Sequence analysis of VP2 gene of canine parvovirus isolated from domestic dogs in Japan in 1999 and 2000

Seven strains of canine parvovirus (CPV) were isolated from affected dogs in Japan between 1999 and 2000, and their VP2 genes were genetically analyzed. Comparison of the predicted amino acid sequences of VP2 suggested that three field isolates corresponded to CPV type 2a, while the other four to CPV type 2b. The phylogenetic tree constructed from the VP2 genes showed that the newly isolated strains are classified into the cluster consisting of recent Japanese and Taiwanese field isolates, which are distinct from Vietnamese isolates, United States Isolates, or classical CPV type 2. These results suggest that the CPV transmission occurred between Japan and Taiwan in 1990s, and the offspring are still circulating in both countries.     

分群分析法获得与多花黑麦草抗叶班病基因连锁的EST-CAPS标记

利用多花黑麦草叶斑病抗性和敏感个体杂交构建F1分离群体,采用分群分析法(bulked segregant analysis,BSA),通过多花黑麦草表达序列标签(expressed sequence tag,EST)的PCR扩增和扩增产物的限制性内切酶酶切多态性(cleaved amplified polymorphic sequence,CAPS)筛选,获得一个同多花黑麦草草抗叶斑病紧密连锁的EST-CAPS标记p56.对照多花黑麦草细胞质雄性不育(CMS)群体构建的遗传连锁图,该EST-CAPS标记位于多花黑麦草的第5遗传连锁群(LG5).对cDNA文库中对应于标记位点p56的EST序列片段分析和基因库搜索结果表明,该EST所编码的氨基酸序列同大麦天冬酰胺合成酶基因HvAS1和HvAS2的部分氨基酸序列片段同源性很高,推测位点p56所处的基因为编码多花黑麦草天冬酰胺合成酶基因.该分子标记可用于多花黑麦草分子标记辅助育种.     

Gonadal sex differentiation in protandrous anemone fish, Amphiprion clarkii

To clarify the process of sex differentiation in protandrous anemone fish, histological structure of their gonads was examined from 1 day to 214 days after hatching (dah). Gonadal development was first characterized by differentiation of ovarian tissues at 61 dah, followed by interspersed appearance of testicular tissues in the ovary at 214 dah.     

Detection of chromosomes carrying genes for seed dormancy of wheat using the backcross reciprocal monosomic method

Preharvest sprouting (PHS) in wheat represents a major constraint to the production of high‐quality grain. Genetic variation for tolerance to PHS is associated with seed dormancy. The present study was initiated to detect homologous chromosome variation associated with seed dormancy genes in a PHS tolerant cultivar ‘Zenkojikomugi’ (Zen) and ‘Chinese Spring’ (CS) using the backcross reciprocal monosomic method. The most striking effect on variation in seed dormancy was associated with chromosome 3A, and followed by group 4 chromosomes. These chromosomes of Zen increased dormancy compared with the respective CS homologues. Chromosomes 2D and 7D of Zen, and 6A of CS seemed to contribute smaller positive effects on dormancy. Chromosomes 2A of CS and Zen, as well as 3B, were equally effective in enhancing dormancy. The chromosome 3 A factors were independent of the grain‐colour gene R‐A1 because Zen was found to carry the white‐grained R‐A1a allele, which was identical to that of CS, and there was no difference in dormancy between the reciprocal F₁ seeds.     

Mapping of EST-derived CAPS markers in Italian ryegrass (Lolium multiflorum Lam.)

New molecular markers derived from expressed sequence tag (EST) sequences were mapped on linkage maps of Italian ryegrass by a two-way pseudo-testcross strategy. cDNA sequences were obtained from various tissues of Italian ryegrass ( Lolium multiflorum ) and converted into cleaved amplified polymorphic sequence (CAPS) markers. Of 260 EST primer pairs that amplified a single band, 74 generated bands that showed clear polymorphisms among individuals of an F₁ mapping family. Of the 74 polymorphic marker loci, 69 were mapped on an Italian ryegrass linkage map previously constructed using amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), and simple sequence repeat (SSR) markers. The newly-developed EST-CAPS markers would be useful as an efficient tool to identify genetic markers and to identify candidate genes for quantitative trait loci (QTLs) associated with important traits in Italian ryegrass.     

