Application of Proteomics to Identify Fertility Markers in Angus Bull Sperm

The goal of the study was to ascertain sperm proteins as fertility markers by identifying sperm proteins in Angus bull sperm using proteomics and validate the markers through comparative sperm biology between Angus and Holstein bulls for which there is reliable fertility data available. We aimed to determine proteins differentially expressed in sperm from Angus bulls with different fertility phenotypes. Two-dimensional differential gel electrophoresis with mass-spectrometry, functional gene clusters, canonical pathways and protein networks, using integrated discovery bioinformatics software and ingenuity pathway analysis were used to identify and analyze sperm proteome. We identified 80 proteins that were differentially expressed in sperm of our experimental population. Using computational biology approaches we demonstrated involvement of structural proteins such as outer dense fiber of sperm tails 2 and enzymes including kinases, and phosphatases having functions in essential pathways in glycolysis/gluconeogenesis and free scavenging. The results are significant because analyzed proteins in Angus sperm are determinants of fertility, gene-environment interactions, as well as potential biomarkers for animal breeding

Comprehensive proteomic analysis of bovine spermatozoa of varying fertility rates and identification of biomarkers associated with fertility

<p>Abstract</p> <p>Background</p> <p>Male infertility is a major problem for mammalian reproduction. However, molecular details including the underlying mechanisms of male fertility are still not known. A thorough understanding of these mechanisms is essential for obtaining consistently high reproductive efficiency and to ensure lower cost and time-loss by breeder.</p> <p>Results</p> <p>Using high and low fertility bull spermatozoa, here we employed differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT) and identified 125 putative biomarkers of fertility. We next used quantitative Systems Biology modeling and canonical protein interaction pathways and networks to show that high fertility spermatozoa differ from low fertility spermatozoa in four main ways. Compared to sperm from low fertility bulls, sperm from high fertility bulls have higher expression of proteins involved in: energy metabolism, cell communication, spermatogenesis, and cell motility. Our data also suggests a hypothesis that low fertility sperm DNA integrity may be compromised because cell cycle: G₂/M DNA damage checkpoint regulation was most significant signaling pathway identified in low fertility spermatozoa.</p> <p>Conclusion</p> <p>This is the first comprehensive description of the bovine spermatozoa proteome. Comparative proteomic analysis of high fertility and low fertility bulls, in the context of protein interaction networks identified putative molecular markers associated with high fertility phenotype.</p

Transcriptional reprogramming of gene expression in bovine somatic cell chromatin transfer embryos

<p>Abstract</p> <p>Background</p> <p>Successful reprogramming of a somatic genome to produce a healthy clone by somatic cells nuclear transfer (SCNT) is a rare event and the mechanisms involved in this process are poorly defined. When serial or successive rounds of cloning are performed, blastocyst and full term development rates decline even further with the increasing rounds of cloning. Identifying the "cumulative errors" could reveal the epigenetic reprogramming blocks in animal cloning.</p> <p>Results</p> <p>Bovine clones from up to four generations of successive cloning were produced by chromatin transfer (CT). Using Affymetrix bovine microarrays we determined that the transcriptomes of blastocysts derived from the first and the fourth rounds of cloning (CT1 and CT4 respectively) have undergone an extensive reprogramming and were more similar to blastocysts derived from <it>in vitro </it>fertilization (IVF) than to the donor cells used for the first and the fourth rounds of chromatin transfer (DC1 and DC4 respectively). However a set of transcripts in the cloned embryos showed a misregulated pattern when compared to IVF embryos. Among the genes consistently upregulated in both CT groups compared to the IVF embryos were genes involved in regulation of cytoskeleton and cell shape. Among the genes consistently upregulated in IVF embryos compared to both CT groups were genes involved in chromatin remodelling and stress coping.</p> <p>Conclusion</p> <p>The present study provides a data set that could contribute in our understanding of epigenetic errors in somatic cell chromatin transfer. Identifying "cumulative errors" after serial cloning could reveal some of the epigenetic reprogramming blocks shedding light on the reprogramming process, important for both basic and applied research.</p

Pengembangan Penanda Fertilitas Sebagai Alat Bantu “Akurat” Dalam Upaya Optimalisasi Sapi Pejantan Unggul Dalam Program Inseminasi Buatan

