scholarly journals 272 Proposing a combination of heritable fertility traits for bull selection

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
Keyword(s):  
Dna Fragmentation ◽  
X Chromosome ◽  
Selective Breeding ◽  
Genetic Correlations ◽  
Research Data ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Sperm Dna ◽  
Fertility Traits ◽  
Protamine Deficiency

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.

Sperm DNA fragmentation measured by sperm chromatin dispersion impacts morphokinetic parameters, fertilization rate and blastocyst quality in ICSI treatments

Zygote ◽  
2021 ◽  
pp. 1-8
Author(s):  
Shikai Wang ◽  
Weihong Tan ◽  
Yueyue Huang ◽  
Xianbao Mao ◽  
Zhengda Li ◽  
...  
Keyword(s):  
Dna Fragmentation ◽  
Embryo Quality ◽  
Fertilization Rate ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Blastocyst Formation ◽  
High Quality ◽  
Morphokinetic Parameters ◽  
Sperm Dna ◽  
Blastocyst Quality

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.

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.

313 ASSESSMENT OF SPERM DNA FRAGMENTATION IN CANINE EJACULATES USING THE Sperm-Halomax® KIT: PRELIMINARY RESULTS

2010 ◽  
Vol 22 (1) ◽  
pp. 312 ◽  
Author(s):  
M. Hidalgo ◽  
M. R. Murabito ◽  
M. J. Gálvez ◽  
S. Demyda ◽  
L. J. De Luca ◽  
...  
Keyword(s):  
Dna Fragmentation ◽  
Sperm Concentration ◽  
Semen Parameters ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Fragmentation Index ◽  
Sperm Dna ◽  
Commercial Kit ◽  
Sperm Dna Fragmentation Index ◽  
Dna Fragmentation Index

Recently, a new procedure for the analysis of sperm DNA fragmentation has been developed for humans and different mammalian species, using a commercial kit based on the sperm chromatin dispersion (SCD) test; however, a descriptive study in canine semen has not been performed. The aim of this work was to assess the sperm DNA fragmentation in canine ejaculates using the SCD test and 2 different staining techniques. For this purpose, ejaculates were collectedby digital manipulation from4 healthy dogs of different breeds (1 German Pointer, 2 Spanish Greyhounds, and 1 Crossbreed). After collection, the sperm-rich fraction of the ejaculates from 3 dogs were pooled each time (n = 4) and then extended in Dulbecco’s phosphate buffered saline. All the pooled semen samples presented physiological values concerning routine semen parameters (motility, morphology, and sperm concentration). The sperm DNA fragmentation was assessed using the Sperm-Halomax® commercial kit specifically developed for canine semen (Halotech DNA SL, Madrid, Spain). Two semen aliquots of the diluted pooled semen samples were processed on each pre-treated slide provided in the kit following the manufacturer’s instructions. The last step was the staining technique. We stained each slide with 2 different staining procedures. The first half of the slide was stained with propidium iodide (Sigma-Aldrich, St. Louis, MO, USA) mixed in a proportion 1 : 1 with an antifading solution. The second half of the slide was stained for 15 min in Wright solution (1.01383.0500, Merck, Whitehouse Station, NJ, USA) 1 :1 in Phosphate Buffer pH 6.88 (1.07294.1000, Merck). The stained slides were observed using fluorescence and light microscopy, respectively. Five hundred sperm per slide were counted. Spermatozoa with fragmented DNA showed a large and spotty halo of chromatin dispersion. Unfragmented sperm only showed a small and compact halo. Statistical analyses were performed using the Statistical Package for Social Science version 12.0 (SPSS Inc., Chicago, IL, USA). The sperm DNA fragmentation index was compared between Wright and fluorescence staining methods by ANOVA. Results were expressed as mean ± standard error of the mean. The first report of the sperm DNA fragmentation index in canine ejaculates was 2.26 ± 0.53% for Wright staining and 1.99 ± 0.10% for fluorescence technique. No differences were found between staining procedures. In conclusion, it was possible to assess the sperm DNA fragmentation of canine ejaculates using 2 different staining procedures, expecting that continuous research could be useful in defining the role of DNA fragmentation SCD test in canine semen evaluation and cryopreservation.

