The identification of disease-induced biomarkers in the urine of BSE infected cattle

Background  

The bovine spongiform encephalopathy (BSE) epidemic and the emergence of a new human variant of Creutzfeldt-Jakob Disease (vCJD) have led to profound changes in the production and trade of agricultural goods. The rapid tests currently approved for BSE monitoring in slaughtered cattle are all based on the detection of the disease related isoform of the prion protein, PrP^d, in brain tissue and consequently are only suitable for post-mortem diagnosis. Objectives: In instances such as assessing the health of breeding stock for export purposes where post-mortem testing is not an option, there is a demand for an ante-mortem test based on a matrix or body fluid that would permit easy access and repeated sampling. Urine and urine based analyses would meet these requirements.     

Amazon Stranger: A Rainforest Chief Battles Big Oil

Amazon Stranger:. Rainforest Chief Battles Big Oil. Mike Tidwell. New York: Lyons and Burford, 1996.216 pp.     

The molecular organization of the beta-globin complex of the deer mouse, Peromyscus maniculatus

Recombinant DNA clones have been isolated that contain 80 kb of thebeta-globin complex from the deer mouse, Peromyscus maniculatus.Comparisons of this complex with that from the laboratory mouse, Musdomesticus (with an order 5'-Hbby, Hbb-bhO, Hbb-bhl, Hbb-bh2, Hbb-bh3,Hbb-bl, Hbb-b2 3') highlight organizational trends in the beta-globincomplex since the two species diverged. Unlike other mammals studied thusfar, the deer mouse possesses three adult genes. Partial sequence analysisindicates that each of the three adult genes is intact and hence may befunctional. Hybridization of one of the two Mus pseudogenes, Hbb-bh3, togenomic blots from Peromyscus reveals that it has a homologous counterpartin Peromyscus. Homologous genes to the two gamma-like Mus genes, Hbb-bhOand Hbb-bhl, are also found in Peromyscus. The strong hybridization betweenthe Hbb-bhl genes and significant nucleotide similarity between the Hbb-bhOgenes suggest that both pairs are important for the ontogeny of these micealthough no known product has been identified for the Hbb-bhO genes. Thepresence of Hbb-bhO and Hbb-bhl in Peromyscus suggests that the duplicationthat created this related gene set occurred before the two lineagesdiverged. A single gene for Hbb-y has been isolated from Peromyscus. Theadult region in Peromyscus has undergone significant divergence from thesame region in Mus, having three rather than two adult genes, theacquisition of at least 15 kb of extra DNA relative to Mus, and possiblythe loss of the Hbb-bh2 pseudogene. The nonadult region of the complex, incontrast, contains the same set of genes apparently distributed over thesame amount of DNA as in the Mus beta- globin complex. This observationsuggests that the embryonic region of the complex is more evolutionarilystable than the adult region.     

Mitochondrial DNA variation and genetic structure in populations of Drosophila melanogaster

The understanding of the genetic structure of a species can be improved byconsidering together data from different types of genetic markers. In thepast, a number of worldwide populations of Drosophila melanogaster havebeen extensively studied for several such markers, including allozymes,chromosomal inversions, and quantitative characters. Here we presentresults from a study of restriction- fragment-length polymorphisms ofmitochondrial DNA (mtDNA) in 92 isofemale lines from many of the samegeographic populations of D. melanogaster. Eleven restriction enzymes wereused, of which four revealed restriction-site polymorphism. A total of 24different haplotypes were observed, of which 18 were unique to singlepopulations. In many populations, the unique haplotypes have reached highfrequency without being observed in neighboring populations. A Wagnerparsimony tree reveals that mutationally close variants show geographicalclumping, suggesting local differentiation of mtDNA in populations. TheOld-World and the New-World populations are differentiated, with thepredominant Old-World haplotype being virtually absent from the New World.These results contrast with those for the nuclear genes, in which many locishow parallel clines in different continents, and suggest a common originof D. melanogaster populations in North America.     

混合线性模型下猪群间遗传联系的度量

采用关联指数（IC）和决定系数（CD）两种方法,度量混合线性模型遗传评估下猪群体间的遗传关联性。结果表明,加拿大安大略省的大约克夏猪、长白猪、杜洛克猪和汉普夏猪4个主要品种群体间具有良好的遗传联系。CD法既组合了数据结构和信息量,又考虑了预测误差方差和遗传变异性,是一个选择判断遗传评估精度的好方法。     

A requirement for trypsin-sensitive cell-surface components for cell-cell interactions of embryonic neural retina cells

A quantitative assay was used to measure the rate of collection of a population of embryonic neural retina cells to the surface of cell aggregates. The rate of collection of freshly trysinized cells was limited in the initial stages by the rate of replacement of trypsin-sensitive cell- surface components. When cells were preincubated, or "recovered," and then added to cell aggregates, collection occurred at a linear rate and was independent of protein and glycoprotein synthesis. The adhesion of recovered cells was temperature and energy dependent, and was reversibly inhibited by cytochalasin B. Colchicine had little effect on collection of recovered cells. Antiserum directed against recovered cell membranes was shown to bind to recovered cells by indirect immunofluorescence. The antiserum also was shown to inhibit collection of recovered cells to aggregates, suggesting that at least some of the antigens identified might be involved in the adhesion process. The inhibitory effect of the antiserum was dose dependent . Freshly trypsinized cells absorbed neither the immunofluorescence activity nor the adhesion-inhibiting activity. Recovered cells absorbed away both activities. In specificity studies, dorsal neural retina cells adhered to aggregates of ventral optic tectum in preference to aggregates of dorsal optic tectum. The adhesive specificity of the dorsal retina cells was less sensitive to trypsin than the adhesive specificity of ventral retina cells which adhered preferentially to dorsal tectal aggregates only after a period of recovery.     

Palatability and efficacy to possums and rats of pest control baits containing bird repellents

Repellents used to reduce by-kill of birds during pest control must not compromise acceptance by target species. Two repellents combined, anthraquinone (AQ; 0.4 g kg^?1) and d-pulegone (DP; 1.0) did not reduce the palatability of blue-coloured carrot baits to laboratory rats (Rattus norvegicus); nor did DP (2.0). Green-coloured carrot baits coated with AQ, DP or AQ + DP were taken from bait stations by wild possums (Trichosurus vulpecula) and rats. Toxic (1080) bait coated with AQ (0.4) and peanut oil (0.1) had reduced palatability but was accepted by laboratory rats. However, laboratory rats did not consume enough baits coated with AQ and bacon, peanut butter, cinnamon or DP to be killed. Anthraquinone (0.4 or 0.8) plus cinnamon and DP (0.5) did not affect palatability or lethality to captive ship rats (R. rattus) or possums. Anthraquinone and DP as surface coatings on baits are therefore acceptable to possums and possibly rats, at concentrations that deter some bird species.