Genetic evidence for multiple introduction events of raccoons (Procyon lotor) in Spain

The common raccoon (Procyon lotor) is endemic to Central and North America, although non-native populations have become established around the world. In Spain, growing evidence of the introduction of raccoons has been reported across the country in the last decade, especially in Central Spain where the largest population is thought to occur. We used mitochondrial and microsatellite DNA data to investigate the genetics of invasive raccoons in Central Spain and to infer: the number of introduction events, the number of founders and the genetic variability of the introduced populations compared to a native population. We found that at least two introduction events have occurred along the Jarama and Henares Rivers in Central Spain, which currently constitute two genetically differentiated subpopulations. In both localities the number of effective founders from a native population was estimated as 2–4 individuals. These newly founded populations have expanded and show evidence of incipient contact and reproduction between them. This may allow for an increase in the genetic variability and adaptive potential of the population(s), possibly increasing the difficulty of controlling this invasive species. Our results reveal the ability to longitudinally monitor the genetics of the raccoon range expansion and emphasize the urgent need to control the pet trade of potentially invasive species.     

Kinetic profiles of ochratoxin A and ochratoxin alpha during in vitro incubation in buffered forestomach and abomasal contents from cows.

Pure ochratoxin A (OA) was added to buffered rumen fluid collected from fistulated cows and incubated under anaerobic conditions. The kinetic pattern of the disappearance of OA and the appearance of ochratoxin alpha (Oalpha) was principally the same with four diets fed to donor animals and with three donor animals. The concentration of OA declined to a very low or non-detectable level with half-lives at 0.17-1.84 h; its rate of disappearance was first order throughout. The concentration of Oalpha increased to a constant level under all conditions examined. The average amounts of Oalpha formed relative to the disappearance of OA were not different (p > 0.05) and ranged between 94 +/- 8 and 98 +/- 8 %. The rate of disappearance of OA differed (p < 0.001) between diets and animals. It was accelerated by increasing the content of concentrate in the diet. Ochratoxin alpha was not metabolized when added in pure form to buffered rumen fluid and incubated under the same conditions as OA. Pure OA was also added to buffered fluids from the forestomach and abomasum of a slaughtered cow. It disappeared exponentially in a mixture of fluids from the rumen and reticulum and in fluid from the omasum, with the average amounts of Oalpha formed relative to OA disappearance being 107 and 109 %, respectively. Ochratoxin A also was not metabolized in fluid from the abomasum. These studies demonstrate that OA is hydrolysed in the rumen via first order kinetics, diet and animal affect the rate of hydrolysis, OA is quantitatively converted to Oalpha and Oalpha is not degraded.     

Zum Konkurrenzverhalten von Mischverunkrautungen bei Wintergerste in Abhängigkeit von ökologischen Bedingungen

Mechanisms of insecticide and acaricide resistance are, as a rule, inherited as single autosomal genes. Pesticide‐treated pest populations with established resistance mechanisms mostly consist of both susceptible and resistant individuals. For practical purposes determination of the level of resistance (percent of resistant individuals) is more informative than the resistance degree. A method of spline regression analysis is presented allowing the evaluation of the status of resistance by calculating bioassay data.     

Trophic basis of production of stream detritivores shifts with reduced forest inputs

Hydrobiologia - Estimating changes in organic matter flow from resource to consumer using trophic basis of production (TBP) is a way to examine resource limitation effects on ecosystem function. We...     

Methylation of the mouse M-lysozyme downstream enhancer inhibits heterotetrameric GABP binding.

Expression of the mouse M-lysozyme gene is a specific marker for the differentiation of macrophage/granulocyte cell lineages. Analysis of the mechanisms regulating M-lysozyme gene expression revealed an enhancer element in the 3'-flanking region of the gene, termed the M-lysozyme downstream enhancer (MLDE). Here we demonstrate that the nuclear factors binding to MLDE are present in all tested myeloid and non-myeloid mouse cell lines. Sequence analysis of MLDE identified two different sequences, CAGGAAGT and CCGGAAGT, which match the consensus binding sequences for proteins of the ets gene superfamily. The two sites are oriented palindromicly and separated by 10 bp. DMS/DEPC interference assays revealed different patterns of DNA-protein contacts on the two sites. Mutation of each consensus sequence leads to an individual change in protein binding in vitro. Despite these differences, both sequences are bound by GABP, forming a heterotetrameric complex. Tissue specificity is correlated with demethylation of a single CpG dinucleotide located in one of the two Ets motifs. This site when methylated inhibits GABP binding to both sequences in non-macrophage cell types.