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.

Sperm DNA fragmentation: causes and identification

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Thais Rose dos Santos Hamilton ◽  
Mayra Elena Ortiz D’Ávila Assumpção
Keyword(s):  
Dna Fragmentation ◽  
Semen Analysis ◽  
Sperm Chromatin ◽  
Dna Integrity ◽  
Sperm Dna Fragmentation ◽  
Functional Capability ◽  
Sperm Dna Integrity ◽  
Sperm Dna ◽  
Fertility Disorders ◽  
Chromatin Integrity

SummarySperm DNA fragmentation is referred to as one of the main causes of male infertility. Failures in the protamination process, apoptosis and action of reactive oxygen species (ROS) are considered the most important causes of DNA fragmentation. Action of ROS or changes in sperm protamination would increase the susceptibility of sperm DNA to fragmentation. Routine semen analysis is unable to estimate sperm chromatin damage. Sperm DNA integrity influences sperm functional capability, therefore tests that measure sperm DNA fragmentation are important to assess fertility disorders. Actually, there is a considerable number of methods for assessing sperm DNA fragmentation and chromatin integrity, sperm chromatin stability assay (SCSA modified), sperm chromatin dispersion (SCD), comet assay, transferase dUTP nick end labelling (TUNEL); and protamine evaluation in sperm chromatin assay, such as toluidine blue, CMA3, protamine expression and evaluation of cysteine radicals. This review aims to describe the main causes of sperm DNA fragmentation and the tests commonly used to evaluate sperm DNA fragmentation.

82 DNA FRAGMENTATION DYNAMICS OF KOALA SPERMATOZOA

2009 ◽  
Vol 21 (1) ◽  
pp. 141 ◽  
Author(s):  
Y. P. Zee ◽  
C. Lopez-Fernandez ◽  
J. Gosalvez ◽  
W. V. Holt ◽  
S. D. Johnston
Keyword(s):  
Dna Fragmentation ◽  
Dna Degradation ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Fragmentation Index ◽  
Sperm Dna ◽  
Rate Of Increase ◽  
Fragmentation Dynamics ◽  
Sperm Dna Fragmentation Index ◽  
Dna Fragmentation Index

Koala sperm chromatin has a tendency to relax following incubation and thawing but the background incidence and dynamics of DNA fragmentation during semen processing at 35°C and following chilled and frozen preservation has not been investigated. This study (n = 10) was designed to establish the fragmentation dynamics of koala sperm DNA at body temperature (35°C), after chilling (4°C) for upward of 16 days, and following a standard freeze–thaw protocol (Johnston SD et al. 2006 Cryobiology 53, 218–228). Sperm DNA fragmentation index (sDFI) was determined using a Halomax kit (ChromaCell SL, Madrid, Spain), which had been customized and validated for koalas (Johnston SD et al. 2007 J. Androl. 28, 891–899). All semen was assessed for sDFI over a 48-h incubation period (T0, T2, T6, T24, and T48) at 35°C. After incubation at 35°C for 48 h, the sDFI and rate of DNA degradation of freshly diluted spermatozoa were highly variable between individuals; the sDFI for 2 koalas remained consistently low (≤2%) whereas the other 8 had sDFI of 8 to 12% after incubation. Chilled storage increased sDFI in all animals, but the rate of increase and the time at which the DNA started to fragment also varied between koalas; sDFI for 1 koala increased immediately upon rewarming after being chilled for 4 h, whereas that of another koala did not increase until after 8 days of chilling and 24 h of incubation at 35°C. Animals also responded to cryopreservation differently; sDFI increased after thawing for 2 of the koalas but did not increase in the others. Subsequent evaluation of frozen–thawed spermatozoa from a greater number of captive koalas (n = 22), and under extended conditions of post-thaw incubation (up to 17 days at 35°C) permitted categorization of the koalas into 3 distinctive groups based on their DNA fragmentation dynamics and rate of DNA degradation. For 7 of the animals, sDFI remained close to the basal level when incubated at 35°C over 7 days, whereas 2 of the koalas had sDFI ranging from 40 to 70% after 24 h of incubation. This study confirmed the occurrence of inter-animal variability in the dynamics of DNA fragmentation, a finding that was apparent whether or not the spermatozoa had been subjected to chilling or cryopreservation.

