Expression and function on embryonic development of lissencephaly-1 genes in zebrafish

Lissencephaly is a severe disease characterized by brain malformation. The main causative gene of lissencephaly is LIS1. Mutation or deletion of LIS1 leads to proliferation and migration deficiency of neurons in brain development. However, little is known about its biological function in embryonic development. In this article, we identified the expression patterns of zebrafish LIS1 gene and investigated its function in embryonic development. We demonstrated that zebrafish consisted of two LIS1 genes, LIS1a and LIS1b. Bioinformatics analysis revealed that LIS1 genes were conserved in evolution both in protein sequences and genomic structures. The expression patterns of zebrafish LIS1a and LIS1b showed that both transcripts were ubiquitously expressed at all embryonic developmental stages and in adult tissues examined. At the protein level, the LIS1 products mainly exist in brain tissue and in embryos at early stages as shown by western blotting analysis. The whole-mount immunostaining data showed that LIS1 proteins were distributed all over the embryos from 1-cell stage to 5 day post-fertilization. Knockdown of LIS1 protein expression through morpholino antisense oligonucleotides resulted in many developmental deficiencies in zebrafish, including brain malformation, circulation abnormality, and body curl. Taken together, our study suggested that zebrafish LIS1 plays a very important role in embryonic development.