The Relationship Between Chromatin Structure and DNA Damage in Mammalian Spermatozoa
| Autor: | Chris D. R. Arca, Kenneth Dominguez, W. Steven Ward |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Sperm Chromatin for the Researcher ISBN: 9781461484585 Sperm Chromatin ISBN: 9781441917812 |
| DOI: | 10.1007/978-1-4614-8459-2_3 |
| Popis: | At least two aspects of sperm chromatin seem to be vulnerable to DNA damage. The first is inherent within the structure of the chromatin, which predicts that the histone-bound segments are more susceptible to any type of DNA damaging agent than the protamine-bound DNA. The data support the conclusion that protamines do protect DNA from exogenous insults. The second aspect is the enzymes that are present in the sperm cell that can modify DNA, and activation of these segments can disrupt fertilization and/or embryonic development. We have reviewed only two of these, but it is possible that others exist that have not yet been documented. The idea that the highly condensed sperm chromatin retains some active enzymatic elements is an important consideration in the future development of assisted reproduction techniques (ARTs) that require the mechanical manipulation and storage of human sperm cells. Mammalian sperm DNA is one among the most compact chromatins in nature. It is condensed to a pseudocrystalline state and in this respect differs markedly from organization of the same DNA in the next stage of its development, the prereplicative paternal pronucleus of the one-cell embryo. However, even the highly condensed sperm chromatin is organized according to functions that the spermatozoon must perform. It has become clear in the past decade that certain structural elements of sperm chromatin packaging are essential for proper embryogenesis, while others function almost entirely to protect the paternal genome during transit. Both types of sperm DNA packaging have implications for clinical infertility. The stability of this highly condensed sperm DNA provides a degree of assurance that the male donor’s genome can withstand mechanical and biochemical manipulations required for ICSI and IVF. Biologically dead spermatozoa can still be used for successful ICSI if the DNA remains intact. However, recent evidence combined with new models for sperm chromatin structure also suggest that sperm DNA may be more sensitive to particular insults than others. Here, we review the current models of sperm chromatin structure with particular emphasis on its stability and unique vulnerability. |
| Databáze: | OpenAIRE |
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