RESUMO
Prox2, together with the previously isolated Prox1, is the vertebrate homolog of the Drosophila homeobox-containing gene prospero, the founder member of a family of transcription factors which have been shown to play critical roles in many developmental events. We have isolated a cDNA which encodes a putative protein that shares a high degree of homology with mammalian Prox1, Prox2, and zebrafish Prox1. Comparative genomic analysis revealed that this protein corresponds to the zebrafish Prox2 homolog being the gene syntenic with the chromosome region hosting mouse Prox2. Whole-mount in situ experiments demonstrated that prox2 is expressed, during zebrafish embryonic development, in defined structures of the central nervous system and the eye, as previously reported in mouse. Additionally, reverse transcriptase-polymerase chain reaction analysis disclosed prox2 expression in several adult organs. Finally, prox1 loss- and gain-of-function assays have been carried out to search for regulative effects on prox2 expression.
Assuntos
Desenvolvimento Embrionário , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar/genética , Embrião não Mamífero/embriologia , Embrião não Mamífero/metabolismo , Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/genética , Humanos , Dados de Sequência Molecular , Filogenia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/química , Proteínas de Peixe-Zebra/genéticaRESUMO
Identification of homocystinuric newborns is hindered by the pitfalls of neonatal screening programs. We propose a fluorimetric HPLC method with a rapid pre-analytical step for homocysteine determination from neonatal dried blood spot cards. Homocysteine in blood spots sampled among 2000 healthy newborns on living day 4, averaged 2.92+/-2.07 microM (range 0.4-7.5). In eight homocystinuric control children, mean values were 61.71+/-52.84 microM (range 18.9-145.7). The method showed a good linearity (r=0.999), precision (RSD<7%) and recovery (95%). The correlation between blood spots and plasma samples was r=0.90. This method has all the essential features for a homocystinuria screening program: an easy and rapid pre-analytical step combined with method linearity and precision.
