title: The novel untranslated exon "exon 0T" encoded between the exon 0 and exon 1 of the rat estrogen receptor alpha (ER alpha) gene.
abstract: We have recently isolated two untranslated first exons, exon 0N and exon 0S, of rat estrogen receptor alpha (ER alpha) gene from the liver by use of 5'-rapid amplification of the cDNA ends (5'-RACE) method. In this communication, we further analyzed the 5'-untranslated region (UTR) of the ER alpha mRNA in rat anterior hypophysis in order to investigate the existence of the other 5'-untranslated exon(s) of rat ER alpha gene. Total RNA from the anterior hypophysis of 8-week-old female Wistar strain male rats was subjected to 5'-RACE with antisense primers located in exon 1 of the rat ER alpha gene and one of the positive clones (clone 35) was sequenced. The nucleotide sequence of clone 35 revealed the insertion of a previously unidentified exon (which we termed "exon 0T") between exon 0 (the first reported 5'-UTR form of rat ER alpha mRNA) and exon 1 of rat ER alpha mRNA. Analysis of rat genomic DNA indicated that exon 0T was located between exon 0 and exon 1 of rat ER alpha gene. We further investigated the distribution of ER alpha mRNA containing exon 0T in several brain regions and various peripheral tissues of 8-week-old male and female Wistar strain rats by use of reverse transcription-polymerase chain reaction (RT-PCR). The distribution of the ER alpha mRNA (0T-1) was essentially similar to that of ER alpha mRNA in which exon 0 was spliced onto exon 1 reported previously. These results indicate that (1) exon 0T is a novel untranslated exon of rat ER alpha gene which is located between exon 0 and exon 1 on rat genomic DNA, (2) exon 0T is inserted between exon 0 and exon 1 of ER alpha mRNA by alternative splicing, and (3) this alternative splicing may occur in tissues where the transcription of ER alpha gene is initiated from exon 0.
authors.affiliation: Department of Obstetrics and Gynecology, Yamanashi Medical University, Nakakoma, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Osada
authors.forename: S
authors.initials: S
authors.lastname: Hirata
authors.forename: T
authors.initials: T
authors.lastname: Shoda
authors.forename: K
authors.initials: K
authors.lastname: Hoshi
mesh_terms: D020121:5' Untranslated Regions; D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D018076:DNA, Complementary / Q000737:chemistry; D047628:Estrogen Receptor alpha; D005091:Exons; D005260:Female; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010903:Pituitary Gland, Anterior / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D011960:Receptors, Estrogen / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D020121:5' Untranslated Regions; D018076:DNA, Complementary; D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D011960:Receptors, Estrogen