Project description:Animal African trypanosomosis, caused by blood protozoan parasites transmitted mainly by tsetse flies, represents a major constraint for millions of cattle in sub-Saharan Africa. Exposed cattle include West African taurine breeds called trypanotolerant according to their ability to control parasite development and to survive and grow in enzootic areas, and indicine breeds that are trypanosusceptible to the disease. Until now the genetic basis of trypanotolerance remains unclear. Here, we improved knowledge in the biological processes involved in trypanotolerance by identifying bovine genes differentially expressed during an experimental infection by Trypanosoma congolense and their biological functions. To this end, whole blood genome-wide transcriptome profiling by RNA sequencing was performed on five West African cattle breeds, three trypanotolerant taurine breeds (N'Dama, Lagune and Baoulé), one susceptible zebu (Zebu Fulani) and one African taurine x zebu admixed breed (Borgou), at four dates, one before and three during infection. As expected, infection had a major impact on cattle blood transcriptome whatever the breed. The functional analysis of differentially expressed genes over time in each breed confirmed an early activation of the innate immune response, followed by an activation of the humoral response and an inhibition of T cells functions at the chronic stage of infection. More importantly, we highlighted overlooked features, as a strong disturbance in host metabolism and cell production energy that differentiate trypantolerant and trypanosusceptible breeds. N'Dama breed showed the earliest regulation of immune response, associated with a strong activation of cellular energy production, this last feature being also shared with Lagune, and to a lesser extent with Baoulé. Susceptible Zebu Fulani breed was distinguished from other breeds by the strongest modification in lipid metabolism regulation. Lastly, basal differences in gene expression reflected the structuration of cattle genetic diversity, and could have consequences on the tolerant or susceptible phenotype. Overall, it would be of value to deeper investigate interactions between immune response and cell metabolism that likely impact disease outcome.
Project description:Background: The Malnad Gidda are unique dwarf Bos indicus cattle native to heavy rainfall Malnad and coastal areas of Karnataka in India. These cattle are highly adapted to harsh climatic conditions and are more resistant to Foot and Mouth disease as compared to other breeds of B.indicus. Since the first genome reference became available from B.taurus Hereford breed, only a few other breeds have been genotyped using high-throughput platforms. Also despite the known reports on high diversity within indicine breeds as compared to taurine breeds, only one draft genome of Nellore and horn transcriptome of Kankrej breed were sequenced at base level resolution. Because of the special characteristics Malnad Gidda possess, it becomes the choice of breed among many indicine cows to study at molecular level and genotyping. Results: Sequencing mRNA from the PBMCs isolated from blood of one selected Malnad Gidda bull resulted in generation of 55 million paired-end reads of 100bp length. Raw sequencing data is processed to trim the adaptor and low quality bases, and are aligned against the whole genome and transcript assemblies of Bos taurus UMD 3.1 and Bos indicus (Nellore breed) respectively. About 72% of the sequenced reads from our study could be mapped against the B.taurus genome where as only 41% of reads could be mapped against the Bos indicus transcript assembly. Transcript assembly from the alignment carried out against the annotated B.taurus UMD 3.1 genome resulted in identification of ~10,000 genes with significant expression (FPKM>1). In a similar analysis against the B.indicus Kankrej assembled transcripts we could identify only ~6,000 transcripts. From the variant analysis of the sequencing data we found ~10,000 SNPs in coding regions among which ~9,000 are novel and ~6,400 are amino acid changing. Conclusions: For the first time we have genotyped and explored the transcriptome of B.indicus Malnad Gidda breed. A comparative analysis of mapping the RNA-Seq data against the available reference genome and transcript sequences is demonstrated. An enhanced utility of transcript sequencing could be achieved by improving or completing the sequence assembly of any B.indicus breed to better characterize the indicine breeds for productivity features and selective breeding.
