Genetic evidence for different migration routes of freshwater fish into Norway revealed by analysis of current perch (Perca fluviatilis) populations in Scandinavia

To elucidate the colonization of freshwater fish into Norway following the last deglaciation of Europe 10 000 years ago, we have performed a survey using mitochondrial DNA variation (20 populations) and multilocus DNA fingerprinting (14 populations) of the widely distributed perch ( Perca fluviatilis ) from the Scandinavian peninsula and the Baltic Sea. Sequence analysis of a 378 bp segment of the perch mitochondrial control region (D-loop) revealed 12 different haplotypes. A nested clade analysis was performed with the aim of separating population structure and population history. This analysis revealed strong geographical structuring of the Scandinavian perch populations. In addition, the level of genetic diversity was shown to differ considerably among the various populations as measured by the bandsharing values ( S -values) obtained from multilocus DNA fingerprinting, with intrapopulation S -values ranging from 0.19 in Sweden to 0.84 in the central part of Norway. Analysis of the intrapopulation S -values, with S -value as a function of lake surface area and region, showed that these differences were significant. The mitochondrial and DNA fingerprinting data both suggest that the perch colonized Norway via two routes: one from the south following the retreating glacier, and the other through Swedish river systems from the Baltic Sea area. Perch utilizing the southern route colonized the area surrounding Oslofjord and the lakes which shortly after deglaciation were close to the sea. Fish migrating from the Baltic Sea seem to have reached no further than the east side of Oslofjord, where they presumably mixed with perch which had entered via the southern route. It seems likely that the migration events leading to the current distribution of perch also apply to other species of freshwater fish showing a similar distribution pattern.     

Improving sugarcane for biofuel: engineering for an even better feedstock

Sugarcane is a proven biofuel feedstock and accounts for about 40% of the biofuel production worldwide. It has a more favorable energy input/output ratio than that of corn, the other major biofuel feedstock. The rich resource of genetic diversity and the plasticity of autopolyploid genomes offer a wealth of opportunities for the application of genomics and technologies to address fundamental questions in sugarcane towards maximizing biomass production. In a workshop on sugarcane engineering held at Rutgers University, we identified research areas and emerging technologies that could have significant impact on sugarcane improvement. Traditional plant physiological studies and standardized phenotypic characterization of sugarcane are essential for dissecting the developmental processes and patterns of gene expression in this complex polyploid species. Breeder friendly DNA markers associated with target traits will enhance selection efficiency and shorten the long breeding cycles. Integration of cold tolerance from Saccharum spontaneum and Miscanthus has the potential to expand the geographical range of sugarcane production from tropical and subtropical regions to temperate zones. The Flex-stock and mix-stock concepts could be solutions for sustaining local biorefineries where no single biofuel feedstock could provide consistent year-round supplies. The ever increasing capacities of genomics and biotechnologies pave the way for fully exploring these potentials to optimize sugarcane for biofuel production.     

Genetic variability among root voles (Microtus oeconomus) from different geographic regions: populations can be distinguished by DNA fingerprinting

Genetic variability among root voles (Microtus oeconomus [Pallas, 1776]) originating from two distantly separate regions of Norway (Valdres and Finnmark) was studied by DNA fingerprinting using the probes 33.15, 33.6 and M13. All three probes revealed polymorphic, although relatively simple, patterns. DNA fingerprint banding patterns were clearly diagnostic of the animals' region of origin. Notably, Valdres animals display a high molecular-weight cluster of bands not found in Finnmark, reflective of the isolation, and possibly an indication of separate colonization events, of the two groups. On the local level in Finnmark, bands associating with a specific trap site were observed in trappings on consecutive years. Comparisons of Finnmark animals taken at three trap sites at approximately 10 km intervals show a gradient of genetic similarity. Captive bred siblings were also compared, yielding average values significantly higher than those seen from same-site comparisons. We suggest that the sensitivity provided by DNA fingerprinting with multi-locus minisatellite probes is appropriate for population genetic studies in M. oeconomus. Also, because band-sharing correlates to spacing in M. oeconomus, we propose that DNA fingerprinting may be used to study dispersal, recruitment and other population processes in this and possibly other rodent species.     

Effects of Impact Perception on Acceptance Capacity for White-Tailed Deer

ABSTRACT Wildlife professionals require conceptually sound methods to integrate biological and social insights for management of wildlife. The concept of acceptance capacity has been suggested to stimulate integration, although methods to link measures of acceptance capacity with measures of wildlife populations are not fully developed. To clarify relationships between acceptance capacity, wildlife populations, and human values, we explored effects of stakeholder characteristics and impact perception (the recognized, important effects arising from interactions with wildlife) on acceptance capacity. We used a mail-back questionnaire (n = 2,190 responses) to rural residents of southern Michigan 1) to examine whether 3 commonly identified stakeholder groups (hunters, farmers, and nonhunting, nonfarming rural residents) that share a common landscape also perceive similar suites of impacts and hold comparable acceptance capacities for white-tailed deer, and 2) to develop an explanatory model of acceptance capacity for deer. Comparisons among stakeholder groups revealed differences in perception of impacts resulting from interactions with deer; however, participation in hunting and farming were poor predictors of acceptance capacity for deer. Model selection criteria indicate that total effect of impacts perceived explains a majority of variation in acceptance capacity. We conclude that impact perception is a meaningful concept for integration of human values into management of wildlife populations because impacts relate to effects of current wildlife populations and can lead to management actions that address needs and interests of multiple stakeholder groups in changing landscapes.     

The Light Induced Protochlorophyll–Chlorophyll a-Transformation and the Succeeding Interconversions of the Different Forms of Chlorophyll

Curve resolution into Gaussian components of the absorption spectra during the varying stages of the Shibata shift in dark grown, irradiated leaves of barley indicates that the chlorophyll a forms formed after irradiation consist of the same main components which have been reported to be present in all hitherto investigated plant materials (peak values in the red region 662, 670, 677 and 683 nm, respectively) but in varying proportions. The spectra during the Shibata shift proper can be satisfied by a mixture of two single components gradually changing their proportions, although a four component system gives a still better fit to the measured absorption curves. It is also shown that curves taken before and after the shift and added together in the appropriate proportions will match the absorption spectrum measured with peak at the isosbestic point (after ca. 15 min at room temperature).