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Zhang J, Zha X, Yang G, Ma X, La Y, Wu X, Guo X, Chu M, Bao P, Yan P, Liang C. Polymorphisms of TXK and PLCE1 Genes and Their Correlation Analysis with Growth Traits in Ashidan Yaks. Animals (Basel) 2024; 14:3506. [PMID: 39682472 DOI: 10.3390/ani14233506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2024] [Revised: 12/02/2024] [Accepted: 12/02/2024] [Indexed: 12/18/2024] Open
Abstract
The tyrosine protein kinase (TXK) gene, as a member of the non-receptor tyrosine kinase Tec family, plays a vital role in signal transduction mediation. Phospholipase C epsilon 1 (PLCE1), a membrane-associated enzyme, is of paramount importance for the differentiation of myoblasts and the normal functioning of muscle tissue. In recent years, both of these genes have been reported to be associated with the economic traits of animals. This study aimed to investigate the relationship between single nucleotide polymorphisms (SNPs) in the TXK and PLCE1 genes and growth traits in Ashidan yaks and to search for potential molecular marker loci that can influence Ashidan yak breeding. A cGPS liquid microarray was utilized to genotype 232 Ashidan yaks and to analyze correlations between two SNP loci in the TXK and PLCE1 genes and yak body weight, body height, body length, and chest circumference at different periods. The results indicated that the g.55,999,531C>T locus of the TXK gene and the g.342,350T>G locus of the PLCE1 gene were significantly correlated with the growth traits of Ashidan yaks. Among these, individuals with the CC genotype at the g.55,999,531C>T locus showed a significantly higher body length at 6 months old compared to TT individuals, and those with the CT genotype at 12 months old had a significantly higher chest circumference than TT individuals. At the g.342,350T>G locus, the body height of GG genotype individuals at 18 months of age was significantly higher than that of TT genotype individuals and TG genotype individuals. The above findings can be used as theoretical support for the subsequent improvement of Ashidan yak breeding.
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Affiliation(s)
- Juanxiang Zhang
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Xita Zha
- Qinghai Qilian County Animal Husbandry and Veterinary Workstation, Qilian 810400, China
| | - Guowu Yang
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Xiaoming Ma
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Yongfu La
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Xiaoyun Wu
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Xian Guo
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Min Chu
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Pengjia Bao
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Ping Yan
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
| | - Chunnian Liang
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou 730050, China
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China
- Qinghai Qilian County Animal Husbandry and Veterinary Workstation, Qilian 810400, China
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Khan MZ, Chen W, Naz S, Liu X, Liang H, Chen Y, Kou X, Liu Y, Ashraf I, Han Y, Peng Y, Wang C, Zahoor M. Determinant genetic markers of semen quality in livestock. Front Endocrinol (Lausanne) 2024; 15:1456305. [PMID: 39429738 PMCID: PMC11489916 DOI: 10.3389/fendo.2024.1456305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Accepted: 09/09/2024] [Indexed: 10/22/2024] Open
Abstract
The reproductive efficiency of livestock is crucial for agricultural productivity and economic sustainability. One critical factor in successful fertilization and the viability of offspring is the quality of semen. Poor semen quality, especially in frozen-thawed semen used in artificial insemination (AI) have been shown to influence conception outcomes, resulting a negative impact on livestock production. Recent advancements in genetic research have identified specific markers linked to semen quality traits in various livestock species, such as cattle, sheep, goats, pigs, buffalo, and equines. These genetic markers are essential in screening males for breeding suitability, which in turn enhances selective breeding programs. Understanding these markers is crucial for improving reproductive performance and increasing productivity in livestock populations. This review offers a comprehensive overview of the genetic markers associated with semen quality in key livestock. It explores the underlying genetic mechanisms and their practical implications in animal breeding and management. The review underscores the importance of integrating genetic insights into breeding strategies to optimize reproductive efficiency and ensure the sustainable development of livestock industries.
