Dissertation Information for Joe Michael Cherry NAME: - Joe Michael Cherry
DEGREE:
- Ph.D.
DISCIPLINE:
- [No Discipline Recorded]
SCHOOL:
- University of California, Berkeley (USA) (1985)
ADVISORS: - None COMMITTEE MEMBERS: - None
MPACT Status: Incomplete - Not_Inspected
Title: INTERNALLY LOCATED TELOMERIC SEQUENCES IN THE MICRONUCLEUS OF TETRAHYMENA THERMOPHILA
Abstract: "The internally located C(,4)A(,2) repeat blocks of the Tetrahymena thermophila micronuclear genome were found to be associated with a DNA element family. These micC(,4)A(,2) were shown to be closely associated with a highly conserved 30 bp sequence. This conserved sequence contains the recognition site for the restriction enzyme BstXl, which cuts the micronuclear genome infrequently. BstXl digestion of micronuclear DNA placed all the micC(,4)A(,2) repeat blocks close to a restriction cut end, and released two major forms of DNA element family designated Tel-1 (Tetrahymena element or Telomere containing element), which are 9.7 and 13.2 kb in length. This family of elements is proposed to be transposable. The C(,4)A(,2) repeats found as part of the terminal inverted repeats of the Tel-1 elements are proposed to be added during or subsequent to the act of transposition. It is proposed that a linear form of the Tel-1 element is acted upon the the telomere addition activity within the micronucleus.
Several of the A+T rich C(,4)A(,2)-flanking sequences from the micC(,4)A(,2) clones were found to be similar to each other. This is believed to be the result of chromosomal duplications. Evidence that the micC(,4)A(,2) are flanked by sequences which are eliminated during macronuclear development is also shown. The micC(,4)A(,2) are not the result of macronuclear telomeres integrating into the micronuclear genome. I show here that at least one micronuclear C(,4)A(,2) repeat is not the direct precursor of a macronuclear telomere. From these data I suggest that micC(,4)A(,2) are not involved in new telomere formation during macronuclear development. Instead, these findings provide strong evidence that most micC(,4)A(,2) are at the ends of a common transposon-like element family.
Many of the micC(,4)A(,2) flanking sequences, despite their lack of close sequence similarity, show a predicted spiral structure as a result of sequence dependent helix bending. A program was written to predict sequence dependent bends in double helical DNA. When this program was applied to the yeast centromere core element II sequences, a spiraling structure was observed which may form a part of the structural properties of these sequences which allow them to make tighter bends."
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MPACT Scores for Joe Michael Cherry A = 0
C = 1
A+C = 1
T = 0
G = 0
W = 0
TD = 0
TA = 0
calculated 2008-01-31 06:33:28
Advisors and Advisees Graph
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