scholarly journals Sperm DNA fragmentation induced by DNAse I and hydrogen peroxide: an in vitro comparative study among different mammalian species

Reproduction ◽  
2010 ◽  
Vol 140 (3) ◽  
pp. 445-452 ◽  
Author(s):  
Paola Villani ◽  
Patrizia Eleuteri ◽  
Maria Giuseppa Grollino ◽  
Michele Rescia ◽  
Pierluigi Altavista ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Comet Assay ◽  
Chromatin Structure ◽  
Dnase I ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Dna Breaks ◽  
Sperm Dna

Sperm DNA damage may have adverse effects on reproductive outcome. Sperm DNA breaks can be detected by several tests, which evaluate DNA integrity from different and complementary perspectives and offer a new class of biomarkers of the male reproductive function and of its possible impairment after environmental exposure. The remodeling of sperm chromatin produces an extremely condensed nuclear structure protecting the nuclear genome from adverse environments. This nuclear remodeling is species specific, and differences in chromatin structure may lead to a dissimilar DNA susceptibility to mutagens among species. In this study, the capacity of the comet assay in its two variants (alkaline and neutral) to detect DNA/chromatin integrity has been evaluated in human, mouse, and bull sperm. The hypothesis that chromatin packaging might influence the amount of induced and detectable DNA damage was tested by treating sperm in vitro with DNAse I, whose activity is strictly dependent upon its DNA accessibility. Furthermore, hydrogen peroxide (H2O2) was used to assess whether spermatozoa of the three species showed a different sensitivity to oxidative stress. DNAse I-induced damage was also assessed by the sperm chromatin structure assay and the TUNEL assay, and the performances of these two assays were compared and correlated with the comet assay results. Results showed a different sensitivity to DNAse I treatment among the species with human sperm resulting the most susceptible. On the contrary, no major differences among species were observed after H2O2 treatment. Furthermore, the three tests show a good correlation in revealing sperm with DNA strand breaks.

scholarly journals Complete Chromatin Decondensation of Pig Sperm Is Required to Analyze Sperm DNA Breaks With the Comet Assay

2021 ◽  
Vol 9 ◽  
Author(s):  
Jordi Ribas-Maynou ◽  
Ariadna Delgado-Bermúdez ◽  
Estela Garcia-Bonavila ◽  
Elisabeth Pinart ◽  
Marc Yeste ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Comet Assay ◽  
Dnase I ◽  
Proteinase K ◽  
Farm Animals ◽  
Sperm Chromatin ◽  
Dna Breaks ◽  
Chromatin Decondensation ◽  
Sperm Dna

Sperm quality is usually evaluated prior to artificial insemination in farm animals. In addition to conventional semen analysis, other biomarkers, such as mitochondrial activity, integrity and lipid disorder of plasma membrane, generation of reactive oxygen species (ROS) and sperm DNA integrity, have been found to be related to fertility rates in different species. While mounting evidence indicates that the Comet assay is a sensitive method for the detection of DNA breaks, complete sperm chromatin decondensation is required in order to properly analyze the presence of single- and double-strand DNA breaks. In this sense, a previous study showed that longer lysis treatment with proteinase K is needed to achieve complete chromatin decondensation. The current work sought to determine which specific lysis treatment leads to complete chromatin decondensation in pig sperm, as this is needed for the measurement of DNA damage in this species. With this purpose, incubation with a lysis solution containing proteinase K for 0, 30, and 180 min was added to the conventional protocol. The impact of the DNA damage induced by hydrogen peroxide (H2O2; 0.01 and 0.1%) and DNAse I (1U and 4U) was also evaluated. Complete chromatin decondensation was only achieved when a long additional lysis treatment (180 min) was included. Furthermore, olive tail moment (OTM) and percentage of tail DNA (TD) indicated that a higher amount of DNA breaks was detected when hydrogen peroxide and DNAse I treatments were applied (P < 0.05). The comparison of treated and control sperm allowed defining the thresholds for OTM; these thresholds revealed that the percentage of sperm with fragmented DNA determined by the alkaline Comet does not depend on chromatin decondensation (P > 0.05). In conclusion, complete chromatin decondensation prior to alkaline and neutral Comet assays is needed to analyze DNA breaks in pig sperm.

