scholarly journals 45 DNA Fragmentation of Epididymal Freeze-Dried Ram Spermatozoa Impairs Embryo Development

2018 ◽  
Vol 30 (1) ◽  
pp. 162
Author(s):  
L. Palazzese ◽  
D. A. Anzalone ◽  
J. Gosálvez´ ◽  
P. Loi ◽  
J. Saragusty

Sperm freeze-drying is a revolutionary technique that resolves many of the drawback of long-term storage under liquid nitrogen. The first significant result of this method was provided by Wakayama and Yanagimachi (1998 Nat. Biotechnol. 16, 639-641, 10.1038/nbt0798-639), demonstrating for the first time the birth of healthy offspring from epididymal freeze-dried (mouse) spermatozoa. Besides models in the mouse and rat, which are the first small mammals born from epididymal lyophilized sperm by intracytoplasmic sperm injection (ICSI), most studies in this field have used ejaculated sperm. In this work, aiming to repeat the result of Wakayama and Yanagimachi, we tried to apply this technique to epididymal spermatozoa from a large mammal (ram). Moreover, we checked the correlation between freeze-dried spermatozoa DNA integrity and embryo development. To do this, epididymal sperm from 4 rams was lyophilized in a medium containing trehalose, glucose, KCl, HEPES, and Trolox. To evaluate DNA damage and fragmentation at rehydration, part of the sperm was processed for sperm chromatin dispersion test (SCD) and two-tailed comet assay and the rest was used for ICSI. Compared with rams 1 and 3, rams 2 and 4 had higher rate of spermatozoa with intact DNA (median: 3.3% v. 16.5%, respectively), lower rate of single strand breaks (SSB; median: 94.2% v. 81.5%, respectively) and lower rate of double-strand breaks (DSB; median: 2.5% v. 2%, respectively). Embryo development following ICSI showed that blastocyst stage was reached only from rams that had sperm with more intact DNA: ram 2 (4.8%, n = 83) and ram 4 (6.3%, n = 64). Spermatozoa from rams 1 and 3 produced no blastocysts. This can be explained by the fact that rams 2 and 4 had higher rate of spermatozoa with intact DNA than rams 1 and 3. Definitively, the implication of sperm DNA damage in embryonic development should depend on the balance between the extent of sperm DNA fragmentation, the type of fragmentation (SSB or DSB), and the oocyte’s repair capacity. Rams 2 and 4 were the only rams that produced blastocyst probably because they had considerably more sperm with normal DNA; thus, it is important to select spermatozoa of the best quality to perform a good ICSI. Fragmentation of DNA due to the lyophilization process impairs embryonic development. To conclude, oocytes injected with epididymal freeze-dried ram spermatozoa can reach the blastocyst stage. These are preliminary results; more conclusive outcomes will be given following embryo transfer experiments that are now in progress.

2017 ◽  
Vol 29 (3) ◽  
pp. 630 ◽  
Author(s):  
S. D. Johnston ◽  
C. López-Fernández ◽  
F. Arroyo ◽  
J. L. Fernández ◽  
J. Gosálvez

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.


Biomonitoring ◽  
2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Hueiwang Anna Jeng ◽  
Ruei-Nian Li ◽  
Wen-Yi Lin

Abstract:The present study aimed to investigate the relationship between semen quality parameters and DNA integrity, and determine whether semen quality parameters could serve as a reliable biomarker for monitoring sperm DNA damage. Conventional semen parameters from a total of 202 male human subjects were analyzed. DNA fragmentation and 8-oxo-7,8-dihydro-2′- deoxyguanosine (8-oxoGuo) were used to assess sperm DNA integrity. DNA fragmentation was analyzed by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and sperm chromatin structure assay (SCSA), while 8-oxodGuo was quantified by the liquid chromatography/tandem mass spectrometry (LC-MS/MS) coupled with an on-line solid phase system. The levels of 8-oxodGuo levels in sperm were related to the percentages of DNA fragmentation measured by both the TUNEL and SCSA (r = 0.22, p = 0.048; r = 0.12, p = 0.039). Sperm vitality, motility and morphology from all of the participants exhibited a weak correlation with the levels of 8-oxodGuo and the percentages of DNA fragmentation. Semen quality parameters may be independent of the formation of DNA fragmentation and oxidative adducts in sperm. Semen quality parameters may be insufficient to monitor sperm DNA fragmentation and oxidative damage. DNA damage in sperm is recommended to be included in routine measurements.


