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

J Neurochem. 1995 Aug;65(2):475-83. 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.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 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
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Serotonin / genetics*
  • Receptors, Serotonin / metabolism*
  • Tumor Cells, Cultured


  • Molecular Probes
  • RNA, Messenger
  • Receptors, Serotonin