A mutant strain of Chymomyza costata (Diptera: Drosophilidae) insensitive to diapause-inducing action of photoperiod

ABSTRACT. From a Japanese population of Chymomyza costata which has been known to have a photoperiodic larval diapause, we selected a mutant strain which did not respond to photoperiod. However, about 70% of the individuals of this strain entered diapause at 11^oC irrespective of photoperiod, and about the same percentage of those of the photoperiod-sensitive strain also did so in continuous illumination at 11^oC. This indicates that low temperature induces diapause independently of photoperiod. On the other hand, a temperature drop from 18 or 25^oC to 15^oC and chilling at 4^oC did not induce diapause.     

Investigation of the efficacy of paclitaxel on some miRNAs profiles in breast cancer stem cells

Understanding of the functions of microRNAs in breast cancer and breast cancer stem cells have been a hope for the development of new molecular targeted therapies. Here, it is aimed to investigate the differences in the expression levels of let-7a, miR-10b, miR-21, miR-125b, miR-145, miR-155, miR-200c, miR-221, miR-222 and miR-335, which associated with gene and proteins in MCF-7 (parental) and MCF-7s (Mammosphere/stem cell-enriched population/CD44+/CD24-cells) cells treated with paclitaxel. MCF-7s were obtained from parental MCF-7 cells. Cytotoxic activity of paclitaxel was determined by ATP assay. Total RNA isolation and cDNA conversion were performed from the samples. Changes in expression levels of miRNAs were examined by RT-qPCR. Identified target genes and proteins of miRNAs were analyzed with RT-qPCR and western blot analysis, respectively. miR-125b was significantly expressed (2.0946-fold; p = 0.021) in MCF-7s cells compared to control after treatment with paclitaxel. Downregulation of SMO, STAT3, NANOG, OCT4, SOX2, ERBB2 and ERBB3 and upregulation of TP53 genes were significant after 48 h treatment in MCF-7s cells. Protein expressions of SOX2, OCT4, SMAD4, SOX2 and OCT4 also decreased. Paclitaxel induces miR-125b expression in MCF-7s cells. Upregulation of miR-125b may be used as a biomarker for the prediction of response to paclitaxel treatment in breast cancer.     

Common anastomosis and internal transcribed spacer RFLP groupings in binucleate Rhizoctonia isolates representing root endophytes of Pinus sylvestris, Ceratorhiza spp. from orchid mycorrhizas and a phytopathogenic anastomosis group

Binucleate Rhizoctonia endophytes from the roots of nursery-grown Pinus sylvestris (Scots pine) seedlings and the orchid Goodyera repens from Scots pine forests were characterized on the basis of morphological characters, anastomosis group membership and PCR-assisted ribosomal DNA fingerprinting. Common hyphal and colony morphological traits displayed by the Finnish binucleate Rhizoctonia isolates and a range of Canadian orchid root endophytes enabled them to be placed in the anamorphic genus Ceratorhiza . Five main anastomosis groups were identified and included groups that contained different combinations of Scots pine, G. repens and Canadian Ceratorhiza spp. isolates. Two Scots pine root endophytes anastomosed with a phytopathogenic Japanese tester isolate, confirming their membership of anastomosis group I, which is known to include the teleomorphic species Ceratobasidium cornigerum . Hierarchical cluster analysis of RFLPs in the internal transcribed spacer of ribosomal DNA enabled the division of isolates into one of five RFLP groups. The RFLP and anastomosis groupings were closely correlated; isolates within each of four RFLP groups, which shared 100% RFLP identity, anastomosed in the cross-pairing anastomosis group tests. However, all represented different vegetatively compatible populations (clones) because the diagnostic killing reaction, a cellular vegetative incompatibility response, was identified at hyphal fusion junctions. These findings indicate a high degree of intraspecific variation within Ceratobasidium cornigerum , which includes isolates able to enter into either mutualistic or pathogenic root association with susceptible host plants. The common anastomosis group/RFLP groupings identified also strongly support the hypothesis that conifer tree roots can act as large inoculum reservoirs for these orchid endophytes, allowing the development of inter-plant connections, via commonly shared hyphal linkages, in boreal forest ecosystems.     

Modulation of respiratory metabolism in response to nutrient changes along a soil chronosequence

Laboratory studies indicate that plant respiratory efficiency may decrease in response to low nutrient availability due to increased partitioning of electrons to the energy‐wasteful alternative oxidase (AOX); however, field confirmation of this hypothesis is lacking. We therefore investigated plant respiratory changes associated with succession and retrogression in soils aged from 10 to 120 000 years along the Franz Josef soil chronosequence, New Zealand. Respiration rates and electron partitioning were determined based on oxygen isotopic fractionation. Leaf structural traits, foliar nutrient status, carbohydrates and species composition were measured as explanatory variables. Although soil nutrient levels and species composition varied by site along the chronosequence, foliar respiration across all sites and species corresponded strongly with leaf nitrogen concentration (r² = 0.8). In contrast, electron partitioning declined with increasing nitrogen/phosphorus (r² = 0.23) and AOX activity correlated with phosphorus (r² = 0.64). Independently, total respiration was further associated with foliar Cu, possibly linked to its effect on AOX. Independent control of AOX and cytochrome pathway activities is also discussed. These responses of plant terminal respiratory oxidases – and therefore respiratory carbon efficiency – to multiple nutrient deficiencies demonstrate that modulation of respiratory metabolism may play an important role in plant responses to nutrient gradients.     