2013 ◽  
Vol 85 (1) ◽  
pp. 8 ◽  
Author(s):  
Giuseppina Peluso ◽  
Alessandro Palmieri ◽  
Pietro Paolo Cozza ◽  
Giancarlo Morrone ◽  
Paolo Verze ◽  
...  

Introduction: Although the pathophysiology of the testicular damage associated with varicocele remains unclear, sperm DNA damage has been identified as a potential explanation for this cause of male infertility. The current study was designed to determine the extent of sperm nuclear DNA damage in patients with varicocele, and to examine its relationship with parameters of seminal motility. Materials and method: Semen samples from 60 patients with clinical varicocele and 90 infertile men without varicocele were examined. Varicocele sperm samples were classified as normal or pathological according to the 1999 World Health Organizzation guidelines. Sperm DNA damage was evalutated using the Halosperm kit, an improved Sperm Chromatin Dispersion (SCD) test. Results: The DNA fragmentation index (DFI: percentage of sperm with denatured nuclei) values was significantly higher in patients with varicocele, either with normal or abnormal (DFI 25.8 ± 3.2 vs 17.4 ± 2.8 - P < 0,01) semen profiles. In addition, an inverse correlation was found between spermatic motility and the degree of spermatic DNA fragmentation in patients with clinical varicocele. Conclusions: Varicocele is associated with high levels of DNA-damage in spermatozoa. In addition, in subjects with varicocele, abnormal spermatozoa motility is associated with higher levels of sperm DNA fragmentation. DNA fragmentation may therefore be an essential additional diagnostic test that should be recommended for patients with clinical varicocele.


2016 ◽  
Vol 283 (1826) ◽  
pp. 20152708 ◽  
Author(s):  
Javier delBarco-Trillo ◽  
Olga García-Álvarez ◽  
Ana Josefa Soler ◽  
Maximiliano Tourmente ◽  
José Julián Garde ◽  
...  

Sperm competition, a prevalent evolutionary process in which the spermatozoa of two or more males compete for the fertilization of the same ovum, leads to morphological and physiological adaptations, including increases in energetic metabolism that may serve to propel sperm faster but that may have negative effects on DNA integrity. Sperm DNA damage is associated with reduced rates of fertilization, embryo and fetal loss, offspring mortality, and mutations leading to genetic disease. We tested whether high levels of sperm competition affect sperm DNA integrity. We evaluated sperm DNA integrity in 18 species of rodents that differ in their levels of sperm competition using the sperm chromatin structure assay. DNA integrity was assessed upon sperm collection, in response to incubation under capacitating or non-capacitating conditions, and after exposure to physical and chemical stressors. Sperm DNA was very resistant to physical and chemical stressors, whereas incubation in non-capacitating and capacitating conditions resulted in only a small increase in sperm DNA damage. Importantly, levels of sperm competition were positively associated with sperm DNA fragmentation across rodent species. This is the first evidence showing that high levels of sperm competition lead to an important cost in the form of increased sperm DNA damage.


