As an essential trace element, copper can be toxic in mammalian cells when present in excess. Metallothioneins (MTs) are small, cysteine-rich proteins that avidly bind copper and thus play an important role in detoxification. Yeast CUP1 is a member of the MT gene family. The aim of this study was to determine whether yeast CUP1 could bind copper effectively and protect cells against copper stress. In this study, CUP1 expression was determined by quantitative real-time PCR, and copper content was detected by inductively coupled plasma mass spectrometry. Production of intracellular reactive oxygen species (ROS) was evaluated using the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assay. Cellular viability was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the cell cycle distribution of CUP1 was analyzed by fluorescence-activated cell sorting. The data indicated that overexpression of yeast CUP1 in HeLa cells played a protective role against copper-induced stress, leading to increased cellular viability (P<0.05) and decreased ROS production (P<0.05). It was also observed that overexpression of yeast CUP1 reduced the percentage of G1 cells and increased the percentage of S cells, which suggested that it contributed to cell viability. We found that overexpression of yeast CUP1 protected HeLa cells against copper stress. These results offer useful data to elucidate the mechanism of the MT gene on copper metabolism in mammalian cells.

The aim of the study was to characterize the polymorphism of the Calpastatin (CAST) gene identified with three restriction enzymes (TaqI, HinfI, MspI) in Meishan and five other pig populations, and to provide information on their potential in marker-assisted selection and conservation. Meishan pigs appeared to be monomorphic at loci CAST/HinfIand CAST/MspI. A high frequency of the favoured genotype, FF, in terms of meat quality was detected in Meishan pigs, a breed well known for high quality meat. However, the frequency of the genotype, FF, was very low in Sutai pigs, a breed developed from a Duroc (50%) * Meishan (50%) cross. This is probably partially due to the fact that genetic improvement in this breed was achieved through the use of traditional quantitative genetics. It is suggested that traditional selection techniques combined with the use of the polymorphisms discovered have an important potential to improve overall meat quality.

Genes such as the Heart Fatty Acid-Binding Protein (H-FABP), the Melanocortin-4 Receptor (MC4R) and the Adipocyte Determination and Differentiation factor-1 (ADD1) play an important role in meat quality in pigs. The Meishan is one of the most prolific pig breeds in the world, but it is in danger, in China, of being replaced by other exotic pig breeds because of its slow growth rate and high body fat content. To know their present genetic status, the polymorphism of the three genes in the Meishan and four other pig populations (Sutai, Yorkshire×Sutai, Landrace×Sutai and Duroc×Landrace×Yorkshire) in China was analysed, using PCR-RFLP and PCR-SSCP, and were further compared with each other. The results showed that gene and genotype frequencies differed significantly between the Meishan and the other four populations. This is suggested to be one of the reasons for the good meat quality of the Meishan compared to the other breeds. In addition, since half of the genetic background of Sutai is from the Meishan, results also indicated that marker assisted selection (MAS) is very important for the development of new pig breeds.