Vegetation shifts towards wetter site conditions on oceanic ombrotrophic bogs in southwestern Sweden

Question: Is ombrotrophic bog vegetation in an oceanic region of southwestern Sweden changing in the same direction over a five year period (1999 ‐ 2004) as northwest European bogs in the last 50 years, i.e. towards drier and more eutrophic vegetation? Location: The province of Halland, southwestern Sweden. Methods: Changes in species composition were monitored in 750 permanently marked plots in 25 ombrotrophic bogs from 1999 to 2004. Changes in species occurrences and richness were analysed and a multivariate statistical method (DCA) was used to analyse vegetation changes. Results: The species composition changed towards wetter rather than drier conditions, which is unlike the general pattern of vegetation change on bogs in northwestern Europe. Species typical of wetter site conditions including most Sphagnum species increased in abundance on the bogs until 2004. The total number of species per plot increased, mostly due to the increased species richness of Sphagnum species. Nitrogen‐demanding (eutrophic) species increased in occurrence. Conclusions: Ombrotrophic bog vegetation in an oceanic region in Sweden became wetter and was resilient to short‐term climatic shifts, after three years of below normal precipitation followed by several years with normal precipitation levels. Shifts towards more nitrogen demanding species were rapid in this region where the deposition levels have been high for several decades.     

Impact of interleukin-6 on the glucose metabolic capacity in rat liver

The actute phase reaction mediated by the proinflammatory cytokine IL6 initiates a number of metabolic changes in the liver, which may contribute to the pathogenesis of the septic shock during prolonged exposition. Here, the impact of IL6 on the hepatic glucose providing capacity was studied by monitoring glycogen degradation and the expression of the gluconeogenic phosphoenolpyruvate carboxykinase (PCK1) in rat livers during the daily feeding rhythm. Eight hours after i.p. injection of IL6, mRNA levels of α2-macroglobulin, a prominent acute phase reactant in rat liver, were elevated as shown by Northern blot analysis and in situ hybridization (ISH). PCK1 mRNA levels were decreased by IL6 to 50% of levels in untreated animals due to the reduction of PCK1 mRNA in the periportal zone of the liver as shown by ISH. PCK1 enzyme activity was not affected by IL6. Glycogen degradation was accelerated by IL6, which led to nearly complete depletion of glycogen pools in periportal areas 8 h after IL6 injection. This was very likely due to inhibition of glycogen pool replenishment. Thus, the depletion of glycogen stores in the liver might contribute to the impairment of hepatic glucose production during prolonged acute phase challenge.     

Linked genetic variants on chromosome 10 control ear morphology and body mass among dog breeds

Background

The domestic dog is a rich resource for mapping the genetic components of phenotypic variation due to its unique population history involving strong artificial selection. Genome-wide association studies have revealed a number of chromosomal regions where genetic variation associates with morphological characters that typify dog breeds. A region on chromosome 10 is among those with the highest levels of genetic differentiation between dog breeds and is associated with body mass and ear morphology, a common motif of animal domestication. We characterised variation in this region to uncover haplotype structure and identify candidate functional variants.

Results

We first identified SNPs that strongly associate with body mass and ear type by comparing sequence variation in a 3 Mb region between 19 breeds with a variety of phenotypes. We next genotyped a subset of 123 candidate SNPs in 288 samples from 46 breeds to identify the variants most highly associated with phenotype and infer haplotype structure. A cluster of SNPs that associate strongly with the drop ear phenotype is located within a narrow interval downstream of the gene MSRB3, which is involved in human hearing. These SNPs are in strong genetic linkage with another set of variants that correlate with body mass within the gene HMGA2, which affects human height. In addition we find evidence that this region has been under selection during dog domestication, and identify a cluster of SNPs within MSRB3 that are highly differentiated between dogs and wolves.

