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Ottmar Distl - One of the best experts on this subject based on the ideXlab platform.
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Genetic parameters and estimated breeding values for traits of raw and frozen-thawed semen in German Warmblood Stallions.
Animal Reproduction Science, 2019Co-Authors: T. Greiser, G Martinsson, H Sieme, Ottmar DistlAbstract:Abstract Objectives of the present study were to estimate genetic parameters for frozen-thawed semen traits of 271 fertile German Warmblood Stallions and genetic correlations with raw semen quality traits. Semen samples were collected from Stallions utilized for semen collection and artificial insemination (AI) on the Lower Saxon National Stud Celle and the North Rhine-Westphalian National Stud Warendorf. Semen quality variables were analyzed in 63,972 raw (gel-free volume, concentration, progressive motility, number of sperm) and 3681 frozen-thawed samples (motility, DNA fragmentation index (DFI), non-viable sperm). A multivariate linear animal model was used to estimate additive genetic and permanent environmental variances among Stallions as well as estimated breeding values (EBVs) for all semen traits. Heritability estimates were greatest for DFI (h2 = 0.45) and least for non-viable sperm counts ( h2 = 0.11). Additive genetic correlations between progressive sperm motility in raw semen and DFI (rg = −0.79) as well as non-viable sperm (rg = −0.45) were negative. The EBVs for frozen-thawed semen traits ranged from 49 to 181 with mean reliabilities of 0.28 to 0.43. The EBVs for progressively motile sperm post-thawing and DFI were the most highly correlated traits with EBVs for Stallion Fertility (r = 0.38 and r = −0.17). Stallions with relatively greater EBVs for progressive motility in raw semen may be most suitable when freezing semen for storage and subsequently thawing it for AI. Using EBVs for semen traits in selection of Stallions to AI mares appears as an option for genetic improvement to enhance Fertility after AI.
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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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Genome-wide association study for semen quality traits in German Warmblood Stallions
Animal Reproduction Science, 2016Co-Authors: Maren Gottschalk, Julia Metzger, H Sieme, G Martinsson, Ottmar DistlAbstract:Abstract We performed a genome-wide association study for semen quality traits in 139 German Warmblood Stallions. Stallions were genotyped using the Illumina equine SNP50 Beadchip. Traits analysed were de-regressed estimated breeding values (EBVs) for gel-free volume, sperm concentration, total number of sperm, progressive motility and the total number of progressively motile sperm. The GWAS revealed 29 SNPs on 12 different chromosomes as genome-wide significantly associated with semen quality traits. For ten genomic regions we could retrieve candidate genes influencing Stallion Fertility. Among the candidate genes, we could find the genes encoding cysteine-rich secretory proteins ( CRISP1 , CRISP2 and CRISP3 ). This was the first GWAS in horses performed for semen quality traits.
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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, G Martinsson, H Sieme, 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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Screening of whole genome sequences identified high-impact variants for Stallion Fertility
BMC Genomics, 2016Co-Authors: Rahel Schrimpf, Maren Gottschalk, Julia Metzger, G Martinsson, H Sieme, 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. Methods Gene ontology (GO) terms and search results from public databases were used to obtain a comprehensive list of human und mice genes predicted to participate in the regulation of male reproduction. The corresponding equine orthologous genes were searched in whole genome sequence data of seven Stallions and four mares and filtered for high-impact genetic variants using SnpEFF, SIFT and Polyphen 2 software. All genetic variants with the missing homozygous mutant genotype were genotyped on 337 fertile Stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. Mixed linear model analysis was employed for an association analysis with de-regressed estimated breeding values of the paternal component of the pregnancy rate per estrus (EBV-PAT). Results We screened next generation sequenced data of whole genomes from 11 horses for equine genetic variants in 1194 human and mice genes involved in male Fertility and linked through common gene ontology (GO) with male reproductive processes. Variants were filtered for high-impact on protein structure and validated through SIFT and Polyphen 2. Only those genetic variants were followed up when the homozygote mutant genotype was missing in the detection sample comprising 11 horses. After this filtering process, 17 single nucleotide polymorphism (SNPs) were left. These SNPs were genotyped in 337 fertile Stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. An association analysis in 216 Hanoverian Stallions revealed a significant association of the splice-site disruption variant g.37455302G>A in NOTCH1 with the de-regressed estimated breeding values of the paternal component of the pregnancy rate per estrus (EBV-PAT). For 9 high-impact variants within the genes CFTR, OVGP1, FBXO43, TSSK6, PKD1, FOXP1, TCP11, SPATA31E1 and NOTCH1 (g.37453246G>C) absence of the homozygous mutant genotype in the validation sample of all 337 fertile Stallions was obvious. Therefore, these variants were considered as potentially deleterious factors for Stallion Fertility. Conclusions In conclusion, this study revealed 17 genetic variants with a predicted high damaging effect on protein structure and missing homozygous mutant genotype. The g.37455302G>A NOTCH1 variant was identified as a significant Stallion Fertility locus in Hanoverian Stallions and further 9 candidate Fertility loci with missing homozygous mutant genotypes were validated in a panel including 19 horse breeds. To our knowledge this is the first study in horses using next generation sequencing data to uncover strong candidate factors for Stallion Fertility.
