A deleterious effect associated with UNH159 is attenuated in twin embryos of an inbred line of blue tilapia Oreochromis aureus

Offspring of a highly inbred gynogenetic line of Oreochromis aureus displayed 12‐fold increase in twinning rate compared to the outbred population. Asymmetric conjoined twins, which consist of a normal embryo attached to a malformed‐atrophic twin, were frequently encountered in both gynogenetic (90·7%) and outbred (38·2%) embryos. The monozygotic origin of these twins was determined using five microsatellite markers. Progeny of heterozygous parents for the microsatellite UNH159 were separated into sub‐sets of twins and normal full‐sibs. Consistent with previous reports, the normal embryo sub‐set exhibited elimination of both types of homozygotes for the UNH159 genetic marker at 2–8 days after fertilization. Unexpectedly, this elimination was less frequent in twins. The UNH159 marker as well as RNA‐binding motif protein, X‐linked (rbmx), SRY‐box containing gene 3 (sox3) and alpha‐thalassemia/mental retardation syndrome X‐linked (atrx) genes were mapped to linkage group 2. These gene orthologues are all located on the mammalian X chromosome and atrx is necessary for the X‐chromosome inactivation.     

Current methods for molecular typing of Campylobacter species

Campylobacter remains one of the most common bacterial causes of gastroenteritis worldwide. Tracking sources of this organism is challenging due to the large numbers of human cases, and the prevalence of this organism throughout the environment due to growth in a wide range of animal species. Many molecular subtyping methods have been developed to characterize Campylobacter species, but only a few are commonly used in molecular epidemiology studies. This review examines the applicability of these methods, as well as the role that emerging whole genome sequencing technologies will play in tracking sources of Campylobacter spp. infection.     

Farm‐scale dispersal of Bactericera cockerelli in potato crops measured using Bt mark‐capture techniques

Natural populations of Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), also known as tomato/potato psyllid, were marked in potato [Solanum tuberosum L. (Solanaceae)] crops using Bacillus thuringiensis Berliner (Bt) to investigate the impact of dispersal on crop infestation and management of potential insecticide resistance in New Zealand. The technique was adapted from previous studies that used conventional spray applications of Bt to mark Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), and identified marked individuals with selective microbiological assays and identification of characteristic crystal inclusions. Initially, marking rates of B. cockerelli were improved by using ultra‐low volume applications of undiluted Bt, but this result was not consistent. Several other pests and natural enemies were also marked. In mark‐capture studies, marked B. cockerelli were captured over 3 days on yellow sticky traps in small trap plots of potatoes at 60, 120, 180, 250, and 350 m from the sprayed crop. Bactericera cockerelli flight activity occurred throughout daylight hours with evidence of bimodal diurnal peaks. Significantly greater numbers of B. cockerelli were captured in downwind traps. The combined dispersal curve derived from two mark‐capture experiments estimated a mean dispersal distance for B. cockerelli of 100 m in 3 days and indicated that 10% of the population dispersed further than ca. 250 m. Over the period of a growing season, this level of dispersal suggests that B. cockerelli can disperse throughout a vegetable‐growing region, with implications for crop infestation and management of potential insecticide resistance.     

Genetic diversity and population structure of Butea monosperma (Lam.) Taub.- a potential medicinal legume tree

Three molecular marker systems, Random Amplified Polymorphic DNA (RAPD), Inter-Simple Sequence Repeats (ISSR) and Sequence-Related Amplified Polymorphism (SRAP) were employed to investigate the genetic structure and diversity among the 14 natural populations of Butea monosperma collected from different geographical regions of India. Detected by 17 RAPD, 15 ISSR and 11 SRAP primer combinations, the proportions of polymorphic bands were 84.2 %, 77.2 % and 91.9 %, respectively, and the mean Nei’s genetic distances among the populations were 0.13, 0.10 and 0.13, respectively. Partitioning of genetic variability by Analysis of molecular variance (AMOVA) revealed that the high genetic diversity was distributed within the populations. AMOVA also revealed that the coefficient of gene differentiation among populations based on F_ST was very high irrespective of markers used. The overall gene flow among populations (Nm) was very low. Cophenetic correlation coefficients of Nei’s distance values and clustering pattern by Mental test were statistically significant for all three marker systems used but poor fit for ISSR data than for RAPD, SRAP and combined data set of all three markers. For all markers, a high similarity in dendrogram topologies was obtained, although some differences were observed with ISSR. The dendrogram obtained by RAPD, SRAP and combined data set of all three markers reflect relationship of most of the populations according to their geographic distribution.     

