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Ottmar Distl - One of the best experts on this subject based on the ideXlab platform.
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Effects of inbreeding and other systematic effects on fertility of Black Forest Draught horses in Germany
Acta Veterinaria Scandinavica, 2017Co-Authors: Maarit Müller-unterberg, Sandra Wallmann, Ottmar DistlAbstract:Background The Black Forest Draught horse (BFDH) is an endangered German coldblood breed with its origin in the area of the Black Forest in South Germany. In this retrospective study, the influence of the inbreeding coefficient on foaling rates was investigated using records from ten breeding seasons. Due to the small population size of BFDH, the level of inbreeding is increasing and may have an effect on foaling rates.The data of the present study included all coverings reported for 1024 BFDH mares in the years 2001–2009. These mares were covered by 32 BFDH Stallions from the State Stud Marbach. Data from 4534 estrus cycles was used to calculate per cycle foaling rate (CFR). Pedigree data contained all studbook data up to the foundation of the breed as early as 1836. The level of inbreeding of the mare, Stallion and expected foal along with other systematic effects on CFR were analysed using a generalized linear mixed model approach. Stallion was employed as a random effect. Systematic fixed effects were month of mating, mating type, age of the mare and Stallion, reproductive status of the mare and Stallion line of the mare. Inbreeding coefficients of the Stallion, mare and expected foal were modelled as linear covariates. Results The average CFR was 40.9%. The mean inbreeding coefficients of the mares, Stallions and expected foals were 7.46, 7.70 and 9.66%. Mating type, age of the mare, reproductive status of the mare and Stallion line of the mare had a significant effect. Conclusions The results showed that the mating type, Stallion line of the mare, sire, age and reproductive status of the mare exerted the largest influences on CFR in BFDH. Inbreeding coefficients of the Stallion, mare and expected foal were not significantly related with CFR.
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relationships among Stallion fertility and semen traits using estimated breeding values of german warmblood Stallions
Theriogenology, 2017Co-Authors: Maren Gottschalk, H Sieme, G Martinsson, Ottmar DistlAbstract:Abstract A high quality of Stallion semen is of particular importance for maximum reproductive efficiency. In the present study, we estimated the relationships among estimated breeding values (EBVs) of semen traits and EBVs for the paternal component of the pregnancy rate per estrus cycle (EBV-PAT) for 100 German Warmblood Stallions using correlation and general linear model analyses. The most highly correlated sperm quality trait was total number of progressively motile sperm ( r = 0.36). EBV-PAT was considered in three classes with Stallions 1 SD below ( 120) the population mean of 100. The general linear model analysis showed significant effects for EBVs of all semen traits. EBVs of sperm quality traits greater than 100 to 110 were indicative for EBV-PAT greater than 120. Recommendations for breeding soundness examinations on the basis of the assessments of sperm quality traits and estimation of breeding values seem to be an option to support breeders to improve Stallion fertility in the present and future Stallion generation.
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screening of whole genome sequences identified high impact variants for Stallion fertility
BMC Genomics, 2016Co-Authors: Rahel Schrimpf, Maren Gottschalk, Julia Metzger, H Sieme, G Martinsson, Ottmar DistlAbstract:Background Stallion fertility is an economically important trait due to the increase of artificial insemination in horses. The availability of whole genome sequence data facilitates identification of rare high-impact variants contributing to Stallion fertility. The aim of our study was to genotype rare high-impact variants retrieved from next-generation sequencing (NGS)-data of 11 horses in order to unravel harmful genetic variants in large samples of Stallions.
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Analysis of breed effects on semen traits in light horse, warmblood, and draught horse breeds
Theriogenology, 2015Co-Authors: Maren Gottschalk, H Sieme, G Martinsson, Ottmar DistlAbstract:In the present study, systematic effects on semen quality traits were investigated in 381 Stallions representing 22 breeds. All Stallions were used for AI either at the Lower Saxon National Stud Celle or the North Rhine-Westphalian National Stud Warendorf. A total of 71,078 fresh semen reports of the years 2001 to 2014 were edited for analysis of gel-free volume, sperm concentration, total number of sperm, progressive motility, and total number of progressively motile sperm. Breed differences were studied for warmblood and light horse breeds of both national studs (model I) and for warmblood breeds and the draught horse breed Rhenish German Coldblood from the North Rhine-Westphalian National stud (model II) using mixed model procedures. The fixed effects of age class, year, and month of semen collection had significant influences on all semen traits in both analyses. A significant influence of the horse breed was found for all semen traits but gel-free volume in both statistical models. Comparing warmblood and light horse Stallions of both national studs, we observed highest sperm concentrations, total numbers of sperm, and total numbers of progressively motile sperm in Anglo-Arabian Stallions. The draught horse breed Rhenish German Coldblood had the highest least squares means for gel-free volume, whereas all other investigated semen traits were significantly lower in this breed compared to the warmblood Stallions under study. The variance components among Stallions within breeds were significant for all semen traits and accounted for 40% to 59% of the total variance. The between-breed-variance among Stallions was not significant underlining the similar size of the random Stallion effect in each of the horse breeds analyzed here. In conclusion, breed and Stallion are accounting for a significant proportion of the variation in semen quality.
