141 Antioxidant Supplementation Alleviates DNA Damage in Boar Sperm Induced by Tropical Heat Stress

Seasonal heat stress is known to significantly diminish reproductive performance in pigs, particularly in the tropics, costing the industry millions in annual losses. The boar’s reduced capacity to sweat and non-pendulous scrotum, combined with the widespread use of European breeds in the tropics, makes this species particularly vulnerable to heat stress. Although heat stress is traditionally considered a sow problem, recent mouse studies demonstrate that heat stress-induced sperm DNA damage can result in arrested development and loss of early embryos. Our study investigated the impact of tropical summer heat stress on the quality and DNA integrity of boar sperm, and trialled antioxidant supplementation to alleviate the problem. Data, expressed as mean ± SEM, were analysed by one-way repeated-measures ANOVA with pairwise Bonferroni tests. Motility of sperm obtained from Large White boars (n = 5) housed in the dry tropics of Townsville, North Queensland, Australia, was characterised by computer-assisted sperm analysis but did not differ between summer, winter, or spring (total motility: 71.3 ± 8.1 v. 90.2 ± 4.2 v. 70.8 ± 5.5%, respectively; P > 0.05; progressive motility: 35.4 ± 7.0 v. 46.6 ± 4.0 v. 41.7 ± 2.8%, respectively; P > 0.05). Sperm DNA integrity in 20,000 sperm/boar per season, evaluated using TUNEL and flow cytometry, revealed 16-fold more DNA-damaged sperm in summer than winter, and nearly 9-fold more than spring (16.1 ± 4.8 v. 1.0 ± 0.2 v. 1.9 ± 0.5%, respectively; P ≤ 0.05). However, boar feed supplemented with 100 g/boar per day of proprietary custom-made antioxidants during summer significantly reduced sperm DNA damage to 9.9 ± 4.5% and 7.2 ± 1.6% (P ≤ 0.05) after 42 and 84 days of treatment respectively. Total and progressive motility were not altered by the supplement. In summary, sperm DNA integrity is compromised in boars during summer, suggesting that boar factors may contribute to seasonal embryo loss in sows. Moreover, such damage appears undetectable using traditional measures of sperm motility. Antioxidant supplementation during summer appears to mitigate the negative impact of heat stress on sperm DNA integrity.

Download Full-text

Revisiting summer infertility in the pig: could heat stress-induced sperm DNA damage negatively affect early embryo development?

Animal Production Science ◽

10.1071/an16079 ◽

2017 ◽

Vol 57 (10) ◽

pp. 1975 ◽

Cited By ~ 8

Author(s):

Santiago T. Peña, Jr ◽

Bruce Gummow ◽

Anthony J. Parker ◽

Damien B. B. P. Paris

Keyword(s):

Dna Damage ◽

Heat Stress ◽

Oxidative Damage ◽

Unsaturated Fatty Acids ◽

Negative Impact ◽

Early Embryo ◽

Antioxidant Systems ◽

Sperm Dna Damage ◽

Sperm Dna ◽

Boar Sperm

Temperature is a crucial factor in mammalian spermatogenesis. The scrotum, pampiniform plexus, and cremaster and dartos muscles in mammals are specific adaptations to ensure sperm production in a regulated environment 4−6°C below internal body temperature. However, the limited endogenous antioxidant systems inherent in mammalian spermatozoa compounded by the loss of cytosolic repair mechanisms during spermatogenesis, make the DNA in these cells particularly vulnerable to oxidative damage. Boar sperm is likely to be more susceptible to the effects of heat stress and thus oxidative damage due to the relatively high unsaturated fatty acids in the plasma membrane, low antioxidant capacity in boar seminal plasma, and the boar’s non-pendulous scrotum. Heat stress has a significant negative impact on reproductive performance in piggeries, which manifests as summer infertility and results in productivity losses that amount to millions of dollars. This problem is particularly prevalent in tropical and subtropical regions where ambient temperatures rise beyond the animal’s zone of thermal comfort. Based on preliminary studies in the pig and other species, this article discusses whether heat stress could induce sufficient DNA damage in boar sperm to significantly contribute to the high rates of embryo loss and pregnancy failure observed in the sow during summer infertility. Heat stress-induced damage to sperm DNA can lead to disrupted expression of key developmental genes essential for the differentiation of early cell lineages, such as the trophectoderm, and can distort the timely formation of the blastocyst; resulting in a failure of implantation and ultimately pregnancy loss. Confirming such a link would prompt greater emphasis on boar management and strategies to mitigate summer infertility during periods of heat stress.