Isolation and characterization of ethanol tolerant yeast strains

Yeast strains are commonly associated with sugar rich environments. Various fruit samples were selected as source for isolating yeast cells. The isolated cultures were identified at Genus level by colony morphology, biochemical characteristics and cell morphological characters. An attempt has been made to check the viability of yeast cells under different concentrations of ethanol. Ethanol tolerance of each strain was studied by allowing the yeast to grow in liquid YEPD (Yeast Extract Peptone Dextrose) medium having different concentrations of ethanol. A total of fifteen yeast strains isolated from different samples were used for the study. Seven strains of Saccharomyces cerevisiae obtained from different fruit sources were screened for ethanol tolerance. The results obtained in this study show a range of tolerance levels between 7%-12% in all the stains. Further, the cluster analysis based on 22 RAPD (Random Amplified polymorphic DNA) bands revealed polymorphisms in these seven Saccharomyces strains.     

甜瓜抗蔓枯病基因Gsb-3的ISSR分子标记

以甜瓜抗病资源PI511890和感病自交系‘白皮脆’及其F1、BC1P1、BC1P2、F2群体为材料,苗期接种蔓枯病菌(Did ymella bryoniae)进行遗传分析.结果表明:(1)对甜瓜苗期蔓枯病菌接种鉴定结果显示,抗源PI511890的抗病基因Gsb-3由显性单基因控制.(2)利用集团分离分析及ISSR分析技术,引物ISSR-100扩增出的多态性条带与Gsb-3表现连锁关系,该多态性片段大小为900 bp.(3)统计ISSR-100在182个F2单株上的多态性,并用JoinMap 4.0软件分析结果显示,ISSR-100与Gsb-3遗传连锁距离为8.3 cM,定名为ISSR-100900.研究认为,ISSR100900可作为甜瓜抗蔓枯病分子育种的备选分子标记.     

Increased Activity of Liver Xanthine Oxidase in Rats from Increasing Dietary Calcium

A new binary vector, pZT4B, containing the UDP-N-acetylglucosamine: dolichol phosphate N-acetylglucosamine-1-P transferase (GPT) gene as a selection marker, was constructed. The green fluorescent protein (GFP) gene was inserted into pZT4B, and the resulting plasmid was used in the transformation of Arabidopsis. All of six independent transformants obtained after selection with 0.3 mg/l tunicamycin contained the transgene and showed GFP fluorescence.     

Recent Advances in Structural Research on Ether Lipids from Archaea Including Comparative and Physiological Aspects

A great number of novel and unique chemical structures of archaeal polar lipids have been reported. Since 1993, when those lipids were reviewed in several review articles, a variety of core lipids and lipids with unique polar groups have been reported successively. We summarize new lipid structures from archaea elucidated after 1993. In addition to lipids from intact archaeal cells, more diverse structures of archaea-related lipids found in environmental samples are also reviewed. These lipids are assumed to be lipids from unidentified or ancient archaea or related organisms. In the second part of this paper, taxonomic and ecological aspects are discussed. Another aspect of archaeal lipid study has to do with its physiological significance, particularly the phase behavior and permeability of archaeal lipid membranes in relation to the thermophily of many archaea. In the last part of this review we discuss this problem.     

Establishment of a New Cross of the Rice Blast Fungus Derived from Japanese Differential Strain Ina168 and Hermaphroditic Rice Pathogen Guy11

Mating experiments between Magnaporthe grisea Japanese rice pathogens and Guy11, a hermaphroditic fertile rice pathogen, were done aimed at identification of avirulence genes. A cross named cross 2107 with thirty-six random progenies was obtained. Segregation analyses of genetic markers found that the cross was less suitable for genetic analysis. Backcrosses with cross 2107 progenies and Guy11 were done and another cross named cross 5307 with sixty-five progenies was obtained. A locus controlling kasugamycin resistance named Ksg1R was identified and used for a model case of genetic mapping. Bulked segregant analysis was done to find adjacent RAPD markers for mapping of the gene. Three adjacent markers to Ksg1R were obtained and a genetic map around the Ksg1R was made, but these markers were not located on a single chromosome. These results suggest that genetic analysis to identify a gene locus is available in cross 5307. Infection assay of parental strains of cross 5307 to Japanese differential rice cultivars suggested the possibility of genetic analysis of cultivar specificity toward four rice cultivars: Aichiasahi, Kusabue, Tsuyuake, and K59.     

遗传标记和免疫学方法在实验动物质量控制中的应用

生命科学发展迅速,实验动物级别逐渐提高,在保证生物制品实验结果可靠性前提下,完善动物由低级别向高级别过渡显得十分必要,最终目的达到实验动物标准化和动物实验规范化。对实验动物质量控制中的遗传标记和免疫学方法进行了综述。