Mammalian keratin associated proteins (KRTAPs) subgenomes: disentangling hair diversity and adaptation to terrestrial and aquatic environments

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Imran Khan (Author) Other; Emanuel Maldonado (Author) Other; Vitor Vasconcelos (Author) FCUP; Stephen J O'Brien (Author) Other; Warren E Johnson (Author) Other; Agostinho Antunes (Author) FCUP

Journal

Title: BMC Genomics

Vol. 15

Final page: 779

ISSN: 1471-2164

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 55 Citations

Scopus - 56 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-009-TB2

DOI: 10.1186/1471-2164-15-779

Abstract (EN): Background: Adaptation of mammals to terrestrial life was facilitated by the unique vertebrate trait of body hair, which occurs in a range of morphological patterns. Keratin associated proteins (KRTAPs), the major structural hair shaft proteins, are largely responsible for hair variation. Results: We exhaustively characterized the KRTAP gene family in 22 mammalian genomes, confirming the existence of 30 KRTAP subfamilies evolving at different rates with varying degrees of diversification and homogenization. Within the two major classes of KRTAPs, the high cysteine (HS) subfamily experienced strong concerted evolution, high rates of gene conversion/recombination and high GC content. In contrast, high glycine-tyrosine (HGT) KRTAPs showed evidence of positive selection and low rates of gene conversion/recombination. Species with more hair and of higher complexity tended to have more KRATP genes (gene expansion). The sloth, with long and coarse hair, had the most KRTAP genes (175 with 141 being intact). By contrast, the "hairless" dolphin had 35 KRTAPs and the highest pseudogenization rate (74% relative to the 19% mammalian average). Unique hair-related phenotypes, such as scales (armadillo) and spines (hedgehog), were correlated with changes in KRTAPs. Gene expression variation probably also influences hair diversification patterns, for example human have an identical KRTAP repertoire as apes, but much less hair. Conclusions: We hypothesize that differences in KRTAP gene repertoire and gene expression, together with distinct rates of gene conversion/recombination, pseudogenization and positive selection, are likely responsible for micro and macro-phenotypic hair diversification among mammals in response to adaptations to ecological pressures.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 18