Download Full-text

Effect of Alcohol Consumption on the Sperm DNA Integrity: A Systematic Review

Journal of Agricultural Science ◽

10.5539/jas.v9n13p136 ◽

2017 ◽

Vol 9 (13) ◽

pp. 136

Author(s):

Farah Hanan Fathihah Jaafar ◽

Khairul Osman ◽

Jaya Kumar ◽

Siti Fatimah Ibrahim

Keyword(s):

Dna Damage ◽

Alcohol Consumption ◽

Alcohol Withdrawal ◽

Semen Parameters ◽

Sperm Chromatin ◽

Dna Integrity ◽

Sperm Dna Damage ◽

Sperm Dna Integrity ◽

Sperm Dna ◽

Keywords Alcohol

There is no solid conclusion on the conventional sperm parameters in association with alcohol consumption, evaluation of sperm DNA integrity thus become a more reliable parameter. Hereby, this literature search was performed to summarize alcohol consumption on the sperm DNA integrity. A computerized database search was done through MEDLINE via Ovid (since 1946 until August 2017) and Cochrane was used. The following set of keywords: ‘alcohol consumption OR alcohol intake OR alcohol diet OR drinking alcohol OR ethanol diet’ AND ‘sperm DNA OR sperm chromatin OR sperm genome OR sperm histone OR sperm protamine’ were utilised. 24 articles were retrieved where only five studies conform to the inclusion criteria All studies demonstrated a negative effect of alcohol consumption on sperm DNA integrity, regardless of various range of alcohol doses and duration of alcohol consumption. Out of five studies reviewed, four studies were using a different approach to measure the sperm DNA damage. Hereby, this review identified a need to use a single approach of DNA damage test by having various method of alcohol administration and/or vice versa so that the extension of sperm DNA damage to alcohol consumption will have a better conclusion. On the same note, a few studies have reported the reversibility on conventional semen parameters, none has been done on the sperm DNA damage upon alcohol withdrawal. Therefore, the role of alcohol withdrawal on the reversibility of sperm DNA damage needs to be as well investigated further.

Download Full-text

A cost for high levels of sperm competition in rodents: increased sperm DNA fragmentation

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.2708 ◽

2016 ◽

Vol 283 (1826) ◽

pp. 20152708 ◽

Cited By ~ 5

Author(s):

Javier delBarco-Trillo ◽

Olga García-Álvarez ◽

Ana Josefa Soler ◽

Maximiliano Tourmente ◽

José Julián Garde ◽

...

Keyword(s):

Dna Damage ◽

Sperm Competition ◽

Dna Fragmentation ◽

Sperm Chromatin ◽

Dna Integrity ◽

Sperm Dna Fragmentation ◽

Sperm Dna Damage ◽

Sperm Dna Integrity ◽

Sperm Dna ◽

Physical And Chemical

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.

Download Full-text

Effect of long-term storage in Safe Cell+ extender on boar sperm DNA integrity and other key sperm parameters

Acta Veterinaria Scandinavica ◽

10.1186/s13028-017-0325-9 ◽

2017 ◽

Vol 59 (1) ◽

Cited By ~ 7

Author(s):

Wiesław Bielas ◽

Wojciech Niżański ◽

Agnieszka Partyka ◽

Anna Rząsa ◽

Ryszard Mordak

Keyword(s):

Sperm Parameters ◽

Dna Integrity ◽

Long Term Storage ◽

Sperm Dna Integrity ◽

Sperm Dna ◽

Boar Sperm ◽

Term Storage

Download Full-text

Effects of boar variability on comet-detected sperm-DNA damage following cryopreservation

Animal Production Science ◽

10.1071/an16274 ◽

2018 ◽

Vol 58 (2) ◽

pp. 252 ◽

Cited By ~ 1

Author(s):

L. Fraser ◽

Ł. Zasiadczyk ◽

C. S. Pareek

Keyword(s):

