CNBP plays an essential role during cranial neural crest development.

WEINER, A; CALCATERRA, N.B.

Carlos Paz, Cordoba

Congreso; XLIV Reunion Annual – 44th Annual Meeting Argentine Society for Biochemistry and Molecular Biology.; 2008

SAIB

Cellular nucleic acid binding protein (CNBP) is a small single-stranded nucleic acid binding protein remarkably conserved among vertebrates. Cellular functions assigned to CNBP range from transcriptional regulation to translational control. Recently, we reported that CNBP is required for forebrain formation during vertebrate embryogenesis by controlling the neural crest cell (NCC) proliferation/survival balance. In this study, we used the zebrafish model system to shed light on the basic understanding of CNBP molecular mechanisms and activity during NCC development. We knocked down CNBP expression during early development using both splicing as well as translation blocking morpholino oligonucleotides (MO). The CNBP depletion yielded forebrain truncation and developmental retardation, but the trunk developed normal. To observe a similar effect and phenotype with both MOs, splicing MO was used at 4-fold lower concentration than translation MO. This finding may be due to dominant negative forms translated from transcripts differentially processed. CNBP depletion caused a reduction in the expression of cranial neural crest markers, such as dlx and sox9. Instead, the expression of trunk neural crest markers, such us sox10 and dct, was not affected. Hence, CNBP is required for craniofacial structures development but it seems not involved in melanoblast development. These data explain the craniofacial anomalies observed in CNBP depleted mice, chicken and fish and, moreover, confirm that CNBP plays an essential and conserved role during vertebrate head development.