biostudies-literatureUnknown9(7)Luis Villanueva-Canas JAgència de Gestió d’Ajuts Universitaris i de RecercaThe birth of genes that encode new protein sequences is a major source of evolutionary innovation. However, we still understand relatively little about how these genes come into being and which functions they are selected for. To address these questions, we have obtained a large collection of mammalian-specific gene families that lack homologues in other eukaryotic groups. We have combined gene annotations and de novo transcript assemblies from 30 different mammalian species, obtaining ∼6,000 gene families. In general, the proteins in mammalian-specific gene families tend to be short and depleted in aromatic and negatively charged residues. Proteins which arose early in mammalian evolution include milk and skin polypeptides, immune response components, and proteins involved in reproductionGenome biology and evolution1886-1900https://www.ebi.ac.uk/biostudies/studies/S-EPMC5554394biostudies-literatureNew Genes and Functional Innovation in Mammals.PMC5554394Alba MMRuiz-Orera JGallo MLuis Villanueva-Canas JAndreu DAgea MIfalseNew Genes and Functional Innovation in Mammals.The birth of genes that encode new protein sequences is a major source of evolutionary innovation. However, we still understand relatively little about how these genes come into being and which functions they are selected for. To address these questions, we have obtained a large collection of mammalian-specific gene families that lack homologues in other eukaryotic groups. We have combined gene annotations and de novo transcript assemblies from 30 different mammalian species, obtaining ∼6,000 gene families. In general, the proteins in mammalian-specific gene families tend to be short and depleted in aromatic and negatively charged residues. Proteins which arose early in mammalian evolution include milk and skin polypeptides, immune response components, and proteins involved in reproduction2017-01-01T00:00:00Z2017 Jul2025-04-26T14:59:09.503Z2019-03-27T02:53:22ZS-EPMC55543942885460310.1093/gbe/evx136