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Using Genetic Networks and Homology to Understand the Evolution of Phenotypic Traits

Homology can have different meanings for different kinds of biologists. A phylogenetic view holds that homology, defined by common ancestry, is rigorously identified through phylogenetic analysis. Such homologies are taxic homologies (=synapomorphies). A second interpretation, “biological homology”...

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Autores principales: McCune, Amy R, Schimenti, John C
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Bentham Science Publishers 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3269019/
https://www.ncbi.nlm.nih.gov/pubmed/22942677
http://dx.doi.org/10.2174/138920212799034785
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author McCune, Amy R
Schimenti, John C
author_facet McCune, Amy R
Schimenti, John C
author_sort McCune, Amy R
collection PubMed
description Homology can have different meanings for different kinds of biologists. A phylogenetic view holds that homology, defined by common ancestry, is rigorously identified through phylogenetic analysis. Such homologies are taxic homologies (=synapomorphies). A second interpretation, “biological homology” emphasizes common ancestry through the continuity of genetic information underlying phenotypic traits, and is favored by some developmental geneticists. A third kind of homology, deep homology, was recently defined as “the sharing of the genetic regulatory apparatus used to build morphologically and phylogenetically disparate features.” Here we explain the commonality among these three versions of homology. We argue that biological homology, as evidenced by a conserved gene regulatory network giving a trait its “essential identity” (a Character Identity Network or “ChIN”) must also be a taxic homology. In cases where a phenotypic trait has been modified over the course of evolution such that homology (taxic) is obscured (e.g. jaws are modified gill arches), a shared underlying ChIN provides evidence of this transformation. Deep homologies, where molecular and cellular components of a phenotypic trait precede the trait itself (are phylogenetically deep relative to the trait), are also taxic homologies, undisguised. Deep homologies inspire particular interest for understanding the evolutionary assembly of phenotypic traits. Mapping these deeply homologous building blocks on a phylogeny reveals the sequential steps leading to the origin of phenotypic novelties. Finally, we discuss how new genomic technologies will revolutionize the comparative genomic study of non-model organisms in a phylogenetic context, necessary to understand the evolution of phenotypic traits.
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spelling pubmed-32690192012-09-01 Using Genetic Networks and Homology to Understand the Evolution of Phenotypic Traits McCune, Amy R Schimenti, John C Curr Genomics Article Homology can have different meanings for different kinds of biologists. A phylogenetic view holds that homology, defined by common ancestry, is rigorously identified through phylogenetic analysis. Such homologies are taxic homologies (=synapomorphies). A second interpretation, “biological homology” emphasizes common ancestry through the continuity of genetic information underlying phenotypic traits, and is favored by some developmental geneticists. A third kind of homology, deep homology, was recently defined as “the sharing of the genetic regulatory apparatus used to build morphologically and phylogenetically disparate features.” Here we explain the commonality among these three versions of homology. We argue that biological homology, as evidenced by a conserved gene regulatory network giving a trait its “essential identity” (a Character Identity Network or “ChIN”) must also be a taxic homology. In cases where a phenotypic trait has been modified over the course of evolution such that homology (taxic) is obscured (e.g. jaws are modified gill arches), a shared underlying ChIN provides evidence of this transformation. Deep homologies, where molecular and cellular components of a phenotypic trait precede the trait itself (are phylogenetically deep relative to the trait), are also taxic homologies, undisguised. Deep homologies inspire particular interest for understanding the evolutionary assembly of phenotypic traits. Mapping these deeply homologous building blocks on a phylogeny reveals the sequential steps leading to the origin of phenotypic novelties. Finally, we discuss how new genomic technologies will revolutionize the comparative genomic study of non-model organisms in a phylogenetic context, necessary to understand the evolution of phenotypic traits. Bentham Science Publishers 2012-03 2012-03 /pmc/articles/PMC3269019/ /pubmed/22942677 http://dx.doi.org/10.2174/138920212799034785 Text en ©2012 Bentham Science Publishers http://creativecommons.org/licenses/by/2.5/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/), which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Article
McCune, Amy R
Schimenti, John C
Using Genetic Networks and Homology to Understand the Evolution of Phenotypic Traits
title Using Genetic Networks and Homology to Understand the Evolution of Phenotypic Traits
title_full Using Genetic Networks and Homology to Understand the Evolution of Phenotypic Traits
title_fullStr Using Genetic Networks and Homology to Understand the Evolution of Phenotypic Traits
title_full_unstemmed Using Genetic Networks and Homology to Understand the Evolution of Phenotypic Traits
title_short Using Genetic Networks and Homology to Understand the Evolution of Phenotypic Traits
title_sort using genetic networks and homology to understand the evolution of phenotypic traits
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3269019/
https://www.ncbi.nlm.nih.gov/pubmed/22942677
http://dx.doi.org/10.2174/138920212799034785
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