DNA fingerprints of dogs and cats

Human minisatellite probes consisting of tandem repeats of the 'core' sequence, a putative recombination signal in human DNA, cross-hybridize to multiple polymorphic fragments in dog and cat DNA to produce individual-specific DNA 'fingerprints'. Pedigree analysis shows that most of the DNA fragments detected in an individual are heterozygous, and that these fragments are derived from multiple dispersed autosomal loci. DNA fingerprints of cats and dogs should prove suitable for individual identification and for establishing family relationships. They are also suitable for rapid marker generation in large pedigrees and could be applied to linkage analysis in these animals.     

DNA fingerprint bands applied to linkage analysis with quantitative trait loci in chickens

Summary
An efficient approach to detect association between quantitative traits and bands of DNA fingerprint patterns uses intra-family tail analysis, which compares fingerprints of DNA mixes from individuals at the two tails of a phenotypic distribution. In analysis of 67 paternal half-sibs of a meat-type chicken family, of 57 sire bands generated by two probes, one sire-specific band (S6–6) was associated with abdominal fat deposition. The band effect was estimated by a linear model analysis to be 0–88 standard deviations, or about 30% of the family mean. The association between band S6–6 and abdominal fat was further examined by testing progeny of paternal half-sibs of the chickens which were used in the tail analysis, establishing genetic linkage between the DNA marker and a genetic locus affecting abdominal fat deposition.     

Footprint on a coprolite: A rarity from the Eocene of Vietnam

A rare ichnological example of a crocodilian footprint on an Eocene crocodilian coprolite has been discovered. The enigmatic specimen, measuring 4 cm in length, was found among 100 coprolites at the Na Duong coal mine in Lang Son province, northern Vietnam. Almost all the discovered coprolites were ascribed to a potential crocodilian producer, suggesting the existence of an ancient lacustrine environment. Furthermore, neoichnological analyses of extant crocodilian footprints also corroborate the inference of a crocodilian as the producer of the footprint. We concluded that the 4-cm-long Na Duong fingerprints most likely belonged to a 2-m-long crocodilian whose IV or V finger of the right manus might have made the fingerprints. Since no other records of foot traces or trackways were identified during the fieldwork in the fall of 2018, the Na Duong fossil site should be investigated for further ichnofossil analysis.     

A structure-based anatomy of the E.coli metabolome

The Escherichia coli metabolome has been characterised using the two-dimensional structures of 745 metabolites, obtained from the EcoCyc and KEGG databases. Physicochemical properties of the metabolome have been calculated to provide an overview of this set of cognate ligands. A library of fragments commonly found among these molecules has been employed to reveal the main constituents of metabolites, and to assist a broad classification of the metabolome into biochemically relevant classes. Fragment-based fingerprints reveal the metabolome as a continuum in the two-dimensional structural space, where clusters of molecules sharing similar scaffolds can be identified, but are generally overlapping. Nucleotide, carbohydrate and amino acid-like molecules are the most prominent, but at high levels of similarity, a more detailed classification is possible. Classification schemes for the metabolome are a promising tool for understanding the chemical diversity of the metabolome. When used in conjunction with existing classifications of the proteome, they can help to elucidate the binding preferences and promiscuity of proteins and their cognate substrates.     

DNA指纹图谱技术在土壤微生物多样性研究中的应用

土壤中的微生物多样性是十分丰富的,传统培养方法对土壤微生物多样性的研究有很大局限性。近年来,各种基于16S rDNA基因的指纹图谱分析技术取得了长足的进步,并广泛应用于土壤微生物多样性的研究。这些技术主要有变性梯度凝胶电泳(DGGE)/温度梯度凝胶电泳(TGGE)、单链构象多态性(SSCP)、随机引物扩增多态性DNA(RAPD)、限制性片段长度多态性(RFLP)和扩增核糖体DNA限制性分析(ARDRA)等。对这些技术近年来在土壤微生物多样性研究领域的应用予以简短综述,并初步探讨未来几年土壤微生物分子生态学发展的方向。     

