Identification of unique thyrotropin receptor (TSHR) splice variants in the chicken: the chicken TSHR gene revisited.
We previously described the cloning of the full-length chicken thyrotropin receptor (TSHRa) and two splice variants, lacking exon 3 (TSHRb) or both exons 2 and 3 (TSHRc). Here we report the identification of three novel splice variants of the chicken TSHR, named TSHRd, -e and -f, differing in their C-terminal region and containing unique exonic sequences that are not present in the other TSHR variants. This finding suggests a TSHR gene structure with 13 rather than the previously assumed 10 exons. The three novel exons appear to be chicken-specific, as no equivalents of these exons were found in other vertebrate genomes. Like the full-length receptor, the five TSHR splice variants are most abundantly expressed in thyroid gland. TSHRb, -d, -e and -f mRNA was also present in virtually all extra-thyroidal tissues expressing TSHRa, whereas TSHRc shows a more restricted tissue distribution. Whether these receptor transcripts are translated to functional proteins needs to be verified, but if so, they could be attributed various physiological roles.
Grommen
Sylvia V H
SV
Research group of Comparative Endocrinology, Animal Physiology and Neurobiology Section, Department of Biology, Catholic University of Leuven, Naamsestraat 61, Box 2464, 3000 Leuven, Belgium.
Taniuchi
Shusuke
S
Darras
Veerle M
VM
Takahashi
Sumio
S
Takeuchi
Sakae
S
De Groef
Bert
B
D000818:Animals; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics / Q000502:physiology*; D017931:DNA Primers; D005091:Exons / Q000235:genetics; D021141:Nucleic Acid Amplification Techniques; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011989:Receptors, Thyrotropin / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014018:Tissue Distribution
D017931:DNA Primers; D020033:Protein Isoforms; D012333:RNA, Messenger; D011989:Receptors, Thyrotropin