Record Details

Crossing-over in a reversed acrocentric attached-X chromosome of Drosophila melanogaster

ScholarsArchive at Oregon State University

Field Value
Title Crossing-over in a reversed acrocentric attached-X chromosome of Drosophila melanogaster
Names Gethmann, Richard Charles (creator)
Mohler, James D. (advisor)
Date Issued 1966-08-08 (iso8601)
Note Graduation date: 1967
Abstract The frequency of exchanges was measured in a reversed
acrocentric compound X chromosome that is deficient for interstitial
heterochromatin. Previous studies on similar chromosomes
containing interstitial heterochromatin have demonstrated a very
low frequency of single exchanges, and high frequencies of the
double and no exchange classes. It has been postulated that this
abnormal distribution of exchanges is due to the interstitial heterochromatin
that is part of the compound. X's structure. The critical
test of this explanation has not been done previously and is now
provided by the present study.
Because the reversed acrocentric is lethal in the absence of
the missing heterochromatin, duplications were used to cover the
deficiency. Thus, the heterochromatin is present within the genome, but as a separate chromosome. Three structurally different
duplications were used. The results were as predicted by the
explanation, the frequency of single exchanges is high, and the
distribution of the exchanges is like that of free X chromosomes.
There was no difference in the effect of the three duplications upon
the exchange patterns.
Genre Thesis/Dissertation
Topic Drosophila melanogaster
Identifier http://hdl.handle.net/1957/47813

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