Peningkatan populasi dan mutu ternak, khususnya sapi dan kerbau d ilakukan melalui program inseminasi buatan (IB). Angka kebuntingan hasil IB di Indonesia, relatif masih rendah, salah satunya diduga disebabkan oleh fertilitas pejantan. Program IB di Indonesia menggunakan semen beku yang diproduksi oleh Balai Inseminasi Buatan (BIB). Standar evaluasi semen bagi pejantan yang digunakan sesuai SNI masih mengacu pada konsentrasi, motilitas pra dan pasca thawing serta skor individu. Perkembangan terbaru menunjukkan bahwa parameter uji tersebut tidak lagi memadai. Protein dan gen pada spermatozoa dan seminal plasma pejantan dapat menjadi kandidat alat bantu “akurat” untuk menentukan fertilitas pejantan sesuai keberhasilan IB di lapangan. Policy brief ini diharapkan dapat menjadi bahan pertimbangan bagi Pemerintah dan BIB dalam p engembangan dan pengaplikasian penanda fertilitas berbasis molekuler sebagai alat bantu “akurat” dalam proses seleksi dan kebijakan pengafkiran pejantan sapi yang akan digunakan untuk IB. Dengan demikian, efisiensi penggunaan pejantan unggul di berbagai Ba lai Inseminasi Buatan, baik Nasional maupun Daerah di Indonesia dapat dioptimalkan

Melatonin protects bovine embryos from heat stress and oxygen tension and improves embryo production in vitro

The objective of this study was to determine melatonin"s ameliorating effects against heat stress and oxygen tension in developing bovine embryos in vitro. The oocytes were collected from ovaries obtained from a local abattoir, followed by in vitro maturation, fertilization, and embryo culture. During in vitro culture, embryos were exposed to 5% (Group I) and 20% (Group II) oxygen tension with 10-3, 10-6, and 10-9 molar (M) melatonin, along with the control group without melatonin (Group III). Compared to the control group, melatonin at 10-6 and 10-9 concentrations increased in vitro development rates and decreased caspase 3/7 activity at 5% and 20% oxygen tension (P<0.01). Onehalf of the zygotes were cultured under normal temperature (38.5ºC) during the culture period, and the other half of the zygotes were heat stressed at 41ºC for six hours. Then they transferred into the normal culture conditions for the rest of the period using 0, 10- 6, and 10-9 M of melatonin (Group IV). Under normal temperature (38.5ºC), melatonin at 10-9 M was beneficial for in vitro development and DNA integrity. Under heat stress at 41ºC, melatonin at 10-6 and 10-9 M was useful for in vitro development and DNA integrity (P<0.05). Supplementation of melatonin to embryo culture medium did not alter the caspase 3 and 7 activities (P>0.05). In conclusion, melatonin prevents the adverse effects of heat stress and O2 tension on preimplantation bovine embryos in vitro

Sperm Functional Genome Associated With Bull Fertility

Bull fertility is an important economic trait in sustainable cattle production, as infertile or subfertile bulls give rise to large economic losses. Current methods to assess bull fertility are tedious and not totally accurate. The massive collection of functional data analyses, including genomics, proteomics, metabolomics, transcriptomics, and epigenomics, helps researchers generate extensive knowledge to better understand the unraveling physiological mechanisms underlying subpar male fertility. This review focuses on the sperm phenomes of the functional genome and epigenome that are associated with bull fertility. Findings from multiple sources were integrated to generate new knowledge that is transferable to applied andrology. Diverse methods encompassing analyses of molecular and cellular dynamics in the fertility-associated molecules and conventional sperm parameters can be considered an effective approach to determine bull fertility for efficient and sustainable cattle production. In addition to gene expression information, we also provide methodological information, which is important for the rigor and reliability of the studies. Fertility is a complex trait influenced by several factors and has low heritability, although heritability of scrotal circumference is high and that it is a known fertility maker. There is a need for new knowledge on the expression levels and functions of sperm RNA, proteins, and metabolites. The new knowledge can shed light on additional fertility markers that can be used in combination with scrotal circumference to predict the fertility of breeding bulls. This review provides a comprehensive review of sperm functional characteristics or phenotypes associated with bull fertility

Two-stage genome-wide association study identifies integrin beta 5 as having potential role in bull fertility

