Analysis of the bone morphogenetic protein 6 gene promoter region in young beef cattle affected by enzootic bovine leukosis

Enzootic bovine leukosis (EBL) is typically observed in cattle over 3 years old. However, some cases of EBL onset in young beef cattle have been reported in Japan. The mechanism for early EBL onset is unclear. In Japan, beef cattle are given large amounts of concentrated feed with low vitamin A. Bone morphogenetic proteins (BMPs) are regulators of cell proliferation, differentiation, and apoptosis, and thought to represent one of the key players in tumor malignancy. The purpose of this study was to evaluate the differences in BMP-6 methylation status between EBL beef cattle under 3 years old and other cattle. We investigated the methylation status of the BMP-6 promoter region in 32 EBL beef cattle under 3 years old. We also compared the methylation status of EBL dairy cattle to that of healthy cattle. Median methylation rate of the BMP-6 promoter region in EBL beef cattle under 3 years old was 8.9%, which was significantly higher than that of other groups. Hypermethylation of the BMP-6 promoter region might contribute to early onset of EBL in beef cattle under 3 years old, and animal feeding management practices specific to beef cattle may affect the methylation status of the BMP-6 promoter region.     

Association of swine vertnin (VRTN) gene with production traits in Duroc pigs improved using a closed nucleus breeding system

Vertnin (VRTN) is involved in the variation of vertebral number in pigs and it is located on Sus scrofa chromosome 7. Vertebral number is related to body size in pigs, and many reports have suggested presence of an association between body length (BL) and meat production traits. Therefore, we analyzed the relationship between the VRTN genotype and the production and body composition traits in purebred Duroc pigs. Intramuscular fat content (IMF) in the Longissimus muscle was significantly associated with the VRTN genotype. The mean IMF of individuals with the wild‐type genotype (Wt/Wt) (5.22%) was greater than that of individuals with the Wt/Q (4.99%) and Q/Q genotypes (4.79%). In addition, a best linear unbiased predictor of multiple traits animal model showed that the Wt allele had a positive effect on the IMF breeding value. No associations were observed between the VRTN genotype and other production traits. The VRTN genotype was related to BL. The Q/Q genotype individuals (100.0 cm) were longer than individuals with the Wt/Q (99.5 cm) and Wt/Wt genotypes (98.9 cm). These results suggest that in addition to the maintenance of an appropriate backfat thickness value, VRTN has the potential to act as a genetic marker of IMF.     

Practical phytoextraction in cadmium-polluted paddy fields using a high cadmium accumulating rice plant cultured by early drainage of irrigation water

Some indica rice varieties are potential phytoextractors for paddy fields polluted with Cd because of their high biomass and because they can accumulate Cd to moderate levels in their shoots. To establish a practical phytoextraction system, phytoextraction using two indica rice cultivars (MORETSU and IR-8) was carried out in a paddy field polluted with moderate Cd levels (2.91 and 2.52 mg kg⁻¹, respectively). The Cd concentration and Cd uptake of MORETSU increased when irrigation water was drained at the maximum tillering stage, and the paddy soil was under oxidative conditions until harvesting. The Cd uptake of MORETSU and IR-8 increased and reached 516 and 657 g ha⁻¹, respectively, at the beginning of October. After phytoextraction using these high Cd accumulating rice varieties for 2 years, the Cd concentration in the paddy field decreased by 18% compared with the initial Cd concentration. The Cd concentration in the rice grains of a japonica ordinary rice variety (HINOHIKARI) subsequently grown on the field after the phytoextraction was lower than the concentration in rice grown on a non-phytoextracted field. These results suggest that phytoextraction using high Cd accumulating rice varieties with early drainage of irrigation water is a practical remediation system for moderate Cd polluted paddy fields in southwest Japan.     

