Positive Selection Linked with Generation of Novel Mammalian Dentition Patterns

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Machado, JP (Author) Other; Philip, S (Author) Other; Maldonado, E (Author) Other; O'Brien, SJ (Author) Other; Johnson, WE (Author) Other; Agostinho Antunes (Author) FCUP

Journal

Title: Genome Biology and Evolution

Vol. 8

Pages: 2748-2759

ISSN: 1759-6653

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-00M-41J

DOI: 10.1093/gbe/evw200

Abstract (EN): A diverse group of genes are involved in the tooth development of mammals. Several studies, focused mainly on mice and rats, have provided a detailed depiction of the processes coordinating tooth formation and shape. Here we surveyed 236 tooth-associated genes in 39 mammalian genomes and tested for signatures of selection to assess patterns of molecular adaptation in genes regulating mammalian dentition. Of the 236 genes, 31 (similar to 13.1%) showed strong signatures of positive selection that may be responsible for the phenotypic diversity observed in mammalian dentition. Mammalian-specific tooth-associated genes had accelerated mutation rates compared with older genes found across all vertebrates. More recently evolved genes had fewer interactions (either genetic or physical), were associated with fewer Gene Ontology terms and had faster evolutionary rates compared with older genes. The introns of these positively selected genes also exhibited accelerated evolutionary rates, which may reflect additional adaptive pressure in the intronic regions that are associated with regulatory processes that influence tooth-gene networks. The positively selected genes were mainly involved in processes like mineralization and structural organization of tooth specific tissues such as enamel and dentin. Of the 236 analyzed genes, 12 mammalian-specific genes (younger genes) provided insights on diversification of mammalian teeth as they have higher evolutionary rates and exhibit different expression profiles compared with older genes. Our results suggest that the evolution and development of mammalian dentition occurred in part through positive selection acting on genes that previously had other functions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12