AbstractsBiology & Animal Science

Growth Hormone (GH) is known as a diabetogenic molecule. In excess it can inhibit insulin's action resulting in insulin resistance and diabetes, which can be seen in the GH receptor knockout (GHR-/-) mice since the absence of GH action throughout the whole body improves insulin sensitivity and increases life span. Three tissues that are both insulin and GH sensitive are liver, adipose tissue, and muscle. To determine their individual contributions, three tissue specific GHR disrupted mouse lines have been independently produced: liver-specific, adipose-specific, and muscle-specific GHR-/- mice using the CRE-LOX system. Tissue specific promoters, albumin, aP2, MCK, were utilized to drive the CRE recombinase expression in liver, adipose, and muscle tissues separately. This thesis aimed to validate the gene deletion in specific tissues at the DNA level. The results confirm that liver and muscle specific GHR-/- mice had the deletion of the GHR gene in the liver and muscle tissues, respectively. However, in the adipose specific GHR-/- mice, all tissues, and not just adipose tissue, had evidence of GHR deletion. These findings need to be taken into account when evaluating the phenotype.