The Function Of Spc105R And Broad-complex(BRC)in The Development Of Optic Lobes In The Drosophila Brain

The Spc105-related gene(Spc105R)encodes a Drosophila protein that is conserved from yeast to higher animal species and plays an important role in kinetochore assembly during mitotic division,but it is unclear whether the deficiency of Spcl05R can lead to defects in brain development.In this study,we knocked down Spcl05R expression in the optic lobes of the brain by expressing Spc105R RNAi using c855a-Gal4 as a driver.We observed brain defects in the mutant brains.In the mutant brains,the lamina is largely absent and the medulla is smaller than those in wild type brains.Morphological changes occurred in neuroepithelial cells that cannot maintain the columnar structure,and the number of neuroepithelial cells decreased significantly.These results demonstrate that Spc105R is necessary for the development of the Drosophila brain,and the deficiency of Spcl05R can result in abnormalities of the optic lobes.The Broad-complex(BRC)gene is one of the early ecdysone response genes,encoding multiple protein isoforms.BRC protein is necessary in 20-hydroxyecdysone mediated metamorphosis,but there is no study to examine its role in Drosophila optic lobe development and its effect on the differentiation of Drosophila neural stem cells.In this study,the expression of BRC RNAi was driven by c855a-Gal4 to knock down the level of BRC in the optic lobes of the Drosophila brain.We observed that the mutant brains of 3rd instar larvae had a smaller lamina and holes in the medulla.In addition,there is a delay in the differentiation of neuroepithelial cells into medullary neural stem cells.Overexpression of BRC promoted differentiation of neuroepithelial cells into medullary neural stem cells,complemtary to RNAi results.From this we conclude that BRC is necessary for the development of the Drosophila brain.The loss of BRC can lead to abnormal development of optic lobes in the brain.