scholarly journals Sperm chromatin structure assay versus sperm chromatin dispersion kits: Technical repeatability and choice of assisted reproductive technology procedure

2020 ◽  
Vol 47 (4) ◽  
pp. 277-283
Author(s):  
Vidya Laxme B ◽  
Silviya Stephen ◽  
Ramyashree Devaraj ◽  
Sridurga Mithraprabhu ◽  
Ricardo P. Bertolla ◽  
...  
Keyword(s):  
Assisted Reproductive Technology ◽  
Chromatin Structure ◽  
Reproductive Technology ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Vitro Fertilization ◽  
Sperm Chromatin Structure Assay ◽  
Sperm Dna ◽  
The Impact

Objective: The sperm DNA fragmentation index (DFI) guides the clinician’s choice of an appropriate assisted reproductive technology (ART) procedure. The DFI can be determined using commercially available methodologies, including sperm chromatin dispersion (SCD) kits and sperm chromatin structure assay (SCSA). Currently, when DFI is evaluated using SCD kits, the result is analyzed in reference to the SCSA-derived threshold for the choice of an ART procedure. In this study, we compared DFI values obtained using SCSA with those obtained using SCD and determined whether the difference affects the choice of ART procedure.Methods: We compared SCSA to two SCD kits, CANfrag (n=36) and Halosperm (n=31), to assess the DFI values obtained, the correlations between tests, the technical repeatability, and the impact of DFI on the choice of ART. Results: We obtained higher median DFI values using SCD kits than when using SCSA, and this difference was significant for the CANfrag kit (p<0.001). The SCD kits had significantly higher coefficients of variation than SCSA (p<0.0001). In vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) would be chosen for a significantly higher proportion of patients if a decision were made based on DFI derived from SCD rather than DFI determined using SCSA (p=0.003). Conclusion: Our results indicate that SCD kit-specific thresholds should be established in order to avoid the unnecessary use of IVF/ICSI based on sperm DNA damage for the management of infertility. Appropriate measures should be taken to mitigate the increased variability inherent to the methods used in these tests.

scholarly journals Validation of the sperm chromatin dispersion (SCD) test in the amphibian Xenopus laevis using in situ nick translation and comet assay

2015 ◽  
Vol 27 (8) ◽  
pp. 1168 ◽  
Author(s):  
K. Pollock ◽  
J. Gosálvez ◽  
F. Arroyo ◽  
C. López-Fernández ◽  
M. Guille ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Xenopus Laevis ◽  
Semen Quality ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Nick Translation ◽  
In Situ Nick Translation ◽  
Sperm Dna

The integrity of sperm DNA is becoming increasingly recognised as an important parameter of semen quality, but there are no published reports of this procedure for any amphibian. The primary aim of this study was to apply a modified sperm chromatin dispersion (SCD) test (Halomax) to an amphibian sperm model (African clawed frog; Xenopus laevis) and to validate the assay against in situ nick translation (ISNT) and the double-comet assay procedure. Inactivated spermatozoa were collected from fresh testes (n = 3). Sperm DNA fragmentation (SDF) for each sperm sample was conducted immediately following activation (T0) and again after 1 h (T1) and 24 h (T24) of incubation at room temperature in order to produce a range of spermatozoa with differing levels of DNA damage. The SCD procedure resulted in the production of three nuclear morphotypes; amphibian sperm morphotype 1 (ASM-1) and ASM-2 showed no evidence of DNA damage, whereas ASM-3 spermatozoa were highly fragmented with large halos of dispersed DNA fragments and a reduced nuclear core. ISNT confirmed that ASM-3 nuclei contained damaged DNA. There was a significant correlation (r = 0.9613) between the levels of ASM-3 detected by the SCD test and SDF revealed by the double-comet assay.

