A molecular investigation of the obese phenotype in the Aston University strain of ob/ob mice and the Japanese Kuo Kondo mice

The aim of this work was to determine the role of the ob gene in the obese phenotype observed in the Aston University Strain of ob/ob mouse and the Japanese Kuo Kondo (KK) mouse. After RT-PCR amplification of the ob RNA, the transcript was cloned into the vector pCR3 and three individual clones from each strain were sequenced. It was confirmed that the Aston University strain of ob/ob mice shared the same C-T mutation found in the Jackson Laboratory C57BL/6J ob/ob strain whereas the Japanese KK mice showed wild-type ob gene expression. This study indicates that the ob mutation has survived unchanged following the separation of the two strains of ob/ob mice, and secondly, that the molecular basis of the obese phenotype in the KK mice is not due to mutations in the ob gene.