Title page for ETD etd-06252007-095106

Type of Document

Dissertation

Author

Coy, Monique Royer

URN

etd-06252007-095106

Title

Dd34e Dna Transposable Elements of Mosquitoes: Whole-Genome Survey, Evolution, and Transposition

Degree

PhD

Department

Biochemistry

Advisory Committee

Advisor Name	Title
Tu, Zhijian Jake	Committee Chair
Adelman, Zachary N.	Committee Member
Gillaspy, Glenda E.	Committee Member
Kennelly, Peter J.	Committee Member
McDowell, John M.	Committee Member

Keywords

interspersed repeat
mosquito
DNA transposable element
evolution
gambol
horizontal transfer
Tc1
transposition assay

Date of Defense

2007-06-13

Availability

unrestricted

Abstract

Transposable elements (TEs) are mobile genetic elements capable of replicating and
spreading within, and in some cases, between genomes. I describe a whole-genome
analysis of DD34E TEs, which belong to the IS630-Tc1-mariner superfamily of DNA
transposable elements, in the African malaria mosquito, Anopheles gambiae. Twenty-six
new transposons as well as a new family, gambol, were identified. The gambol family
shares the DD34E catalytic motif with Tc1-DD34E transposons, but is distinct from these
elements in their phylogenetic relationships. Although gambol appears to be related to a
few DD34E transposons from cyanobacteria and fungi, no gambol elements have been
reported in any other insects or animals thus far. This discovery expands the already
expansive diversity of the IS630-Tc1-mariner TEs, and raises interesting questions as to
the origin of gambol elements and their apparent diversity in An. gambiae. Several
DD34E transposons discovered in An. gambiae possess characteristics that are associated
with recent transposition, such as high sequence identity between copies, and intact
terminal-inverted repeats and open reading frames. One such element, AgTango, was also
found in a distantly related mosquito species, Aedes aegypti, at high amino acid sequence
identity (79.9%). It was discovered that Tango transposons have patchy distribution
among twelve mosquito species surveyed using PCR as well as genomic searches,
suggesting a possible case for horizontal transfer. Additionally, it was discovered that in
some mosquito genomes, there are several Tango transposons. These observations
suggest differential evolutionary scenarios and/or TE-host interaction of Tango elements
between mosquito species. This strengthened the case that AgTango may be a functional
transposase, and I sought to test its potential activity in a cell culture-based inter-plasmid
transposition assay using the Herves plasmids as a positive control (Arensburger et al.,
2005). AgTango constructs were successfully constructed; however, no transposition
events were detected for Tango or Herves. Because the positive control failed to work, no
assessment can be made concerning Tango's transposase. Possible causes and solutions
for these results, alternative means to detect transposition, as well as future directions
with Tango are discussed.

Files

Filename		Size	Approximate Download Time (Hours:Minutes:Seconds)
Filename		Size	28.8 Modem	56K Modem	ISDN (64 Kb)	ISDN (128 Kb)	Higher-speed Access
	Coy_Dissertation_2007_11.pdf	3.16 Mb	00:14:38	00:07:31	00:06:35	00:03:17	00:00:16