Mycorrhizal specificity does not limit the distribution of an endangered orchid species

What factors determine the distribution of a species is a central question in ecology and conservation biology. In general, the distribution of plant species is assumed to be controlled by dispersal or environmentally controlled recruitment. For plant species which are critically dependent on mycorrhizal symbionts for germination and seedling establishment, specificity in mycorrhizal associations and availability of suitable mycorrhizal fungi can be expected to have a major impact on successful colonization and establishment and thus ultimately on a species distribution. We combined seed germination experiments with soil analyses and fungal assessments using 454 amplicon pyrosequencing to test the relative importance of dispersal limitation, mycorrhizal availability and local growth conditions on the distribution of the orchid species Liparis loeselii, which, despite being widely distributed, is rare and endangered in Europe. We compared local soil conditions, seed germination and mycorrhizal availability in the soil between locations in northern Belgium and France where L. loeselii occurs naturally and locations where conditions appear suitable, but where adults of the species are absent. Our results indicated that mycorrhizal communities associating with L. loeselii varied among sites and plant life cycle stages, but the observed variations did not affect seed germination, which occurred regardless of current L. loeselii presence and was significantly affected by soil moisture content. These results indicate that L. loeselii is a mycorrhizal generalist capable of opportunistically associating with a variety of fungal partners to induce seed germination. They also indicate that availability of fungal associates is not necessarily the determining factor driving the distribution of mycorrhizal plant species.     

新疆克拉玛依侏罗纪古蝉类化石,兼论中国的古蝉科(同翅目:古蝉科)(英文)

描述了产自新疆克拉玛依吐孜沟下侏罗统八道湾组的古蝉科化石3新种,即plachutellaexculptasp．nov,Fletcherianajurassicasp．nov．和Pseudocossusstrenussp．nov。这是古蝉科在我国西北地区的首次发现。八十年代以来,古蝉科在我国华北和东北地区被陆续发现,但其中一些种类在分类上存在一些问题,笔者对此作了修正,并对有蝉科在我国的地质、地理分布作了回顾。     

Effects of variable discharge on the velocity use and shoaling behaviour of Phoxinus phoxinus

The swimming and shoaling behaviour of Phoxinus phoxinus was investigated in four identical channels connected to the River Frome, U.K. Minnows (mean length 29.5 mm) were stocked at an initial density of 100 fish per channel (22.2 fish m⁻²). The position of all visible fish in the channels was recorded at basal and elevated discharges, and use of velocity habitats inferred. Although a range of velocities (including zero) was present at both discharges, the fish selected higher mean velocities at elevated discharges than at basal discharges. Habitat suitability was significantly different between periods, emphasizing the effect of habitat availability and past experience upon habitat use. This appeared to result from the fish holding position at points with variable flow conditions, rather than moving to points with more suitable conditions. Shoal size tended to be reduced during and after elevated discharge, although variability between replicates was high. Small groups of fish tended to break off during the high flow events.     

横脊叶蝉亚科四新种：同翅目：叶蝉科

本文记述采自河南省伏牛铁横脊叶蝉４新种;双突横脊叶蝉Ｅｖａｃａｎｔｈｕｓ ｐｒｏｃｅｒｕｓ Ｃａｉ ｅｔ Ｓｈｅｎ．长突横脊叶蝉Ｅ．ｌｏｎｇｕｓ Ｃａｉ ｅｔ Ｓｈｅｎ,白斑横脊叶蝉Ｅ．ａｌｂｏｍａｃｕｌａｔｕｓ Ｃａｉ ｅｔ Ｓｈｅｎ和双斑角突叶蝉Ｔａｐｅｒｕｓ ｂｉｍａｃｕｌａｔｕｓ Ｃａｉ ｅｔ Ｓｈｅｎ,模式标本保存在安徽农业大学。     

Paternity assessment and population subdivision in a natural population of the larger mouse-eared bat Myotis myotis

A hypervariable simple sequence locus and mitochondrial D-loop sequences were used to analyse genetically a natural population of the larger mouse-eared bat Myotis myotis in southern Bavaria. Tests for population subdivision and direct observations suggest that females return to their natal sites, while males disperse. The males present in female nursery colonies are not related to the females. Paternity assessment for 46 offspring from a particular nursery colony showed that there are no males that monopolize the reproduction, and that the resident males in the colony had only a small mating success. Instead, the results suggest that females actively seek matings outside their colony. Most interestingly, it appears that a group of males about 16 km away from the nursery colony had a relatively high mating success and that this group of males may be related to the females of the nursery colonies. If this finding can be confirmed in a larger study, it may have important consequences for future conservation strategies.     