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genome wide association study identifies phospholipase c zeta 1 plcz1 as a Stallion fertility locus in hanoverian warmblood horses
PLOS ONE, 2014Co-Authors: Rahel Schrimpf, H Sieme, G Martinsson, Claudia Dierks, Ottmar DistlAbstract:A consistently high level of Stallion fertility plays an economically important role in modern horse breeding. We performed a genome-wide association study for estimated breeding values of the paternal component of the pregnancy rate per estrus cycle (EBV-PAT) in Hanoverian Stallions. A total of 228 Hanoverian Stallions were genotyped using the Equine SNP50 Beadchip. The most significant association was found on horse chromosome 6 for a single nucleotide polymorphism (SNP) within phospholipase C zeta 1 (PLCz1). In the close neighbourhood to PLCz1 is located CAPZA3 (capping protein (actin filament) muscle Z-line, alpha 3). The gene PLCz1 encodes a protein essential for spermatogenesis and oocyte activation through sperm induced Ca2+-oscillation during fertilization. We derived equine gene models for PLCz1 and CAPZA3 based on cDNA and genomic DNA sequences. The equine PLCz1 had four different transcripts of which two contained a premature termination codon. Sequencing all exons and their flanking sequences using genomic DNA samples from 19 Hanoverian Stallions revealed 47 polymorphisms within PLCz1 and one SNP within CAPZA3. Validation of these 48 polymorphisms in 237 Hanoverian Stallions identified three intronic SNPs within PLCz1 as significantly associated with EBV-PAT. Bioinformatic analysis suggested regulatory effects for these SNPs via transcription factor binding sites or microRNAs. In conclusion, non-coding polymorphisms within PLCz1 were identified as conferring Stallion fertility and PLCz1 as candidate locus for male fertility in Hanoverian warmblood. CAPZA3 could be eliminated as candidate gene for fertility in Hanoverian Stallions.
Jodi F Hedges - One of the best experts on this subject based on the ideXlab platform.
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lateral transmission of equine arteritis virus among lipizzaner Stallions in south africa
Equine Veterinary Journal, 2010Co-Authors: A J Guthrie, Jodi F Hedges, Anna-mari Bosman, William H. Mccollum, P G Howell, Udeni B R Balasuriya, Nigel J MaclachlanAbstract:REASONS FOR PERFORMING STUDY: A serological study conducted in 1995 revealed that 7 Stallions at the Lipizzaner Centre, Gauteng, South Africa, were seropositive for antibody to equine arteritis virus (EAV). A Lipizzaner Stallion imported into South Africa from Yugoslavia in 1981 had previously (1988) been confirmed to be an EAV carrier. Despite being placed under life-long breeding quarantine, EAV had been transmitted between Stallions at the Lipizzaner Centre. OBJECTIVES: To investigate the phylogenetic relationships between the strain of EAV shed in the semen of the original carrier Stallion and strains recovered from the semen of 5 other Stallions; and to investigate the means whereby lateral transmission of EAV occurred among 7 in-contact, nonbreeding Stallions at the Centre. METHODS: EAV was isolated from semen collected from the seropositive Stallions using RK-13 cells. Viral RNA was reverse transcribed and amplified by polymerase chain reaction using ORF 5-specific primers, subjected to sequence and phylogenetic analysis. RESULTS: Phylogenetic analysis of strains of EAV recovered from the semen of 6 persistently infected Stallions confirmed that all viruses were closely related and probably derived from a common ancestor, i.e. the Stallion imported from Yugoslavia. Lateral transmission subsequently occurred among 7 in-contact, nonbreeding Stallions at the Centre. It is speculated that these Stallions may have been exposed to virus from bedding or fomites contaminated with semen. CONCLUSIONS: These data confirm that lateral transmission of EAV can occur from shedding Stallions to susceptible, in-contact horses, including other Stallions, which may become persistently infected with the virus. POTENTIAL RELEVANCE: The findings are consistent with lateral spread of a single, unique strain of EAV among a group; and suggest that transmission of EAV may be initiated by infection of one or more Stallions with virus on bedding or other fomites contaminated with EAV- infected semen.