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Affiliation(s)
- Muhammad Zahoor Khan
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Wenting Chen
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Saima Naz
- Department of Zoology, Government Sadiq College Women University, Bahawalpur, Pakistan
| | - Xiaotong Liu
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Huili Liang
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Yinghui Chen
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Xiyan Kou
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Yihong Liu
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Iqra Ashraf
- Department of Zoology, Government Sadiq College Women University, Bahawalpur, Pakistan
| | - Ying Han
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Yongdong Peng
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Changfa Wang
- Liaocheng Research Institute of Donkey High-Efficiency Breeding and Ecological Feeding, Liaocheng University, Liaocheng, China
| | - Muhammad Zahoor
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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Fabbri MC, Tiezzi F, Crovetti A, Maltecca C, Bozzi R. Investigation of cosmopolitan and local Italian beef cattle breeds uncover common patterns of heterozygosity. Animal 2024; 18:101142. [PMID: 38636149 DOI: 10.1016/j.animal.2024.101142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 04/20/2024] Open
Abstract
The analysis of livestock heterozygosity is less common compared to the study of homozygous patterns. Heterozygous-Rich Regions (HRRs) may harbor significant loci for functional traits such as immune response, survival rate, and fertility. For this reason, this study was conducted to investigate and characterize the heterozygosity patterns of four beef cattle breeds, which included two cosmopolitan breeds (Limousine and Charolaise) and two local breeds (Sarda and Sardo Bruna). Our analysis identified regions with a high degree of heterozygosity using a consecutive runs approach, the Tajima D test, nucleotide diversity estimation, and Hardy Weinberg equilibrium test. These regions exhibited recurrent heterozygosity peaks and were consistently found on specific chromosomes across all breeds, specifically autosomes 15, 16, 20, and 23. The cosmopolitan and Sardo Bruna breeds also displayed peaks on autosomes 2 and 21, respectively. Thirty-five top runs shared by more than 25% of the populations were identified. These genomic fragments encompassed 18 genes, two of which are directly linked to male fertility, while four are associated with lactation. Two other genes play roles in survival and immune response. Our study also detected a region related to growth and carcass traits in Limousine breed. Our analysis of heterozygosity-rich regions revealed particular segments of the cattle genome linked to various functional traits. It appears that balancing selection is occurring in specific regions within the four examined breeds, and unexpectedly, they are common across cosmopolitan and local breeds. The genes identified hold potential for applications in breeding programs and conservation studies to investigate the phenotypes associated with these heterozygous genotypes. In addition, Tajima D test, Nucleotide diversity, and Hardy Weinberg equilibrium test confirmed the presence of heterozygous fragments found with Heterozygous-Rich Regions analysis.
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Affiliation(s)
- M C Fabbri
- Dipartimento di Scienze e Tecnologie Agrarie, Alimentari, Ambientali e Forestali, Università di Firenze, Firenze, Italy.
| | - F Tiezzi
- Dipartimento di Scienze e Tecnologie Agrarie, Alimentari, Ambientali e Forestali, Università di Firenze, Firenze, Italy
| | - A Crovetti
- Dipartimento di Scienze e Tecnologie Agrarie, Alimentari, Ambientali e Forestali, Università di Firenze, Firenze, Italy
| | - C Maltecca
- Dipartimento di Scienze e Tecnologie Agrarie, Alimentari, Ambientali e Forestali, Università di Firenze, Firenze, Italy; Department of Animal Science, North Carolina State University, Raleigh, NC 27695, United States
| | - R Bozzi
- Dipartimento di Scienze e Tecnologie Agrarie, Alimentari, Ambientali e Forestali, Università di Firenze, Firenze, Italy
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Spanner EA, de Graaf SP, Rickard JP. Factors affecting the success of laparoscopic artificial insemination in sheep. Anim Reprod Sci 2024; 264:107453. [PMID: 38547814 DOI: 10.1016/j.anireprosci.2024.107453] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/06/2024] [Accepted: 03/10/2024] [Indexed: 05/01/2024]
Abstract
Successful artificial breeding underpins rapid genetic and production gains in animal agriculture. In sheep, artificial insemination with frozen semen is performed via intrauterine laparoscopy as frozen-thawed spermatozoa do not traverse the cervix in sufficient numbers for high fertility and transcervical insemination is anatomically impossible in most ewes. Historically, laparoscopic artificial insemination has always been considered reasonably successful, but recent anecdotal reports of poor fertility place it at risk of warning adoption. Understanding the male, female and environmental factors that influence the fertility of sheep is warranted if the success of artificial insemination is to be improved and genetic progress maximised for the sheep industry. This review details the current practice of laparoscopic AI in sheep. It explores the effects of semen quantity and quality, the ewe, her preparation, and environmental conditions, on the fertility obtained following laparoscopic artificial insemination.