Diphenyleneiodonium induces ROS-independent p53 expression and apoptosis in human RPE cells

The diphenyleneiodonium (DPI) is widely used as an inhibitor of flavoenzymes, particularly NADPH oxidase. In this study, we investigated the effect of DPI on the apoptosis of human RPE cells. DPI treatment in ARPE-19 cells evoked a dose- and time-dependent growth inhibition, and also induced DNA fragmentation and protein content of the proapoptotic factor Bax. In addition, DPI significantly induced the expression and phosphorylation of p53, which induces proapoptotic genes in response to DNA damage or irreparable cell cycle arrest. ROS have been implicated as a key factor in the activation of p53 by many chemotherapeutic drugs. Recent data on the regulation of intracellular ROS by DPI are controversial. Therefore, we analyzed whether DPI could contribute to the generation of intracellular ROS. Although there was increase in ROS level from cells treated for 24h with DPI, it was not detectable at early time points, required to induce p53 expression. And DPI-induced p53 expression was not affected by the ROS scavenger NAC. We conclude that DPI induces the expression of p53 by ROS-independent mechanism in ARPE-19 cells, and renders cells sensitive to drug-induced apoptosis by induction of p53 expression.     

VIP in cerebrospinal fluid of patients with multiple sclerosis

The concentration of VIP was measured radioimmunochemically in cerebrospinal fluid (CSF) from 14 healthy volunteers and from 22 patients with multiple sclerosis. Significantly lower levels of VIP was obtained in the patients (18 +/- 3 pmol/l) than in controls (37 +/- 4 pmol/l). There was no correlation between the level of VIP in CSF and other CSF parameters such as albumin. IgG or cell content; nor between VIP concentration and the physical handicap or neuropsychiatric symptoms. There was a trend towards lower values of VIP in patients with steadily progressing rather than intermittent course of the disease but the difference between the groups was not significant.     

Global diversity and adaptations of avian eggshell thickness indices

The amniote eggshell is a fundamental aspect of the embryo life-support system, protecting it from UV light, microbes and mechanical damage, while regulating gas exchange and providing calcium for growth. The thickness of eggshells is highly diverse across modern birds and influences multiple eggshell functions, yet the selective pressures driving eggshell thickness have not been clearly identified. Here, we use a global dataset of avian eggshell thickness indices for 4260 (> 41%) avian species to assess trends in eggshell thickness across the phylogeny, as these indices are strongly correlated with direct measures of eggshell thickness and are non-destructive to the sample. We analysed the dataset within a phylogenetic framework to assess the relative importance of climatic and ecological explanations for variation in eggshell thickness indices. The distribution of avian eggshell thickness indices across species was found to be primarily driven by phylogenetic relatedness, in addition to evolutionary processes that do not match a Brownian model of evolution. Across modern birds, thicker eggshells were more prevalent in species (1) with precocial young, (2) which exhibit a scavenger-based diet, (3) which primarily feed on vertebrates or plants (excluding nectivores, seed and fruit specialists) and (4) which breed in open habitats. Thicker eggshells found in species with precocial young probably enable higher rates of calcium removal for the more advanced embryo development. Excessive light transmission through the shell damages developing embryos, while too little light transmission can impede development. Eggs in shaded habitats experience low light exposure, and thus thinner shells are more prevalent in these environments potentially to increase light transmission through the shell. Overall, variation in eggshell thickness indices appears to be driven largely by phylogeny, with certain life-history traits linked to embryo growth rate, calcium content of their food, and the need to mitigate excessive light transmission through the shell.     

The first baleen whale marine protected area proposed for Bryde's whales in the Beibu Gulf,China

The establishment of marine protected areas (MPAs) for cetaceans is an important strategy to mitigate human disturbance and protect biodiversity. Despite abundant cetacean species, there are only a few MPAs dedicated to cetacean conservation in China, all of which are for inshore dolphins. Bryde's whales, the only nearshore baleen whale population in mainland China, are conflicting with intensive human activities, yet an effective conservation strategy is lacking. This study used species distribution models to analyze distribution patterns and suitable habitats of Bryde's whales in the Beibu Gulf and proposes the first baleen whale MPA in China. Our results showed Bryde's whales have a seasonal distribution pattern in the Beibu Gulf, and that the waters around Weizhou Island and the southeastern coast of Vietnam were their core habitats. The seasonal nighttime light data indicated a negative relationship between the number of ship lights and Bryde's whale sightings and suggest that Bryde's whales might be threatened by fisheries. We proposed an MPA based on the results, suggesting that the waters within 20 km around Weizhou Island should be declared a protected area. Furthermore, we recommend that anthropogenic activities in the waters around Weizhou Island are better managed to reduce negative impacts on marine life.