; Central Nervous System - growth & development; Central Nervous System - metabolism; Embryo, Mammalian - metabolism; Embryonic and Fetal Development; Genetic Variation; Mice; Molecular Probes - genetics; Molecular Sequence Data; Peripheral Nerves - embryology; Peripheral Nerves - growth & development; Peripheral Nerves - metabolism; Rats; Rats, Sprague-Dawley; Receptors, Serotonin - genetics; Receptors, Serotonin - metabolism; RNA, Messenger - genetics; RNA, Messenger - metabolism; Tumor Cells, Cultured
• ISSN: 0022-3042
• DOI: 10.1046/j.1471-4159.1995.65020475.x

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.