Biological tube formation in Drosophila tracheal system with loss of function mutant by CRISPR-Cas9 genome editing

The Drosophila melanogaster trachea is the premier genetic system used to study the fundamental mechanism of the mammalian lung and blood vessel formation process. Seven members of the Osiris (Osi) gene family are highly expressed in the trachea system of Drosophila. Protein localization of Osi proteins suggests its potential role in the lumen formation in the Drosophila trachea. Tracheal Osi genes are predicted to function redundantly. To reveal the mechanism of Osiris genes in the Drosophila trachea, we will generate a triple knockout mutant by removing the function of 3 out of the 7-trachea expressing Osi genes. Specifically, we will generate an Osi9 (CG15592) loss of function mutant in a previously generated double knockout background of Osi15+19. To do this, we will use clustered regularly interspaced short palindromic repeats (CRISPR)‐associated (Cas) 9 protein system: an efficient and important genome‐editing tool. This technology has been wildly used in cells, insects, and mammals to study the function of novel genes by generating loss of function mutants. The generation of these triple loss of function mutants and phenotypic analysis of these mutants will reveal a novel mechanism of tubular organ formation.