Dwarfing effect associated with the threshability gene Q on wheat chromosome 5A

A dwarfing effect of the 44.1 cM chromosomal region between the threshability gene Q and Xfba068 on the long arm of hexaploid wheat chromosome 5A has been reported. To clarify whether Q or its adjacent region is responsible for regulating culm elongation, two precise genetic stocks of near‐isogenic lines (NIL), a single chromosome substitution line, ‘Chinese Spring’ (CS; ‘Cappelle‐Desprez’ 5A) (NIL‐Q) and a single chromosome recombinant substitution line (NIL‐q) were used. The target segment of NIL‐q included the q allele and QEet.ocs‐5A.1, an earlinessper se gene, from spelt wheat in the CS genetic background. They were grown under 16‐h day length with and/ or without vernalization treatment. Being independent of heading date, NIL‐Q showed shorter elongation in lower internodes and decreased internode differentiation in comparison with NIL‐q. The culm‐length reduction associated with Q was confirmed in the recombinant F5 population derived from the cross between NIL‐Q and NIL‐q. Vernalization promotion had a tendency to reduce this dwarfing effect.     

Genetic Control of Vernalization, Day-length Response, and Earliness per se by Homoeologous Group-3 Chromosomes in Wheat

To identify homoeologous group-3 chromosomes that carry genes for vernalization, day-length responses, and earliness per se, a series of aneuploid lines (mono-somics and tetrasomics) and chromosome-substitution lines in ‘Chinese Spring’ (CS) were surveyed under different vernalization and day-length regimes in controlled environments. The results indicated that genes on all three chromosomes of group 3 can have striking effects on ear-emergence time. The replacement of CS 3B by its homologues in ‘Lutescens 62’ and ‘Cheyenne’ produced an increased insensitivity to vernalization, while 3B homologues from ‘Ceska Presivka’ gave CS a remarkable sensitivity to vernalization. This provided evidence for multiple allelism at a new Vrn locus on chromosome 3B. A negative association between gene dosage and day-length response was found in CS 3D which was thought to carry a gene for promoting insensitivity to day-length. The behaviour of CS monosomic 3A and CS (Timstein 3A), in reducing numbers of days to heading independently of environmental stimuli, suggested the presence of earliness per se genes on this chromosome.     

Evaluation of maturity of poultry manure compost by phospholipid fatty acids analysis

To study the influence of the physical properties of compost feedstock on some characteristics associated with maturity, two types of compost were made from poultry manure, rice husk, and rice bran. The bulk density of one type (PMC) was always higher than that of another type (NMC) during composting. In the case of PMC, the change in temperature, decrease in NH₄⁺, appearance of NO₃^–, and increase in germination indices (GI) with Japanese Komatsuna (Brassica campestris cv. Osome) were all more delayed than in NMC. As the composting process progressed, the proportion of branched (iso-, anteiso-, 10Me-) and saturated phospholipid fatty acids (PLFA) [BRANCHED FAMES (fatty acid methyl esters), biomarkers for gram-positive bacteria] gradually increased, then reached plateau. The high proportion of BRANCHED FAMES was maintained over a long storage period. The straight hydroxyl and saturated PLFAs (SOH-FAMES) initially increased, then disappeared with the progress of composting. The increase in BRANCHED FAMES and the decrease in SOH-FAMES were more delayed in PMC than NMC. The day on which the proportion of BRANCHED FAMES reached plateau and the proportion of SOH-FAMES dipped below 2 mol% coincided with the maturity stage based on the changes of physicochemical characteristics and GI. The composition of BRANCHED FAMES showed highly positive and negative correlation with GI and NH₄⁺, respectively. In the case of SOH-FAMES, inverse correlations were observed. This indicates that the proportion of BRANCHED FAMES and/or SOH-FAMES can be used as a tool for evaluating the maturity of poultry manure compost.     

Detection of recombinant DNA segments introduced to genetically modified maize (Zea mays)

Polymerase Chain Reaction (PCR) techniques are increasingly used for the detection of genetically modified (GM) crops in foods. In this paper, recombinant DNAs introduced into the seven lines of GM maize, such as Event 176, Bt11, T25, MON810, GA21, DLL25, and MON802, are sequenced. On the basis of the obtained sequence, 14 primer pairs for the detection of the segments, such as promoter, terminator regions, and construct genes, were designed. To confirm the specificities of the designed primer pairs, PCR was performed on genomic DNAs extracted from GM and non-GM maize, GM and non-GM soy, and other cereal crops. Because the presence of the corresponding DNA segments was specifically detected in GM crops by the designed primer pairs, it was concluded that this method is useful for fast and easy screening of GM crops including unauthorized ones.