A population genomics insight into the Mediterranean origins of wine yeast domestication

The domestication of the wine yeast Saccharomyces cerevisiae is thought to be contemporary with the development and expansion of viticulture along the Mediterranean basin. Until now, the unavailability of wild lineages prevented the identification of the closest wild relatives of wine yeasts. Here, we enlarge the collection of natural lineages and employ whole‐genome data of oak‐associated wild isolates to study a balanced number of anthropic and natural S. cerevisiae strains. We identified industrial variants and new geographically delimited populations, including a novel Mediterranean oak population. This population is the closest relative of the wine lineage as shown by a weak population structure and further supported by genomewide population analyses. A coalescent model considering partial isolation with asymmetrical migration, mostly from the wild group into the Wine group, and population growth, was found to be best supported by the data. Importantly, divergence time estimates between the two populations agree with historical evidence for winemaking. We show that three horizontally transmitted regions, previously described to contain genes relevant to wine fermentation, are present in the Wine group but not in the Mediterranean oak group. This represents a major discontinuity between the two populations and is likely to denote a domestication fingerprint in wine yeasts. Taken together, these results indicate that Mediterranean oaks harbour the wild genetic stock of domesticated wine yeasts.     

Impact of Continuous Cropping of Lettuce on the Disease Dynamics of Bottom Rot and Genotypic Diversity of Rhizoctonia solani AG 1‐IB

The impact of continuous cropping of lettuce on the disease dynamics of bottom rot and genotypic diversity of the causal pathogen Rhizoctonia solani AG 1‐IB was studied over 3 years with two crops per year within a field naturally infested with R. solani the pathogen. This field had not had lettuce cultivated in it for 7 years. The disease incidence (DI) and disease severity (DS) were assessed at each harvest and mapped. Surprisingly, a high DI was already observed in the first crop of year one of this field study. In addition, the pathogen was also found to be evenly distributed. Severely infected plants occurred mainly in patches, and the position varied between crops. A significant increase in DS was already observed in the second year, and both temperature conditions and continuous cropping influenced the DS on average over time. Rhizoctonia isolates were randomly collected from the first crop in 1999 and the sixth crop in 2001. The genotypic diversity within the subgroup of R. solani AG 1‐IB was analysed by BOX‐PCR genomic fingerprinting and the aggressiveness of isolates by bioassay. The fingerprints revealed a high level of genotypic diversity within the AG 1‐IB field population. However, continuous cropping was found not to have an impact on genotypic diversity and aggressiveness.     

黄瓜育成品种"春玉"RAPD指纹图谱分析

从300条随机引物中筛选出能稳定扩增的26个引物．对黄瓜育成品种“春玉”等21个实验材料进行扩增,在扩增出的173条谱带中,多态性带有80条,比例为46．24％。“春玉”在用引物E13扩增时有特异缺失条带,大小为400bp,可作为特征性指纹图谱,为其产权保护提供分子依据。利用各材料的DNA指纹可将不同参试材料鉴别出来。同时利用MEGA软件进行UPGMA聚类分析,将参试材料在相似系数0．706处分为4个组群。     

近交系大鼠DNA指纹分析研究

目的建立DNA指纹技术对近交系大鼠遗传监测的方法.方法采用DNA指纹图法对国内已知的7个品系9个近交系大鼠群体进行了分析,并对相同DNA进行了多次DNA指纹图重复实验.结果(1)不同品系之间DNA指纹图差异较大,其平均图带数为16.360±2.178,共有带率为0.061±0.008,相似系数为0.062±0.008,相同DNA指纹图概率为3.691×10-23.(2)同一群体不同个体之间DNA指纹图带的相似系数和共有带率(除SHR(哈)和WKY(哈)小于0.7外),其他均在大于0.9.(3)不同地区同一SHR和同一WKY品系间DNA指纹图也存在不同,其相似系数和共有带率均小于0.6.(4)相同DNA不同次制作的DNA指纹图谱基本一致(P>0.05).结论证实了该方法在近交系大鼠遗传监测中的可行性.