Application of population genetic analysis of linked, mapped microsatellites to the identification of loci under selection for disease resistance

We have sought to test the possibility of detecting regions of the genome under selection through effects on variation at linked neutral genetic markers. Particularly, we investigated three genomic regions identified by mapping in a cross-bred pedigree as harbouring QTL for trypanosomiasis tolerance. Population genetic analysis is used with mapped microsatellites to try to infer selection for trypanotolerance in West African cattle populations

Cytokine mRNA profiling of peripheral blood mononuclear cells from trypanotolerant and trypanosusceptible cattle infected with Trypanosoma congolense

To examine differences in cytokine profiles that may confer tolerance/susceptibility to bovine African trypanosomiasis, N'Dama (trypanotolerant, n = 8) and Boran (trypanosusceptible, n = 8) cattle were experimentally challenged with Trypanosoma congolense. Blood samples were collected over a 34-day period, and RNA was extracted from peripheral blood mononuclear cells. The expression levels of a panel of 14 cytokines were profiled over the time course of infection and between breeds. Messenger RNA (mRNA) transcript levels for the IL2, IL8, and IL1RN genes were significantly downregulated across the time course of infection in both breeds. There was an early increase in transcripts for genes encoding proinflammatory mediators (IFNG, IL1A, TNF, and IL12) in N'Dama by 14 days postinfection (dpi) compared with preinfection levels that was not detected in the susceptible Boran breed. By the time of peak parasitemia, a type 2 helper T cells (TH2)-like cytokine environment was prevalent that was particularly evident in the Boran. Increases in transcripts for the IL6 (29 and 34 dpi) and IL10 (21, 25, and 29 dpi) genes were detected that were higher in the Boran compared with N'Dama. These findings highlight the implications for using murine models to study the bovine immune response to trypanosomiasis, where in some cases cytokine expression patterns differ. Overall, these data suggest that the trypanotolerant N'Dama are more capable of responding very early in infection with proinflammatory and TH1 type cytokines than the trypanosusceptible Boran and may explain why N'Dama control parasitemia more efficiently than Boran during the early stages of infection

Data from: Genetic origin, admixture and population history of aurochs (Bos primigenius) and primitive European cattle

This file contains the information for 777,962 markers genotyped in 143 samples using the Illumina BovineHD BeadChip. The vcf file contains the aurochs genotypes, which corresponds to SNP positions in Illumina BovineHD Beadchip

Genetic diversity of South African dairy goats for genetic management and improvement

The dairy goatindustry is a small, butimportant role player in the South African agricultural sector. The limited number of animals representing the three main breeds (Saanen, British Alpine and Toggenburg) has raised concerns over the genetic diversity of these animals and the impact on their genetic management. In this study, 240 dairy goats representing three breeds were genotyped with 25 microsatellite markers. Sufficientlevels of genetic diversity were observed in all the breeds, with observed heterozygosity values exceeding 60%. A slight population differentiation was indicated by the low FST values across and within the populations. This was confirmed by the AMOVA analyses with most of the variation shown within populations (91.7%). Negative FIS values in the three breeds indicated limited inbreeding. Population structure analyses revealed six distinct groups, with the Saanen population clustering into three sub-groups. The Toggenburg and British Alpine breeds formed their own separate cluster, with a last cluster formed by animals from all three pure-bred populations, indicating high levels of admixture. These results caution farmers against uncontrolled crossbreeding practices and recommend routine evaluation of genetic diversity.This work is based on the research supported in part by a number of grants from the National Research Foundation of South Africa (UID: 78566 (NRF RISP grant for the ABI3500)).http://www.elsevier.com/locate/smallrumreshb2017Animal and Wildlife Science