Gene Family: Structure, Organization and Evolution

Gene families are considered as groups of homologous genes which they share very similar sequences and they may have identical functions. Members of gene families may be found in tandem repeats or interspersed through the genome. These sequences are copies of the ancestral genes which have underwent changes. The multiple copies of each gene in a family were constructed based on gene duplications and reverse transcription in the genome, which in turn, would give rise to gene variability in an individual or population. Furthermore, it would provide the cell`s vital demands for duplication, transcription, and translation. Differences in family size due to gene duplication and gene loss in cell-specific lineages may provide insights of evolutionary forces that have shaped the mammalian genome. Positive selection and concerted evolution are the main forces and the original candidates of shaping gene families and their larger partner, gene superfamily.