‘Random‐flight’ dispersal in tropical fruit‐feeding butterflies? High mobility,long lifespans and no home ranges

1. Tropical fruit‐feeding Nymphalidae butterflies are widely used in research, monitoring, and conservation projects, but to date a key aspect of their behaviour – dispersal – remains poorly understood. They have anecdotally been described as ‘relatively sedentary’ based on movement vectors from mark‐recapture studies, but this may be inaccurate because plot‐based studies in small sampling areas often underrepresent long‐distance movements. 2. Based on data from a peat‐swamp forest in Borneo, it was found that these butterflies may be much more mobile than previously thought, as they frequently moved distances of 1–2 km between sampling plots. Median daily movements were approximately 200–250 m, and over lifespans of one or more months these movements may sum to total life‐time dispersals of several kilometres. 3. Recapture rates for long‐distance movements between sampling plots were between 28.2% and 41.6% of the re‐encounter rates that would be predicted by a random‐walk approximation/Brownian motion (without accounting for survival rates), supporting the hypothesis that it is a suitable model of dispersal in this group, although further research is needed to confirm this. 4. There was no evidence that butterflies occupied permanent home ranges, and it is suggested that a permanent home range or territorial behaviour would be maladaptive in this group. Pseudo‐replication caused by ‘trap‐happy’ behaviour was not found to be widespread, and some recommendations are provided regarding the treatment of recapture data in trap‐based studies. 5. These findings substantially increase the spatial parameters for future research and conservation projects in this group and are also applicable to theoretical modelling studies. An abstract for this article in Bahasa Indonesia is included in the online supporting information File S1.     

Re‐building brown trout populations in dredged boreal forest streams: in‐stream restoration combined with stocking of young trout

1. Rivers in boreal forested areas were often dredged to facilitate the transport of timber resulting in channels with simplified bed structure and flow fields and reduced habitat suitability for stream organisms, especially lotic fishes. Currently, many streams are being restored to improve their physical habitat, by replacing boulders and gravel and removing constraining embankments. The most compelling justification behind stream restoration of former floatways has been the enhancement of native fish populations, specifically salmonids. 2. We examined the success of a stream management programme aimed at re‐building diminished brown trout (Salmo trutta) populations by monitoring densities of young‐of‐year and older trout in 18 managed and three reference streams during 2000–2005. Rehabilitation included in‐stream restoration combined with a 5‐year post‐restoration period of stocking young brown trout. Our space‐for‐time substitution design comprised four pre‐management, four under‐management, 10 post‐management and three reference streams. 3. Densities of young‐of‐year brown trout, indicating population establishment, were significantly higher in post‐ compared with pre‐management streams. However, density of young‐of‐year brown trout in post‐management streams was significantly lower compared with near‐pristine reference streams. Furthermore, success of managed brown trout population re‐building varied, indicating stream‐specific responses to management measures. Density of burbot (Lota lota), a native generalist predator, was associated with low recruitment of brown trout. 4. Stream‐specific responses imply that rehabilitation of brown trout populations cannot be precisely predicted thereby limiting application. Our findings support the importance of adaptive stream restoration and management, with focus on identifying factor(s) limiting the establishment of target fish populations.     

DIVERSITY, TAPHONOMY and PALAEOECOLOGY OF AN ANGIOSPERM FLORA FROM THE CRETACEOUS (CENOMANIAN–CONIACIAN) IN SOUTHERN PATAGONIA, ARGENTINA

Abstract:  This paper describes the diversity, taphonomy and palaeoecology of angiosperm leaves that dominate a palaeoflora of Cretaceous (Cenomanian–Coniacian) age from the Mata Amarilla Formation in the Austral Basin, south-west Patagonia, Argentina. Twelve morphotypes of angiosperm leaves are recognized based on foliar morphotype analysis of more than 500 specimens. These were divided into six morphological groups based on major architectural patterns. The relative dominance of these morphotypes, mode of preservation and relationship with sedimentary facies were evaluated from two levels within the formation. This analysis identified two different plant palaeocommunities. The lower, María Elena, level (MEL) was deposited in a marine coastal area on a subaerial delta plain; the dominant angiosperm morphotypes preserved in it are group 1 (MA100) and group 2 (MA101, 102); morphotypes MA109 and 110 are scarce but exclusive to this level. The upper, Mata Amarilla, level (MAL), accumulated inland in flood-plain environments; the most abundant angiosperm morphotypes are groups 3 (MA103–105), 4 (MA106) and 1 (MA100); morphotypes MA103–105 and 108 are exclusive to this level. Comparisons with other floras of similar age from Antarctica, Australia and New Zealand indicate that the Mata Amarilla flora has a slightly higher morphological diversity of angiosperm leaves, providing the first evidence for an angiosperm-dominated early Late Cretaceous macroflora in south-west Gondwana.