Ben Colenbrander - One of the best experts on this subject based on the ideXlab platform.
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Exposure of progesterone receptors on the plasma membranes of Stallion spermatozoa as a parameter for prediction of Fertility.
Journal of reproduction and fertility, 2020Co-Authors: R. Rathi, A. Van Buiten, Mirjam Nielen, F.p. Cheng, Ben ColenbranderAbstract:: SubFertility in Stallions is attributed to the inability of spermatozoa to undergo the acrosome reaction in response to progesterone. In the present study, it was assessed whether there is a correlation between Stallion Fertility, defined on the basis of first cycle foaling rate and first cycle 'non-return rate', and the proportion of spermatozoa with exposed progesterone receptors on their plasma membranes. Semen from Dutch Warmblood (n=10) and Friesian (n=4) Stallions was analysed. Progesterone 3-(o-carboxymethyl) oxime-BSA coupled with fluorescein isothiocyanate was used as a progesterone receptor probe and ethidium homodimer was used as a supravital stain. A high correlation was observed between the proportion of spermatozoa with exposed progesterone receptors and Stallion Fertility (r > 0.70; P < 0.01). This result indicates that exposure of progesterone receptors is a potential parameter for predicting Stallion Fertility.
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Use of sperm binding to homologous hemizona pellucida to predict Stallion Fertility
Equine Veterinary Journal, 2010Co-Authors: Alireza Fazeli, J M Parlevliet, W. Steenweg, Verena Bracher, Mart M Bevers, Ben ColenbranderAbstract:Summary Equine oocytes were obtained post mortem from slaughterhouse ovaries and by transvaginal ultrasound-guided follicle aspiration. The oocytes were denuded and stored in salt solution at 4°C. On the day of the experiment the oocytes were bisected by micromanipulation surgery, thus providing two equal matching hemizonae from each oocyte. Three pairs of Stallions were formed, each consisting of a fertile and subfertile Dutch Warmblood Stallion. Matching hemizonae from 5 oocytes were used for each pair of fertile and subfertile Stallions and the number of spermatozoa bound to the outer-side of each hemizona during incubation in vitro was assessed. The numbers of bound spermatozoa from fertile Stallions were significantly higher than those from subfertile Stallions (P
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use of sperm binding to homologous hemizona pellucida to predict Stallion Fertility
Equine Veterinary Journal, 2010Co-Authors: Alireza Fazeli, J M Parlevliet, W. Steenweg, Verena Bracher, Mart M Bevers, Ben ColenbranderAbstract:Summary Equine oocytes were obtained post mortem from slaughterhouse ovaries and by transvaginal ultrasound-guided follicle aspiration. The oocytes were denuded and stored in salt solution at 4°C. On the day of the experiment the oocytes were bisected by micromanipulation surgery, thus providing two equal matching hemizonae from each oocyte. Three pairs of Stallions were formed, each consisting of a fertile and subfertile Dutch Warmblood Stallion. Matching hemizonae from 5 oocytes were used for each pair of fertile and subfertile Stallions and the number of spermatozoa bound to the outer-side of each hemizona during incubation in vitro was assessed. The numbers of bound spermatozoa from fertile Stallions were significantly higher than those from subfertile Stallions (P<0.05). The results of this investigation encourage further use of the hemizona assay for evaluation of Stallion Fertility.