The assessment of sperm DNA fragmentation in the saltwater crocodile (Crocodylus porosus)

2017 ◽  
Vol 29 (3) ◽  
pp. 630 ◽  
Author(s):  
S. D. Johnston ◽  
C. López-Fernández ◽  
F. Arroyo ◽  
J. L. Fernández ◽  
J. Gosálvez
Keyword(s):  
Dna Damage ◽  
Dna Fragmentation ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Fragmented Dna ◽  
Sperm Dna ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus ◽  
Dispersion Test ◽  
Sperm Nuclei

Herein we report a method of assessing DNA fragmentation in the saltwater crocodile using the sperm chromatin dispersion test (SCDt) after including frozen–thawed spermatozoa in a microgel (Halomax; Halotech DNA, Madrid, Spain). Following controlled protein depletion, which included a reducing agent, sperm nuclei with fragmented DNA showed a homogeneous and larger halo of chromatin dispersion with a corresponding reduced nucleoid core compared with sperm with non-fragmented DNA. The presence of DNA damage was confirmed directly by incorporation of modified nucleotides using in situ nick translation (ISNT) and indirectly by studying the correlation of the SCDt with the results of DNA damage visualisation using a two-tailed comet assay (r = 0.90; P = 0.037). Results of the SCDt immediately following thawing and after 5 h incubation at 37°C in order to induce a range of DNA damage revealed individual crocodile differences in both the baseline level of DNA damage and DNA longevity.

Sperm DNA fragmentation: awakening the sleeping genome

2007 ◽  
Vol 35 (3) ◽  
pp. 626-628 ◽  
Author(s):  
J.A. Shaman ◽  
Y. Yamauchi ◽  
W.S. Ward
Keyword(s):  
Dna Synthesis ◽  
Dna Fragmentation ◽  
Sperm Chromatin ◽  
Sperm Function ◽  
Sperm Dna Fragmentation ◽  
Dna Breaks ◽  
Mouse Sperm ◽  
Sperm Dna ◽  
Total Digestion ◽  
Mammalian Spermatozoa

We have recently demonstrated that mammalian spermatozoa have the ability to degrade their DNA by a mechanism that is similar to apoptosis in somatic cells. When this mechanism is activated, the DNA is first degraded into loop-sized fragments by TOP2B (topoisomerase IIB). This degradation, termed sperm chromatin fragmentation, can be reversed by EDTA, which causes TOP2B to religate the double-stranded breaks it originally produced. Under certain conditions, a nuclease then degrades the sperm DNA further, digesting the entire sperm genome. When mouse spermatozoa which have been treated to induce TOP2B-mediated DNA breaks are injected into oocytes, the paternal DNA is specifically and completely degraded. This total digestion of paternal DNA occurs at the time of DNA synthesis initiation. In the present study, we explore the significance of an active TOP2B in the nucleus for mouse sperm function.

scholarly journals Rapid rates of sperm DNA damage after activation in tench (Tinca tinca: Teleostei, Cyprinidae) measured using a sperm chromatin dispersion test

Reproduction ◽  
2009 ◽  
Vol 138 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Carmen López-Fernández ◽  
Matthew J G Gage ◽  
Francisca Arroyo ◽  
Altea Gosálbez ◽  
Ana M Larrán ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Dna Fragmentation ◽  
Living Organism ◽  
Sperm Chromatin ◽  
Tinca Tinca ◽  
External Fertilization ◽  
Sperm Dna Damage ◽  
Sperm Dna ◽  
Dispersion Test

Spermatozoal haplotypic DNA is prone to damage, leading to male fertility problems. So far, the assessment of sperm DNA breakage has been challenging because protamines render the nuclear chromatin highly compacted. Here, we report the application of a new test to quantify DNA fragmentation in spermatozoa of an externally fertilizing teleost fish. The sperm chromatin dispersion (SCD) test uses a species-specific lysing solution to generate controlled protein depletion that, followed by DNA-specific fluorescent labelling, allows an easy morphological discrimination between nuclei affected by DNA damage. Using tench (Tinca tinca) as our model, we first trialled the test against established, but more technically demanding, assays employing in situ nick translation (ISNT) and the comet assay. The SCD test showed high concordance with ISNT, comet assay measures and a chromatin-swelling test, confirming the application of this straightforward SCD technique to various aspects of reproductive biology. Second, we examined between-male variation in DNA damage, and measured changes through time following spermatozoal activation. Between-male variation in the basal levels of average DNA damage ranged from 0 to 20% of sperm showing damage, and all showed increases in DNA fragmentation through time (0–60 min). The rates of DNA damage increase are the fastest so far recorded in sperm for a living organism, and may relate to the external fertilization mode. Our findings have relevance for broodstock selection and optimizing IVF protocols routinely used in modern aquaculture.

