Understanding the importance of RNA export factor, Nxt1, during the metamorphosis and in ovaries in Drosophila melanogaster

Autor: Van Der Graaf, Kevin
Rok vydání: 2018
Druh dokumentu: Electronic Thesis or Dissertation
Popis: The RNA export pathway is vital for export-competent mRNA to be exported from the nucleus to the cytoplasm. Without this pathway, RNA is unable to be translated into proteins for their function. A hetero-dimer comprised of Nxt1-Nxf1 is required to bind to the export-competent mRNA for a functional interaction between Nxf1 and the nuclear pore complex. Without Nxt1, Nxf1 interacts less effectively with the complex. In this thesis, the importance of Nxt1 is further examined during metamorphosis and in ovaries. I have shown that a reduction of functional Nxt1 during metamorphosis affects the muscle integrity in third instar larvae. This, in turn, affects the migration of the air bubble, which moves from the posterior to the anterior end, leading to dead pupae with no head eversion. Increasing the expression of a single gene, abba, rescues the muscle phenotype, but not the pupa viability. Further examination of differentially expressed genes revealed that genes with many and long introns were the most affected. In the ovaries, I have shown that Nxt1 is important in the piRNA pathway. Microarray and qRT-PCR have shown that transposons are de-repressed with less Nxt1, leading to sterility and death. Two rounds of small RNA-sequencing were performed, however, discrepancies between the two rounds made it difficult to analyse the data. Either Nxt1 influences the derepression of transposons or Nxt1 has a mild effect on de-repression of transposons and is more involved in the silencing process. Together with our collaborators we also got a first insight into which potential Nxf protein is interacting with Nxt1 in the piRNA pathway.
Databáze: Networked Digital Library of Theses & Dissertations