Theileria parva is a protozoan parasite that causes East Coast fever (ECF), an economically important disease of cattle in Africa. It is transmitted mainly by the tick Rhipicephalus appendiculatus. Research efforts to develop a subunit vaccine based on parasite neutralizing antibodies and cytotoxic T-lymphocytes have met with limited success. The molecular mechanisms underlying T. parva life cycle stages in the tick vector and bovine host are poorly understood, thus limiting progress toward an effective and efficient control of ECF. Transcriptomics has been used to identify candidate vaccine antigens or markers associated with virulence and disease pathology. Therefore, characterization of gene expression throughout the parasite's life cycle should shed light on host-pathogen interactions in ECF and identify genes underlying differences in parasite stages as well as potential, novel therapeutic targets. Recently, the first gene expression profiling of T. parva was conducted for the sporoblast, sporozoite, and schizont stages. The sporozoite is infective to cattle, whereas the schizont is the major pathogenic form of the parasite. The schizont can differentiate into piroplasm, which is infective to the tick vector. The present study was designed to extend the T. parva gene expression profiling to the piroplasm stage with reference to the schizont. Pairwise comparison revealed that 3,279 of a possible 4,084 protein coding genes were differentially expressed, with 1,623 (49%) genes upregulated and 1,656 (51%) downregulated in the piroplasm relative to the schizont. In addition, over 200 genes were stage-specific. In general, there were more molecular functions, biological processes, subcellular localizations, and pathways significantly enriched in the piroplasm than Atchou et al. Theileria Parva Developmental Stages' Transcriptomics in the schizont. Using known antigens as benchmarks, we identified several new potential vaccine antigens, including TP04_0076 and TP04_0640, which were highly immunogenic in naturally T. parva-infected cattle. All the candidate vaccine antigens identified have yet to be investigated for their capacity to induce protective immune response against ECF.

Livestock production is an important component of the Benin economy contributing an upward of 25% of the agricultural Gross Domestic Products (GDP). Indigenoues cattle sector contributes more to the GDP compared to other livestock species. Despite the economic role played by the sector, there has been little or no efforts to genetically improve the indigenous cattle in the country. Recently, the government and other development partners have embarked on projects to improve the sector performance. The first step would be to morphologically and genetically characterize the cattle populations so as to match them with the available resources for optimal conservation and utilization. There exist no genetic diversity information for the different cattle types in Benin. The objective of this study was thus to determine the genetic diversity of the three most abundant indigenous cattle types. A total of 86 cattle from all three breeds were genotyped at the 14 loci. High levels of allelic and gene diversity were observed with an overall mean of 8.67 and 0.76 respectively. The mean inbreeding estimate within breeds was found to be negative at-0.124,-0.111 and-0.146 in Azawak, Borgou and Somba cattle breeds respectively. The global F statistics and AMOVA resulted in low genetic differentiation among the breeds with 1.14% of total variation being attributed to betweenbreed differences. Neighbor-joining tree revealed Azawak and Borgou clustered together while Somba breed being relatively distinct from the aforementioned. High levels of admixture were evident from the distribution of pairwise inter-individual allele sharing distances. Besides, the STRUCTURE analysis confirmed the tight genetic linkage between the breeds. High genetic diversity and poor genetic structure among the cattle breeds investigated could be due to historic zebu-taurine admixture and unstructured breeding practices. This results will aid in design of sustainable indigenous cattle genetic improvement programmes.