Conclusions

We characterise genetically linked variants that potentially influence ear type and body mass in dog breeds, both key traits that have been modified by selective breeding that may also be important for domestication. The finding that variants on long haplotypes have effects on more than one trait suggests that genetic linkage can be an important determinant of the phenotypic response to selection in domestic animals.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1702-2) contains supplementary material, which is available to authorized users.     

Distance to semi-natural grassland influences seed production of insect-pollinated herbs

Marginal grassland fragments, such as road verges and field margins, may act as important supplemental habitats for grassland plants in the modern agricultural landscape. However, abundance of pollinators in such fragments has been found to decline with distance to larger natural and semi-natural habitats, and this could have corresponding effects on plant pollination. In this study, we performed a field experiment on road verges with three insect-pollinated grassland herbs to examine the relationship between distance to semi-natural grassland and plant reproductive success in two landscapes with contrasting farming intensities. In Lychnis viscaria and Lotus corniculatus, seed production tended to decrease with increasing distance to semi-natural grassland, but only in the landscape with high farming intensity. Seed production in Armeria maritima spp. maritima decreased with distance in both landscapes. Although many studies have investigated effects of natural habitat on crop pollination, little is known about the impact on pollination in native plants. The results from this study indicate that management of semi-natural grasslands improves not only biodiversity within the actual grassland but also pollination of native plants in the surrounding agricultural landscape.     

柽柳属和水柏枝属植物化学分类的研究

运用植物化学分类学的实验方法,即薄层层析和紫外吸收光谱对柽柳属（Ｔａｍａｒｉａｘ Ｌｉｎｎ）和水柏枝属（Ｍｙｉｃａｒｉａ Ｄｅｓｖ）的４种植物进行了分析测定,提出了柽柳属和水柏枝属的植物化学分类检索表,并对存有疑问的白花柽柳（Ｔ．ａｌｂｉｆｌｏｎｕｍ）进行了植物化学方面的分析鉴定。     

Effect of endurance flight on haematocrit in migrating birds

The effects of an endurance flight on the haematocrit, the percentage of packed red blood cells per blood volume, were examined within the framework of six possible factors explaining possible changes in the haematocrit. Two approaches were adopted: (1) the haematocrit was studied in four species of passerine birds which landed on an Italian island after having crossed the Mediterranean Sea on their spring migration in a non-stop flight; (2) the haematocrit was evaluated in six individual red knots after a flight of 1, 2, 4 and 10 h in a wind tunnel and the data thus obtained compared with data on resting birds with or without food. In the four passerine species, the haematocrit decreased from 51% in fat birds to 48% in lean birds. In lean birds, the haematocrit dropped from 48% in birds with well-developed breast muscles to 36% in birds with emaciated breast muscles. In the red knots, the haematocrit was dependent on body mass in flying and resting birds. The haematocrit decreased from about 51% pre-flight to about 49% within 1 h of flight and remained at this level for up to 10 h of flight. Taking the results from the passerines and the red knots together, it seems that the haematocrit drops by a few percentage points within 1 h after the onset of flight, decreases very slowly with decreasing body mass and decreases more steeply in very lean birds having entered stage III of fasting. This indicates that dehydration is not an underlying factor in decreased haematocrit because if this were the case we would expect an increase with endurance flight. We found no effect of the presence of blood parasites on haematocrit. With the onset of flight, haemodilution may be adaptive, because it reduces blood viscosity and, thereby, energy expenditure by the heart, or it may be a sign of water conservation as an insurance against the risk of dehydration during long non-stop flights. During endurance flight, a reduction in the haematocrit may be adaptive, in that oxygen delivery capacity is adjusted to the decreased oxygen needs as body mass decreases. A decreasing haematocrit would also allow birds to reduce heart beat frequency and/or heart size, because blood viscosity decreases disproportionally with decreasing haematocrit. However, when energy stores are about to come to an end and birds increase protein breakdown, the haematocrit decreases even further, and birds probably become anaemic due to a reduced erythropoiesis.