These represent a new class of regulatory sequences and may have played an important role in the development of specific traits and behavior that distinguish closely related organisms from each other.
[4] This involved firstly identifying a subset of 37,251 human deletions (hDELs)[5] through pairwise comparisons of chimpanzee and macaque genomes.
Another noticeable characteristic of hCONDELs (and other groups of identified CONDELs such as those from mouse and chimpanzee) is that they tend to be specifically skewed towards GC poor regions.
In situ hybridization experiments done by Mclean et al.[3] by fusion of mouse constructs fused to basal promoter with LacZ expression[14] for hCONDELs near the androgen receptor (AR) locus and the growth arrest and DNA-damage-inducible protein GADD45 gamma (GADD45G) locus suggest a role in deletions that affect regulatory sequences in humans.
An hCONDEL located near the locus of the androgen receptor (AR) gene may be responsible for the loss of whiskers and penile spines in humans compared to its close relatives, including chimpanzees.
Using the mouse construct with LacZ expression showed localization of this hCONDEL region (AR enhancer) to the mesenchyme of vibrissae follicles and the mesoderm cells of penile organs.