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genetic characterization of equine arteritis virus during persistent infection of Stallions
Journal of General Virology, 2004Co-Authors: Udeni B R Balasuriya, Jodi F Hedges, William H. Mccollum, Peter J. Timoney, Victoria L Smalley, Andrea Navarrette, Eric J Snijder, James N MaclachlanAbstract:Equine arteritis virus (EAV) causes a persistent infection of the reproductive tract of carrier Stallions. The authors determined the complete genome sequences of viruses (CW96 and CW01) that were present 5 years apart in the semen of a carrier Stallion (CW). The CW96 and CW01 viruses respectively had only 85·6 % and 85·7 % nucleotide identity to the published sequence of EAV (EAV030). The CW96 and CW01 viruses had two 1 nt insertions and a single 1 nt deletion in the leader sequence, and a 3 nt coding insertion in ORF1a; thus their genomes included 12 708 nt as compared to the 12 704 nt in EAV030. Variation between viruses present in the semen of Stallion CW and EAV030 was especially marked in the replicase gene (ORF1a and 1b), and the greatest variation occurred in the portion of ORF1a encoding the nsp2 protein. The ORFs 3 and 5, which respectively encode the GP3 and GP5 envelope proteins, showed greatest variation amongst ORFs encoding structural EAV proteins. Comparative sequence analyses of CW96 and CW01 indicated that ORFs 1a, 1b and 7 were highly conserved during persistent infection, whereas there was substantial variation in ORFs 3 and 5. Although the variation that occurs in ORF5 results in the emergence of novel phenotypic viral variants as determined by neutralization assay, all variants were neutralized by high-titre polyclonal equine antisera, suggesting that immune evasion is unlikely to be responsible for the establishment of persistent EAV infection of carrier Stallions. Northern blot analyses of RNA extracted from cell culture propagated viruses isolated from 10 different persistently infected Stallions failed to demonstrate any large genomic deletions, suggesting that defective interfering particles are also unlikely to be important in either the maintenance or clearance of persistent EAV infection of the reproductive tract of carrier Stallions.
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Genetic stability of equine arteritis virus during horizontal and vertical transmission in an outbreak of equine viral arteritis
Journal of General Virology, 1999Co-Authors: Jodi F Hedges, William H. Mccollum, Peter J. Timoney, Steven A. Nadler, N. James MaclachlanAbstract:An imported carrier Stallion (A) from Europe was implicated in causing an extensive outbreak of equine viral arteritis (EVA) on a Warmblood breeding farm in Pennsylvania, USA. Strains of equine arteritis virus (EAV) present in the semen of two carrier Stallions (A and G) on the farm were compared to those in tissues of foals born during the outbreak, as well as viruses present in the semen of two other Stallions that became persistently infected carriers of EAV following infection during the outbreak. The 2822 bp segment encompassing ORFs 2-7 (nt 9807-12628; which encode the G(S), GP3, GP4, G(L), M and N proteins, respectively) was directly amplified by RT-PCR from semen samples and foal tissues. Nucleotide and phylogenetic analyses confirmed that virus present in the semen of Stallion A initiated the outbreak. The genomes of viruses present in most foal tissues (10/11) and serum from an acutely infected mare collected during the outbreak were identical to that of virus present in the lung of the first foal that died of EVA. Virus in the placenta of one foal differed by one nucleotide (99.9% identity) from the predominant outbreak virus. The relative genetic stability of viruses that circulated during the outbreak contrasts markedly with the heterogeneous virus populations variously present in the semen of persistently infected Stallions on the farm. These findings are consistent with the hypothesis that the carrier Stallion can be a source of genetic diversity of EAV, and that outbreaks of EVA can be initiated by the horizontal aerosol transmission of specific viral variants that occur in the semen of particular carrier Stallions.
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equine arteritis virus derived from an infectious cdna clone is attenuated and genetically stable in infected Stallions
Virology, 1999Co-Authors: Udeni B R Balasuriya, Jodi F Hedges, Eric J Snijder, Leonie C Van Dinten, Hans W Heidner, David W Wilson, Pamela J Hullinger, James N MaclachlanAbstract:Abstract Virus derived from an infectious cDNA clone of equine arteritis virus (EAV030H) was intranasally inoculated into two Stallions, neither of which subsequently developed clinical manifestations of equine viral arteritis (EVA). Virus was isolated from nasal swabs and mononuclear cells collected from both Stallions ≤14 days p.i. and from the semen of one Stallion only at 7 days p.i. Similarly, viral RNA was detected by RT nested-PCR in nasal swabs and mononuclear cells for ≤14 days p.i. and at 7 days p.i. in the semen of the one Stallion. Both Stallions seroconverted to EAV by 10 days p.i. and maintained high neutralizing antibody titers thereafter. Sequence and restriction digestion analysis demonstrated that the recombinant virus present in nasal swabs, mononuclear cells, and semen from the two Stallions was identical to the infectious clone-derived virus that was used to inoculate them. Furthermore analysis of multiple clones derived by RT nested-PCR amplification from several samples indicated that the recombinant EAV030H virus was stable during replication in horses. These studies document for the first time that a recombinant virus derived from an infectious cDNA clone of a member of the order Nidovirales is replication competent in animals, and the genetic stability of the recombinant virus during in vivo replication indicates that it will be useful for the characterization of genetic determinants of virulence and persistence of EAV. The genetic conservation of the cloned recombinant virus during in vivo infection is similar to that which occurs during natural horizontal and vertical transmission of EAV in horses and contrasts with the heterogeneous virus population (quasispecies) that occurs in the semen of carrier Stallions.
