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1.
ROBIN M. OVERSTREET WILLIAM E. HAWKINS JOHN W. FOURNIE 《The Journal of eukaryotic microbiology》1984,31(2):332-339
Calyptospora n. g. was erected for Eimeria funduli because the sporocyst of that species lacks Stieda and sub-Stieda bodies, has a veil supported by sporopodia, and has an anterior apical opening. A suture may be present, but it does not completely divide the sporocyst into two valves. Because C. funduli has an obligatory invertebrate intermediate host, we established Calyptosporidae n. fam. to accommodate Calyptospora and tentatively to accept Goussia. A new subgenus, Plagula, is erected for species of Goussia with a sporocystic veil not supported by sporopodia. We consider the family more primitive than Eimeriidae, Sarcocystidae, and possibly Lankesterellidae. 相似文献
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Julia C Jones Carmelo Fruciano Falk Hildebrand Hasan Al Toufalilia Nicholas J Balfour Peer Bork Philipp Engel Francis LW Ratnieks William OH Hughes 《Ecology and evolution》2018,8(1):441-451
There is growing recognition that the gut microbial community regulates a wide variety of important functions in its animal hosts, including host health. However, the complex interactions between gut microbes and environment are still unclear. Honey bees are ecologically and economically important pollinators that host a core gut microbial community that is thought to be constant across populations. Here, we examined whether the composition of the gut microbial community of honey bees is affected by the environmental landscape the bees are exposed to. We placed honey bee colonies reared under identical conditions in two main landscape types for 6 weeks: either oilseed rape farmland or agricultural farmland distant to fields of flowering oilseed rape. The gut bacterial communities of adult bees from the colonies were then characterized and compared based on amplicon sequencing of the 16S rRNA gene. While previous studies have delineated a characteristic core set of bacteria inhabiting the honey bee gut, our results suggest that the broad environment that bees are exposed to has some influence on the relative abundance of some members of that microbial community. This includes known dominant taxa thought to have functions in nutrition and health. Our results provide evidence for an influence of landscape exposure on honey bee microbial community and highlight the potential effect of exposure to different environmental parameters, such as forage type and neonicotinoid pesticides, on key honey bee gut bacteria. This work emphasizes the complexity of the relationship between the host, its gut bacteria, and the environment and identifies target microbial taxa for functional analyses. 相似文献
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BENJAMIN POULTER FRED HATTERMANN ED HAWKINS SÖNKE ZAEHLE STEPHEN SITCH NATALIA RESTREPO‐COUPE URSULA HEYDER WOLFGANG CRAMER 《Global Change Biology》2010,16(9):2476-2495
Climate change science is increasingly concerned with methods for managing and integrating sources of uncertainty from emission storylines, climate model projections, and ecosystem model parameterizations. In tropical ecosystems, regional climate projections and modeled ecosystem responses vary greatly, leading to a significant source of uncertainty in global biogeochemical accounting and possible future climate feedbacks. Here, we combine an ensemble of IPCC‐AR4 climate change projections for the Amazon Basin (eight general circulation models) with alternative ecosystem parameter sets for the dynamic global vegetation model, LPJmL. We evaluate LPJmL simulations of carbon stocks and fluxes against flux tower and aboveground biomass datasets for individual sites and the entire basin. Variability in LPJmL model sensitivity to future climate change is primarily related to light and water limitations through biochemical and water‐balance‐related parameters. Temperature‐dependent parameters related to plant respiration and photosynthesis appear to be less important than vegetation dynamics (and their parameters) for determining the magnitude of ecosystem response to climate change. Variance partitioning approaches reveal that relationships between uncertainty from ecosystem dynamics and climate projections are dependent on geographic location and the targeted ecosystem process. Parameter uncertainty from the LPJmL model does not affect the trajectory of ecosystem response for a given climate change scenario and the primary source of uncertainty for Amazon ‘dieback’ results from the uncertainty among climate projections. Our approach for describing uncertainty is applicable for informing and prioritizing policy options related to mitigation and adaptation where long‐term investments are required. 相似文献
4.
LAURA I. WEBER STEPHEN J. HAWKINS 《Biological journal of the Linnean Society. Linnean Society of London》2002,77(3):341-353
The genetic and morphological structure of Patella candei in the Macaronesian Islands were studied by allozyme electrophoresis and multivariate analysis (canonical discriminant analysis), respectively. Sixteen enzymes, yielding 21 resolvable loci were analysed for all populations using the BIOSYS-1 program. A disjunct distribution of genetically similar populations from the Azores and Selvagens Islands ( P.c. gomesii – P.c. candei ) was found, which showed two diagnostic loci with P.c. ordinaria from Madeira. Patella c. crenata from the Canaries showed an intermediate composition of 92% P.c. ordinaria and 8% P.c. gomesii–P.c. candei . Hypotheses are presented to explain the evolution of the genetic and morphological structure of P.c. candei in the Macaronesian Islands, including the interaction of natural processes and human intervention. Patella c. candei is considered to represent the ancestral form. An extinction or near extinction event may have happened in Madeira after which P.c. ordinaria arose, carrying only a small part of the diversity of the original form, which evolved in isolation. The ancestral form, P.c. candei , was depleted by human extraction from high levels of the shore in the Azores and Canaries. Patella c. gomesii , from the Azores evolved by phyletic evolution, colonizing low levels of the shore, leaving only a relict population in the Selvagens Islands, that remained almost free of human exploitation. Patella c. crenata is a hybrid with a high degree of introgression to P.c. ordinaria , which is maintained by the forces of human extraction at high-tide levels and by intraspecific competition at low-tide levels. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 77 , 341−353. 相似文献
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The ultrastructure of the pallial tentacles of seven speciesof patellid limpet is described. The tip of most of the tentaclesexamined bears a crown of long cilia, whereas the shaft of thetentacles has small tufts (510 µm diameter) ofshorter cilia. Sections through the ciliated tufts show themto be composed of several cells, each bearing cilia. The ciliacontain 57 central microtubules and therefore do nothave the conventional 9 + 2 arrangement of microtubules. Nerveprocesses run from the base of each ciliated cell to a nervebundle in the centre of the tentacle, suggesting a sensory function.Estimates of densities of ciliated tufts suggest that the territoriallimpets (Patella cochlear and P. longicosta) have the greaternumber of tufts. Electron dense plate-like structures are foundin the centre of the pallial tentacles of Patella cochlear,P. longicosta, P. granularis, P. barbara and Helcion pruinosus.Each plate is about 0.2 µm wide and is surrounded by adouble membrane. It is suggested that these may play a rolein scattering or reflecting light and thus form part of thedermal light sensing ability of these animals. (Received 26 January 1987; 相似文献