Alternative splicing generates two isoforms of the β 3 ‐adrenoceptor which are differentially expressed in mouse tissues

The β 3 ‐adrenoceptor (AR) differs from the β 1 ‐AR and β 2 ‐ARs in having introns within and downstream of the coding block. This study demonstrates two splice variants of the mouse β 3 ‐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 β 3 ‐adrenoceptor. The novel β 3b ‐AR has 17 amino acids encoded by exon 2 (SSLLREPRHLYTCLGYP) which differ from the 13 in the known β 3a ‐AR (RFDGYEGARPFPT). β 3b ‐AR mRNA is differentially expressed in mouse tissues, with levels relative to β 3a ‐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