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genetic divergence with emergence of novel phenotypic variants of equine arteritis virus during persistent infection of Stallions
Journal of Virology, 1999Co-Authors: Jodi F Hedges, William H. Mccollum, Udeni B R Balasuriya, Peter J. Timoney, Nigel J MaclachlanAbstract:The persistently infected carrier Stallion is the critical natural reservoir of equine arteritis virus (EAV), as venereal infection of mares frequently occurs after breeding to such Stallions. Two Thoroughbred Stallions that were infected during the 1984 outbreak of equine viral arteritis in central Kentucky subsequently became long-term EAV carriers. EAV genomes amplified from the semen of these two Stallions were compared by sequence analysis of the six 3′ open reading frames (ORFs 2 through 7), which encode the four known structural proteins and two uncharacterized glycoproteins. The major variants of the EAV population that sequentially arose within the reproductive tract of each carrier Stallion varied by approximately 1% per year, and the heterogeneity of the viral quasispecies increased during the course of long-term persistent infection. The various ORFs of the dominant EAV variants evolved independently, and there was apparently strong selective pressure on the uncharacterized GP3 protein during persistent infection. Amino acid changes also occurred in the V1 variable region of the GL protein. This region has been previously identified as a crucial neutralization domain, and selective pressures exerted on the V1 region during persistent EAV infection led to the emergence of virus variants with distinct neutralization properties. Thus, evolution of the EAV quasispecies that occurs during persistent infection of the Stallion clearly can influence viral phenotypic properties such as neutralization and perhaps virulence.
E L Squires - One of the best experts on this subject based on the ideXlab platform.
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intrahost selection pressure drives equine arteritis virus evolution during persistent infection in the Stallion reproductive tract
Journal of Virology, 2019Co-Authors: Bora Nam, E L Squires, Zelalem Mekuria, Mariano Carossino, Ying Zheng, Jianqiang Zhang, Frank R Cook, Kathleen M Shuck, J R Campos, Mats H.t. TroedssonAbstract:Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a reproductive and respiratory disease of horses. Following natural infection, 10 to 70% of infected Stallions can become carriers of EAV and continue to shed virus in the semen. In this study, sequential viruses isolated from nasal secretions, buffy coat cells, and semen of seven experimentally infected and two naturally infected EAV carrier Stallions were deep sequenced to elucidate the intrahost microevolutionary process after a single transmission event. Analysis of variants from nasal secretions and buffy coat cells lacked extensive positive selection; however, characteristics of the mutant spectra were different in the two sample types. In contrast, the initial semen virus populations during acute infection have undergone a selective bottleneck, as reflected by the reduction in population size and diversifying selection at multiple sites in the viral genome. Furthermore, during persistent infection, extensive genome-wide purifying selection shaped variant diversity in the Stallion reproductive tract. Overall, the nonstochastic nature of EAV evolution during persistent infection was driven by active intrahost selection pressure. Among the open reading frames within the viral genome, ORF3, ORF5, and the nsp2-coding region of ORF1a accumulated the majority of nucleotide substitutions during persistence, with ORF3 and ORF5 having the highest intrahost evolutionary rates. The findings presented here provide a novel insight into the evolutionary mechanisms of EAV and identified critical regions of the viral genome likely associated with the establishment and maintenance of persistent infection in the Stallion reproductive tract.IMPORTANCE EAV can persist in the reproductive tract of infected Stallions, and consequently, long-term carrier Stallions constitute its sole natural reservoir. Previous studies demonstrated that the ampullae of the vas deferens are the primary site of viral persistence in the Stallion reproductive tract and the persistence is associated with a significant inflammatory response that is unable to clear the infection. This is the first study that describes EAV full-length genomic evolution during acute and long-term persistent infection in the Stallion reproductive tract using next-generation sequencing and contemporary sequence analysis techniques. The data provide novel insight into the intrahost evolution of EAV during acute and persistent infection and demonstrate that persistent infection is characterized by extensive genome-wide purifying selection and a nonstochastic evolutionary pattern mediated by intrahost selective pressure, with important nucleotide substitutions occurring in ORF1a (region encoding nsp2), ORF3, and ORF5.
