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131.
K van Oers A W Santure I De Cauwer N EM van Bers R PMA Crooijmans B C Sheldon M E Visser J Slate M AM Groenen 《Heredity》2014,112(3):307-316
Linking variation in quantitative traits to variation in the genome is an important, but
challenging task in the study of life-history evolution. Linkage maps provide a valuable
tool for the unravelling of such trait−gene associations. Moreover, they give
insight into recombination landscapes and between-species karyotype evolution. Here we
used genotype data, generated from a 10k single-nucleotide polymorphism (SNP) chip, of
over 2000 individuals to produce high-density linkage maps of the great tit (Parus
major), a passerine bird that serves as a model species for ecological and
evolutionary questions. We created independent maps from two distinct populations: a
captive F2-cross from The Netherlands (NL) and a wild population from the United Kingdom
(UK). The two maps contained 6554 SNPs in 32 linkage groups, spanning 2010 cM and
1917 cM for the NL and UK populations, respectively, and were similar in size and
marker order. Subtle levels of heterochiasmy within and between chromosomes were
remarkably consistent between the populations, suggesting that the local departures from
sex-equal recombination rates have evolved. This key and surprising result would have been
impossible to detect if only one population was mapped. A comparison with zebra finch
Taeniopygia guttata, chicken Gallus gallus and the green anole lizard
Anolis carolinensis genomes provided further insight into the evolution of
avian karyotypes. 相似文献
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133.
Aim This paper describes the distribution pattern (occurrence) of badgers (Meles meles L. 1758) in a Mediterranean mountain area of central Spain, in relation to landscape characteristics and climatic data. We test the fit of the badger occurrence pattern to the niche hypothesis predictions. Location We sampled twenty-four survey plots randomly distributed in the mountains of central Spain (Sierra de Guadarrama, Madrid): ten in the north and fourteen in the south slopes. All habitat types and climatic conditions typical of central Spain can be found. Methods The ocurrence of badgers in the plots were recorded through an exhaustive search of setts and latrines in four different (and evenly spaced) points in each plot. The index of occurrence was made by dividing the number of positive points (badger presence) by the total number of points sampled (four in all plots). Landscape patterns (% type of habitat in each plot) were obtained from detailed maps and climate data from meteorological stations placed in the plot. We analyse the contribution of landscape variables and climate data to explain the differences in badger occurrence through Pearson correlations and fixed one-way ANCOVA with climatic data as fixed factor, vegetation cover as covariates and badger occurrence as response variable. Additionally, we use an one-way ANOVA to check the differences in occurrence between north and south plots with the location of each plot as fixed factor. Results The results indicate that the badger is more abundant in rainy areas of the mountains, and in open landscapes vegetated by ash-tree forests than in closed landscapes vegetated by holm oak forests. In addition, the species is more abundant in the northern plots than in the southern ones. Northern plots were homogeneous areas characterized by their open landscape and wet climate, while southern plots were characterized by their dry climate and closed landscapes. In addition, climate (measured as summer rain) is more determinant than habitat type (holm oak cover) to explain the pattern of badger occurrence. Main conclusions Overall, we consider that the typical Mediterranean landscapes are poor habitats for badgers due to changes in the environmental conditions associated with concomitant changes in food resources. These data support the niche hypothesis to explain the changes in abundance or occurrence close to the edge of the distribution of species, and in particular, in Palearctic species in the Mediterranean area. 相似文献
134.
J. Lozano E. Virgós A.F. Malo D.L. Huertas J.G. Casanovas 《Biodiversity and Conservation》2003,12(5):921-935
The European wildcat (Felis silvestris) is a threatened species in Europe. Suitable management of forests has been considered crucial for its conservation in Europe. However, this recommendation may not be general due to the lack of studies that test these hypotheses in the Mediterranean area, where landscapes are very different from those of central-north Europe. In this study, wild-living cat habitat associations were analyzed by means of scat surveys in 78 areas distributed in the four main vegetation types of the Mediterranean area of central Spain, where feral cat populations are probably scarce and restricted. Results show higher occurrences of wild-living cats in landscapes covered by scrub–pastureland mosaics rather than forests. Several applied recommendations are given: (1) to include the scrub–pastureland mosaics as protected habitats for wildcats; (2) to encourage further studies about the importance of this habitat in other areas; (3) to avoid the extensive scrubland removal associated with management practices against fires or infrastructure development; and (4) to promote land management practices that enhance these mosaics, and to use shrub species in the reforestation programmes founded by the European Agricultural Policy. 相似文献
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136.
Nuria Gomez‐Casanovas Tara W. Hudiburg Carl J. Bernacchi William J. Parton Evan H. DeLucia 《Global Change Biology》2016,22(4):1348-1360
Increases in atmospheric nitrogen deposition (Ndep) can strongly affect the greenhouse gas (GHG; CO2, CH4, and N2O) sink capacity of grasslands as well as other terrestrial ecosystems. Robust predictions of the net GHG sink strength of grasslands depend on how experimental N loads compare to projected Ndep rates, and how accurately the relationship between GHG fluxes and Ndep is characterized. A literature review revealed that the vast majority of experimental N loads were higher than levels these ecosystems are predicted to experience in the future. Using a process‐based biogeochemical model, we predicted that low levels of Ndep either enhanced or reduced the net GHG sink strength of most grasslands, but as experimental N loads continued to increase, grasslands transitioned to a N saturation‐decline stage, where the sensitivity of GHG exchange to further increases in Ndep declined. Most published studies represented treatments well into the N saturation‐decline stage. Our model results predict that the responses of GHG fluxes to N are highly nonlinear and that the N saturation thresholds for GHGs varied greatly among grasslands and with fire management. We predict that during the 21st century some grasslands will be in the N limitation stage where others will transition into the N saturation‐decline stage. The linear relationship between GHG sink strength and N load assumed by most studies can overestimate or underestimate predictions of the net GHG sink strength of grasslands depending on their N baseline status. The next generation of global change experiments should be designed at multiple N loads consistent with future Ndep rates to improve our empirical understanding and predictive ability. 相似文献
137.
Rat pancreatic islet homogenates catalyze the incorporation of [2,5–3-H]histamine into endogenous proteins recovered in both the stacking gel and a Mr 84000 protein separated by polyacrylamide electrophoresis. The labelling of these proteins represents a Ca2+-dependent process inhibited by glycine methylester, but not sarcosine methylester, and enhanced after preincubation of the islets at a high concentration of D-glucose. Although transglutaminase activity is found in both soluble and particlate subcelluler fractions, the endogenous transglutaminase substrates were located mainly in paarticulate, possibly membrane-associated, material. 相似文献
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140.
Marieke Biegstraaten Ivo N van Schaik Wouter Wieling Frits A Wijburg Carla EM Hollak 《BMC neurology》2010,10(1):38