A new evolutionary model for the vertebrate actin family including two novel groups

• Published in: Molecular phylogenetics and evolution Vol. 141; p. 106632
• Main Authors: Witjes, Laura, Van Troys, Marleen, Vandekerckhove, Joël, Vandepoele, Klaas, Ampe, Christophe
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2019
• Subjects: Acta4; Acte1; Actin family; Actins - genetics; Animals; Evolution, Molecular; Exons - genetics; Likelihood Functions; Models, Genetic; Muscle, Smooth - metabolism; Nomenclature; Phylogeny; Species Specificity; Synteny; Synteny - genetics; Vertebrate actin evolution; Vertebrates - genetics; Actin family; Acte1; Nomenclature; Vertebrate actin evolution; Synteny; Acta4
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2019.106632

[Display omitted] •Improved classification and names of the vertebrate actin family based on synteny.•The vertebrate actin family consists of 8 instead of 6 orthologous groups.•The two new actin groups were assigned gene symbols Acta4 and Acte1.•A new actin evolutionary model shows that 3 actin groups originate earlier.•During evolution actin gene loss occurred in multiple orthologousgroups. Database surveys in the vertebrate model organisms: chicken (Gallus gallus), western clawed frog (Xenopus tropicalis), anole lizard (Anolis carolinensis) and zebrafish (Danio rerio) indicate that in some of these species the number of actin paralogues differs from the well-established six paralogues in mouse (Mus musculus). To investigate differential functions of actins and for establishing disease models it is important to know how actins in the different model organisms relate to each other and whether the vertebrate actin family is truly limited to six groups. Primarily through synteny analyses we discovered that the vertebrate actin family consists of eight instead of six orthologous actin groups for which we propose improved gene nomenclature. We also established that α-skeletal muscle, γ-enteric smooth muscle and γ-cytoplasmic actin genes originated prior to tetrapods contradicting an earlier and widely accepted model of actin evolution. Our findings allow a more reliable predictive classification of actin paralogues in (non-mammalian) vertebrates and contribute to a better understanding of actin evolution as basis for biomedical research on actin-related diseases.