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presence of bacteria on the external genitalia of healthy Stallions and its transmission to the mare at the time of breeding by live cover
Journal of Equine Veterinary Science, 2014Co-Authors: Katheryn L Cerny, Mats H.t. Troedsson, Tom V Little, C F Scoggin, R J Coleman, E L SquiresAbstract:Abstract The current field study used thoroughbred Stallions and mares from central Kentucky to investigate the occurrence of potentially pathogenic bacteria on the Stallion's external genitalia, based on cultures, and investigated the occurrence of bacteria and type of isolate in the mare's uterus after breeding by live cover to Stallions with or without positive bacterial cultures. Fifteen thoroughbred Stallions and 206 mares from two central Kentucky thoroughbred farms were used during the 2010 and 2011 breeding seasons. Samples for bacteriological evaluation were taken from the prepuce and postejaculate urethra (n = 201) of Stallions. Uterine swabs (n = 264) were collected 12-18 hours postbreeding. For statistical analyses, a chi-squared test was used to test the relationship between Stallion culture results and postbreeding uterine culture results, as well as the effect of bacterial types found on the Stallion cultures with bacterial types found on the postbreeding uterine cultures. Of Stallion cultures, 22.4% were positive for potentially pathogenic bacteria, with Streptococcus equi subspecies zooepidemicus (51.1%) being the most common isolate. Uterine cultures resulted in a 29.2% positive rate for potentially pathogenic bacteria, with S. equi subsp. zooepidemicus (90.9%) being the most common. There was no difference ( P > .05) in the occurrence of bacteria or type of isolate found on uterine cultures after breeding Stallions with or without positive cultures. In conclusion, potentially pathogenic bacteria found on the Stallion's external genitalia did not affect the occurrence and type of bacterial isolate found in the mare's uterus after breeding by live cover.
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adding cholesterol to the Stallion sperm plasma membrane improves cryosurvival
Cryobiology, 2005Co-Authors: Amanda I Moore, E L Squires, J K GrahamAbstract:Cryopreservation induces partially irreversible damage to equine sperm membranes. Part of this damage occurs due to membrane alterations induced by the membrane changing from the fluid to the gel-state as the temperature is reduced lower than the membrane transition temperature. One way to prevent this damage is to increase the membrane fluidity at low temperatures by adding cholesterol to the membrane. Different concentrations of cholesterol-loaded-cyclodextrins (CLC) were added to Stallion sperm to determine the CLC concentration that optimizes cryosurvival. Higher percentages of motile sperm were maintained after thawing when 1.5 mg CLC was added to sperm from Stallions whose sperm do not survive freezing well, compared to control sperm from those same Stallions (67% vs. 50%; P<0.05). Addition of CLCs increased the percentages of membrane intact sperm surviving cryopreservation compared to untreated sperm for all Stallions (P<0.05). The amount of cholesterol that incorporated into the membranes of the sperm cells increased in a polynomial fashion (R2=0.9978) and incorporated into all sperm membranes. In addition, there was a significant loss of cholesterol from sperm membranes after cryopreservation; however, addition of CLCs to sperm prior to cryopreservation maintained higher cholesterol levels in the sperm after freezing and thawing than untreated sperm (P<0.05). Addition of CLCs also resulted in more sperm binding to the zona pellucida of bovine oocytes after cryopreservation than control sperm (48 vs. 15; P<0.05). In conclusion, CLCs improved the percentage of post-thaw viability in equine sperm as well as increased the number of sperm that bind to zona pellucida. Addition of CLCs to Stallion sperm prior to cryopreservation is a simple procedure that increases the cryosurvival of cells.
