<P> Several mutations of genes involving the melanocortins (used in brain signaling associated with appetite) and their receptors have also been identified as causing obesity in a larger portion of the population than leptin mutations . </P> <P> In 2007, researchers isolated the adipose gene, which those researchers hypothesize serves to keep animals lean during times of plenty . In that study, increased adipose gene activity was associated with slimmer animals . Although its discoverers dubbed this gene the adipose gene, it is not a gene responsible for creating adipose tissue . </P> <P> Pre-adipocytes are undifferentiated fibroblasts that can be stimulated to form adipocytes . Recent studies shed light into potential molecular mechanisms in the fate determination of pre-adipocytes although the exact lineage of adipocyte is still unclear . </P> <P> Adipose tissue has a density of ~ 0.9 g / ml . Thus, a person with more adipose tissue will float more easily than a person of the same weight with more muscular tissue, since muscular tissue has a density of 1.06 g / ml . </P>

Where are deposits of adipose tissues usually found