Research On The Effects Of Bap170 And Sayp,SWI/SNF Chromatin Remodeling Complex Members,during Border Cell Migration In Drosophila Melonagaster

Cell migration plays a vital role in embryonic development,in which tissue need to be rearranged,differentiated and then formed into organ.Except this,cell migration is also important for other normal life activities,such as tissue wounding repairing and immune response.However,it also leads to detrimental outcomes,such like tumor metastasis.Cell migration consists of two types:single cell migration and collective cell migration.Single cell migrates on a flat surface,the cell needs adhesion and contacts with the extracellular matrix(ECM),which can support traction.Single cell migration mainly happens in immune cell and germ cell.Collective cell migration,which need differs from single cell migration,is a phenomenon that cells migrate together and keep consistent interaction by mechanical force and signaling pathway while migrating.Drosophila melanogaster,which has some characteristics,such as clear genetic background,convenient manipulation,cheap and prolific propagation,provides a good example for genetic research.A cluster of cells named border cells that migrate together in the Drosophila ovary is an excellent example of collective cell migration.Border cells,arising from epithelium,migrate from the anterior of egg chamber into the border between oocyte and nurse cells to contribute to form the micropyle,which is a tunnel for the combination of sperm and oocyte.JAK/STAT signaling pathway is essential for cell proliferation and differentiation.From previous research,Upd,secreted by polar cell,can activate JAK/STAT signaling pathway,which affect border cell cluster recruiting and migration.SWI/SNF chromatin remodeling complex can bind with chromatin and affect gene transcription positively or negatively by altering chromatin structure and affecting the combination between transcription factor and promoter.SWI/SNF chromosome remodeling complexes are consisted of two family in Drosophila Melonagaster:BAP complex,defined as containing Osa and lacking Bap 170,Polybromo and Sayp;PBAP complex,defined as containing Bap 170,Polybromo and Sayp and lacking Osa.Although their distribution and function have some similarities,they play different roles in various tissues.In this thesis,we find that Bap60,Bap111,Bap170 and Sayp can regulate border cell migration.We mainly focus on Bap 170 and Sayp,which belong to SWI/SNF chromatin remodeling complex PBAP family,can regulate JAK/STAT signaling pathway positively and affect border cell migration by disrupting cluster recruiting.Sayp has severe effects on border cell migration,and it does not regulate Stat transcriptional level directly,but downregulates this pathway activity by affecting downstream gene transcriptional level of JAK/STAT signaling pathway.Cell migration can have a great influence on normal life activities,and ectopic migration may result in disease development,like metastasis.SWI/SNF complexes exist some mutations in tumor cells,which affect gene expression.From our research,we could have better understanding of the roles in tumor metastasis.