Current Genomics - Volume 5, Issue 5, 2004

Genetic diversity is the raw material needed by a species allowing adaptation to changing environmental conditions and thus ensuring long-term sustainability. The development of technologies for environmental genomics provides us with the opportunity to link information, at the whole genome level, with the response of an organism to its natural environment. Over the past 15 years a small tropical fish native to the rive Read More

The amount of research on human aging and longevity has been growing rapidly in recent years. Multidisciplinary approaches, which integrate classic population genetics methods with the principles of epidemiological and demographic investigation, are emerging as powerful tools for disentangling the complex gene network which modulates human lifespan. We try to summarize the different approaches and discuss th Read More

Phenotypic variation among individuals often results from complex interactions between multiple factors: genetic, epigenetic, environmental and stochastic. Interaction between alleles of the same gene that is subject to allelic exclusion represents a particular case of regulatory variation. In mammals allelic exclusion is achieved through epigenetic silencing. DNA methylation, X-chromosome inactivation and genomic imprintin Read More

Definitions of polymorphism in a gene include occurrence of a rarer allele of at least 1% frequency; or occurrence of the commonest allele at less than 95% frequency. Many alleles of single nucleotide polymorphisms (SNPs) in genes occur at much higher frequency (up to 50%). Many common diseases have a substantial genetic component. The prevailing hypothesis for the molecular basis of common diseases is that it involves Read More

Since the appearance of gene expression microarrays, the data produced has been used to guide the discovery of regulatory protein binding sites in the sequence upstream genes. In some instances, novel motifs have been discovered in the promoter region of genes with similar expression patterns. An other group of articles suggests the use of expression microarray data to sort through long lists of putative motifs. A comm Read More

Nuclear hormone receptor function is controlled by a number of ancillary factors termed coregulators. Such coactivators and corepressors afford considerable flexibility in the coordinate expression of gene networks in numerous physiological, developmental and metabolic processes. PGC-1α, originally described as transcriptional coactivator of PPARγ, has since been shown to act in a much broader context. PGC-1α coordinates Read More

The signal transducers and activators of transcription (STATs) are a family of transcription factors which were originally identified on the basis of their ability to transduce a signal from a cellular receptor into the nucleus and modulate the transcription of specific genes. Interestingly, recent studies have demonstrated that STAT-1 plays a key role in promoting apoptosis in a variety of cell types, whereas STAT-3 has an anti-apo Read More