Author(s):  
M. Hachemi ◽  

: Objectives: The objective of this study is to propose thresholds of the sperm DNA fragmentation rate (IFA≤30% IFA31%-60% IFA>60%), in order to assess the clinical effects of the paternal genome on intra cytoplasmic sperm injection parameters, in particular the effect of the latter on early embryonic development. Materials and Methods: The procedure is a retrospective study, which involved 101 patients enrolled in an ICSI program with their partners. The index of spermatic DNA fragmentation rate was measured using the Sperm Chromatin Dispersion assay. Results: There is a negative correlation between high levels of the spermatic DNA fragmentation index and spermiological characteristics: Concentration P=0.002 and mobility P=0.0001. For ICSI results, there are different observations on the existence of a correlation between the spermatic DNA fragmentation index and fertility rate. On the other hand, the rate of sperm DNA fragmentation does not seem to influence early embryonic development, and even couples whose partners have a high fragmentation index manage to obtain the best quality embryos (P=0.002). We observe a decrease in the rate of implantation with an increase in the rate of alteration of the sperm genome, but this remains insignificant P > 0.05. Conclusion: ICSI remains the only alternative for men with a high rate of sperm DNA fragmentation. Moreover, the operator seems to influence the results more than is suggested. This does not exclude the paternal effect which may influence the quality of the concepltus later on. Keywords: DNA Fragmentation Index, ICSI, Fertilization Rate, Embryos Quality.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Valeria Maria Iommiello ◽  
Elena Albani ◽  
Alessandra Di Rosa ◽  
Alessandra Marras ◽  
Francesca Menduni ◽  
...  

Oxidative stress (OS) plays an essential role in male infertility aetiology by affecting sperm quality, function, and also the integrity of sperm DNA. The assessment of oxidative stress in semen may be an important tool to improve the evaluation of sperm reproductive capacity. The purpose of this study was the evaluation of any possible relation between the unbalance of oxidative stress caused by superoxide anion in the ejaculate with the presence of sperm DNA fragmentation and high concentration of round cells. 56 semen samples from males from couples suffering from infertility were evaluated according to World Health Organisation (WHO) 2010 guidelines. Oxidative stress levels from N1 (low) to N4 (high) were assessed in ejaculates using oxiSperm; DFI (sperm DNA fragmentation index) as assessed by the SCSA (Sperm Chromatin Structure Assay) was used for evaluation of sperm chromatin integrity. Our data show that high oxidative stress (N3-N4 levels) correlated positively with aDFI≥30%(P=0.0379)and round cells≥1.500.000/mL(P=0.0084). In conclusion, OS increases sperm DNA damage. Thus evaluation of semen OS extent of sperm DNA damage in infertile man could be useful to develop new therapeutic strategies and improve success of assisted reproduction techniques (ART).


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Teoman Cem Kadioglu ◽  
Emin Aliyev ◽  
Murad Celtik

Background. Varicocele is associated with high levels of DNA damage in spermatozoa due to oxidative stress and elevated levels of sperm DNA fragmentation, which has been currently proposed to be an essential additional diagnostic test to be recommended for patients with clinical varicocele. The aim of this study was to evaluate the parameters of semen and the DNA fragmentation index (DFI) in patients with varicocele before and after varicocelectomy.Methods. The details of 92 consecutive patients were retrospectively analyzed from January 2010 to December 2012. The sperm samples were evaluated according to the World Health Organization Guidelines. Sperm DNA damage, characterized as DFI, was evaluated by sperm chromatin structure assay using flow cytometry.Results. There was a statistically significant improvement in the semen concentration, the total motile count, the total normal sperm count, and the sperm DNA fragmentation index (DFI; the percentage of sperm with denatured DNA) after varicocelectomy. There was a large decrease in DFI from a preoperative mean of 42.6% to a postoperative mean of 20.5% (P<0.001). A higher preoperative DFI was associated with a larger decrease in postoperative DFI, and significant negative correlations were observed between the DFI and sperm motility (r=-0.42,P<0.01).Conclusion. Our data suggest that varicocelectomy can improve multiple semen parameters and sperm DNA damage in infertile men with varicocele. The patients with preoperative defects in those parameters showed greater improvement postoperatively. Further research in this area is needed to understand the exact mechanisms of DNA damage in infertile men with varicocele.


Zygote ◽  
2021 ◽  
pp. 1-8
Author(s):  
Shikai Wang ◽  
Weihong Tan ◽  
Yueyue Huang ◽  
Xianbao Mao ◽  
Zhengda Li ◽  
...  