Background: Fertility is one of the most critical factors controlling biological and financial performance of animal production systems and genetic improvement of lines. The objective of this study was to identify molecular defects in the sperm that are responsible for uncompensable fertility in Holstein bulls. We performed a comprehensive genome wide analysis of single nucleotide polymorphisms (SNP) for bull fertility followed by a second-stage replication in additional bulls for a restricted set of markers. Results: In the Phase I association study, we genotyped the genomic sperm DNA of 10 low-fertility and 10 high-fertility bulls using Bovine SNP Gene Chips containing approximately 10,000 random SNP markers. In these animals, 8,207 markers were found to be polymorphic, 97 of which were significantly associated with fertility (p \u3c 0.01). In the Phase II study, we tested the four most significant SNP from the Phase I study in 101 low-fertility and 100 high-fertility bulls, with two SNPs (rs29024867 and rs41257187) significantly replicated. Rs29024867 corresponds to a nucleotide change of C → G 2,190 bp 3′ of the collagen type I alpha 2 gene on chromosome 4, while the rs41257187 (C → T) is in the coding region of integrin beta 5 gene on chromosome 1. The SNP rs41257187 induces a synonymous (Proline → Proline), suggesting disequilibrium with the true causative locus (i), but we found that the incubation of bull spermatozoa with integrin beta 5 antibodies significantly decreased the ability to fertilize oocytes. Our findings suggest that the bovine sperm integrin beta 5 protein plays a role during fertilization and could serve as a positional or functional marker of bull fertility. Conclusion: We have identified molecular markers associated with bull fertility and established that at least one of the genes harboring such variation has a role in fertility. The findings are important in understanding mechanisms of uncompensatory infertility in bulls, and in other male mammals. The findings set the stage for more hypothesis-driven research aimed at discovering the role of variation in the genome that affect fertility and that can be used to identify molecular mechanisms of development. © 2009 Feugang et al; licensee BioMed Central Ltd

Extender development for optimal cryopreservation of buck sperm to increase reproductive efficiency of goats

Preservation of sperm significantly contributes to the advancement of assisted reproductive technologies, genetic conservation and improvement efforts, and precision breeding of livestock. This review distills knowledge from the existing information and emerging patterns in the field of buck sperm cryopreservation. The primary focus is on the challenges and opportunities associated with improving extender formulations and freezing techniques in order to enhance the vitality of sperm after thawing and to increase the potential for conception. This review assesses the efficacy and limitations of conventional extenders derived from egg yolk or soybean lecithin, and the adverse impacts of seminal plasma enzymes on sperm quality during the processes of chilling and cryopreservation. Significant progress has been made in the fields of molecular biology namely lipidomics, proteomics, metabolomics, DNA methylation providing valuable knowledge regarding the unique reactions of sperm to cryopreservation. The utilization of the “omics” technologies has shown intricate molecular transformation that occur in sperm during freezing and thawing. Moreover, detection of molecular biomarkers that indicate the quality of sperm and their ability to withstand freezing provides opportunities to choose the best sperm samples for cryopreservation. This, in turn, enhances the results of artificial insemination and genetic conservation endeavors. This review emphasizes the necessity for adopting a comprehensive approach that combines molecular and cellular knowledge with practical methods in the field of sperm cryopreservation to ensure production of goats as major food animals in the global scale

Solutions For Grand Challenges In Goat And Sheep Production

Goats and sheep are valuable livestock as they produce food, such as meat, milk, fleece, and other products. In addition, goats and sheep are important both for agriculture and biomedical research. Even though these small ruminants provide essential goods, there are major obstacles preventing the efficient, sustainable, and profitable production of goats and sheep. This review is significant because it summarizes major challenges facing goat and sheep production, their negative impacts, and specific science-based solutions to overcome them. These challenge areas are education and training, research, translational research/biotechnology, goat and sheep health, and effective/efficient/sustainable/profitable agribusiness. The solutions include effective teaching of goat and sheep science to next generation and empowering the public, supporting and pursuing innovative and translational research, preventing and treating diseases, facilitating technology transfer, and developing sound agribusinesses. This resource is expected to be helpful to scientists, students, and goat and sheep producers. In addition, the information on the current state of goat and sheep agriculture will help the public better understand and appreciate challenges and opportunities in small ruminant production