scholarly journals Evidence that single-stranded DNA breaks are a normal feature of koala sperm chromatin, while double-stranded DNA breaks are indicative of DNA damage

Reproduction ◽  
2009 ◽  
Vol 138 (2) ◽  
pp. 267-278 ◽  
Author(s):  
Yeng Peng Zee ◽  
Carmen López-Fernández ◽  
F Arroyo ◽  
Stephen D Johnston ◽  
William V Holt ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Dna Fragmentation ◽  
Sperm Nucleus ◽  
Severe Form ◽  
Sperm Chromatin ◽  
Dna Breaks ◽  
Single Stranded Dna ◽  
Double Stranded Dna ◽  
Dispersion Test

In this study, we have used single and double comet assays to differentiate between single- and double-stranded DNA damage in an effort to refine the interpretation of DNA damage in mature koala spermatozoa. We have also investigated the likelihood that single-stranded DNA breakage is part of the natural spermiogenic process in koalas, where its function would be the generation of structural bends in the DNA molecule so that appropriate packaging and compaction can occur. Koala spermatozoa were examined using the sperm chromatin dispersion test (SCDt) and comet assays to investigate non-orthodox double-stranded DNA. Comet assays were conducted under 1) neutral conditions; and 2) neutral followed by alkaline conditions (double comet assay); the latter technique enabled simultaneous visualisation of both single-stranded and double-stranded DNA breaks. Following the SCDt, there was a continuum of nuclear morphotypes, ranging from no apparent DNA fragmentation to those with highly dispersed and degraded chromatin. Dispersion morphotypes were mirrored by a similar diversity of comet morphologies that could be further differentiated using the double comet assay. The majority of koala spermatozoa had nuclei with DNA abasic-like residues that produced single-tailed comets following the double comet assay. The ubiquity of these residues suggests that constitutive alkali-labile sites are part of the structural configuration of the koala sperm nucleus. Spermatozoa with ‘true’ DNA fragmentation exhibited a continuum of comet morphologies, ranging from a more severe form of alkaline-susceptible DNA with a diffuse single tail to nuclei that exhibited both single- and double-stranded breaks with two comet tails.

scholarly journals Study of DNA damage induced by dental bleaching agents in vitro

2006 ◽  
Vol 20 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Daniel Araki Ribeiro ◽  
Mariângela Esther Alencar Marques ◽  
Daisy Maria Fávero Salvadori
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Comet Assay ◽  
Single Cell ◽  
Chinese Hamster ◽  
Dental Bleaching ◽  
Dna Breakage ◽  
The Mean ◽  
Positive Controls

Dental bleaching is a simple and conservative procedure for aesthetic restoration of vital and non-vital discolored teeth. Nevertheless, a number of studies have demonstrated the risk of tissue damage from the contact of these agents with the oral mucosa. In the current study, the genotoxic potential associated with exposure to dental bleaching agents was assessed by the single cell gel (comet) assay in vitro. Chinese hamster ovary (CHO) cells in vitro were exposed to six commercial dental bleaching agents (Clarigel Gold - Dentsply; Whitespeed - Discus Dental; Nite White - Discus Dental; Magic Bleaching - Vigodent; Whiteness HP - FGM and Lase Peroxide - DMC). The results pointed out that all dental bleaching agents tested contributed to DNA damage as depicted by the mean tail moment, being the strongest effect observed with the highest dose of hydrogen peroxide (Whiteness HP and Lase Peroxide, at a 35% concentration). On the other hand, Magic Bleaching (Vigodent) induced the lowest level of DNA breakage. Negative and positive controls displayed absence and presence of DNA-damaging, respectively. Taken together, these results suggest that dental bleaching agents may be a factor that increases the level of DNA damage. A higher concentration of hydrogen peroxide produced higher noxious activities in the genome as detected by single cell gel (comet) assay.

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