Genetic diversity of Sicyos angulatus in central and north-eastern Japan by inter-simple sequence repeat analysis

For the development of effective procedures to control invasive plants, it is necessary to learn about their mechanism of spread, for which an understanding of the plant's genetic variation may be important. Sicyos angulatus is a widespread and invasive weed that grows among forage crops and natural vegetation in Japan. Inter-simple sequence repeat (ISSR) genotyping was used to detect the regional patterns of genetic variation of S. angulatus in its introduced range in Japan. The goal of this research was to assess the introduction dynamics and mechanism of spread of S. angulatus in Japan. Four screened ISSR primers produced 15 reliable bands, and 12 of these were polymorphic among six areas in central and north-eastern Japan. The analysis of molecular variance ( amova ) revealed that 88.4% of genetic variation occurred within areas rather than between the two regions (1.1%), or among areas within regions (10.5%). While the total gene diversity among areas ( Ht ) was 0.1684, the coefficient of gene differentiation was low among two geographically distinct regions ( Gst = 0.053). The genetic diversity indices ( h  = 0.116; I  = 0.173) of the Fuji river area, assumed to be near the first introduction site, were not higher than other areas (total h  = 0.165; total I  = 0.263). In contrast, those of the Chikuma river and Tenryu river areas were relatively high ( h  = 0.173 and 0.187; I  = 0.276 and 0.277 respectively). The Mantel test showed no significant correlation between geographical and genetic distances. These results suggest multiple introductions from the same gene pools into both central and north-eastern regions of Japan.     

Metabolism of N-[(R)-1-(2,4-dichlorophenyl)ethyl]-2-cyano-3,3-dimethylbutanamide (Delaus, S-2900) and its isomer, N-[(S)-1-(2,4-dichlorophenyl)ethyl]-2-cyano-3,3-dimethylbutanamide (S-2900S), in rats. 1. Identification of metabolites in feces and urine

Rats were orally dosed with a 1:1 diastereomixture of N-[(R)-1-(2,4-dichlorophenyl)ethyl]-2-cyano-3,3-dimethylbutanamide (Delaus, S-2900) and N-[(S)-1-(2,4-dichlorophenyl)ethyl]-2-cyano-3,3-dimethylbutanamide (S-2900S), both labeled with 14C, at 200 mg/kg/day for 5 consecutive days, and 16 metabolites in urine and feces were purified by a combination of several chromatographic techniques. The chemical structures of all isolated metabolites were identified by spectroanalyses (NMR and MS). Several of them were unique decyanated and/or cyclic compounds (lactone, imide, cyclic amide, cyclic imino ether forms). Major biotransformation reactions of the mixture of S-2900 and S-2900S in rats are proposed on the basis of the metabolites identified in this study.     

浙江粳稻与日本粳稻品种间遗传差异的SSR分析

从424对分布于水稻12条染色体的SSR引物中筛选出44对用于12份日本粳稻和12份浙江粳稻的多态分析,44对引物多态性筛选结果表明,19对引物在12份日本粳稻间有多态,15对引物在浙江粳稻间有多态,44对引物对两个地区品种的多态检出率分别为43.2和34.1.品种间引物多态性分析结果表明,日本粳稻和浙江粳稻的品种(系)内平均多态检出率分别为50.5和38.7.UPGMA聚类分析表明,日本粳稻间相似系数在0.5以上,且分为两大类;而浙江粳稻相似系数也在0.5以上且为同一大类.说明浙江粳稻间的遗传差异与日本粳稻间的差异相仿或低于日本粳稻.     

Quantitative trait loci for leg weakness traits in a Landrace purebred population

Leg weakness in pigs is a serious problem in the pig industry. We performed a whole genome quantitative trait locus (QTL) analysis to find QTLs affecting leg weakness traits in the Landrace population. Half-sib progeny ( n  = 522) with five sires were measured for leg weakness traits. Whole genome QTL mapping was performed using a half-sib regression-based method using 190 microsatellite markers. No experiment-wide significant QTLs affecting leg weakness traits were detected. However, at the 5% chromosome-wide level, QTLs affecting leg weakness traits were detected on chromosomes 1, 3, 10 and 11 with QTL effects ranging from 0.07 to 0.11 of the phenotypic variance. At the 1% chromosome-wide level, QTLs affecting rear feet score and total leg score were detected on chromosomes 2 and 3 with QTL effects of 0.11 and 0.13 of the phenotypic variance, respectively. On chromosome 3 and 10, some QTLs found in this study were located at nearby positions. The present study is one of the first reports of QTLs affecting fitness related traits such as leg weakness traits, that segregate within the Landrace population. The study also provides useful information for studying QTLs in purebred populations.