Conservation of Zebrafish MicroRNA-145 and Its Role during Neural Crest Cell Development

The neural crest is a multipotent cell population that develops from the dorsal neural fold of vertebrate embryos in order to migrate extensively and differentiate into a variety of tissues. A number of gene regulatory networks coordinating neural crest cell specification and differentiation have been extensively studied to date. Although several publications suggest a common role for microRNA-145 (miR-145) in molecular reprogramming for cell cycle regulation and/or cellular differentiation, little is known about its role during in vivo cranial neural crest development. By modifying miR-145 levels in zebrafish embryos, abnormal craniofacial development and aberrant pigmentation phenotypes were detected. By whole-mount in situ hybridization, changes in expression patterns of col2a1a and Sry-related HMG box (Sox) transcription factors sox9a and sox9b were observed in overexpressed miR-145 embryos. In agreement, zebrafish sox9b expression was downregulated by miR-145 overexpression. In silico and in vivo analysis of the sox9b 3′UTR revealed a conserved potential miR-145 binding site likely involved in its post-transcriptional regulation. Based on these findings, we speculate that miR-145 participates in the gene regulatory network governing zebrafish chondrocyte differentiation by controlling sox9b expressionThis research was funded by a CONICET External Grant (March 2018 to A.M.J.W.), an ANPCyT PICT Grant (PICT-2017-0509 to A.M.J.W.), and a CONICET PIP Grant (PIP-2015-0719 to N.B.C.)S

Rol de los microARNs durante la especificación de la cresta neural

La cresta neural (CN) es una población transitoria de células multipotentes cuya formación ocurre temprano en el desarrollo. Al cerrarse el tubo neural, las células sufren una transición epitelio-mesénquima, luego delaminan, migran y finalmente se diferencian en diversas estructuras. Cada etapa del desarrollo de las células de cresta neural (CCN) está caracterizada por la activación de ciertos factores de transcripción fundamentales para el éxito de las mismas. La expresión de estos factores es estrictamente regulada por varios mecanismos, siendo uno de ellos los microARNs. Nuestro objetivo es contribuir al conocimiento del rol que cumplen los microARNs durante el desarrollo de las CCN. En este trabajo se analizaron los efectos de la alteración de la biogénesis de microARNs en embriones de pez cebra, con un enfoque en los derivados craneofaciales de la CN. Se analizó además el efecto de los microARNs sobre el gen especificador de la CN sox9b y sobre el gen del colágeno mayoritario en cartílago, col2a1. A su vez, se diseñaron dos sondas para la detección in situ de sox9b y se detectó un microARN por RT-qPCR. En conjunto, los resultados obtenidos sugieren que los microARNs están involucrados en la regulación de dichos genes al haber observado cambios en los niveles de mensajero de sox9b, en el patrón de expresión espacio-temporal de col2a1 y en los parámetros craneofaciales estudiados.Fil: Steeman, Tomás José. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET); Argentina

Conservation of Zebrafish MicroRNA-145 and Its Role during Neural Crest Cell Development

The neural crest is a multipotent cell population that develops from the dorsal neural fold of vertebrate embryos in order to migrate extensively and differentiate into a variety of tissues. A number of gene regulatory networks coordinating neural crest cell specification and differentiation have been extensively studied to date. Although several publications suggest a common role for microRNA-145 (miR-145) in molecular reprogramming for cell cycle regulation and/or cellular differ entiation, little is known about its role during in vivo cranial neural crest development. By modifying miR-145 levels in zebrafish embryos, abnormal craniofacial development and aberrant pigmentation phenotypes were detected. By whole-mount in situ hybridization, changes in expression patterns of col2a1a and Sry-related HMG box (Sox) transcription factors sox9a and sox9b were observed in overexpressed miR-145 embryos. In agreement, zebrafish sox9b expression was downregulated by miR-145 overexpression. In silico and in vivo analysis of the sox9b 3 0UTR revealed a conserved potential miR-145 binding site likely involved in its post-transcriptional regulation. Based on these findings, we speculate that miR-145 participates in the gene regulatory network governing zebrafish chondrocyte differentiation by controlling sox9b expression.Fil: Steeman, Tomás José. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Argentina.Fil: Rubiolo, Juan Andrés. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Argentina.Fil: Sánchez, Laura E. Universidade de Santiago de Compostela. Facultad de Veterinaria. Departamento de Zoología Genética y Antropología Física.Fil: Calcaterra, Nora B. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Argentina.Fil: Weiner, Andrea María Julia. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Argentina