145 Effect of Dietary Organic Zinc Levels on Boar (Sus scrofa domesticus) Sperm DNA Fragmentation Dynamics

2018 ◽  
Vol 30 (1) ◽  
pp. 212
Author(s):  
A. Martínez ◽  
J. Gosálvez ◽  
C. López-Fernández ◽  
J. A. G. González ◽  
C. G. Artiga ◽  
...  
Keyword(s):  
Dna Fragmentation ◽  
Sus Scrofa ◽  
Molecular Probes ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Sperm Dna ◽  
Boar Sperm ◽  
Fragmentation Dynamics ◽  
Sus Scrofa Domesticus ◽  
Organic Zn

Zinc (Zn) is essential for the development and activity of sperm, although its cytotoxic effect on sperm has been little studied. This study evaluated the effect of organic Zn; that is, Zn-methionate (Zn-Met), on the DNA fragmentation of boar sperm. Domestic boars (York × Landrace, Sus scrofa domesticus; n = 15) were randomly allocated into 3 levels of Zn dietary concentrations: 25 (Control), 150, or 200 ppm. Sperm DNA fragmentation dynamics were evaluated over an 8-wk period after Zn-Met supplementation. The Sperm-Sus-Halomax® Kit (Halosperm SL, Madrid, Spain), a 1:1 mixture of SYBR I (10×; Invitrogen Molecular Probes, Thermo Fisher Scientific, Waltham, MA, USA) in Vectashield Mounting Medium (Vector Laboratories Inc., Burlingame, CA, USA) for DNA staining, and fluorescence microscopy (Nikon Eclipse 80i; Nikon, Tokyo, Japan) were used to analyse DNA fragmentation dynamics; that is, sperm chromatin dispersion (SCD) test, of the boar sperm. Samples were diluted 2:10 (v:v) in either (a) Beltsville Thawing Solution (BTS) extender, or (b) PBS, to determine the effects, if any, of extender. Extended sperm were stored at 15°C for 8 days for daily SCD testing. Data were analysed as a completely randomised design with repeated-measures serially in time (SAS Institute Inc., Cary, NC, USA). Main effects of the variables (i.e. dietary Zn and extender) and their interaction were studied. Means were compared using Tukey´s test, with significance set at the <0.05 α-level. Supplementation of the diet with 200 ppm of Zn-Met had an adverse effect on the integrity of pig sperm DNA from the beginning of supplementation to the last day of the experiment (i.e. fresh ejaculate 0 h = 9.44% fragmented, motility = 79.6%). However, Control and 150 ppm Zn-Met dietary levels did not significantly affect sperm DNA integrity (i.e. fresh ejaculate 0 h = 1.43% and 1.73% fragmented and motility = 84.1% and 84.5%, respectively). With regard to the semen extenders BTS and PBS, there was no difference (P > 0.05) in sperm DNA fragmentation dynamics for the first 3 days in extender: Day 3 = 4.09 and 6.45%, respectively. However, the sperm DNA fragmentation index was different (P < 0.05) between extenders BTS and PBS based on extended sperm for Day 4: 4.28 and 7.28%, respectively, through Day 8 (5.52 and 10.02%). These results demonstrated the importance of providing the correct amount of organic Zn in boar diets and potential impacts on reproduction.

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