During growth and division of cells in the body, the DNA at the ends of chromosomes becomes shorter owing to an inability of cells to fully replicate these sites, which are called telomeres. Excessively short telomeres are dysfunctional and cause cells to stop dividing, and in many cases commit suicide. Thus, telomere shortening provides a """"""""timer"""""""" that limits the growth potential of most cells in the body. How cells escape this limit is a critical question for understanding the genesis of cancer. The work proposed here uses the fruitfly, Drosophila melanogaster, as a model system to identify the genetic mechanisms either guide cells to suicide, or allow them to escape that fate. Specially engineered chromosomes are used to provide a system that efficiently, and on command, causes loss of one telomere in a cell. Most cells die in response, but a few cells escape and divide repeatedly. The experiments described in this proposal will define the mechanisms that cells use to escape death, providing important insight into the earliest stages of carcinogenesis. In reproductive cells, the loss of a telomere is often followed by construction of a new telomere. The proposed work will define the genetic control over this chromosome healing. Inappropriately healed chromosomes are associated with a number of human disorders. Moreover, healing is a common feature of cancer cells, adding further relevance to human health.

Public Health Relevance

The first part of this work will define the mechanisms that cells use to escape the normal limits to growth when faced with unrepairable DNA damage. The second part will identify the genetic regulators of these mechanisms. The third part will determine how these genetic controls interact to control cell fate. Understanding the genes that control these processes may lead to prevention or treatment of cancer or inherited chromosomal deficiencies.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM065604-12
Application #
8607961
Study Section
Molecular Genetics C Study Section (MGC)
Program Officer
Carter, Anthony D
Project Start
2001-09-01
Project End
2016-01-31
Budget Start
2014-02-01
Budget End
2015-01-31
Support Year
12
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Utah
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
City
Salt Lake City
State
UT
Country
United States
Zip Code
84112
Karg, Travis J; Golic, Kent G (2018) Photoconversion of DAPI and Hoechst dyes to green and red-emitting forms after exposure to UV excitation. Chromosoma 127:235-245
Kurzhals, Rebeccah L; Fanti, Laura; Ebsen, A C Gonzalez et al. (2017) Chromosome Healing Is Promoted by the Telomere Cap Component Hiphop in Drosophila. Genetics 207:949-959
Rong, Yikang S; Golic, Mary M; Golic, Kent G (2016) The pugilistDominant Mutation of Drosophila melanogaster: A Simple-Sequence Repeat Disorder Reveals Localized Transport in the Eye. PLoS One 11:e0151377
Chakraborty, Riddhita; Li, Ying; Zhou, Lei et al. (2015) Corp Regulates P53 in Drosophila melanogaster via a Negative Feedback Loop. PLoS Genet 11:e1005400
Akbari, Omar S; Bellen, Hugo J; Bier, Ethan et al. (2015) BIOSAFETY. Safeguarding gene drive experiments in the laboratory. Science 349:927-9
Hill, Hunter; Golic, Kent G (2015) Preferential Breakpoints in the Recovery of Broken Dicentric Chromosomes in Drosophila melanogaster. Genetics 201:563-72
Titen, Simon W A; Lin, Ho-Chen; Bhandari, Jayaram et al. (2014) Chk2 and p53 regulate the transmission of healed chromosomes in the Drosophila male germline. PLoS Genet 10:e1004130
Golic, Kent G (2013) RNA-guided nucleases: a new era for engineering the genomes of model and nonmodel organisms. Genetics 195:303-8
Kurzhals, Rebeccah L; Titen, Simon W A; Xie, Heng B et al. (2011) Chk2 and p53 are haploinsufficient with dependent and independent functions to eliminate cells after telomere loss. PLoS Genet 7:e1002103
Golic, Mary M; Golic, Kent G (2011) A simple and rapid method for constructing ring-X chromosomes in Drosophila melanogaster. Chromosoma 120:159-64

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