title: Differential evolutionary constraints in the evolution of chemoreceptors: a murine and human case study.
abstract: Chemoreception is among the most important sensory modalities in animals. Organisms use the ability to perceive chemical compounds in all major ecological activities. Recent studies have allowed the characterization of chemoreceptor gene families. These genes present strikingly high variability in copy numbers and pseudogenization degrees among different species, but the mechanisms underlying their evolution are not fully understood. We have analyzed the functional networks of these genes, their orthologs distribution, and performed phylogenetic analyses in order to investigate their evolutionary dynamics. We have modeled the chemosensory networks and compared the evolutionary constraints of their genes in Mus musculus, Homo sapiens, and Rattus norvegicus. We have observed significant differences regarding the constraints on the orthologous groups and network topologies of chemoreceptors and signal transduction machinery. Our findings suggest that chemosensory receptor genes are less constrained than their signal transducing machinery, resulting in greater receptor diversity and conservation of information processing pathways. More importantly, we have observed significant differences among the receptors themselves, suggesting that olfactory and bitter taste receptors are more conserved than vomeronasal receptors.
authors.affiliation: Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, 90040-180 Porto Alegre, RS, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: D'Oliveira Albanus
authors.affiliation: Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, 90040-180 Porto Alegre, RS, Brazil.
authors.forename: Rodrigo Juliani
authors.initials: RJ
authors.lastname: Siqueira Dalmolin
authors.affiliation: Departamento de Física e Biofísica, Universidade Estadual Paulista, Distrito de Rubião Júnior, S/N, 18618-970 Botucatu, SP, Brazil.
authors.forename: José Luiz
authors.initials: JL
authors.lastname: Rybarczyk-Filho
authors.affiliation: Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, 90040-180 Porto Alegre, RS, Brazil.
authors.forename: Mauro Antônio
authors.initials: MA
authors.lastname: Alves Castro
authors.affiliation: Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, 90040-180 Porto Alegre, RS, Brazil.
authors.forename: José Cláudio
authors.initials: JC
authors.lastname: Fonseca Moreira
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002628:Chemoreceptor Cells / Q000378:metabolism*; D016000:Cluster Analysis; D019295:Computational Biology; D019143:Evolution, Molecular; D063990:Gene Ontology; D006801:Humans; D051379:Mice; D008957:Models, Genetic; D010802:Phylogeny; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D013045:Species Specificity
chemical_list: D043562:Receptors, G-Protein-Coupled