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the predictive value of semen analysis in the evaluation of Stallion Fertility
Reproduction in Domestic Animals, 2003Co-Authors: Ben Colenbrander, B M Gadella, T A E StoutAbstract:Contents Pregnancy rates in managed horse populations depend on the innate Fertility of the mares and Stallions involved and on the quality of breeding management. Of course, because a single Stallion usually mates many mares, Stallion Fertility is a critical factor in the overall success of a breeding program. Unfortunately, accurate evaluation of Stallion Fertility per se requires a large number of normal mares to be mated and is necessarily retrospective. Rather, the ideal is to predict Fertility in advance of the Stallion's breeding career, and this is currently attempted by way of a thorough physical examination and a routine analysis of semen quality. However, while such a ‘breeding soundness examination’ identifies Stallions that clearly lack the capacity for adequate Fertility, it is of limited use for predicting the level of Fertility and fails to identify some seriously sub-fertile animals. Similarly, while various sperm function tests (e.g., sperm head morphometry, the hypoosmotic swelling test, glass wool-sephadex filtration, progesterone receptor exposure) have been shown to correlate fairly well with Fertility in the field, most examine only a single or a narrow range of the attributes that a sperm must possess if it is to fertilize an oocyte in vivo, and are thus more useful for identifying specific causes of sub-Fertility than for predicting the level of Fertility. On the other hand, combining the results of the various sperm function tests does improve the reliability of Fertility estimation and current research is therefore concentrated on identifying a range of tests that covers as many important sperm attributes as possible but that can be performed rapidly and cheaply. In this respect, flow-cytometry has proven to be an ideal tool because it allows the objective, rapid and simultaneous analysis of a number of properties in a large number of sperm. Moreover, stains are available for an increasing range of sperm characteristics including viability, capacitation and acrosome status, mitochondrial activity and chromatin integrity. Flow-cytometric analysis of sperm with appropriate probes thus offers considerable promise for the prediction of Stallion Fertility.
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Validation of non-return rate as a parameter for Stallion Fertility
Livestock Production Science, 1999Co-Authors: A. Van Buiten, J Van Den Broek, Ynte H. Schukken, Ben ColenbranderAbstract:The non-return rate is evaluated as a parameter for assessment of reproductive performance of Stallions. This parameter gives the percentage of mares that did not return (NR) for breeding within a specific time after last insemination. Breeding data were recorded in a computerised registration system, from six studfarms on 18 Dutch Warmblood, seven Friesian and 11 Shetland pony Stallions used for artificial insemination or natural mating. Mares (n=3731) were inseminated or served in a total of 6361 cycles. Non-return rates at 21, 28, 35, 42 and 56 days and at the end of the season were, respectively, 84, 72, 68, 64, 59 and 54%. The average NR rate after first cycle at 28 days was 73, 67 and 72% for the Dutch Warmblood, the Friesian, and the Shetland pony Stallions, respectively, and gradually decreased towards 50% for all the breeds by the end of the season. The NR rate differed remarkably between Stallions. The ranking of the Stallions according to NR at 28 days did not change when the length of this NR period increased. A live born foal was registered for 67% of the mares. Correlation between non-return rates at 21, 28, 35, 42 and 56 days and at the end of the season were, respectively, 0.77, 0.86, 0.89, 0.92, 0.92 and 0.95. The probability of a live foal increased from 50% at NR 21 days to 84% at NR for the end of season irrespective of Stallion. The non-return rate at 28 days proved to be a valuable parameter for early assessment of Fertility of Stallions.