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Affiliation(s)
- E A Spanner
- The University of Sydney, Faculty of Science, School of Life and Environmental Sciences, NSW 2006, Australia.
| | - S P de Graaf
- The University of Sydney, Faculty of Science, School of Life and Environmental Sciences, NSW 2006, Australia
| | - J P Rickard
- The University of Sydney, Faculty of Science, School of Life and Environmental Sciences, NSW 2006, Australia
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Dementieva NV, Dysin AP, Shcherbakov YS, Nikitkina EV, Musidray AA, Petrova AV, Mitrofanova OV, Plemyashov KV, Azovtseva AI, Griffin DK, Romanov MN. Risk of Sperm Disorders and Impaired Fertility in Frozen-Thawed Bull Semen: A Genome-Wide Association Study. Animals (Basel) 2024; 14:251. [PMID: 38254422 PMCID: PMC10812825 DOI: 10.3390/ani14020251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 01/08/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024] Open
Abstract
Cryopreservation is a widely used method of semen conservation in animal breeding programs. This process, however, can have a detrimental effect on sperm quality, especially in terms of its morphology. The resultant sperm disorders raise the risk of reduced sperm fertilizing ability, which poses a serious threat to the long-term efficacy of livestock reproduction and breeding. Understanding the genetic factors underlying these effects is critical for maintaining sperm quality during cryopreservation, and for animal fertility in general. In this regard, we performed a genome-wide association study to identify genomic regions associated with various cryopreservation sperm abnormalities in Holstein cattle, using single nucleotide polymorphism (SNP) markers via a high-density genotyping assay. Our analysis revealed a significant association of specific SNPs and candidate genes with absence of acrosomes, damaged cell necks and tails, as well as wrinkled acrosomes and decreased motility of cryopreserved sperm. As a result, we identified candidate genes such as POU6F2, LPCAT4, DPYD, SLC39A12 and CACNB2, as well as microRNAs (bta-mir-137 and bta-mir-2420) that may play a critical role in sperm morphology and disorders. These findings provide crucial information on the molecular mechanisms underlying acrosome integrity, motility, head abnormalities and damaged cell necks and tails of sperm after cryopreservation. Further studies with larger sample sizes, genome-wide coverage and functional validation are needed to explore causal variants in more detail, thereby elucidating the mechanisms mediating these effects. Overall, our results contribute to the understanding of genetic architecture in cryopreserved semen quality and disorders in bulls, laying the foundation for improved animal reproduction and breeding.
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Affiliation(s)
- Natalia V. Dementieva
- Russian Research Institute of Farm Animal Genetics and Breeding—Branch of the L. K. Ernst Federal Research Centre for Animal Husbandry, Pushkin, 196601 St. Petersburg, Russia; (A.P.D.); (Y.S.S.); (E.V.N.); (A.A.M.); (A.V.P.); (O.V.M.); (A.I.A.)
| | - Artem P. Dysin
- Russian Research Institute of Farm Animal Genetics and Breeding—Branch of the L. K. Ernst Federal Research Centre for Animal Husbandry, Pushkin, 196601 St. Petersburg, Russia; (A.P.D.); (Y.S.S.); (E.V.N.); (A.A.M.); (A.V.P.); (O.V.M.); (A.I.A.)
| | - Yuri S. Shcherbakov
- Russian Research Institute of Farm Animal Genetics and Breeding—Branch of the L. K. Ernst Federal Research Centre for Animal Husbandry, Pushkin, 196601 St. Petersburg, Russia; (A.P.D.); (Y.S.S.); (E.V.N.); (A.A.M.); (A.V.P.); (O.V.M.); (A.I.A.)
