Analysis of zebrafish nolc1l: the orthologue of the human gene involved in Treacher Collins syndrome

WEINER ANDREA; SCAMPOLI NADIA; CALCATERRA NORA

Puerto Madryn

Congreso; XLV Reunion Annual ? 45th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2010

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:ES-AR; mso-fareast-language:ES-AR;} span.mediumtext {mso-style-name:medium_text;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Treacher Collins Syndrome (TCS) is a congenital craniofacial disorder characterized by head and neck anomalies, such as hypoplasia of the facial bones, cleft palate, and ear defects that result in conductive deafness. TCS is caused by autosomal dominant mutations in tcof1 gene. To date, the in vivo functions of tcof1 and its encoded protein, Treacle, are poorly understood. The main goal of this work was to shed light on the tcof1 role during embryonic development using zebrafish as animal model. The zebrafish tcof1 gene has not been described, but a homologue to mouse and human tcof1, called nolc1l, was found by in silico genome analysis. The nolc1l cDNA was cloned, and its expression pattern analyzed by semi-quantitative RT-PCR and whole-mount in situ hybridization during embryogenesis. High levels of mRNA were detected in 1-cell stage, indicating its maternal origin. The lowest level was detected at 12 hours post-fertilization (hpf); the expression increased again from that stage reaching a plateau at 24 hpf. Similarly to mammalian tcof1, nolc1l is ubiquitously expressed until late somitogenesis stages, from which it becomes localized to cephalic regions and the notochord. Finally, by using splicing morpholinos we knocked down nolc1l expression by generating dominant negative proteins. This is the first work identifying the sequence and biological behavior of TCS gene in zebrafish.