Wnt gene expression in sea urchin development: heterochronies associated with the evolution of developmental mode.
Evol Dev
; 3(1): 24-33, 2001.
Article
em En
| MEDLINE
| ID: mdl-11256431
ABSTRACT
The Wnt genes encode a large family of conserved secreted proteins that are widely involved in animal development. The variety and ubiquity of this ancient family suggest that Wnt genes may have been important in the evolution of animal development, including early development. To test this hypothesis, we have characterized the expression of several Wnt genes in closely related sea urchins that exhibit radically different modes of early development. Wnt-1, -4, and -5 genes exhibit several conserved molecular and developmental characteristics, both within sea urchins and with Wnt genes examined in other animals (Ferkowicz et al. 1998). Here, we demonstrate that sea urchin Wnt-5 transcripts are specifically detected by in situ hybridization in discrete embryonic, larval, and developing adult tissues and processes (1) in a band of vegetal ectoderm in mesenchyme blastula stage embryos, (2) in the larval ciliary bands, (3) in tissues that form the early adult rudiment (left coelomic pouch and overlying vestibular ectoderm), and (4) in the developing adult radial nervous system. We find that the sites of Wnt-5 transcript accumulation are conserved in species exhibiting either indirect- or direct-developmental modes, suggesting that Wnt-5 function(s) have been conserved in sea urchin development. However, dramatic heterochronic changes in Wnt-5 gene expression have occurred in the direct-developing species that parallel the accelerated morphological changes that occur during direct development. These results suggest that heterochronic changes in the expression of conserved developmental regulatory genes, such as the Wnt family members, are agents of evolutionary change in animal development.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ouriços-do-Mar
/
Família Multigênica
/
Proteínas Proto-Oncogênicas
/
Proteínas de Peixe-Zebra
/
Evolução Biológica
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Evol Dev
Assunto da revista:
BIOLOGIA
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Estados Unidos