RESUMEN
Growth differentiation factors 1 (GDF1) and 3 (GDF3) are members of the transforming growth factor superfamily (TGF-ß) that is involved in fundamental early-developmental processes that are conserved across vertebrates. The evolutionary history of these genes is still under debate due to ambiguous definitions of homologous relationships among vertebrates. Thus, the goal of this study was to unravel the evolution of the GDF1 and GDF3 genes of vertebrates, emphasizing the understanding of homologous relationships and their evolutionary origin. Our results revealed that the GDF1 and GDF3 genes found in anurans and mammals are the products of independent duplication events of an ancestral gene in the ancestor of each of these lineages. The main implication of this result is that the GDF1 and GDF3 genes of anurans and mammals are not 1:1 orthologs. In other words, genes that participate in fundamental processes during early development have been reinvented two independent times during the evolutionary history of tetrapods.
Asunto(s)
Proteínas Anfibias/genética , Factor 1 de Diferenciación de Crecimiento/genética , Factor 3 de Diferenciación de Crecimiento/genética , Filogenia , Animales , Anuros , MamíferosAsunto(s)
Anomalías del Ojo/genética , Factores de Transcripción Forkhead/genética , Mutación , Aldehído Oxidorreductasas/genética , Alelos , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Estudios de Casos y Controles , Análisis Mutacional de ADN , Factor 3 de Diferenciación de Crecimiento/genética , Humanos , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADNRESUMEN
OBJECTIVE: Klippel-Feil syndrome is characterized by faulty segmentation of two or more cervical vertebrae and, in its most severe form, consists of massive cervical vertebral fusion, short neck, low posterior hairline, and limitation of head movement. Several cases associating Klippel-Feil syndrome with situs inversus totalis have been reported. In the present study, we describe the clinical features of a novel case of Klippel-Feil syndrome associated with situs inversus totalis and searched for mutations in GDF1, GDF3 and GDF6 genes, which were recently implicated in the development of skeletal and visceral anomalies. METHODS: A case of Klippel-Feil syndrome associated with situs inversus totalis underwent a full clinical examination including X-ray of cervical spine and thorax, abdominal ultrasound, and computerized tomography scanning of thorax and abdomen. PCR amplification and automated nucleotide sequencing of coding exons and intron-exon junctions of GDF1, GDF3, and GDF6 genes were performed in genomic DNA. RESULTS: No molecular alterations were found in GDF1, GDF3 and GDF6 genes in this patient. CONCLUSION: An additional patient associating Klippel-Feil syndrome and situs inversus totalis is reported. Mutations in GDF1, GDF3, and GDF6 genes were excluded as the cause of this unusual clinical association.