Cover illustration
The ecological adaptability of cloned sheep to free-grazing in the Tengger Desert of Inner Mongolia, China.The cloned sheep (indicated by blue circle) is free-grazing with a flock of Alashan sheep, equipped with a GPS collar (indicated by blue arrow).
(Xinxin LI, Huijuan WANG, Guanghua SU, Zhuying WEI, Chunling BAI, Wuni-MENGHE, Yanhui HOU, Changqing YU, Shorgan BOU, Guangpeng LI, pp. 191-200
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The genetic diversity and structure of 72 Appaloosa horses belonging to a closed breeding population from an ecological reserve in Buenos Aires, Argentina, was investigated using eight microsatellite markers from the International Society for Animal Genetics panel. Our data showed that this Appaloosa horse population had an elevated degree of genetic diversity (He= 0.746) and did not present a significant increase of homozygous individuals (FIS~0). However, the short tandem repeats, AHT5, ASB2, HTG10 and VHL20, were not in Hardy–Weinberg equilibrium (P-value<0.05). Genetic relationships between this population and other well known horse breeds showed that Appaloosa horses from Argentina could have had their origin in the horses of the Nez Perce’s people in Idaho while other Appaloosa horses may have had influences from Andalusian and Lusitano breeds. This closed breeding population conserves an important degree of Appaloosa genetic diversity and notwithstanding its particular breeding characteristics, represents a valuable genetic resource for conservation.
Butyrylcholinesterase (BCHE) is a natural bioscavenger that protects humans against organophosphate toxicity. Due to the limited yield of human BCHE (hBCHE) when purifying from human plasma, it is necessary to find an alternative method to produce this protein. One potential method is to produce transgenic livestock that make modified milk containing high concentration of hBCHE. In this study, we cloned the hBCHEgene into a human lactoferrin (hLF) bacterial artificial chromosome (BAC) construct to make a hLF-hBCHE BAC construct. Subsequently, we injected the BAC construct into pronuclei of mouse fertilized embryos and generated transgenic mice. Expression analysis showed that recombinant hBCHE (rhBCHE) was expressed efficiently in the mammary gland of the transgenic mice and the concentration of rhBCHE in the milk of individual mice ranged from 76±12 to 159±28 mg·L-1. Protein function tests showed that rhBCHE has the same enzymatic activity as the native hBCHE. Our results pave the way for making transgenic livestock to produce large quantities of rhBCHE.
DNA damage is one of the most common threats to meiotic cells. It has the potential to induce infertility and genetic abnormalities that may be passed to the embryo. Here, we reviewed exogenous factors which could induce DNA damage. Specially, we addressed the different effects of DNA damage on mouse oocytes and embryonic development. Complex DNA damage, double-strand breaks, represents a more difficult repair process and involves various repair pathways. Understanding the mechanisms involved in DNA damage responses may improve therapeutic strategies for ovarian cancer and fertility preservation.
Since the birth of the first cloned sheep, somatic cell nuclear transfer technology has been successfully used to clone a variety of mammals. Cloned livestock have no apparent health risks, and the quality and safety of the cloned animal products are similar to non-cloned animals. The social behavior and environmental adaptability of postnatal cloned animals, especially when used for grassland farm production purposes, is unknown. In the present study, the cloned Dorper sheep equipped with GPS location devices were free-grazed in a harsh natural environment similar to conditions commonly experienced by Mongolian sheep. The main findings of this research were as follows. (1) Under free-grazing conditions, the cloned sheep showed excellent climatic and ecological adaptability. In extreme temperature conditions ranging from -30 to 40°C, the cloned sheep maintained acceptable body condition and behaved as other sheep. (2) The cloned sheep quickly adapted from a herd feeding strategy to the harsh environment and quickly exhibited a grazing regimen as other free-grazing sheep. (3) The cloned sheep exhibited free-grazing patterns and social behavior as other sheep. (4) The cloned sheep in the harsh environment thrived and produced healthy lambs. Overall, the cloned Dorper sheep exhibited excellent ecological adaptation, which is an important consideration for breeding meat sheep by cloning. The Dorper sheep readily adapted to the free-grazing conditions on the Mongolian plateau grassland, which attests to their ability to withstand harsh environmental conditions.
In the bone marrow and spleen, the developing B cell populations undergo both negative and positive selections to shape their B cell receptor repertoire. To gain insight into the shift of the immunoglobulin heavy (IgH) chain repertoire during B cell development, we undertook large scale Ig μ chain repertoire analysis of pre-B, immature B and spleen B cell populations. We found that the majority of VH gene segments, VH families, JH and D gene segments, were observed to have significantly different usage frequencies when three B cell populations were compared, but the usage profile of the VH, D, and JH genes between different B cell populations showed high correlations. In both productive and nonproductive rearrangements, the length of CDRH3 shortened significantly on average when B cells entered the periphery. However, the CDRH3 length distribution of nonproductive rearrangements did not follow a Gaussian distribution, but decreased successively in the order 3n-2, 3n-1 and 3n, suggesting a direct correlation between mRNA stability and CDRH3 length patterns of nonproductive rearrangements. Further analysis of the individual components comprising CDRH3 of productive rearrangements indicated that the decrease in CDRH3 length was largely due to the reduction of N addition at the 5′ and 3′ junctions. Moreover, with development, the amino acid content of CDRH3 progressed toward fewer positively charged and nonpolar residues but more polar residues. All these data indicated that the expressed Ig μ chain repertoire, especially the repertoire of CDRH3, was fine-tuned when B cells passed through several checkpoints of selection during the process of maturation.
