Characterisation of bovine peroxisome proliferator-activated receptors gamma 1 and gamma 2: genetic mapping and differential expression of the two isoforms.

In this report we describe the isolation and characterisation of the cDNAs encoding two isoforms of peroxisome proliferator-activated receptor gamma (PPAR gamma), gamma 1 and gamma 2, in cattle. The cDNA sequences show strong conservation with the corresponding sequences reported in other species. The distribution of PPAR gamma mRNAs in various bovine tissues was investigated using Northern blot analysis. The highest expression was detected in adipose tissue with about equal amounts of the both transcripts while a differential expression was found in other tissues investigated. PPAR gamma 1 was expressed at relatively high levels in bovine spleen and lung and to a lower extent in ovary, mammary gland, and small intestine. The amount of PPAR gamma 2 was apparently lower than that of PPAR gamma 1 in spleen, lung, and ovary. These results indicate a modulation of tissue distribution for the two transcripts in cattle. Using genetic linkage analysis we have also assigned the PPAR gamma gene to bovine chromosome 22.