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, G Martinsson, H Sieme, 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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Screening of whole genome sequences identified high-impact variants for Stallion Fertility
BMC Genomics, 2016Co-Authors: Rahel Schrimpf, Maren Gottschalk, Julia Metzger, G Martinsson, H Sieme, 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. Methods Gene ontology (GO) terms and search results from public databases were used to obtain a comprehensive list of human und mice genes predicted to participate in the regulation of male reproduction. The corresponding equine orthologous genes were searched in whole genome sequence data of seven Stallions and four mares and filtered for high-impact genetic variants using SnpEFF, SIFT and Polyphen 2 software. All genetic variants with the missing homozygous mutant genotype were genotyped on 337 fertile Stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. Mixed linear model analysis was employed for an association analysis with de-regressed estimated breeding values of the paternal component of the pregnancy rate per estrus (EBV-PAT). Results We screened next generation sequenced data of whole genomes from 11 horses for equine genetic variants in 1194 human and mice genes involved in male Fertility and linked through common gene ontology (GO) with male reproductive processes. Variants were filtered for high-impact on protein structure and validated through SIFT and Polyphen 2. Only those genetic variants were followed up when the homozygote mutant genotype was missing in the detection sample comprising 11 horses. After this filtering process, 17 single nucleotide polymorphism (SNPs) were left. These SNPs were genotyped in 337 fertile Stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. An association analysis in 216 Hanoverian Stallions revealed a significant association of the splice-site disruption variant g.37455302G>A in NOTCH1 with the de-regressed estimated breeding values of the paternal component of the pregnancy rate per estrus (EBV-PAT). For 9 high-impact variants within the genes CFTR, OVGP1, FBXO43, TSSK6, PKD1, FOXP1, TCP11, SPATA31E1 and NOTCH1 (g.37453246G>C) absence of the homozygous mutant genotype in the validation sample of all 337 fertile Stallions was obvious. Therefore, these variants were considered as potentially deleterious factors for Stallion Fertility. Conclusions In conclusion, this study revealed 17 genetic variants with a predicted high damaging effect on protein structure and missing homozygous mutant genotype. The g.37455302G>A NOTCH1 variant was identified as a significant Stallion Fertility locus in Hanoverian Stallions and further 9 candidate Fertility loci with missing homozygous mutant genotypes were validated in a panel including 19 horse breeds. To our knowledge this is the first study in horses using next generation sequencing data to uncover strong candidate factors for Stallion Fertility.
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Implication of FKBP6 for male Fertility in horses.
Reproduction in Domestic Animals, 2014Co-Authors: Rahel Schrimpf, Julia Metzger, H Sieme, G Martinsson, Ottmar DistlAbstract:Contents In Stallions, impaired acrosome reaction (IAR) may often cause subFertility. Single nucleotide polymorphisms (SNPs) within FK506-binding protein (FKBP6) seem to be associated with IAR in Stallions. However, their effect on Stallion Fertility has not yet been quantified. Using whole-genome sequence data of seven Stallions, we searched FKBP6 for mutations to perform an association study in Hanoverian Stallions with estimated breeding values for the paternal component of the pregnancy rate per oestrus cycle (EBV-PAT) as target trait. Genotyping five exonic mutations within FKBP6 revealed a significant association of the SNP g.11040379C>A (p.167H>N) with EBV-PAT in 216 Hanoverian Stallions. The difference among the two homozygous genotypes was 7.62% in EBV-PAT, corresponding to one standard deviation of EBV-PAT. In conclusion, in Hanoverian Stallions, the FKBP6-associated SNP g.11040379C>A confers higher conception rates in A/A homozygous and lower conception rates in C/C homozygous Hanoverian Stallions. Thus, an FKBP6-associated missense mutation is significantly associated with Stallion Fertility.
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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, Claudia Dierks, G Martinsson, 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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Genome-wide association study for semen quality traits in German Warmblood Stallions
Animal Reproduction Science, 2016Co-Authors: Maren Gottschalk, Julia Metzger, H Sieme, G Martinsson, Ottmar DistlAbstract:Abstract We performed a genome-wide association study for semen quality traits in 139 German Warmblood Stallions. Stallions were genotyped using the Illumina equine SNP50 Beadchip. Traits analysed were de-regressed estimated breeding values (EBVs) for gel-free volume, sperm concentration, total number of sperm, progressive motility and the total number of progressively motile sperm. The GWAS revealed 29 SNPs on 12 different chromosomes as genome-wide significantly associated with semen quality traits. For ten genomic regions we could retrieve candidate genes influencing Stallion Fertility. Among the candidate genes, we could find the genes encoding cysteine-rich secretory proteins ( CRISP1 , CRISP2 and CRISP3 ). This was the first GWAS in horses performed for semen quality traits.