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comparison of in vitro laboratory analyses with the fertility of cryopreserved Stallion spermatozoa
Theriogenology, 2005Co-Authors: E S Kirk, E L Squires, J K GrahamAbstract:Abstract Assessing the fertilizing potential of a semen sample is important for effective Stallion management and for rapid progress in evaluating new cryopreservation technologies. Unfortunately, sperm motility does not estimate fertility well. These experiments established assays to measure cell viability, acrosomal integrity and mitochondrial function for cryopreserved Stallion spermatozoa, using flow cytometry, and determined the variability associated with these assays. Correlations between results for these laboratory assays and Stallion fertility were also determined. The inter-assay variability for visual motility, computer assisted motility, and sperm velocity, sperm viability, percent viable-acrosome intact cells and mitochondrial function of cells were all similar, however, intra-assay variability was lower for flow cytometric assays than for motility assays. The reliability of all assays were >0.72, except for sperm velocity (0.32). Although visual motility and the straightness of sperm motility conducted 90 min after thawing were correlated with seasonal fertility (0.56 and 0.55, respectively), data from no single assay were correlated with first-cycle fertility rates ( P > 0.05). Best models using data from multiple assays explained 66 to 73, 76 to 89 and 79 to 94% of the variability in fertilizing potential, when two, three and four variables were included, respectively. Caution is required in interpreting these data, as only a few Stallions were evaluated and relatively few mares were bred to each Stallion, however, they do indicate that using a few rapid and inexpensive sperm assays, we can begin to understand factors important in Stallion sperm fertilizing capacity, and we can use these assays to more effectively evaluate new methods for cryopreserving Stallion spermatozoa.
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evaluation of alternative cryoprotectants for preserving Stallion spermatozoa
Theriogenology, 2004Co-Authors: E L Squires, S L Keith, J K GrahamAbstract:Abstract Although use of cryopreserved Stallion spermatozoa is currently accepted by many breed registries, utilization of this technique remains limited due to poor fertility for some Stallions. One reason for these results is osmotic stress that spermatozoa experiences when the cryoprotectant (glycerol) is added to the cells prior to freezing and removal from the cells after thawing. In an effort to minimize osmotic damage, alternative cryoprotectants, having lower molecular weights and greater membrane permeability than glycerol, were evaluated to determine their effectiveness for cryopreserving Stallion spermatozoa. In the first experiment, equal molar concentrations of several amides were compared to determine if they could preserve the motility of sperm as well as glycerol. At 0.55 M concentration, addition of glycerol to a skim milk–egg yolk (SMEY) diluent resulted in higher percentages of motile sperm (61%) than methyl formamide (40%) or dimethyl formamide (38%, P P P >0.05). In conclusion, both methyl formamide and dimethyl formamide protected Stallion spermatozoa from cryodamage as effectively as glycerol. Since these compounds permeate the plasma membrane more effectively than glycerol, they should cause less osmotic damage to Stallion spermatozoa than glycerol. Therefore, these compounds may prove very effective in the cryopreservation of Stallion spermatozoa, and may be particularly useful for spermatozoa from Stallions that produce spermatozoa that have poor post-thaw characteristics when glycerol is used as the cryoprotectant.
Rahel Schrimpf - One of the best experts on this subject based on the ideXlab platform.
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screening of whole genome sequences identified high impact variants for Stallion fertility
BMC Genomics, 2016Co-Authors: Rahel Schrimpf, Maren Gottschalk, Julia Metzger, H Sieme, G Martinsson, Ottmar DistlAbstract:Background Stallion fertility is an economically important trait due to the increase of artificial insemination in horses. The availability of whole genome sequence data facilitates identification of rare high-impact variants contributing to Stallion fertility. The aim of our study was to genotype rare high-impact variants retrieved from next-generation sequencing (NGS)-data of 11 horses in order to unravel harmful genetic variants in large samples of Stallions.
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genome wide association study identifies phospholipase c zeta 1 plcz1 as a Stallion fertility locus in hanoverian warmblood horses
PLOS ONE, 2014Co-Authors: Rahel Schrimpf, H Sieme, G Martinsson, Claudia Dierks, Ottmar DistlAbstract:A consistently high level of Stallion fertility plays an economically important role in modern horse breeding. We performed a genome-wide association study for estimated breeding values of the paternal component of the pregnancy rate per estrus cycle (EBV-PAT) in Hanoverian Stallions. A total of 228 Hanoverian Stallions were genotyped using the Equine SNP50 Beadchip. The most significant association was found on horse chromosome 6 for a single nucleotide polymorphism (SNP) within phospholipase C zeta 1 (PLCz1). In the close neighbourhood to PLCz1 is located CAPZA3 (capping protein (actin filament) muscle Z-line, alpha 3). The gene PLCz1 encodes a protein essential for spermatogenesis and oocyte activation through sperm induced Ca2+-oscillation during fertilization. We derived equine gene models for PLCz1 and CAPZA3 based on cDNA and genomic DNA sequences. The equine PLCz1 had four different transcripts of which two contained a premature termination codon. Sequencing all exons and their flanking sequences using genomic DNA samples from 19 Hanoverian Stallions revealed 47 polymorphisms within PLCz1 and one SNP within CAPZA3. Validation of these 48 polymorphisms in 237 Hanoverian Stallions identified three intronic SNPs within PLCz1 as significantly associated with EBV-PAT. Bioinformatic analysis suggested regulatory effects for these SNPs via transcription factor binding sites or microRNAs. In conclusion, non-coding polymorphisms within PLCz1 were identified as conferring Stallion fertility and PLCz1 as candidate locus for male fertility in Hanoverian warmblood. CAPZA3 could be eliminated as candidate gene for fertility in Hanoverian Stallions.
