Application and prospect of gene chip in genetic breeding of livestock and poultry.

Gene chip is a high-throughput technique for detecting specific DNA sequences by DNA or DNA-RNA complementary hybridization, among which SNP genotyping chips have been widely employed in the animal genetics and breeding, and have made great achievements in cattle (Bos taurus), pigs (Sus scrofa), sheep (Caprinae), chickens (Gallus gallus) and other livestock. However, genomic selection applied in production merely uses genomic information and cannot fully explain the molecular mechanism of complex traits genetics, which limits the accuracy of genomic selection. With the continuous progresses in epigenetic research, the development of commercial methylation chips and the application of the epigenome-wide association study (EWAS), DNA methylation has been extensively used to draw the causal connections between genetics and phenotypes. In the future, it is hopefully expected to develop methylation chips customized for livestock and poultry and explore methylation sites significantly related to economic traits of livestock and poultry through EWAS thereby extending the understanding of causal variation of complex traits. Combining methylation chips and SNP chips, we can capture the epigenomic and genomic information of livestock and poultry, interpret genetic variation more precisely, improve the accuracy of genome selection, and promote the fine evolution of molecular genetic breeding of livestock and poultry. In this review, we summarize the application of SNP chips and depict the prospects of the application of methylation chips in livestock and poultry. This review will provide valuable insights for further application of gene chips in farm animal breeding.

Calorimetry study of microwave absorption of some solid materials.

In practice, the dielectric constant of a material varies the applied frequency the material composition, particle size, purity, temperature, physical state (solid or liquid), and moisture content. All of these parameters might change during processing, therefore, it is difficult to predict how well a material will absorb microwave energy in a given process. When the temperature is measured by a digital thermometer, it could not accurately reflect the true temperature of the bulk materials, especially for mixed materials. Thus, in this paper we measured the microwave absorption characteristics of different materials by calorimetry. The microwave power levels, irradiation times, and masses of the materials were varied. It was difficult to predict the microwave energy absorption characteristics of reagent-grade inorganic compounds based on their color, metallic cation, or water stoichiometry. CuO, MnO2, Fe3O4, and MnSO4 x H2O (Taishan) strongly absorbed microwave energy. Most of the remaining inorganic compounds were poor absorbers, with silica hardly absorbing any microwave energy. Carbon-based materials had significantly different microwave absorption characteristics. Activated carbon and coke were especially sensitive to microwaves, but different types of coal were poor absorbers. The jamesonite concentrate absorbed microwave energy strongly, while the zinc concentrate was a poor absorber.