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A porcine genome linkage map composed of 194 microsatellite markers was constructed with a large-scale White Duroc x Erhualian resource population. The marker order on this linkage map was consistent with the USDA-MARC reference map except for two markers on SSC3, two markers on SSC13 and two markers on SSCX. The length of the sex-averaged map (2344.9 cM) was nearly the same as that of the USDA-MARC and NIAI map. Highly significant heterogeneity in recombination rates between sexes was observed. Except for SSC1 and SSC13, the female autosomes had higher average recombination rates than the male autosomes. Moreover, recombination rates in the pseudoautosomal region were greater in males than in females. These observations are consistent with those of previous reports. The recombination rates on each paternal and maternal chromosome of F(2) animals were calculated. Recombination rates were not significantly affected by the age (in days) or parity of the F(1) animals. However, recombination rates on paternal chromosomes were affected by the mating season of the F(1) animals. This could represent an effect of environmental temperature on spermatogenesis.

There is evidence that NR6A1 is a strong candidate for being a causal gene underlying vertebral number in pigs. The Licha Black is one of the leanest Chinese indigenous pig breeds, having an average vertebral number of 21.5. The introgression of Western germplasm into Licha Black, resulting in increased vertebral number, has been assumed but is not confirmed. This study detected allele frequencies of the NR6A1 causative mutation (c.575T>C) in 519 pigs from three Western and seven Chinese breeds including Licha Black, and evaluated the genetic variation in a 650-kb region containing NR6A1 in the 10 breeds. Allele T for increased vertebral number was fixed in Western breeds. In contrast, this allele was very rare in most of the Chinese native breeds. Notably, the T allele was present in the Licha Black at a rather higher frequency (0.585) and in the Laiwu at lower frequency (0.250). As expected, selection pressure has wiped out the genetic variability in the 650 kb region in Western breeds. Conversely, Chinese indigenous breeds showed a high degree of genetic variability in this region. However, the Licha Black displayed dramatically reduced heterozygosity at the loci proximal to the causative mutation. Moreover, a high proportion (45.9%) of Licha Black pigs and a small number (21%) of Laiwu pigs had the Western NR6A1 haplotype, and the two breeds showed closer relationships with Western commercial breeds than other Chinese breeds in the phylogenic tree. When the results are taken together, this study supports the assumption that the Western NR6A1 haplotypes were introduced into Licha Black and possibly Laiwu and are associated with increased vertebral number.

The direct synthesis of dimethyl carbonate (DMC) from CO and CH OH was achieved at room temperature with 74 % CH OH conversion in the presence of an imidazolium hydrogen carbonate ionic liquid ([C C Im][HCO ]). Experimental and theoretical results reveal that [C C Im][HCO ] can transform quickly into a CO adduct, which serves as an effective catalyst and dehydrant. Its dehydration ability is reversible. The energy barrier of the rate-determining step for the DMC synthesis is only 21.7 kcal mol . The ionic liquid can be reused easily without a significant loss of its catalytic and dehydrating ability.

The number of vertebrae is associated with body size and meat production in pigs. To identify quantitative trait loci (QTL) for the number of vertebrae, phenotypic values were measured in 1029 individuals from a White Duroc × Chinese Erhualian intercross F(2) population. A whole genome scan was performed with 194 microsatellite markers in the F(2) population. Four genome-wide significant QTL and eight chromosome-wide significant QTL for the number of vertebrae were identified on pig chromosomes (SSC) 1, 2, 6, 7, 10 and 12. The most significant QTL was detected on SSC7 with a confidence interval of 1 cM, explaining 42.32% of the phenotypic variance in the thoracic vertebral number. The significant QTL on SSC1, 2 and 7 confirmed previous reports. A panel of 276 animals representing seven Western and Chinese breeds was genotyped with 34 microsatellite markers in the SSC7 QTL region. No obvious selective sweep effect was observed in the tested breeds, indicating that intensive selection for enlarged body size in Western commercial breeds did not wipe out the genetic variability in the QTL region. The Q alleles for increased vertebral number originated from both Chinese Erhualian and White Duroc founder animals. A haplotype block of approximately 900 kb was found to be shared by all Q-bearing chromosomes of F(1) sires except for one distinct Q chromosome. The critical region harbours the newly reported VRTN gene associated with vertebral number. Further investigations are required to confirm whether VRTN or two other positional candidate genes, PROX2 and FOS, cause the QTL effect.

Gold(i) isocyanide shows high catalytic ability for the hydration of different alkynes at room temperature.