The Alu family represents the most ubiquitous interspersed repeated DNA sequence in the primate genome. There are about 500,000 of these 300 bp elements and they appear to amplify themselves throughout the genome via an RNA mediated mechanism termed retroposition. Because these sequences have a modest preference for integrating in gene-rich regions of the genome, we would expect that their interspersion would result in significant damage to the genome. We do know of several cases where these insertions have led to disease and it is certain that many more such events have occurred in the past, but not been passed on because of their lethality. Thus, it is important to understand the method and rate of amplification of these sequences, as well as its regulation. Recent evolutionary studies suggest that the vast majority of Alu family members are pseudogene copies of a limited set of """"""""master"""""""" genes. The data are consistent with the possibility that there has only been one master gene responsible for the majority of Alu amplification and evolution. It is our goal to molecularly clone an Alu """"""""master"""""""" gene and determine whether it has bene the primary source of all Alu amplifications. The isolation of this master gene will allow us to determine whether this gene is under evolutionary selection, and therefore may have a function. It will also lead to studies which will define the expression pattern and regulation of this gene and potentially to a laboratory system in which the Alu retroposition process can be characterized. It is also possible that it will provide us with the opportunity to determine whether there is a significant level of Alu amplification in somatic cells, perhaps leading to tumors in some cases. Previous efforts to clone an Alu master gene have been thwarted by the extremely high copy number of Alu sequences that must be sorted through to find the master. We had previously defined a subfamily of 500 sequences that are the most recently inserted and came from a distinct master gene. More recently, an Alu family member has been found that inserted in the NF1 gene of a patient, causing neurofibromatosis. This insertion occurred during the last generation and, although it had all the markings of our recent subfamily, it also had two new sequence changes. We can now use those two changes as molecular handles to isolate the master gene which made that most recent insertion. This will then allow us to determine the qualities that define a master gene.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM045668-03
Application #
2183309
Study Section
Mammalian Genetics Study Section (MGN)
Project Start
1993-05-01
Project End
1997-04-30
Budget Start
1995-05-01
Budget End
1996-04-30
Support Year
3
Fiscal Year
1995
Total Cost
Indirect Cost
Name
Louisiana State University Hsc New Orleans
Department
Biochemistry
Type
Schools of Dentistry
DUNS #
782627814
City
New Orleans
State
LA
Country
United States
Zip Code
70112
Servant, Geraldine; Streva, Vincent A; Deininger, Prescott L (2017) Transcription coupled repair and biased insertion of human retrotransposon L1 in transcribed genes. Mob DNA 8:18
Servant, Geraldine; Streva, Vincent A; Derbes, Rebecca S et al. (2017) The Nucleotide Excision Repair Pathway Limits L1 Retrotransposition. Genetics 205:139-153
Morales, Maria E; Derbes, Rebecca S; Ade, Catherine M et al. (2016) Heavy Metal Exposure Influences Double Strand Break DNA Repair Outcomes. PLoS One 11:e0151367
Servant, Geraldine; Deininger, Prescott L (2015) Insertion of Retrotransposons at Chromosome Ends: Adaptive Response to Chromosome Maintenance. Front Genet 6:358
Streva, Vincent A; Jordan, Vallmer E; Linker, Sara et al. (2015) Sequencing, identification and mapping of primed L1 elements (SIMPLE) reveals significant variation in full length L1 elements between individuals. BMC Genomics 16:220
Morales, Maria E; White, Travis B; Streva, Vincent A et al. (2015) The contribution of alu elements to mutagenic DNA double-strand break repair. PLoS Genet 11:e1005016
White, Travis B; McCoy, Adam M; Streva, Vincent A et al. (2014) A droplet digital PCR detection method for rare L1 insertions in tumors. Mob DNA 5:30
Ade, Catherine; Roy-Engel, Astrid M; Deininger, Prescott L (2013) Alu elements: an intrinsic source of human genome instability. Curr Opin Virol 3:639-45
Wallace, Nicholas A; Gasior, Stephen L; Faber, Zachary J et al. (2013) HPV 5 and 8 E6 expression reduces ATM protein levels and attenuates LINE-1 retrotransposition. Virology 443:69-79
Streva, Vincent A; Faber, Zachary J; Deininger, Prescott L (2013) LINE-1 and Alu retrotransposition exhibit clonal variation. Mob DNA 4:16

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