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genome wide association study identifies phospholipase c zeta 1 plcz1 as a Stallion fertility locus in hanoverian warmblood horses
PLOS ONE, 2014Co-Authors: Rahel Schrimpf, H Sieme, G Martinsson, Claudia Dierks, Ottmar DistlAbstract:A consistently high level of Stallion fertility plays an economically important role in modern horse breeding. We performed a genome-wide association study for estimated breeding values of the paternal component of the pregnancy rate per estrus cycle (EBV-PAT) in Hanoverian Stallions. A total of 228 Hanoverian Stallions were genotyped using the Equine SNP50 Beadchip. The most significant association was found on horse chromosome 6 for a single nucleotide polymorphism (SNP) within phospholipase C zeta 1 (PLCz1). In the close neighbourhood to PLCz1 is located CAPZA3 (capping protein (actin filament) muscle Z-line, alpha 3). The gene PLCz1 encodes a protein essential for spermatogenesis and oocyte activation through sperm induced Ca2+-oscillation during fertilization. We derived equine gene models for PLCz1 and CAPZA3 based on cDNA and genomic DNA sequences. The equine PLCz1 had four different transcripts of which two contained a premature termination codon. Sequencing all exons and their flanking sequences using genomic DNA samples from 19 Hanoverian Stallions revealed 47 polymorphisms within PLCz1 and one SNP within CAPZA3. Validation of these 48 polymorphisms in 237 Hanoverian Stallions identified three intronic SNPs within PLCz1 as significantly associated with EBV-PAT. Bioinformatic analysis suggested regulatory effects for these SNPs via transcription factor binding sites or microRNAs. In conclusion, non-coding polymorphisms within PLCz1 were identified as conferring Stallion fertility and PLCz1 as candidate locus for male fertility in Hanoverian warmblood. CAPZA3 could be eliminated as candidate gene for fertility in Hanoverian Stallions.
H Sieme - One of the best experts on this subject based on the ideXlab platform.
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relationships among Stallion fertility and semen traits using estimated breeding values of german warmblood Stallions
Theriogenology, 2017Co-Authors: Maren Gottschalk, H Sieme, G Martinsson, Ottmar DistlAbstract:Abstract A high quality of Stallion semen is of particular importance for maximum reproductive efficiency. In the present study, we estimated the relationships among estimated breeding values (EBVs) of semen traits and EBVs for the paternal component of the pregnancy rate per estrus cycle (EBV-PAT) for 100 German Warmblood Stallions using correlation and general linear model analyses. The most highly correlated sperm quality trait was total number of progressively motile sperm ( r = 0.36). EBV-PAT was considered in three classes with Stallions 1 SD below ( 120) the population mean of 100. The general linear model analysis showed significant effects for EBVs of all semen traits. EBVs of sperm quality traits greater than 100 to 110 were indicative for EBV-PAT greater than 120. Recommendations for breeding soundness examinations on the basis of the assessments of sperm quality traits and estimation of breeding values seem to be an option to support breeders to improve Stallion fertility in the present and future Stallion generation.
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screening of whole genome sequences identified high impact variants for Stallion fertility
BMC Genomics, 2016Co-Authors: Rahel Schrimpf, Maren Gottschalk, Julia Metzger, H Sieme, G Martinsson, Ottmar DistlAbstract:Background Stallion fertility is an economically important trait due to the increase of artificial insemination in horses. The availability of whole genome sequence data facilitates identification of rare high-impact variants contributing to Stallion fertility. The aim of our study was to genotype rare high-impact variants retrieved from next-generation sequencing (NGS)-data of 11 horses in order to unravel harmful genetic variants in large samples of Stallions.
