Research On The Function Of Zinc Finger Protein CG12744 In Drosophila Gut Immunity

Drosophila only has the innate immunity system,which is different from mammals.The gut immunity,an important part of innate immunity system,has been a significant issue for research.The Drosophila gut immunity include three sections:first,infection with pathogens causes the production of reactive oxygen species(ROS)in the gut;second,the gut epithelial cells secrete antimicrobial peptides(AMPs)to kill the pathogens that can not be eliminated by ROS;last,the proliferation and differentiation of intestinal stem cells(ISCs)are essential for the gut homeostasis in Drosophila.Recently,it has become rapidly evident that several evolutionarily conserved signaling pathways have been implicated in the regulation of ISC proliferation and differentiation after infection,yet whether the zinc-finger proteins have pivotal role in long-term maintenance of gut tissue homeostasis in response to damage has not been well understood.The zinc-finger domain,like a finger shape,is a ubiquitous structural motif within the DNA-binding proteins.Most zinc-finger proteins are crucial accommodators of genetic expression.The gene CG12744 contains a zinc-finger C2H2-type DNA-binding domain with gene sequence location of 2R:5762786...5763747 in Drosophila.Several functions of CG12744 products have been described,including the molecular function of both metal ion binding and nucleic acid binding,and the biological process of defense response to fungus.Previous research has revealed that the zinc-finger protein Charlatan(Chn)is a potential regulator of gut homeostasis,however,the function of CG12744 in gut homeostasis has remained elusive.Therefore,we speculate that CG12744 gene may have a role in this field.In this study,the research material used here were w118(WT)and CG12744 low expression mutants.We study the Drosophila survival,the activity of ISC proliferation and differentiation,the production of secreting peptide and the lipogenesis by using immunostaining after Gram negative bacteria Erwinia carotovora carotovora 15(Eccl5)infection.The main results obtained are as follows:1.SurvivalCG12744 gene which,when depleted,can contribute to an increased susceptibility of Ecc15-ijnfected flies,appeared to be required for proper resistance,maintaining the viability following bacterial challenge.2.Precursor numberPrecursor-derived CG12744 affected the EB population after Eccl5 infection.Compared with control,esgteGal4>CG12744RNAiline showed a reduction of 60%in the number of EBs,but not ISC population.There was no difference in the number of EBs in the absence of tissue damage.Precursor-derived CG12744 had no affect on the precursor population in the copper cell region(CCR).3.Differentiation(1)The result of intestinal cell differentiation showed that there is a defect in EC differentiation of esgtsGal4>CG12744RNAi line after Ecc15 infection.esgtsGa14>CG12744RNAi line displayed a reduction of 70%in the number of ECs compared with control.(2)There was no direct link between CG12744 and Notch,but CG12744 regulated osa in EC to affect EC differentiation.(3)esgtsGal4>CG12744RNAi gut had a lower activity of JNK signaling compared with control after Ecc15 infection.(4)EE specification was specially controlled by EB-derived CG72744 after ingestion of Eccl5.Su(H)Gal4>CG12744RNAi line showed an increase of 200%in the number of EEs compared with control.4.Intestinal morphologyThe analysis of gut morphology suggested that EC-derived CG12744 maintains the morphology and integrality of epithelial cells.After infection,NP1Gal4>CG12744RNAiline had an unordered arrangement of irregular shaped ECs with armadillo activity degradative in precursors,and there were larger nucleus cells in the NP1Gal4>CG12744RNAi line compared with control.5.Stem cell activityEE-specific expression of CG12744 was responsible for ISC proliferation after immune challenge.Compared with control,the activity of ISC divisions increased observably in voilaGal4>CG12744RNAi line.6.LipogenesisCG12 744-mediated regulation of commitment into the EE fate in Su(H)Gal4>CG12744RNAi line increased the level of Tachykinin(TK)accumulation in Ecc15-induced midgut,which resulted in an decreased level of lipogenesis.In a word,after Ecc15 infection,Drosophil,CG12744 gene affected the EB population,the differentiation of EC cells and EEs,and the integrity of epidermal cell morphology;this gene played an important role in the TK secretion and lipogenesis.We look far ahead into the prospect in this field,which make the theoretical base of the research for the mechanisms of ISC proliferation and differentiation in both the Drosophila and mammals.