Prevalence of zoonotic Bartonella species among rodents and shrews in Thailand

We investigated the prevalence of Bartonella species in 10 rodent and one shrew species in Thailand. From February 2008 to May 2010, a total of 375 small animals were captured in 9 provinces in Thailand. Bartonella strains were isolated from 57 rodents (54 from Rattus species and 3 from Bandicota indica) and one shrew (Suncus murinus) in 7 of the 9 provinces, and identified to the species level. Sequence analysis of the citrate synthase and RNA polymerase β subunit genes identified the 58 isolates from each Bartonella-positive animal as B. tribocorum in 27 (46.6%) animals, B. rattimassiliensis in 17 (29.3%) animals, B. elizabethae in 10 (17.2%) animals and B. queenslandensis in 4 (6.9%) animals. R. norvegicus, R. rattus, and Suncus murinus carried B. elizabethae, which causes endocarditis in humans. The prevalence of Bartonella bacteremic animals by province was 42.9% of the animals collected in Phang Nga, 26.8% in Chiang Rai, 20.4% in Sa Kaeo, 16.7% in Nakhon Si Thammarat, 12.0% in Surat Thani, 9.1% in Mae Hong Son and Loei Provinces.     

Bacterial contamination on eggs during incubation and hatching,and of fluffs of newly‐hatched chicks

1. Average numbers of bacteria on clean and dirty eggs produced from a specified‐pathogen‐free chicken flock were 10^3.0 and 10^4.5, respectively. When the eggs were washed with running tap water at about 40°C, the respective bacterial counts were reduced to 10^2.0 and 10^2.7, the latter difference being not significant.

2. After fumigation with formaldehyde from 40 ml formalin (372 g formaldehyde/1) and 20 g potassium permanganate/m³ for 1 h, no bacteria were recovered from clean eggs by agar plate culture, while a small number of bacteria were detected in three out of five dirty eggs.

3. Average numbers of bacteria detected in clean fumigated eggs were 10^0.8 to 10^1.1 during the first 19 d of incubation and 10^1.2 and 10^1.4 were recovered on days 20 and 21 of incubation, respectively. At the end of hatching, eggs containing dead embryos were highly contaminated with 10^3.8 organisms on average.

4. Fluffs of newly‐hatched chicks scattered inside the hatcher were contaminated with bacteria at 10^4.0 to 10^8.4 organisms/g. Water in the basin placed in the hatcher and floating fluffs in water were highly contaminated with bacteria.     

Structure-physicochemical function relationships of soybean glycinin at subunit levels assessed by using mutant lines

Glycinin is a hexameric protein composed of five kinds of subunits. The subunits are classified into two groups, group I (A1aB1b, A1bB2, and A2B1a) and group II (A3B4 and A5A4B3). We purified four mutant glycinins composed of only group I subunits (group I-glycinin), only group II subunits (group II-glycinin), only A3B4 (A3B4-glycinin), and only A5A4B3 (A5A4B3-glycinin) from mutant soybean lines. The physicochemical properties of these glycinin samples were compared with those of the normal glycinin (11S) composed of five kinds of subunits. The thermal stabilities (as measured by thermal denaturation midpoint temperatures) of 11S, group I-glycinin, and group II-glycinin were similar to each other, although that of A3B4-glycinin was significantly lower than those of the others. The orders of aromatic and aliphatic surface hydrophobicities were the same: A3B4-glycinin > group II-glycinin > A5A4B3-glycinin > 11S > group I-glycinin. The solubility of 11S as a function of pH at mu = 0.5 was governed by that of group I-glycinin and followed this order at acidic pH: 11S = group I-glycinin > A3B4-glycinin > group II-glycinin = A5A4B3-glycinin. The order of emulsifying abilities was A5A4B3-glycinin > group II-glycinin > A3B4-glycinin > 11S > group I-glycinin. This order was consistent with that of the length of their hypervariable regions. Except for this relationship, there was no significant relationship among the other physicochemical properties of the mutant glycinins.     

Identification of genomic regions associated with low phosphorus tolerance in japonica rice (Oryza sativa L.) by QTL-Seq

ABSTRACT

Phosphorus (P) is a major nutrient supporting rice productivity. Improving low-P tolerance of rice is expected to reduce dependence on P fertilizer, thereby reducing rice production costs and environmental impacts. This report describes the mapping of quantitative trait loci (QTL) associated with P deficiency tolerance in japonica rice. An F5 population derived from a cross of the low-P tolerant cultivar Akamai (Yamagata) and the sensitive cultivar Koshihikari was evaluated for shoot growth under low-P conditions. Then single nucleotide polymorphism (SNP) profiles of the low-P tolerant and sensitive bulks were compared on a genome-wide scale by QTL-Seq, a rapid QTL mapping method using next-generation sequencing technology. Results show a major QTL associated with low-P tolerance located on the long arm of chromosome 12. It has been named QTL for low-P tolerance 1 or qLPT1. SNPs were detected in 45 genes of qLPT1 region and the 5 genes were harboring synonymous SNPs, although none of them had been reported as involved in low-P tolerance. This result implies that the novel gene responsible for low-P tolerance exists in qLPT1. This study will contribute to the elucidation of mechanisms underlying low-P tolerance of Akamai and will facilitate the breeding of rice with low-P tolerance.     

