Comprehensive assessment of genetic diversity, structure, and relationship in four Japanese cattle breeds by Illumina 50 K SNP array analysis.

There are four unique cattle breeds in Japan: Japanese Black, Japanese Brown, Japanese Polled, and Japanese Shorthorn. The objective of this study was to comprehensively assess the genetic diversity, structure, relationship, and the degree of influence from foreign breeds (Angus, Simmental, Hanwoo, Shorthorn, Ayrshire, Brown Swiss, and Devon) in the Japanese cattle breeds using Illumina 50 K SNP array. In principal component analysis, each Japanese breed was separately clustered except for Japanese Shorthorn and Shorthorn. Japanese cattle breeds also showed different genetic components from each other at K ≥ 5 in population structure analysis. Japanese Shorthorn, on the other hand, had a very similar structure to Shorthorn at K ≤ 9, and Japanese Polled had a partially similar component with Angus at K = 3-7. Such close relationships were also observed in the phylogenetic tree. These findings imply that Japanese cattle breeds share genetic components with European cattle breeds to some extent while they have been almost differentiated. In population structure analysis, Japanese Black cattle shared little genetic component (3.5%) with European breeds. This is the first study to determine the extent to which European breeds impact Japanese breeds.

QTL Mapping for Grain Zinc and Iron Concentrations in Bread Wheat.

Deficiency of micronutrient elements, such as zinc (Zn) and iron (Fe), is called "hidden hunger," and bio-fortification is the most effective way to overcome the problem. In this study, a high-density Affymetrix 50K single-nucleotide polymorphism (SNP) array was used to map quantitative trait loci (QTL) for grain Zn (GZn) and grain Fe (GFe) concentrations in 254 recombinant inbred lines (RILs) from a cross Jingdong 8/Bainong AK58 in nine environments. There was a wide range of variation in GZn and GFe concentrations among the RILs, with the largest effect contributed by the line × environment interaction, followed by line and environmental effects. The broad sense heritabilities of GZn and GFe were 0.36 ± 0.03 and 0.39 ± 0.03, respectively. Seven QTL for GZn on chromosomes 1DS, 2AS, 3BS, 4DS, 6AS, 6DL, and 7BL accounted for 2.2-25.1% of the phenotypic variances, and four QTL for GFe on chromosomes 3BL, 4DS, 6AS, and 7BL explained 2.3-30.4% of the phenotypic variances. QTL on chromosomes 4DS, 6AS, and 7BL might have pleiotropic effects on both GZn and GFe that were validated on a germplasm panel. Closely linked SNP markers were converted to high-throughput KASP markers, providing valuable tools for selection of improved Zn and Fe bio-fortification in breeding.

Towards genomic selection for facial eczema disease tolerance in the New Zealand sheep industry.

Pithomycotoxicosis, more commonly known as facial eczema (FE), is a liver disease that occurs predominantly in New Zealand because of its toxigenic Pithomyces chartarum strains. The first reported case was in sheep in 1887. Since the 1930s, a number of studies have been conducted in an attempt to mitigate the problems FE has on the sheep and dairy industries. The research in these studies included work on fungicide and biological control of the saprophytic fungus, use of different pasture plants to inhibit fungal growth, stock management with respect to pasture fungal spore counts and the use of zinc prophylaxis on animals. The finding that there was a genetic basis in FE sensitivity in sheep prompted research for a genetic approach to mitigation in the form of a diagnostic DNA test for susceptibility to the disease. Recently, we have used the Illumina OvineSNP50 BeadChip to develop a genome-enabled prediction approach to screen for FE-tolerant sheep. Our current best genomic prediction for FE is for the Romney breed and has an accuracy of 0.38. This prediction accuracy is not as high as the individual accuracy gained by an artificial challenge test (0.64). However, it has the advantage of being a non-invasive test and can be provided as part of genomic testing for other traits at minimal cost.