Effects Of Spen On The Proliferation And Differentiation Of Intestinal Stem Cells In Drosophila Melanogaster

Frequent contact with microorganisms in the intestine of animals causes immune response,and persistent pathogen infection leads to the occurrence of gastrointestinal diseases.Drosophila has a natural immune regulation mechanism similar to that of mammals.Drosophila intestinal tract is an ideal model for homeostasis regulation,and natural immunity plays an important role in protecting Drosophila against various pathogens.The morphology,structure and function of Drosophila intestinal tract are very similar to that of mammalian small intestine,and Drosophila intestinal tract has a multifunctional stem cell system that maintains homeostasis and conserved signal transduction pathways.Drosophila genetics system can be flexible control of gene expression,a clear track cell lineage differentiation of multiplication,therefore,model organism Drosophila is one of the important model study disease and organ development mechanism.Split end(Spen)protein contains three RNA recognition motif(RRM)and one Spoc domain,which has the ability of RNA binding and is involved in RNA output and processing.Studies on a variety of cancers have found that Spen protein is mutated,which is also considered as a tumor suppressor protein.However,the function of Spen protein in intestinal immunity of Drosophila is still unclear.Therefore,we speculate that the protein may play a certain role in regulating the proliferation and differentiation of intestinal stem cells.In this paper,the main use of Drosophila intestinal cells specificity Gal4 lines further to explore the specific mechanism of the gene function,through the use of a variety of antibody immune staining methods to analyze the intestinal cells number changes and differences in cell size,etc,and the expression of genes related to signal transduction pathways in level detection,delve into value-added Spen proteins in fruit flies the intestinal stem cells and differentiation of regulating mechanism.The results showed that:1.Spen protein is localized in precursor cells,ECs,EEs and VMs of the intestine2.The low expression of spen gene in the precursor cells will cause defects in the development of Drosophila's chest and wings,reduce the self-renewal of stem cells,and reduce the number of precursor cells and EEs,while the overexpression of spen in all intestinal specific Gal4 will cause the phenomenon of overdifferentiation.Spen protein can affect the proliferation and differentiation of stem cells in ISCs,EBs,ECs and EEs,but has no regulatory effect in VMs.3.Spen protein deficiency in precursor cells can reduce the activity of EGFR,JAK/STAT,and Notch signaling pathways,but does not affect JNK,Wg,and InR signaling pathways,thereby regulating intestinal homeostasis.In this study,a variety of genetic systems were used to explore the lineage of midgut intestinal stem cells and their signal regulation mechanisms,mainly focusing on the exploration of Spen protein in regulating the proliferation and differentiation of Drosophila intestinal stem cells.The results can provide a theoretical basis for revealing the function of Spen protein in Drosophila and mammals and the mechanism of proliferation and differentiation of intestinal stem cells.