Genomic neighbourhood and the regulation of gene expression

'Genomic neighbourhoods' or 'domains' are segments of the genome with specific characteristics associated with them (e.g. epigenetic modifications, interaction with nuclear lamina, etc.). Genomic neighbourhood influences the transcriptional activity of genes within it, and genetic manipulation or natural mutations that alter the neighbourhood of a gene have been shown to affect its expression. Several molecular mechanisms or factors (e.g. non-allelic homologous recombination, mobile elements, etc.) can alter the neighbourhood of genes. Over different time-scales such events have been suggested to contribute to speciation, introduce diversity in a population, result in germ-line and somatic mosaicism, and cause specific diseases. Understanding the role of genomic neighbourhood on gene regulation has fundamental implications for evolution, development, disease and genetic engineering.