Alternative splicing generates two isoforms of the β3‐adrenoceptor which are differentially expressed in mouse tissues

The β3‐adrenoceptor (AR) differs from the β1‐AR and β2‐ARs in having introns within and downstream of the coding block. This study demonstrates two splice variants of the mouse β3‐AR which differ within the coding region. Reverse transcription/polymerase chain reaction with intron‐spanning primers was used to demonstrate the splice variant of the mouse β3‐adrenoceptor. The novel β3b‐AR has 17 amino acids encoded by exon 2 (SSLLREPRHLYTCLGYP) which differ from the 13 in the known β3a‐AR (RFDGYEGARPFPT). β3b‐AR mRNA is differentially expressed in mouse tissues, with levels relative to β3a‐AR mRNA highest in hypothalamus, cortex and white adipose tissue, and lower in ileum smooth muscle and brown adipose tissue. British Journal of Pharmacology (1999) 127, 1525–1531; doi:10.1038/sj.bjp.0702688