| | - Elena V. Nikitkina
- Russian Research Institute of Farm Animal Genetics and Breeding—Branch of the L. K. Ernst Federal Research Centre for Animal Husbandry, Pushkin, 196601 St. Petersburg, Russia; (A.P.D.); (Y.S.S.); (E.V.N.); (A.A.M.); (A.V.P.); (O.V.M.); (A.I.A.)
| | - Artem A. Musidray
- Russian Research Institute of Farm Animal Genetics and Breeding—Branch of the L. K. Ernst Federal Research Centre for Animal Husbandry, Pushkin, 196601 St. Petersburg, Russia; (A.P.D.); (Y.S.S.); (E.V.N.); (A.A.M.); (A.V.P.); (O.V.M.); (A.I.A.)
| | - Anna V. Petrova
- Russian Research Institute of Farm Animal Genetics and Breeding—Branch of the L. K. Ernst Federal Research Centre for Animal Husbandry, Pushkin, 196601 St. Petersburg, Russia; (A.P.D.); (Y.S.S.); (E.V.N.); (A.A.M.); (A.V.P.); (O.V.M.); (A.I.A.)
| | - Olga V. Mitrofanova
- Russian Research Institute of Farm Animal Genetics and Breeding—Branch of the L. K. Ernst Federal Research Centre for Animal Husbandry, Pushkin, 196601 St. Petersburg, Russia; (A.P.D.); (Y.S.S.); (E.V.N.); (A.A.M.); (A.V.P.); (O.V.M.); (A.I.A.)
| | - Kirill V. Plemyashov
- Federal State Budgetary Educational Institution of Higher Education “St. Petersburg State University of Veterinary Medicine”, 196084 St. Petersburg, Russia;
| | - Anastasiia I. Azovtseva
- Russian Research Institute of Farm Animal Genetics and Breeding—Branch of the L. K. Ernst Federal Research Centre for Animal Husbandry, Pushkin, 196601 St. Petersburg, Russia; (A.P.D.); (Y.S.S.); (E.V.N.); (A.A.M.); (A.V.P.); (O.V.M.); (A.I.A.)
| | | | - Michael N. Romanov
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, UK;
- L. K. Ernst Federal Research Centre for Animal Husbandry, Dubrovitsy, 142132 Podolsk, Moscow Oblast, Russia
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EL Nagar AG, Salem MMI, Amin AMS, Khalil MH, Ashour AF, Hegazy MM, Abdel-Shafy H. A Single-Step Genome-Wide Association Study for Semen Traits of Egyptian Buffalo Bulls. Animals (Basel) 2023; 13:3758. [PMID: 38136796 PMCID: PMC10740893 DOI: 10.3390/ani13243758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/17/2023] [Accepted: 11/24/2023] [Indexed: 12/24/2023] Open
Abstract
The present study aimed to contribute to the limited research on buffalo (Bubalus bubalis) semen traits by incorporating genomic data. A total of 8465 ejaculates were collected. The genotyping procedure was conducted using the Axiom® Buffalo Genotyping 90 K array designed by the Affymetrix Expert Design Program. After conducting a quality assessment, we utilized 67,282 SNPs genotyped in 192 animals. We identified several genomic loci explaining high genetic variance by employing single-step genomic evaluation. The aforementioned regions were located on buffalo chromosomes no. 3, 4, 6, 7, 14, 16, 20, 22, and the X-chromosome. The X-chromosome exhibited substantial influence, accounting for 4.18, 4.59, 5.16, 5.19, and 4.31% of the genomic variance for ejaculate volume, mass motility, livability, abnormality, and concentration, respectively. In the examined genomic regions, we identified five novel candidate genes linked to male fertility and spermatogenesis, four in the X-chromosome and one in chromosome no. 16. Additional extensive research with larger sample sizes and datasets is imperative to validate these findings and evaluate their applicability for genomic selection.
