Three Different Turkey Luteinizing Hormone Receptor (tLH-R) Isoforms I: Characterization of Alternatively Spliced tLH-R Isoforms and Their Regulated Expression in Diverse Tissues

Abstract Using combinations of reverse transcription-polymerase chain reaction (RT-PCR) and 5′- and 3′-rapid amplification of cDNA ends, three different, alternatively spliced, partial turkey LH receptor (tLH-R) cDNA isoforms were characterized from ovarian mRNA. The first cDNA (tLH-Rintact) showed 98% and 72–75% similarity with chicken and mammalian LH-R sequences, respectively. The second cloned cDNA isoform (tLH-Rinsert) contained an in-frame TGA stop codon within an 86-base pair insertion that was located in the extracellular domain of the seven-transmembrane region. The tLH-Rinsert isoform could encode a truncated soluble protein isoform that lacked the transmembrane region. The third cDNA isoform truncated the transmembrane region (tLH-Rtrunc) and was derived by the deletion of the last exon by incomplete splicing. Generation of multiple transcripts by alternative splicing was elucidated by partial characterization of tLH-R genomic sequences. The differentially regulated expression of the tLH-R mRNA...