Publication List

@article{Toll-Riera2011a,
title = {Lineage-specific variation in intensity of natural selection in mammals.},
author = {Toll-Riera, Macarena and Laurie, Steve and Albà, M Mar},
url = {http://www.ncbi.nlm.nih.gov/pubmed/20688808},
issn = {1537-1719},
year = {2011},
date = {2011-01-01},
journal = {Molecular biology and evolution},
volume = {28},
number = {1},
pages = {383--98},
abstract = {The molecular clock hypothesis states that protein-coding genes evolve at an approximately constant rate. However, this is only expected to be true as long as the function and the tertiary structure of the molecule remain unaltered. An important implication of this statement is that significant deviations in the rate of evolution of a gene with respect to the species clock are likely to reflect functional and/or structural alterations. Here, we present a method to identify such deviations and apply it to a data set of 2,929 high-quality coding sequence alignments corresponding to one-to-one orthologous genes from six mammalian species--human, macaque, mouse, rat, cow, and dog. Deviated branches are defined as those that present significant alterations in both the rate of nonsynonymous substitutions (dN) and the selective pressure (dN/dS). Strikingly, we find that as many as 24.5% of the genes show branch-specific deviations in dN and dN/dS, though this is a relatively well-conserved set of genes. Around half of these genes show branch-specific acceleration of evolutionary rates. Positive selection (PS) tests based on divergence data only identify 17.7% of the accelerated branches. Failure to identify PS in accelerated branches with an excess of radical amino acid replacements suggests that these tests are conservative. Interestingly, genes with accelerated branches are significantly enriched in neural proteins, indicating that this type of protein might play a more important role than previously thought in species diversification, although they are generally not detected by PS tests. We discuss in detail several examples of genes that show lineage-specific evolutionary rate acceleration and are involved in synaptic transmission, chemosensory perception, and ubiquitination.},
keywords = {Amino Acid Sequence, Amino Acid Substitution, Animals, Evolution, F-Box Proteins, F-Box Proteins: genetics, G-Protein-Coupled, G-Protein-Coupled: genetics, Genetic, Genetic Variation, Humans, Mammals, Mammals: genetics, Molecular, Molecular Sequence Data, N-Methyl-D-Aspartate, N-Methyl-D-Aspartate: genetics, Odorant, Odorant: genetics, Receptors, Selection, Sequence Alignment}
}

@article{Farre2010,
title = {Heterogeneous patterns of gene-expression diversification in mammalian gene duplicates.},
author = {Farré, Domènec and Albà, M Mar},
url = {http://www.ncbi.nlm.nih.gov/pubmed/19822635},
issn = {1537-1719},
year = {2010},
date = {2010-01-01},
journal = {Molecular biology and evolution},
volume = {27},
number = {2},
pages = {325--35},
abstract = {Gene duplication is a major mechanism for molecular evolutionary innovation. Young gene duplicates typically exhibit elevated rates of protein evolution and, according to a number of recent studies, increased expression divergence. However, the nature of these changes is still poorly understood. To gain novel insights into the functional consequences of gene duplication, we have undertaken an in-depth analysis of a large data set of gene families containing primate- and/or rodent-specific gene duplicates. We have found a clear tendency toward an increase in protein, promoter, and expression divergence with increasing number of duplication events undergone by each gene since the human-mouse split. In addition, gene duplication is significantly associated with a reduction in expression breadth and intensity. Interestingly, it is possible to identify three main groups regarding the evolution of gene expression following gene duplication. The first group, which comprises around 25% of the families, shows patterns compatible with tissue-expression partitioning. The second and largest group, comprising 33-53% of the families, shows broad expression of one of the gene copies and reduced, overlapping, expression of the other copy or copies. This can be attributed, in most cases, to loss of expression in several tissues of one or more gene copies. Finally, a substantial number of families, 19-35%, maintain a very high level of tissue-expression overlap (>0.8) after tens of millions of years of evolution. These families may have been subject to selection for increased gene dosage.},
keywords = {Animals, Evolution, Gene Duplication, Genetic, Humans, Mammals, Mammals: genetics, Models, Molecular}
}