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Affiliation(s)
- Ayman G. EL Nagar
- Department of Animal Production, Faculty of Agriculture at Moshtohor, Benha University, Benha 13736, Egypt;
| | - Mohamed M. I. Salem
- Department of Animal and Fish Production, Faculty of Agriculture (El-Shatby), Alexandria University, Alexandria 21545, Egypt;
| | - Amin M. S. Amin
- Animal Production Research Institute, Agricultural Research Center, Dokki, Giza 12619, Egypt; (A.M.S.A.); (A.F.A.); (M.M.H.)
| | - Maher H. Khalil
- Department of Animal Production, Faculty of Agriculture at Moshtohor, Benha University, Benha 13736, Egypt;
| | - Ayman F. Ashour
- Animal Production Research Institute, Agricultural Research Center, Dokki, Giza 12619, Egypt; (A.M.S.A.); (A.F.A.); (M.M.H.)
| | - Mohammed M. Hegazy
- Animal Production Research Institute, Agricultural Research Center, Dokki, Giza 12619, Egypt; (A.M.S.A.); (A.F.A.); (M.M.H.)
| | - Hamdy Abdel-Shafy
- Department of Animal Production, Faculty of Agriculture, Cairo University, El-Gamma Street, Giza 12613, Egypt;
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Riveros JAN, Pereira IC, Teixeira ACB, Diniz JHW, Borges AM, Díaz JFG, Beletti ME, Oliveira LZ. Sperm head morphometry and chromatin alterations in bulls with different conception rates. Anim Reprod Sci 2023; 255:107275. [PMID: 37311270 DOI: 10.1016/j.anireprosci.2023.107275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/02/2023] [Accepted: 06/05/2023] [Indexed: 06/15/2023]
Abstract
The objective of this investigation was to analyze timed-AI conception rates (CRs) of different sires in light of their conventional semen quality parameters, sperm head morphometry, and chromatin alterations. Semen was collected in the field from six Angus bulls and used for the timed-AI of 890 suckled multiparous Nellore cows at a single farm. Semen batches were evaluated on the following in vitro parameters: sperm motility, concentration, and morphology, sperm head morphometry, and chromatin alteration types. The overall CR was 49% and Bulls 1 (43%) and 2 (40%) presented reduced (P < 0.05) pregnancies per AI compared to Bull 6 (61%), even though no differences were observed between their conventional semen quality parameters. Bull 1, however, presented higher (P = 0.0001) shape factor, smaller (P = 0.0025) antero-posterior symmetry, and elevated (P = 0.0141) Fourier 1 parameter, whereas Bull 2 exhibited a higher (P = 0.0023) percentage of chromatin alteration along the central axis of the sperm head. In conclusion, bulls with varying CRs may present sperm head morphometric differences and/or chromatin alterations while not presenting differences in conventional in vitro semen quality parameters. Although further studies are needed to elucidate the concrete implications of chromatin alterations on field fertility, sperm morphometric differences and chromatin alterations may be at least partially causative of the lower pregnancies per timed-AI of certain sires.
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Affiliation(s)
- José Andrés Nivia Riveros
- Department of Veterinary Clinics and Surgery, Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG 31270-901, Brazil
| | - Isabelle Cristina Pereira
- Department of Veterinary Clinics and Surgery, Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG 31270-901, Brazil
| | - Ana Carolina Bahia Teixeira
- Department of Veterinary Clinics and Surgery, Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG 31270-901, Brazil
| | - Juliana Horta Wilke Diniz
- Department of Veterinary Clinics and Surgery, Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG 31270-901, Brazil
| | - Alan Maia Borges
- Department of Veterinary Clinics and Surgery, Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG 31270-901, Brazil
| | - Juan Felipe García Díaz
- Faculty of Veterinary Medicine and Animal Science, National University of Colombia, Bogotá 111321, Colombia
| | - Marcelo Emílio Beletti
- School of Veterinary Medicine, Federal University of Uberlandia, Uberlândia, MG 38400-902, Brazil
| | - Leticia Zoccolaro Oliveira
- Department of Veterinary Clinics and Surgery, Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG 31270-901, Brazil.
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