Facile Design and Fabrication of Superwetting Surfaces with Excellent Wear-Resistance.

Preparation of mechanically durable superwetting surfaces is imperative, yet challenging for the wide range of real applications where high durability is required. Mechanical wear on superwetting surfaces usually degrades weak roughness, leading to loss of functions. In this study, wear-resistant superhydrophilic/underwater superoleophobic and superhydrophobic surfaces are prepared by anchoring reinforced coatings via adhesive-swelling and adhesive-bonding processes, respectively. The results of the sandpaper abrasion (grit no. 600, 24 kPa) show that superhydrophilic nylon/SiO2 coatings and superhydrophobic polyurethane/TiO2 coatings retain their functions after suffering the abrasion distances of 70 cm and more than 1000 cm, respectively. Reinforced coatings formed by consecutive roughness and improved adhesion between coatings and substrates are responsible for repeatedly generated superwettability after exposure to mechanical stresses and demonstrated to be feasible for designing wear-resistant superwetting surfaces. Furthermore, this novel architecture of "reinforced coating with consecutive roughness + high adhesion" may demand desired coating materials and reliable coating-fixing techniques for sustaining sufficient roughness and is superior to currently existing technologies in advancing wear-resistance of superwetting surfaces.

Acceleration of genetic gain in cattle by reduction of generation interval.

Genomic selection (GS) approaches, in combination with reproductive technologies, are revolutionizing the design and implementation of breeding programs in livestock species, particularly in cattle. GS leverages genomic readouts to provide estimates of breeding value early in the life of animals. However, the capacity of these approaches for improving genetic gain in breeding programs is limited by generation interval, the average age of an animal when replacement progeny are born. Here, we present a cost-effective approach that combines GS with reproductive technologies to reduce generation interval by rapidly producing high genetic merit calves.

Aggregation of bovine cloned embryos at the four-cell stage stimulated gene expression and in vitro embryo development.

Pre-implantation embryos produced by somatic cell nuclear transfer (SCNT) have varied developmental potentials. The majority of SCNT blastocysts do not develop to term, and the mechanisms inhibiting development are still largely unknown. Aggregation of cloned embryos has been attempted to compensate for the developmental deficiency of individual cloned embryos. In this report, we investigated the impact of aggregation of bovine cloned embryos at the four-cell stage on in vitro development and gene expression of the embryos. Cell numbers and development rate of aggregated (NTagg) and non-aggregated (NT) blastocysts were characterized and compared. The blastocyst formation after aggregation was modeled using the binominal distribution. The results indicate that aggregation enhances the blastocyst formation but does not increase the overall blastocyst rate. Additionally, utilizing microarray gene chip analysis 8.8% of 8,059 genes analyzed were differentially expressed between NTagg and NT blastocysts, with more than 80% of the differentially expressed genes up-regulated in the NTagg blastocysts. Up-regulated genes include those involved in transcription, biosynthesis and signaling such as TDGF1, HNFA, CAV1, GLU5, and CD81. Our results indicate that aggregation of bovine cloned embryos at an early stage promotes the in vitro development of the resulting pre-implantation embryos.

Global gene expression analysis of bovine blastocysts produced by multiple methods.

Reproductive efficiency using somatic cell nuclear transfer (SCNT) technology remains suboptimal. Of the various efforts to improve the efficiency, chromatin transfer (CT) and clone-clone aggregation (NTagg) have been reported to produce live cloned animals. To better understand the molecular mechanisms of somatic cell reprogramming during SCNT and assess the various SCNT methods on the molecular level, we performed gene expression analysis on bovine blastocysts produced via standard nuclear transfer (NT), CT, NTagg, in vitro fertilization (IVF), and artificial insemination (AI), as well as on somatic donor cells, using bovine genome arrays. The expression profiles of SCNT (NT, CT, NTagg) embryos were compared with IVF and AI embryos as well as donor cells. NT and CT embryos have indistinguishable gene expression patterns. In comparison to IVF or AI embryos, the number of differentially expressed genes in NTagg embryos is significantly higher than in NT and CT embryos. Genes that were differentially expressed between all the SCNT embryos and IVF or AI embryos are identified. Compared to AI embryos, more than half of the genes found deregulated between SCNT and AI embryos appear to be the result of in vitro culture alone. The results indicate that although SCNT methods have altered differentiated somatic nuclei gene expression to more closely resemble that of embryonic nuclei, combination of insufficient reprogramming and in vitro culture condition compromise the developmental potential of SCNT embryos. This is the first set of comprehensive data for analyzing the molecular impact of various nuclear transfer methods on bovine pre-implantation embryos.