With the increase in consumer demand, wheat grain quality improvement has become a focus in China and worldwide. Transcriptome analysis is a powerful approach to research grain traits and elucidate their genetic regulation. In this study, two cDNA libraries from the developing grain and leaf-stem components of bread wheat cultivar, Nongda211, were sequenced using Roche/454 technology. There were 1061274 and 1516564 clean reads generated from grain and leaf-stem, respectively. A total of 61393 high-quality unigenes were obtained with an average length of 1456 bp after de novo assembly. The analysis of the 61393 unigenes involved in the biological processes of the grain showed that there were 7355 differentially expressed genes upregulated in the grain library. Gene ontology enrichment and the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that many transcription products and transcription factors associated with carbohydrate and protein metabolism were abundantly expressed in the grain. These results contribute to excavate genes associated with wheat quality and further study how they interact.
Wheat stripe rust caused by Puccinia striiformis f. sp. tritici occurs widely in China and seriously affects wheat production. Global warming could profoundly impact the incidence and prevalence of low-temperature diseases such as stripe rust. Studies on the effects of temperature on the distribution of overwintering stripe rust could help us understand the incidence and prevalence of the disease and could also provide support for monitoring, forecasting and developing control strategies. An exponential model and a spherical model of the ordinary Kriging method in the ArcGIS platform were used to predict the overwintering regions of stripe rust based on the probability that the average temperature of the coldest month from December to February was higher than -6 or -7°C from 2001 to 2012. The results showed that the areas with a probability between 70% and 90% were transition regions for the overwintering of stripe rust. Based on annual mean temperature of the coldest month from December to February for 2001 to 2012, overwintering distribution of stripe rust was likewise evaluated. The boundary for overwintering of stripe rust was consistent with the areas where the probability was predicted to be 70% to 90% for the overwintering distribution of stripe rust, but the boundary was shifted northward toward Beijing in North China. Some areas in Xinjiang, including Akto, Pishan, Hotan and Yutian, were also predicted to be suitable for the overwintering of stripe rust.
Pig meat off-flavor is attributed to trimethylamine (TMA) concentration, and it is considered as the precursor of the fishy off-flavor problems. In this study, TMA concentrations in pig meat were determined, and the interactions with breed and gender effects were discussed. In addition, the TMA threshold for meat off-flavor and pig meat natural quality was measured in relation to meat storage and movement, and the influential factors including the pig breed and storage time were discussed. The results indicated positive effects on the precursor of the fishy off-flavor and the TMA threshold. Native breeds were found to have lower TMA concentrations than European breeds (P<0.01), and females and castrated males had significantly lower TMA concentration than males (P<0.01), The threshold concentration of TMA when meat was classed as off-flavored was 25 μg·g-1, and this occurred after 35–38 h of storage. The natural qualities, such as appearance, flavor, color and overall acceptable scores declined significantly after 4 days in storage (P<0.01). It is concluded that pig meat off-flavor, breed and gender were essential factors affecting flavor for meat breeding programs, and storage time is important for pig meat natural quality.
A unique characteristic of the Silkie chicken is its fibromelanosis phenotype. The dermal layer of its skin, its connective tissue and shank dermis are hyperpigmented. This dermal hyperpigmentation phenotype is controlled by the sex-linked inhibitor of dermal melanin gene (ID) and the dominant fibromelanosis allele. This study attempted to confirm the genomic region associated with ID. By genotyping, ID was found to be closely linked to the region between GGA_rs16127903 and GGA_rs14685542 (8406919 bp) on chromosome Z, which contains ten functional genes. The expression of these genes was characterized in the embryo and 4 days after hatching and it was concluded that MTAP, encoding methylthioadenosinephosphorylase, would be the most likely candidate gene. Finally, target DNA capture and sequence analysis was performed, but no specific SNP(s) was found in the targeted region of the Silkie genome. Further work is necessary to identify the causal ID mutation located on chromosome Z.
Foot-and-mouth-disease virus (FMDV) replicates in epithelial cells. The restriction of FMDV RNA to the basal cell layer of epithelia suggests a possible link between FMDV replication in vivo and the cell status. This paper describes in vitro studies in which FMDV infection was investigated in cells that were held at various cell division phases using cell cycle inhibitors. The results suggest that when cells were arrested at the G1 or G1/S phase, high levels of viral RNA were detected by quantitative real-time reverse transcription PCR and viral protein synthesis was observed by specific labeling techniques. In contrast, when cells were arrested at the G2/M phase, reduced or no viral RNA synthesis was detected.