Genome-wide linkage disequilibrium and past effective population size in three Korean cattle breeds.

The routine collection and use of genomic data are useful for effectively managing breeding programs for endangered populations. Linkage disequilibrium (LD) using high-density DNA markers has been widely used to determine population structures and predict the genomic regions that are associated with economic traits in beef cattle. The extent of LD also provides information about historical events, including past effective population size (Ne ), and it allows inferences on the genetic diversity of breeds. The objective of this study was to estimate the LD and Ne in three Korean cattle breeds that are genetically similar but have different coat colors (Brown, Brindle and Jeju Black Hanwoo). Brindle and Jeju Black are endangered breeds with small populations, whereas Brown Hanwoo is the main breeding population in Korea. DNA samples from these cattle breeds were genotyped using the Illumina BovineSNP50 Bead Chip. We examined 13 cattle breeds, including European taurines, African taurines and indicines, and hybrids to compare their LD values. Brown Hanwoo consistently had the lowest mean LD compared to Jeju Black, Brindle and the other 13 cattle breeds (0.13, 0.19, 0.21 and 0.15-0.22 respectively). The high LD values of Brindle and Jeju Black contributed to small Ne values (53 and 60 respectively), which were distinct from that of Brown Hanwoo (531) for 11 generations ago. The differences in LD and Ne for each breed reflect the breeding strategy applied. The Ne for these endangered cattle breeds remain low; thus, effort is needed to bring them back to a sustainable tract.

Genetic parameters for yearling weight, carcass traits, and primal-cut yields of Hanwoo cattle.

Genetic parameters associated with yearling weight, carcass traits, and primal-cut yields of male Hanwoo cattle were investigated using univariate and bivariate animal models. The mean yearling weight (YWT), carcass weight (CWT), longissimus muscle area (LMA), backfat thickness (BFT), and marbling score (MS) were 352.47 ± 0.40 kg, 337.39 ± 0.64 kg, 78.28 ± 0.13 cm2, 8.45 ± 0.05 mm, and 3.25 ± 0.03, respectively. Total primal-cut yield (TPC) was 78.95 ± 0.10% of CWT, of which 42.3% was contributed by the forequarters (chuck, CHK; shoulder, SLD; ribs, RIB; and brisket and flank, BAF). Loins, top round (TRND), and round (RND) were associated with yields of 13.57%, 5.45 ± 0.01%, and 8.87 ± 0.02%, respectively. The largest cut studied was ribs (15.67 ± 0.03%). The estimated heritabilities (h2) of YWT, CWT, LMA, BFT, and MS were 0.18 ± 0.02, 0.29 ± 0.04, 0.38 ± 0.05, 0.45 ± 0.05, and 0.62 ± 0.07, respectively. Shoulder yield was highly heritable in Hanwoo steers (0.83 ± 0.13), followed by the yields of round (0.66 ± 0.12), striploin (0.64 ± 0.12), top round (0.62 ± 0.12), sirloin (0.60 ± 0.12), and total primal-cut yield (0.52 ± 0.11). The h2 values of CHK, BAF, RIB, and tenderloin (TLN) ranged from 0.19 ± 0.09 to 0.41 ± 0.11. Generally, the genetic CV was low for most traits (2.33%-6.15%), except for CHK, BFT, and MS. The genetic correlation (rg) was strong between YWT and CWT (0.77 ± 0.06). The greatest positive and negative rg among carcass traits were those between LMA and CWT (0.52 ± 0.08) and between LMA and BFT (-0.30 ± 0.09), respectively. The correlation between CHK and SLD (0.81 ± 0.14), and those between SLD, TLN, TRND, and RND, were mostly strong (0.77-0.87), but the rg between RIB and other traits were strongly negative. The TPC yield showed moderate to high rg with most primal cuts. The YWT, CWT, and LMA correlated notably with CHK, SLD, and loin yields, especially LMA. However, BFT and MS were negatively correlated with many primal cuts but RIB. Those rg estimates were also opposite of that of LMA and CWT with primal cuts. Phenotypic correlations (rp) were generally weaker than rg estimates. The rp of YWT, CWT, and LMA were either zero or moderately negative compared to those of the BFT and MS with primal cuts. Most primal cuts yielded positive rp estimates among them, except for RIB. Our results suggest that direct selection for YWT, various carcass traits, and primal-cut yields may increase the carcass value of Hanwoo males.

Determination of tadalafil and N-desmethylsibutramine in health and dietary supplements using ultra-performance liquid chromatography (UPLC) coupled with quadrupole-time-of-flight mass spectrometry (Q-TOF MS).

The adulteration of dietary supplements with drugs is potentially dangerous for human health. In this study, a method was used to test simultaneously for the presence of three synthetic PDE-5 inhibitors (sildenafil, vardenafil and tadalafil), and sibutramine and its two major metabolites (N-desmethylsibutramine and N-didesmethylsibutramine) using ultra-performance liquid chromatography (UPLC) coupled with quadrupole-time-of-flight mass spectrometry (Q-TOF MS) in dietary supplements. This approach with UPLC/Q-TOF MS uses the high accurate mass of six compounds for identification and has a short run time. The recovery was from 87% to 113%; precision was less than 12.8%. The limit of detection and limit of quantification were from 0.4 to 2.0 µg kg(-1) and from 1.3 to 6.0 µg kg(-1), respectively. This method allows easy and fast analysis and detection of diverse adulterants.

Reassortment between genetically distinct Japanese and US strains of Soil-borne wheat mosaic virus: RNA1 from a Japanese strain and RNA2 from a US strain make a pseudorecombinant virus.

Soil-borne wheat mosaic virus (SBWMV), the type species of the genus Furovirus, has a plus-sense bipartite RNA genome. Japanese and US strains of SBWMV are genetically distantly related, despite their biologically identical properties. Here we report formation of a pseudorecombinant virus consisting of RNA1 from a Japanese strain and RNA2 from a US strain, using infectious in vitro transcripts for both strains. Full-length infectious cDNA clones for a Japanese strain were previously constructed (Yamamiya and Shirako [38]). For RNA1 of a US strain, due to instability of full-length cDNA clones in Escherichia coli cells, it was necessary to prepare a full-length template DNA for in vitro transcription by combining overlapping 5'-terminal and 3'-terminal cDNAs individually cloned in two plasmids, whereas for RNA2 a full-length cDNA clone was the template. For infectivity assays, Chenopodium quinoa, a local lesion host, and wheat, a systemic host, were used. A mixture of Japanese RNA1 transcripts and US RNA2 transcripts caused formation of local lesions on C. quinoa leaves and systemic infection to wheat plants. The nucleotide sequence of the progeny viral RNA2 was identical to that of the US RNA2. The reciprocal combination was not infectious to either host. These results confirm that the Japanese and US SBWMV are genetically distantly related strains belonging to a single species.