Sex determinants in the genome--lessons from the animal kingdom.

The immense value of sex differentiation as a means of enriching and evolving the genome has been proven by the vast variety of sex determining mechanisms to which organisms of all kinds resort. From single gene switching pathways found in lower level organisms to haplodiploid reproduction in hymenoptera, temperature-determined sex in reptiles and sex chromosomes in mammals and avians, nature and evolution have designated an impressive amount of effort to ensure that sex-specific variations remain under well-regulated control. Therefore enhancing our efforts to study some of the strategies recruited for the above may also lead to a better understanding of the inherent complexity of sexual dimorphism in general.