Summary To determine the effects of sperm DNA fragmentation (SDF) on embryo morphokinetic parameters, cleavage patterns and embryo quality, this retrospective study analyzed 151 intracytoplasmic sperm injection (ICSI) cycles (1152 embryos collected) between November 2016 and June 2019. SDF was assessed using sperm chromatin dispersion. The cycles were divided into two groups based on the SDF rate: SDF < 15% (n = 114) and SDF ≥ 15% (n = 37). The embryo morphokinetic parameters, cleavage patterns, and embryo quality were compared between the two groups. The morphokinetic parameters tPNf, t2, t3, t4, t5, t6, and t8 were achieved significantly earlier in the SDF < 15% group compared with in the SDF ≥ 15% group. The fertilization and 2PN rates seemed to be significantly higher in the SDF < 15% group compared with in the SDF ≥ 15% group, while the abnormal cleavage rates were similar. However, a significantly higher rate of chaotic cleavage (CC) was observed in the SDF ≥ 15% group. The D3 high-quality embryo and available embryo rates were similar between the two groups. The blastocyst formation, high-quality blastocyst, and available blastocyst rates in the SDF < 15% group were significantly higher than those in the SDF ≥ 15% group. With an increase in SDF level, the chemical pregnancy, clinical pregnancy and implantation rates tended to decrease, while the miscarriage rate increased. This study demonstrated that SDF ≥ 15% reduces the fertilization rate of ICSI cycles and affects certain morphokinetic parameters. A higher SDF level can also induce a higher rate of CC, with subsequent decreases in the blastocyst formation rate and blastocyst quality.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 83-84
Author(s):  
Marina Fortes ◽  
Wei Liang Andre Tan ◽  
Laercio R Porto-Neto ◽  
Antonio Reverter ◽  
Gry B Boe-Hansen

Abstract Traits such as sperm morphology and motility are routine in veterinarian evaluations of bull fertility. However, they rarely are included in livestock breeding programs, which typically use only scrotal circumference (SC) and some female traits for fertility selection. We studied 25 male fertility traits measured in two research populations of bulls (1,099 Brahman, and 1,719 Tropical Composite) and one commercial population (2,490 Santa Gertrude bulls). Measurements included standard semen evaluation (e.g. sperm motility and morphology) and SC. In the research data, we also measured sperm DNA fragmentation and sperm protamine deficiency for about 50% of the bulls. Using a mixture of genomic and pedigree analyses, we estimated heritabilities and genetic correlations for all traits, in each population. Our analyses suggest that bull fertility traits have a heritable component, which makes selective breeding possible. The phenotype variation in sperm DNA fragmentation and sperm protamine deficiency traits also have a heritable component (h2 ~ 0.05–0.22). These first estimates for heritability of sperm chromatin phenotypes require further studies, with larger datasets, to corroborate present results. In all three populations, we observed genetic correlations across traits that were favorable, but not high. For example, the percentage of normal sperm (PNS) from the sperm morphology evaluation was positively correlated with SC. In the research data, sperm DNA fragmentation was negatively correlated with PNS (r2 ~ 0.23–0.33), meaning that bulls with a higher PNS had less DNA fragmentation, being therefore more fertile according to both indicators. Given the favorable and yet not high genetic correlations between traits, it is possible to envision that sperm chromatin phenotypes might form a panel, together with PNS and SC, for a comprehensive bull fertility index. Selection indices that include fertility traits are being implemented in the dairy industry and could be recommended for beef cattle, too. An index that benefits from the favorable genetic correlations between traits that describe different aspects of bull fertility is a sensible approach to selective breeding. The clinical use of complementary indicators for male fertility is largely accepted, when deciding on bull fitness for the mating season. We propose extending this rationale to create a multi-trait index that captures genetic merit for bull fertility. In addition, we performed genome-wide association analyses in the research data and identified eight QTLs in the X chromosome. Correlations and shared SNP associations support the hypothesis that these phenotypes have the same underlying cause: abnormal spermatogenesis. In conclusion, it is possible to improve bull fertility through selective breeding, by measuring complementary fertility traits. Genomic selection for bull fertility might be more accurate if the X chromosome mutations that underlie the discovered QTL are included in the analyses. Polymorphisms associated with fertility in the bull accumulate in the X chromosome, as they do in humans and mice, thus suggesting specialization of this chromosome.


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