Search

Your search keyword '"Fetchko, Michael"' showing total 91 results
Start Over Author "Fetchko, Michael"
91 results on '"Fetchko, Michael"'

47. In vivo construction of transgenes in Drosophila

Author

Takeuchi, Hajime, Georgiev, Oleg, Fetchko, Michael, Kappeler, Michael, Schaffner, Walter, and Egli, Dieter

Subjects
Drosophila -- Genetic aspects, Drosophila -- Research, Genetic transformation -- Usage, Genetic transformation -- Research, Transposons -- Usage, Transposons -- Research, Biological sciences
Abstract

Transgenic flies are generated by transposon-mediated transformation. A drawback of this approach is the size limit of transposable elements. Here, we propose a novel method that allows the extension of transgenes in vivo. This method is based on an incomplete transgene that has been constructed in vitro and integrated into the Drosophila genome by conventional transgenesis. The incomplete transgene contains two short stretches of DNA homologous to the 5'- and 3'-ends of a larger DNA segment of interest. Between the short stretches of homology an I-SceI recognition site is located. Once activated, I-SceI endonuclease introduces a DNA double-strand break, which triggers ectopic recombination between the stretches of homology and the endogenous locus. Through gap repair, the transgene obtains the complete region of interest in vivo. Our results show that this method is effective for copying up to 28 kb of genomic DNA into the transgene, thereby eliminating the technical difficulties associated with the in vitro construction of large transgenes and extending the size limits of current transgenesis protocols. In general, this method may be a useful technique for genetic engineering of eukaryotic model organisms.

Published
2007

50. Repression of Drosophila photoreceptor cell fate through cooperative action of two transcriptional repressors yan and tramtrack

Author

Lai, Zhi-Chun, Fetchko, Michael, and Li, Ying

Subjects
Drosophila -- Genetic aspects, Genetic transcription -- Research, Gene expression -- Research, Biological sciences
Abstract

The Drosophila yan gene encodes an E twenty-six (ETS) domain nuclear protein with a transcription repressor activity that can be downregulated through phosphorylation by mitogen-activated protein kinase (MAPK). Before photoreceptor precursor cells commit to a particular cell fate, Yan is required to maintain them in an undifferentiated state. We report here identification of tramtrack (ttk) mutations that act as dominant enhancers of yan. We show that ttk synergistically interacts with yan to inhibit the R7 photoreceptor cell fate. Since ttk products are nuclear proteins with zinc-finger DNA-binding motifs, yan and ttk represent two nuclear regulators essential for the control of cellular competence for neural differentiation. Reduction of either yan or ttk activity suppresses eye phenotypes of the kinase suppressor of ras (ksr) gene mutation, which is consistent with the involvement of yan and ttk in the Ras/MAPK pathway.

Published
1997

Catalog

Books, media, physical & digital resources
See catalog results