Genome-wide analysis reveals genetic diversity, linkage disequilibrium, and selection for milk production traits in Chinese buffalo breeds.

The water buffalo is an important dual-purpose livestock that is widespread throughout central and southern China. However, there has been no characterization of the population genetics of Chinese buffalo. Using an Axiom buffalo genotyping array (Thermo Fisher Scientific, Wilmington, DE), we analyzed the genetic diversity, linkage disequilibrium pattern, and signature of selection in 176 Chinese buffaloes from 13 breeds. A total of 35,547 SNP passed quality control and were used for further analyses. Population genetic analysis revealed a clear separation between swamp and river types. Ten Chinese indigenous breeds were clustered into the swamp group, the Murrah and Nili-Ravi breeds were clustered into the river group, and the crossbred breed was closer to the river group. Genetic diversity analysis showed that the swamp group had a lower average expected heterozygosity. Linkage disequilibrium decay distance was much shorter in the swamp group compared with the river group, with an average square of correlation coefficient value of 0.2 of approximately 50 kb. Analysis of runs of homozygosity indicated extensive remote and recent inbreeding within swamp and river groups, respectively. Moreover, one genomic region under selection was detected between the river and swamp groups. Our findings contribute to our understanding of the characterization of population genetics in Chinese buffaloes, which in turn may be used in buffalo breeding programs.

Validating genome-wide associated signals for clinical mastitis in German Holstein cattle.

A validation study for six genomic regions previously identified by a genome-wide association study for somatic cell score was conducted with data of clinical mastitis in German Holstein cattle. Out of 10 tested SNPs, five on chromosomes 6, 13 and 19 were significantly associated with clinical mastitis (P < 0.05). Three SNPs on chromosomes 6 and 19 had the same direction of effect as those previously reported in the initial genome-wide association study for somatic cell score. The other two SNPs on chromosome 13 had opposite effects. As well as validating associations within known QTL from previous studies, e.g. chromosomes 6 and 19, novel loci on chromosome 13 were confirmed. Promising candidate genes are, for example: deoxycytidine kinase, immunoglobulin J chain, vitamin D binding protein, forkhead box K2, sodium/hydrogen exchanger 8 and cytoplasmic nuclear factor of activated T-cells 2. Our confirmation study provides additional evidence for the functional role of the linked genomic regions to immune response. This information can be used as a basis for further functional studies for those potential genes.

The role of the cement industry in the contamination of air, water, soil and plant with vanadium in Cairo.

Levels of vanadium in air, water, soil and plants resulting from the operation of a cement factory in south Cairo were extensively studied. Results obtained were compared with the level of vanadium in a relatively non-polluted residential area. It was concluded that the studied cement factory is the main source of the element to the adjacent environment. This is essentially due to the fact that this cement factory is using fossil fuels and raw materials that both contain high levels of vanadium without adequate control of the release of pollutants. Continuous release of air-borne dust from the cement industry will increase the level of vanadium in the surrounding environment in the long run.