An in vivo zebrafish functional assay to characterize IGFALS gene variants

ESTEFANIA LANDI; PAOLA PLAZAS; PAULA SCAGLIA; LUCIA MARTUCCI; HECTOR JASPER; HORACIO DOMENE; SABINA DOMENE

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

ALS is essential for the stabilization of IGF-I and IGFBP-3 as ternary complexes in the vascular system. ALS deficient (ACLSD) patients, homozygous or compound heterozygous for IGFALS gene mutations present severe IGF-I, IGFBP-3 deficiencies and a variable degree of growth retardation. The aim of this study was to evaluate the consequences of ACLSD in a zebrafish model to establish an in vivo assay for determining the pathogenic effect of IGFALS gene variants found in ACLSD patients. To do this we performed knockdown of zebrafish igfals using morpholinos to evaluate the absence of ALS in the context of a whole organism and designed a rescue assay using wildtype human IGFALS mRNA and a frameshift variant (p.E35Gfs*17) identified in an ACLSD patient. We also characterized the expression pattern of igfals in the zebrafish by RT-PCR and in situ hybridization at different stages of development and in adult tissues for the first time. Igfals is expressed throughout development in zebrafish embryos by RT-PCR and is mainly restricted to the kidney, heart, liver, muscle, and ovary during adulthood. In situ hybridization of zebrafish embryos shows igfals expression only in the brain and liver. Knockdown of zebrafish igfals using 6 ng of morpholinos shows severe dorsalization in 185/214 embryos, p