Data/hora: 09/06/2024 00:49:34

Provedor de dados: 	Genetics and Molecular Biology	
País: 	Brazil	
Título: 	Changes in G+C content of a neutrally evolving gene under a non-reversible dynamics measured by computer simulations based on experimental evolution data	
Autores: 	Brunstein,Adriana; Varuzza,Leonardo; Sanson,Gerdine F. O.; Briones,Marcelo R. S.	
Data: 	2004-01-01	
Ano: 	2004	
Palavras-chave: 	Molecular evolution; Experimental phylogenetics; Neutral theory; Mathematical models of nucleotide substitutions.	
Resumo: 	To evaluate the effects of non-reversibility on compositional base changes and the distribution of branch lengths along a phylogeny, we extended, by means of computer simulations, our previous sequential PCR in vitro evolution experiment. In that study a 18S rRNA gene evolved neutrally for 280 generations and a homogeneous non-stationary model of base substitution based on a non-reversible dynamics was built from the in vitro evolution data to describe the observed pattern of nucleotide substitutions. Here, the process was extended to 840 generations without selection, using the model parameters calculated from the in vitro evolution experiment. We observed that under a non-reversible model the G+C content of the sequences significantly increases when compared to simulations with a reversible model. The values of mean and variance of the branch lengths are reduced under a non-reversible dynamics although they follow a Poisson distribution. We conclude that the major implication of non-reversibility is the overall decrease of branch lengths, although no transition from a stochastic to an ordered process is observed. According to our model the result of this neutral process will be the increase in the G+C content of the descendant sequences with an overall decrease in the frequency of substitutions.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000400026	
Editor: 	Sociedade Brasileira de Genética	
Relação: 	10.1590/S1415-47572004000400026	
Formato: 	text/html	
Fonte: 	Genetics and Molecular Biology  v.27 n.4 2004	
Fonte: 	info:eu-repo/semantics/openAccess