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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, G Martinsson, H Sieme, 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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Screening of whole genome sequences identified high-impact variants for Stallion Fertility
BMC Genomics, 2016Co-Authors: Rahel Schrimpf, Maren Gottschalk, Julia Metzger, G Martinsson, H Sieme, 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. Methods Gene ontology (GO) terms and search results from public databases were used to obtain a comprehensive list of human und mice genes predicted to participate in the regulation of male reproduction. The corresponding equine orthologous genes were searched in whole genome sequence data of seven Stallions and four mares and filtered for high-impact genetic variants using SnpEFF, SIFT and Polyphen 2 software. All genetic variants with the missing homozygous mutant genotype were genotyped on 337 fertile Stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. Mixed linear model analysis was employed for an association analysis with de-regressed estimated breeding values of the paternal component of the pregnancy rate per estrus (EBV-PAT). Results We screened next generation sequenced data of whole genomes from 11 horses for equine genetic variants in 1194 human and mice genes involved in male Fertility and linked through common gene ontology (GO) with male reproductive processes. Variants were filtered for high-impact on protein structure and validated through SIFT and Polyphen 2. Only those genetic variants were followed up when the homozygote mutant genotype was missing in the detection sample comprising 11 horses. After this filtering process, 17 single nucleotide polymorphism (SNPs) were left. These SNPs were genotyped in 337 fertile Stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. An association analysis in 216 Hanoverian Stallions revealed a significant association of the splice-site disruption variant g.37455302G>A in NOTCH1 with the de-regressed estimated breeding values of the paternal component of the pregnancy rate per estrus (EBV-PAT). For 9 high-impact variants within the genes CFTR, OVGP1, FBXO43, TSSK6, PKD1, FOXP1, TCP11, SPATA31E1 and NOTCH1 (g.37453246G>C) absence of the homozygous mutant genotype in the validation sample of all 337 fertile Stallions was obvious. Therefore, these variants were considered as potentially deleterious factors for Stallion Fertility. Conclusions In conclusion, this study revealed 17 genetic variants with a predicted high damaging effect on protein structure and missing homozygous mutant genotype. The g.37455302G>A NOTCH1 variant was identified as a significant Stallion Fertility locus in Hanoverian Stallions and further 9 candidate Fertility loci with missing homozygous mutant genotypes were validated in a panel including 19 horse breeds. To our knowledge this is the first study in horses using next generation sequencing data to uncover strong candidate factors for Stallion Fertility.
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Implication of FKBP6 for male Fertility in horses.
Reproduction in Domestic Animals, 2014Co-Authors: Rahel Schrimpf, Julia Metzger, H Sieme, G Martinsson, Ottmar DistlAbstract:Contents In Stallions, impaired acrosome reaction (IAR) may often cause subFertility. Single nucleotide polymorphisms (SNPs) within FK506-binding protein (FKBP6) seem to be associated with IAR in Stallions. However, their effect on Stallion Fertility has not yet been quantified. Using whole-genome sequence data of seven Stallions, we searched FKBP6 for mutations to perform an association study in Hanoverian Stallions with estimated breeding values for the paternal component of the pregnancy rate per oestrus cycle (EBV-PAT) as target trait. Genotyping five exonic mutations within FKBP6 revealed a significant association of the SNP g.11040379C>A (p.167H>N) with EBV-PAT in 216 Hanoverian Stallions. The difference among the two homozygous genotypes was 7.62% in EBV-PAT, corresponding to one standard deviation of EBV-PAT. In conclusion, in Hanoverian Stallions, the FKBP6-associated SNP g.11040379C>A confers higher conception rates in A/A homozygous and lower conception rates in C/C homozygous Hanoverian Stallions. Thus, an FKBP6-associated missense mutation is significantly associated with Stallion Fertility.
