Molecular dosimetry of chemical mutagens: measurement of molecular dose and DNA repair germ cells Page: 6 of 21
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
5
protamine as a possible cause of, at least, a portion of the dominant lethals
produced by EMS in the mouse. In fact the germ cell stages most sensitive
to the action of EMS are those that have just replaced the usual chromosomal
histones with protamine at the time of treatment.13,22,41 As dominant
lethals are generally attributed to chromosomal aberrations, it is possible
that ethylated protamine could lead to dominant lethals through a weakening
of the chromatin structure, perhaps by ethylating the sulfhydryl groups of
cystonie and blocking normal disulfide bond formation in the condensing
sperm nucleus.
From the results discussed above it is appa-ent that the GST for the
induction of dominant lethals in the germ cells of male mice by EMS has
not yet been clearly established. Although the germ cell DNA is the most
likely GST it may not be the only one. Until the relationship between the
extent of protamine ethylation and dominant lethal frequency is established
it will not be possible to say whether or not mouse protamine is a GST.
Therefore, the possible role of mouse protamine in the induction of dominant
lethals by various alkylating agents is under investigation in our laboratory.
II. DNA repair in the germ cells of male mice
Another ver important area of investigation in molecular mechanisms
of mutagenesis in mammals is that of repair of damaged germ cell DNA.
Repair studies may also prove useful as an indirect measure of the molecular
dose received by the DNA, for as the molecular dose is raised the number
of DNA lesions and the amount of repair should also increase. Of course
at very high doses the repair system may be inhibited and a reduction in
repair could occur. In general, though, repair of damaged germ celi DNA
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Sega, G.A. Molecular dosimetry of chemical mutagens: measurement of molecular dose and DNA repair germ cells, article, January 1, 1975; Tennessee. (https://digital.library.unt.edu/ark:/67531/metadc870855/m1/6/: accessed April 25, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.