Comparison of protein chemical and physicochemical properties of rapeseed cruciferin with those of soybean glycinin

Rapeseeds contain cruciferin (11S globulin), napin (2S albumin), and oleosin (oil body protein) as major seed proteins. The effects of oil expression and drying conditions on the extraction of these proteins from rapeseed meal were examined. The conditions strongly affected the extraction of oleosin and only weakly affected the extraction of cruciferin and napin. The protein chemical and physicochemical properties of cruciferin, the major protein present, were compared with those of glycinin (soybean 11S globulin) under various conditions. In general, cruciferin exhibited higher surface hydrophobicity, lower thermal stability, and lower and higher solubility at mu= 0.5 and mu = 0.08, respectively, than did glycinin. At the pHs (6.0, 7.6, and 9.0) and ionic strengths (mu= 0.08 and 0.5) examined, the emulsifying ability of cruciferin was worse than that of glycinin, except at mu= 0.08 and pH 7.6. The emulsifying abilities of cruciferin and glycinin did not correlate with thermal stability and surface hydrophobicity. Higher protein concentration, higher heating temperature, higher pH, and lower ionic strength were observed to produce harder gels from cruciferin. Gel hardness partly correlated with the structural stability of cruciferin.     

Structural characterization of the trisaccharide chain from the skin mucus glycoprotein of the rainbow trout, Salmo gairdneri

Skin mucus glycoprotein (RGP) was extracted from the skin mucus of rainbow trout, Salmo gairdneri. Alkaline borohydride treatment of RGP yielded a major oligosaccharide alditol NeuAcα2 to6GalNAc-ol and several minor oligosaccharide alditols. A trisaccharide alditol (OS-I) was purified by Sephadex G-25 gel filtration and high-performance liquid chromatography (HPLC). The amount of OS-I was estimated to be 7% in RGP from the amount of GalNAc-ol. Structural determination of the OS-I was examined. Structure of OS-I was identified to be NeuAcα2 to6 (GalNAcα1 to3) GalNAc-ol by α-N-acetylgalactosaminidase digestion, methylation analysis, and ¹H-NMR spectroscopy. This revised version was published online in August 2006 with corrections to the Cover Date.     

两系法杂交稻育种现状

 石明松发现光敏核不育水稻，开辟了杂交稻研究的新篇章。两系法杂交稻的发展依赖于新的遗传工具，即光敏核不育水稻（PGMR）和 温敏核不育水稻（TGMR）。研究表明，农垦58S系统的不育系不存在绝对的光敏不育性或绝对的温敏不育性，其育性转换都是受光 温共同作用的结果。到目前为止，已育成了一批两系法品种间杂交稻组合。这些组合已经在长江流域的双季稻区作晚稻种植了6000多hm²，一般产量6.75－7.50 t/hm²，比同生育期的常规粳稻鄂晚5号和鄂宜105等增产10%－15%，与同生育期的三系杂交稻汕优64等产量持平。此外，具有强优势的亚种间杂交稻组合也已初步选出     

Evidence for the neutral hypothesis of protein polymorphism

Data for some 400 polymorphic proteins were examined with special reference to molecular evolution, by using a statistic that depends on neither mutation rate, population structure, nor other ecological factors. The result indicates that most of these polymorphisms are maintained in a population by mutation and random genetic drift.     

Seroprevalence of Toxoplasma gondii antibodies in stray cats and dogs in the Bangkok metropolitan area, Thailand

Cats and dogs are the most popular pet animals worldwide. Cats are the natural reservoir of Toxoplasma gondii and excrete the resistant oocyst to environments. On the other hands, dogs play a role in the mechanical transmission of the parasite. Stray cats and dogs in the Bangkok metropolitan area are becoming a public concern because there is a considerable increase in their number annually. These facts indicate the risk of mechanically spreading zoonoses including toxoplasmosis to humans since human acquire the infection from infected mammals, either directly or indirectly. In the present study, the presence of T. gondii antibodies was examined in 592 cats and 427 dogs from October 2001 to September 2002 by using a latex agglutination test. T. gondii antibodies were detected in 65 (11.0%) of the 592 cats and 40 (9.4%) of the 427 dogs. The antibody titers in the positive animals ranged from 1:64 to 1:2048. Seroprevalence was significantly higher in female cats than in male cats. The present study suggested that T. gondii was widespread in the stray animals in the Bangkok metropolitan area; therefore, it is essential to control the number of stray cats and dogs in order to reduce the transmission of toxoplasmosis to animals and humans.