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Genomics and Fertility in Stallions
Journal of Equine Veterinary Science, 2012Co-Authors: H Sieme, Ottmar DistlAbstract:Stallion Fertility is of high economic importance for the horse industry. The discovery of molecular mechanisms affecting Fertility will be facilitated by the horse genome assembly, the development of genome-wide transcript and single-nucleotide polymorphism (SNP) arrays, and next-generation sequencing of whole mammalian genomes for analyzing complex Fertility traits. Candidate genes can be identified via their involvement in key processes of horse reproduction or other species and their Fertility-influencing mutations in genes described for species other than horses. We prioritized candidate genes that have been shown to play a major role in Stallion reproduction and for which a relevant role in male reproduction in man or mice has been revealed, and located these genes on the horse genome assembly EquCab2.0. First, we sequenced candidate genes for Stallion reproduction, including CRISP3, SPATA1, INHBA, ACE, SP17, FSHB, and PRLR, and screened these genes for polymorphisms associated with pregnancy rate per estrus in Stallions. Genome-wide association studies using the equine Illumina 50K beadchip were performed to discover highly associated SNPs for Stallion Fertility. Among the candidate genes identified, we could find associations for candidate genes not yet analyzed. Molecular genetic studies of candidate genes from known pathways are encouraging, and with the novel tools available for genome-wide association studies and whole-genome sequencing, our knowledge on genetics of Stallion Fertility will be advanced.
Maren Gottschalk - 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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Genome-wide association study for semen quality traits in German Warmblood Stallions
Animal Reproduction Science, 2016Co-Authors: Maren Gottschalk, Julia Metzger, H Sieme, G Martinsson, Ottmar DistlAbstract:Abstract We performed a genome-wide association study for semen quality traits in 139 German Warmblood Stallions. Stallions were genotyped using the Illumina equine SNP50 Beadchip. Traits analysed were de-regressed estimated breeding values (EBVs) for gel-free volume, sperm concentration, total number of sperm, progressive motility and the total number of progressively motile sperm. The GWAS revealed 29 SNPs on 12 different chromosomes as genome-wide significantly associated with semen quality traits. For ten genomic regions we could retrieve candidate genes influencing Stallion Fertility. Among the candidate genes, we could find the genes encoding cysteine-rich secretory proteins ( CRISP1 , CRISP2 and CRISP3 ). This was the first GWAS in horses performed for semen quality traits.
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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, G Martinsson, H Sieme, 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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Screening of whole genome sequences identified high-impact variants for Stallion Fertility
BMC Genomics, 2016Co-Authors: Rahel Schrimpf, Maren Gottschalk, Julia Metzger, G Martinsson, H Sieme, 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. Methods Gene ontology (GO) terms and search results from public databases were used to obtain a comprehensive list of human und mice genes predicted to participate in the regulation of male reproduction. The corresponding equine orthologous genes were searched in whole genome sequence data of seven Stallions and four mares and filtered for high-impact genetic variants using SnpEFF, SIFT and Polyphen 2 software. All genetic variants with the missing homozygous mutant genotype were genotyped on 337 fertile Stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. Mixed linear model analysis was employed for an association analysis with de-regressed estimated breeding values of the paternal component of the pregnancy rate per estrus (EBV-PAT). Results We screened next generation sequenced data of whole genomes from 11 horses for equine genetic variants in 1194 human and mice genes involved in male Fertility and linked through common gene ontology (GO) with male reproductive processes. Variants were filtered for high-impact on protein structure and validated through SIFT and Polyphen 2. Only those genetic variants were followed up when the homozygote mutant genotype was missing in the detection sample comprising 11 horses. After this filtering process, 17 single nucleotide polymorphism (SNPs) were left. These SNPs were genotyped in 337 fertile Stallions of 19 breeds using KASP genotyping assays or PCR-RFLP. An association analysis in 216 Hanoverian Stallions revealed a significant association of the splice-site disruption variant g.37455302G>A in NOTCH1 with the de-regressed estimated breeding values of the paternal component of the pregnancy rate per estrus (EBV-PAT). For 9 high-impact variants within the genes CFTR, OVGP1, FBXO43, TSSK6, PKD1, FOXP1, TCP11, SPATA31E1 and NOTCH1 (g.37453246G>C) absence of the homozygous mutant genotype in the validation sample of all 337 fertile Stallions was obvious. Therefore, these variants were considered as potentially deleterious factors for Stallion Fertility. Conclusions In conclusion, this study revealed 17 genetic variants with a predicted high damaging effect on protein structure and missing homozygous mutant genotype. The g.37455302G>A NOTCH1 variant was identified as a significant Stallion Fertility locus in Hanoverian Stallions and further 9 candidate Fertility loci with missing homozygous mutant genotypes were validated in a panel including 19 horse breeds. To our knowledge this is the first study in horses using next generation sequencing data to uncover strong candidate factors for Stallion Fertility.