Project description:The incidence of sub-fertility is higher in crossbred bulls compared to zebu bulls. In the present study, we analysed the metabolomic profile of seminal plasma from crossbred and zebu bulls and uncovered differentially expressed metabolites between these two breeds. Using a high-throughput LC-MS/MS-based approach, we identified 990 and 1,002 metabolites in crossbred and zebu bull seminal plasma respectively. After excluding the exogenous metabolites, we found that 50 and 68 putative metabolites were unique to crossbred and zebu bull seminal plasma, respectively, whilst 87 metabolites were common to both. After data normalisation, 63 metabolites were found to be dysregulated between crossbred and zebu bull seminal plasma. Observed pathways included Linoleic acid metabolism (observed metabolite was phosphatidylcholine) in crossbred bull seminal plasma whereas inositol phosphate metabolism (observed metabolites were phosphatidylinositol-3,4,5-trisphosphate/inositol 1,3,4,5,6-pentakisphosphate/myo-inositol hexakisphosphate) was observed in zebu bull seminal plasma. Abundance of Tetradecanoyl-CoA was significantly higher, whilst abundance of Taurine was significantly lower in crossbred bull seminal plasma. In conclusion, the present study established the seminal plasma metabolomic profile in crossbred and zebu bulls and suggest that increased lipid peroxidation coupled with low concentrations of antioxidants in seminal plasma might be associated with high incidence of sub-fertility in crossbred bulls.
Project description:Tropical theileriosis in a cattle disease of global economic importance, caused by the tick-borne protozoan parasite Theileria annulata. Conventional control strategies are failing to contain the disease and an attractive alternative is the use of pre-existing genetic resistance or tolerance. However, tropical theileriosis tolerant cattle are less productive than some susceptible breeds. To combine resistance and production traits requires an understanding of the mechanisms involved in resistance. Therefore, we have compared the response of monocytes derived from tolerant (Sahiwals, Bos indicus) and susceptible (Holstein-Friesians, B. taurus) cattle to in vitro infection with T. annulata. Over 150 genes exhibited breed-specific differential expression during the course of infection and nearly one third were differentially expressed in resting cells, implying that there are inherent differences between monocytes from the breeds. Fifty sequences currently only match ESTs or are unique to the library used to generate the microarray. The differential expression of a selection of genes was validated by quantitative RT-PCR, e.g. CD9, prion protein and signal-regulatory protein alpha. A large proportion of the differentially expressed genes encode proteins expressed on the plasma membrane or in the extracellular space and cell adhesion was one of the major Gene Ontology biological processes identified. We therefore hypothesise that the breed-specific tolerance of Sahiwal cattle compared to Holstein-Friesians is due to the interaction of infected cells with other immune cells, which influences the immune response generated against T. annulata infection. The BoMP microarray is available from the ARK-Genomics facility (www.ark-genomics.org).
Project description:Malnad Gidda is one among the 43 registered cattle breeds of India with unique traits and spread over Western Ghats and coastal regions of Karnataka state in India. Selection of highly elite fertile bulls for the breeding purpose is a critical control point in animal breeding programmes. Therefore, to characterize the semen proteome and to understand the semen biology of this breed, a comprehensive proteomic analysis of spermatozoa and seminal plasma has been carried out by employing SCX and bRPLC fractionation strategies in a mass-spectrometry platform. The semen samples from three Malnad Gidda bulls maintained at Southern Regional Station of ICAR-NDRI under standard managemental conditions were used in the study. The proteomic characterisation of semen from Malnad Gidda breed resulted in the identification of 5, 84,520 PSMs, from 24,467 peptides from 2,815 proteins in spermatozoa and identification of 2, 77,583 PSMs from 12,047 peptides, which resulted in 1,974 proteins from seminal plasma. Out of 2,815 proteins in spermatozoa and 1,974 proteins from seminal plasma, 969 proteins were common to both seminal plasma and spermatozoa. The biological processes and cellular localization of spermatozoa proteins were studied using DAVID tool and were further enriched the identical GO terms using REVIGO online tool. The functional enrichment analysis of identified proteins indicated their roles in the biological processes like sperm motility, spermatid development, spermatogenesis, and so on. GO studies showed the commonalities and differences in the molecular functions of the proteins exclusively identified in spermatozoa, seminal plasma and common proteins. This is the first proteomic investigation conducted on the semen samples of an Indian indigenous breed; therefore, we believe that our preliminary data should significantly advance our understanding of semen proteome of Indian cattle.