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Admixture mapping affords a powerful approach to genetic mapping of complex traits and may be particularly suited to investigation in cattle where many breeds and populations are hybrids of the two divergent ancestral genomes, derived from Bos taurus and Bos indicus. Here we design a minimal genome wide SNP panel for tracking ancestry in recent hybrids of Holstein–Friesian and local Arsi zebu in a field sample from a region of high bovine tuberculosis (BTB) endemicity in the central Ethiopian highlands. We first demonstrate the utility of this approach by mapping the red coat color phenotype, uncovering a highly significant peak over the MC1R gene and a second peak with no previously known candidate gene. Secondly, we exploit the described differential susceptibility to BTB between the ancestral strains to identify a region in which Bos taurus ancestry associates, at suggestive significance, with skin test positivity. Interestingly, this association peak contains the toll-like receptor gene cluster on chromosome 6. With this work we have shown the potential of admixture mapping in hybrid domestic animals with divergent ancestral genomes, a recurring condition in domesticated species.

BackgroundValidation of previously identified candidate biomarkers and identification of additional candidate gene expression profiles to facilitate diagnosis of tuberculosis (TB) disease and monitoring treatment responses in the Ethiopian context is vital for improving TB control in the future.MethodsExpression levels of 105 immune-related genes were determined in the blood of 80 HIV-negative study participants composed of 40 active TB cases, 20 latent TB infected individuals with positive tuberculin skin test (TST+), and 20 healthy controls with no Mycobacterium tuberculosis (Mtb) infection (TST-), using focused gene expression profiling by dual-color Reverse-Transcription Multiplex Ligation-dependent Probe Amplification assay. Gene expression levels were also measured six months after anti-TB treatment (ATT) and follow-up in 38 TB patients.ResultsThe expression of 15 host genes in TB patients could accurately discriminate between TB cases versus both TST+ and TST- controls at baseline and thus holds promise as biomarker signature to classify active TB disease versus latent TB infection in an Ethiopian setting. Interestingly, the expression levels of most genes that markedly discriminated between TB cases versus TST+ or TST- controls did not normalize following completion of ATT therapy at 6 months (except for PTPRCv1, FCGR1A, GZMB, CASP8 and GNLY) but had only fully normalized at the 18 months follow-up time point. Of note, network analysis comparing TB-associated host genes identified in the current HIV-negative TB cohort to TB-associated genes identified in our previously published Ethiopian HIV-positive TB cohort, revealed an over-representation of pattern recognition receptors including TLR2 and TLR4 in the HIV-positive cohort which was not seen in the HIV-negative cohort. Moreover, using ROC cutoff ≥ 0.80, FCGR1A was the only marker with classifying potential between TB infection and TB disease regardless of HIV status.ConclusionsOur data indicate that complex gene expression signatures are required to measure blood transcriptomic responses during and after successful ATT to fully diagnose TB disease and characterise drug-induced relapse-free cure, combining genes which resolve completely during the 6-months treatment phase of therapy with genes that only fully return to normal levels during the post-treatment resolution phase.

BACKGROUND: Mycobacterium tuberculosis complex (MTBC) and its human host are the most competent organisms with co-evolutionary trajectory. This review determined the phylogeography, clinical phenotype-related genotype and transmission dynamics of MTBC in Africa.METHODS: Spoligotyping and mycobacterial interspersed repetitive units-variable number tandem repeats (MIRU-VNTR) based articles from Africa published in the English language were included. Articles were retrieved from PubMed and Scopus on 12 May 2018.RESULTS: In Africa, respectively 92% and 7% of tuberculosis (TB) cases were caused by M. tuberculosis and M. africanum. Among M. tuberculosis lineages (L), L4 was the predominant, at 67%, followed by L3/Central Asian (CAS; 10%). L7/ETH1 and L5/6/Maf were restricted to the Horn and Western Africa, respectively. L4.6/SIT37, H37Rv like, L4.1.2/Haarlem and H3-Ural were proportionally more frequent among tuberculous lymphadenitis (TBLN) than among pulmonary tuberculosis (PTB) cases. On 24-locus MIRU-VNTR, clustering rate was 31%; the secondary case rate from a single primary source case was 20%.CONCLUSION: Africa in general, and the east-west pole of Africa in particular, harboured a genetically diverse population of MTBC, with characteristics of geographic segregation. Both generalist and specialist genotypes are circulating in the region. L4 is dominant across the continent, while M. bovis is rarely detected as a cause for human TB. The clinical significance of genetic diversity of MTBC in the different geographic and population groups of Africa is not fully understood. Both person-to-person transmission and reactivation mode of TB is significant in Africa. Prevention and control strategies should therefore envisage these two scenarios.

Small ruminants are mainly kept for immediate cash sources and they are also sources of foreign currency. Nonetheless, there is a lack of well-functioning marketing systems. In addition, the different live animals supplied to the market by pastoralists and farmers do not meet the quality attributes required by diverse markets. Randomly 1120 farmers were selected and using double hurdle model, the article identified determinants of participation decision and level of participation in small ruminants market in 7 districts of five regional states of Ethiopia. Out of the total interviewed households, 77.3% and 22.7% were participated and not-participated to the small ruminants market, respectively. The first-hurdle model estimation results for participation decision indicate that Region, access to credit, distance to the market, distance to veterinary service, extension contact and access to market information were found that significantly influenced small ruminants’ market participation The results also show that most of the factors determining decision of participation also determined the level of small ruminants market participation. Therefore, government or any other bodies who are concerned on small ruminants product should help producers on Improving the accessibility of market places; need to facilitate a long term relationship with different actors in order to get reasonable price for the producers.

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