The Dyslexia-associated gene KIAA0319L is involved in neuronal migration in the developing chick visual system

The gene KIAA0319-Like (KIAA0319L) is thought to confer susceptibility for developmental dyslexia. Dyslexia may be caused by alterations in neuronal migration, and in utero knockdown of KIAA0319L in rats indicated migration errors. However, studies carried out with KIAA0319L knockout mice did not reveal an altered neuronal migration phenotype. Gene knockout may activate compensatory mechanisms to buffer against genetic mutations during development. Here we assessed the role of KIAA0319L on migrating neurons in the chick developing tectum. Whole mount in situ hybridization was performed for KIAA0319L on embryonic day (E)3 - E5 chick embryos and in situ hybridization on sections was performed at later stages. The specificity and efficiency of engineered microRNA (miRNA) constructs targeting KIAA0319L for knocking down KIAA0319L were verified. miRNAs were electroporated into E5 chick optic tecta. Our studies demonstrate that KIAA0319L is expressed in the developing chick visual system, as well as in the otic vesicles. Knockdown of KIAA0319L in the optic tectum results in abnormal neuronal migration, strengthening the argument that KIAA0319L is involved in this developmental process.