We report the sequencing at 131× coverage, de novo assembly and analyses of the genome of a female Tibetan wild boar. We also resequenced the whole genomes of 30 Tibetan wild boars from six major distributed locations and 18 geographically related pigs in China. We characterized genetic diversity, population structure and patterns of evolution. We searched for genomic regions under selection, which includes genes that are involved in hypoxia, olfaction, energy metabolism and drug response. Comparing the genome of Tibetan wild boar with those of neighboring Chinese domestic pigs further showed the impact of thousands of years of artificial selection and different signatures of selection in wild boar and domestic pig. We also report genetic adaptations in Tibetan wild boar that are associated with high altitudes and characterize the genetic basis of increased salivation in domestic pig.

A simple synthesis of high‐quality Cu2O, a material of high interest in optics because of its photon exciton interconversion properties, in the form of nanowires (see Figure for a TEM image) is reported by the authors. Reduction of Cu(OH)2, freshly prepared from CuCl2, with hydrazine hydrate in basic solution in the presence of the surfactant polyethylene glycol (PEG) yields Cu2O nanowires 5–8 nm in diameter and 10–20 nm long.

It is evident that epigenetic factors, especially DnA methylation, have essential roles in obesity development. Here, using pig as a model, we investigate the systematic association between DnA methylation and obesity. We sample eight variant adipose and two distinct skeletal muscle tissues from three pig breeds living within comparable environments but displaying distinct fat level. We generate 1,381 Gb of sequence data from 180 methylated DnA immunoprecipitation libraries, and provide a genome-wide DnA methylation map as well as a gene expression map for adipose and muscle studies. The analysis shows global similarity and difference among breeds, sexes and anatomic locations, and identifies the differentially methylated regions. The differentially methylated regions in promoters are highly associated with obesity development via expression repression of both known obesity-related genes and novel genes. This comprehensive map provides a solid basis for exploring epigenetic mechanisms of adipose deposition and muscle growth.

Semiconductor nanowires and nanoribbons are under intensive study as building blocks for next-generation nanodevices.[1±7] Much effort has focused on developing nanowires and nanoribbons for optoelectronic applications such as lasers, [2,3,7±10] waveguides, [11] and optical switches. [12] In 2003, lasing in a single ZnS nanoribbon [2] and in ZnO nanowires and nanoribbons [7] were reported by Lee's and Yang's groups, respectively. Recently, we have also observed lasing in CdS nanoribbons.[9] So far, lasing activity in nanoribbons and nanowires has been obtained only for fixed wavelengths corresponding to their near-bandgap emission. Yet, for practical applications the ability to fabricate lasers of a predetermined wavelength is often critical. In this work, we show that nanoribbons of the ternary alloy Zn x Cd 1±x S are able to sustain lasing action for a broad range of compositions of x. Specifically, we can continuously change the lasing emission of Zn x Cd 1±x S nanoribbons in two spectral regions, 485 to 515 nm and 340 to 390 nm, by controlling the composition x close to CdS (0.25 ³ x ³ 0) and ZnS (0.75 £ x £ 1), respectively. These results suggest the exciting possibility that semiconductor nanolasers of preselected ªtunableº wavelengths covering the full visible spectrum may be achieved using nanoribbons or nanowires via control of their composition, size, and dimensionality. Bandgap engineering has already been utilized in group II± VI materials for preparing superlattices, [13] heterostructures, [14] and quantum wells, [15,16] which can produce bluegreen lasers. To date, group II±VI materials are considered potential contenders for optoelectronic applications, [17] although major problems [18±21] continue to hamper their development. Notably, these problems include 1) lack of high-quality bulk single crystals of group II±VI semiconductors suitable for use as substrates; 2) presence of defects derived from the polytypism of group II±VI compounds; and 3) lack of reproducible doping to obtain the desired electrical conductivity. COMMUNICATIONS

Uncovering genetic variation through resequencing is limited by the fact that only sequences with similarity to the reference genome are examined. Reference genomes are often incomplete and cannot represent the full range of genetic diversity as a result of geographical divergence and independent demographic events. To more comprehensively characterize genetic variation of pigs (Sus scrofa), we generated de novo assemblies of nine geographically and phenotypically representative pigs from Eurasia. By comparing them to the reference pig assembly, we uncovered a substantial number of novel SNPs and structural variants, as well as 137.02-Mb sequences harboring 1737 protein-coding genes that were absent in the reference assembly, revealing variants left by selection. Our results illustrate the power of whole-genome de novo sequencing relative to resequencing and provide valuable genetic resources that enable effective use of pigs in both agricultural production and biomedical research.

Nanorods of SnO2 have successfully been prepared by calcining precursors that are produced in inverse microemulsions. The water/oil microemulsions used to prepare the precursors form an ideal nanostructural reactor for producing monodispersed nanoparticles, which can then decompose to form SnO2 nanorods (see Figure). The mechanism of formation of the nanorods by nucleation and growth processes is discussed.

No abstract

Background: MicroRNAs (miRNAs), a large family of short endogenous RNAs known to post-transcriptionally repress gene expression, participate in the regulation of almost every cellular process. Changes in miRNA expression are associated with many pathologies. Ovarian folliculogenesis and testicular spermatogenesis are complex and coordinated biological processes, in which tightly regulated expression and interaction of a multitude of genes could be regulated by these miRNAs. Identification and preliminary characterization of gonad-specific miRNAs would be a prerequisite for a thorough understanding of the role that miRNA-mediated posttranscriptional gene regulation plays in mammalian reproduction.Method: Here, we present the identification of a repertoire of porcine miRNAs in adult ovary and testis using deep sequencing technology. A bioinformatics pipeline was developed to distinguish authentic mature miRNA sequences from other classes of small RNAs represented in the sequencing data.Results: Using this approach, we detected 582 precursor hairpins (pre-miRNAs) encoding for 732 mature miRNAs, of which 673 are unique. Statistically, 224 unique miRNAs (out of 673, 33.28%) were identified which had significant differential expression (DE) between ovary and testis libraries (P < 0.001). Most of DE miRNAs located on the X chromosome (X-linked miRNAs) (24 out of 34, 70.59%) significantly up-regulated in ovary versus testis (P < 0.001). Predictably, X-linked miRNAs are expressed in a testis-preferential or testis-specific pattern. To explore the potential for co-expression among genomic location clusters of X-linked miRNAs, we surveyed the relationship between the distance separating miRNA loci and the coordinate expression patterns of 32 high confidence X-linked miRNAs in seven normal pig tissues using the real-time quantitative PCR (q-PCR) approach. Our results show that proximal pairs of miRNAs are generally co-expressed implying that miRNAs within 50 kb of genomic bases are typically derived from a common transcript.Conclusions: The present study characterizes the miRNA transcriptome of adult porcine gonads, with an emphasis on the co-expression patterns of X-linked miRNAs. Our report should facilitate studies of the organ-specific reproductive roles of miRNAs.