Dna Damage ◽

Membrane Integrity ◽

Tail Length ◽

Dna Integrity ◽

Comet Tail ◽

Sperm Dna Damage ◽

Type Iv ◽

Sperm Dna ◽

Damage Type

Assessment of sperm-DNA integrity is a crucial issue in male fertility. In the present study, parameters derived from the image analysis of comets after single-cell gel electrophoresis were used to analyse the types of DNA damage of frozen–thawed boar spermatozoa. Semen, frozen in a cryoprotectant-free extender or in cryoprotectant-based extenders, was analysed for DNA fragmentation and with the following comet tail measures: percentage DNA in comet tail, comet tail length and olive tail moment. The percentages of sperm DNA damage in the comet tails were classified as Type 0 (no DNA damage), Type I (very low DNA damage), Type II (light DNA damage), Type III (medium DNA damage) and Type IV (heavy DNA damage). Sperm motility characteristics and membrane integrity were assessed in the pre-freeze and frozen–thawed semen samples. Assessment of sperm DNA fragmentation and comet tail measures showed marked inter-boar variability following cryopreservation. However, consistent differences among the boars, with respect to cryo-induced sperm DNA damage, were detected by the comet tail length and olive tail moment. Besides Type IV, all types of DNA damage were detected in the cryoprotectant-based extenders. It was found that the frequency of Type II and Type III of DNA damage of frozen–thawed spermatozoa was significantly greater in the cryoprotectant-based and cryoprotectant-free extenders respectively. Deterioration in the quality of the sperm DNA integrity was concomitant with a marked decline in sperm motility characteristics, reduced plasma membrane integrity and higher lipid peroxidation and aspartate aminotransferase activity after cryopreservation. It can be suggested that the comet-assay parameters, coupled with routine laboratory tests, are useful to improve the sperm evaluations of post-thaw quality of semen from individual boars and would offer more comprehensive information for a better understanding of the degree of cryo-induced sperm-DNA damage.

Download Full-text

Sperm DNA damage or progressive motility: which one is the better predictor of fertilizationin vitro?

Systems Biology in Reproductive Medicine ◽

10.3109/19396368.2011.553984 ◽

2011 ◽

Vol 57 (3) ◽

pp. 133-138 ◽

Cited By ~ 57

Author(s):

Luke Simon ◽

Sheena E. M. Lewis

Keyword(s):

Dna Damage ◽

Sperm Dna Damage ◽

Progressive Motility ◽

Sperm Dna

Download Full-text

miR-424/322 is downregulated in the semen of patients with severe DNA damage and may regulate sperm DNA damage

Reproduction Fertility and Development ◽

10.1071/rd15052 ◽

2016 ◽

Vol 28 (10) ◽

pp. 1598 ◽

Cited By ~ 14

Author(s):

Kai Zhao ◽

Yaoping Chen ◽

Ruifeng Yang ◽

Yang Bai ◽

Cuiling Li ◽

...

Keyword(s):

Dna Damage ◽

Human Sperm ◽

Vital Role ◽

Dna Integrity ◽

Dna Double Strand Breaks ◽

Human Seminal Plasma ◽

Sperm Dna Damage ◽

Sperm Dna ◽

Murine Homologue

Sperm DNA integrity is an essential factor for accurate transmission of genetic information. Human sperm DNA damage is a common cause of male infertility but the exact mechanism remains poorly understood. Considering the vital role of microRNA (miRNA) in multiple pathophysiological processes, we hypothesised that testicular miRNA is involved in sperm DNA damage during spermatogenesis. Infertile patients with high sperm DNA fragment index (DFI; n = 94) were selected from 1090 infertile men and a total of 18 testis-specific seminal miRNAs previously identified from human seminal plasma were chosen and tested. miR-29c and miR-424 were downregulated in men with high DFI. The inhibition of these two miRNAs in mice confirmed the role of miR-424 (murine homologue miR-322) in sperm DNA damage during spermatogenesis; by contrast, miR-29c exhibited a negative result. Thus, miR-424/322 is involved in sperm DNA damage. Furthermore, the dysregulation of this miRNA can induce DNA double-strand breaks during spermatogenesis.

Download Full-text