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Analysis of breed effects on semen traits in light horse, warmblood, and draught horse breeds
Theriogenology, 2015Co-Authors: Maren Gottschalk, H Sieme, G Martinsson, Ottmar DistlAbstract:In the present study, systematic effects on semen quality traits were investigated in 381 Stallions representing 22 breeds. All Stallions were used for AI either at the Lower Saxon National Stud Celle or the North Rhine-Westphalian National Stud Warendorf. A total of 71,078 fresh semen reports of the years 2001 to 2014 were edited for analysis of gel-free volume, sperm concentration, total number of sperm, progressive motility, and total number of progressively motile sperm. Breed differences were studied for warmblood and light horse breeds of both national studs (model I) and for warmblood breeds and the draught horse breed Rhenish German Coldblood from the North Rhine-Westphalian National stud (model II) using mixed model procedures. The fixed effects of age class, year, and month of semen collection had significant influences on all semen traits in both analyses. A significant influence of the horse breed was found for all semen traits but gel-free volume in both statistical models. Comparing warmblood and light horse Stallions of both national studs, we observed highest sperm concentrations, total numbers of sperm, and total numbers of progressively motile sperm in Anglo-Arabian Stallions. The draught horse breed Rhenish German Coldblood had the highest least squares means for gel-free volume, whereas all other investigated semen traits were significantly lower in this breed compared to the warmblood Stallions under study. The variance components among Stallions within breeds were significant for all semen traits and accounted for 40% to 59% of the total variance. The between-breed-variance among Stallions was not significant underlining the similar size of the random Stallion effect in each of the horse breeds analyzed here. In conclusion, breed and Stallion are accounting for a significant proportion of the variation in semen quality.
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genome wide association study identifies phospholipase c zeta 1 plcz1 as a Stallion fertility locus in hanoverian warmblood horses
PLOS ONE, 2014Co-Authors: Rahel Schrimpf, H Sieme, G Martinsson, Claudia Dierks, Ottmar DistlAbstract:A consistently high level of Stallion fertility plays an economically important role in modern horse breeding. We performed a genome-wide association study for estimated breeding values of the paternal component of the pregnancy rate per estrus cycle (EBV-PAT) in Hanoverian Stallions. A total of 228 Hanoverian Stallions were genotyped using the Equine SNP50 Beadchip. The most significant association was found on horse chromosome 6 for a single nucleotide polymorphism (SNP) within phospholipase C zeta 1 (PLCz1). In the close neighbourhood to PLCz1 is located CAPZA3 (capping protein (actin filament) muscle Z-line, alpha 3). The gene PLCz1 encodes a protein essential for spermatogenesis and oocyte activation through sperm induced Ca2+-oscillation during fertilization. We derived equine gene models for PLCz1 and CAPZA3 based on cDNA and genomic DNA sequences. The equine PLCz1 had four different transcripts of which two contained a premature termination codon. Sequencing all exons and their flanking sequences using genomic DNA samples from 19 Hanoverian Stallions revealed 47 polymorphisms within PLCz1 and one SNP within CAPZA3. Validation of these 48 polymorphisms in 237 Hanoverian Stallions identified three intronic SNPs within PLCz1 as significantly associated with EBV-PAT. Bioinformatic analysis suggested regulatory effects for these SNPs via transcription factor binding sites or microRNAs. In conclusion, non-coding polymorphisms within PLCz1 were identified as conferring Stallion fertility and PLCz1 as candidate locus for male fertility in Hanoverian warmblood. CAPZA3 could be eliminated as candidate gene for fertility in Hanoverian Stallions.
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genome wide association study identifies phospholipase c zeta 1 plcz1 as a Stallion fertility locus in hanoverian warmblood horses
PLOS ONE, 2014Co-Authors: Rahel Schrimpf, H Sieme, G Martinsson, Claudia Dierks, Ottmar DistlAbstract:A consistently high level of Stallion fertility plays an economically important role in modern horse breeding. We performed a genome-wide association study for estimated breeding values of the paternal component of the pregnancy rate per estrus cycle (EBV-PAT) in Hanoverian Stallions. A total of 228 Hanoverian Stallions were genotyped using the Equine SNP50 Beadchip. The most significant association was found on horse chromosome 6 for a single nucleotide polymorphism (SNP) within phospholipase C zeta 1 (PLCz1). In the close neighbourhood to PLCz1 is located CAPZA3 (capping protein (actin filament) muscle Z-line, alpha 3). The gene PLCz1 encodes a protein essential for spermatogenesis and oocyte activation through sperm induced Ca2+-oscillation during fertilization. We derived equine gene models for PLCz1 and CAPZA3 based on cDNA and genomic DNA sequences. The equine PLCz1 had four different transcripts of which two contained a premature termination codon. Sequencing all exons and their flanking sequences using genomic DNA samples from 19 Hanoverian Stallions revealed 47 polymorphisms within PLCz1 and one SNP within CAPZA3. Validation of these 48 polymorphisms in 237 Hanoverian Stallions identified three intronic SNPs within PLCz1 as significantly associated with EBV-PAT. Bioinformatic analysis suggested regulatory effects for these SNPs via transcription factor binding sites or microRNAs. In conclusion, non-coding polymorphisms within PLCz1 were identified as conferring Stallion fertility and PLCz1 as candidate locus for male fertility in Hanoverian warmblood. CAPZA3 could be eliminated as candidate gene for fertility in Hanoverian Stallions.
