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991.
The penicillate genus Unixenus Jones, 1944 is widespread, with species found in Africa, Madagascar, India and Australia. Each of the two Australian species was originally described from single samples from Western Australia. In this study, collections of Penicillata from museums in all states of Australia were examined to provide further details of the two described species, to revise the diagnoses for both the genus and the species, and to better understand the distribution of the two species in Australia. In addition, two new species Unixenus karajinensissp. n. and Unixenus corticolussp. n. are described. 相似文献
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994.
The major histocompatibility complex (MHC) is a critical component of the adaptive immune response in vertebrates. Due to the role that MHC plays in immunity, absence of variation within these genes may cause species to be vulnerable to emerging diseases. The freshwater fish family Cyprinidae comprises the most diverse and species-rich group of freshwater fish in the world, but some are imperiled. Despite considerable species richness and the long evolutionary history of the family, there are very few reports of MHC sequences (apart from a few model species), and no sequences are reported from endemic North American cyprinids (subfamily Leuciscinae). Here we isolate and characterize the MH Class II beta genes from complementary DNA and genomic DNA of the non-model, endangered Rio Grande silvery minnow (Hybognathus amarus), a North American cyprinid. Phylogenetic reconstruction revealed two groups of divergent MH alleles that are paralogous to previously described loci found in deeply divergent cyprinid taxa including common carp, zebrafish, African large barb and bream. Both groups of alleles were under the influence of diversifying selection yet not all individuals had alleles belonging to both allelic groups. We concluded that the general organization and pattern of variation of MH class II genes in Rio Grande silvery minnow is similar to that identified in other cyprinid fishes studied to date, despite distant evolutionary relationships and evidence of a severe genetic bottleneck. 相似文献
995.
McMurray MA Stefan CJ Wemmer M Odorizzi G Emr SD Thorner J 《Biological chemistry》2011,392(8-9):699-712
Membrane trafficking via targeted exocytosis to the Saccharomyces cerevisiae bud neck provides new membrane and membrane-associated factors that are critical for cytokinesis. It remains unknown whether yeast plasma membrane abscission, the final step of cytokinesis, occurs spontaneously following extensive vesicle fusion, as in plant cells, or requires dedicated membrane fission machinery, as in cultured mammalian cells. Components of the endosomal sorting complexes required for transport (ESCRT) pathway, or close relatives thereof, appear to participate in cytokinetic abscission in various cell types, but roles in cell division had not been documented in budding yeast, where ESCRTs were first characterized. By contrast, the septin family of filament-forming cytoskeletal proteins were first identified by their requirement for yeast cell division. We show here that mutations in ESCRT-encoding genes exacerbate the cytokinesis defects of cla4Δ or elm1Δ mutants, in which septin assembly is perturbed at an early stage in cell division, and alleviate phenotypes of cells carrying temperature-sensitive alleles of a septin-encoding gene, CDC10. Elevated chitin synthase II (Chs2) levels coupled with aberrant morphogenesis and chitin deposition in elm1Δ cells carrying ESCRT mutations suggest that ESCRTs normally enhance the efficiency of cell division by promoting timely endocytic turnover of key cytokinetic enzymes. 相似文献
996.
Megan Hardin Edwin K Silverman R Graham Barr Nadia N Hansel Joyce D Schroeder Barry J Make James D Crapo Craig P Hersh 《Respiratory research》2011,12(1):127
Background
The coexistence of COPD and asthma is widely recognized but has not been well described. This study characterizes clinical features, spirometry, and chest CT scans of smoking subjects with both COPD and asthma.Methods
We performed a cross-sectional study comparing subjects with COPD and asthma to subjects with COPD alone in the COPDGene Study.Results
119 (13%) of 915 subjects with COPD reported a history of physician-diagnosed asthma. These subjects were younger (61.3 vs 64.7 years old, p = 0.0001) with lower lifetime smoking intensity (43.7 vs 55.1 pack years, p = 0.0001). More African-Americans reported a history of asthma (33.6% vs 15.6%, p < 0.0001). Subjects with COPD and asthma demonstrated worse disease-related quality of life, were more likely to have had a severe COPD exacerbation in the past year, and were more likely to experience frequent exacerbations (OR 3.55 [2.19, 5.75], p < 0.0001). Subjects with COPD and asthma demonstrated greater gas-trapping on chest CT. There were no differences in spirometry or CT measurements of emphysema or airway wall thickness.Conclusion
Subjects with COPD and asthma represent a relevant clinical population, with worse health-related quality of life. They experience more frequent and severe respiratory exacerbations despite younger age and reduced lifetime smoking history.Trial registration
ClinicalTrials.gov: NCT00608764相似文献997.
Archetti M Scheuring I Hoffman M Frederickson ME Pierce NE Yu DW 《Ecology letters》2011,14(12):1300-1312
We review recent work at the interface of economic game theory and evolutionary biology that provides new insights into the evolution of partner choice, host sanctions, partner fidelity feedback and public goods. (1) The theory of games with asymmetrical information shows that the right incentives allow hosts to screen-out parasites and screen-in mutualists, explaining successful partner choice in the absence of signalling. Applications range from ant-plants to microbiomes. (2) Contract theory distinguishes two longstanding but weakly differentiated explanations of host response to defectors: host sanctions and partner fidelity feedback. Host traits that selectively punish misbehaving symbionts are parsimoniously interpreted as pre-adaptations. Yucca-moth and legume-rhizobia mutualisms are argued to be examples of partner fidelity feedback. (3) The theory of public goods shows that cooperation in multi-player interactions can evolve in the absence of assortment, in one-shot social dilemmas among non-kin. Applications include alarm calls in vertebrates and exoenzymes in microbes. 相似文献
998.
Bárbara?Serra-Pereira Fernando?Afonso Inês?Farias Pedro?Joyce Megan?Ellis Ivone?Figueiredo Leonel?Serrano?Gordo 《Helgoland Marine Research》2011,65(3):399-411
The reproductive processes of chondrichthyans are complex. Knowledge of the development and maturation of the oviducal gland
is vital for understanding the reproductive biology of a species. This study represents the first contribution of this subject
for skates. In the oviparous thornback ray, Raja clavata, oviducal gland development begins early in the developing stage with the formation of gland tubules and the distinct lamellae
of each zone: club, papillary, baffle and terminal. Oviducal development is complete by the end of the developing stage when
the storage and secretion of products is evident within the gland tubules of each zone. Periodic acid-Schiff and alcian blue
histological staining showed that the secretory mucous cells of the club and papillary zones produce neutral and sulfated
acid mucins. The last row of gland tubules of the papillary zone stains intensely for sulfated acid mucins. The baffle zone,
which is responsible for the production of the egg capsule, represented 60–80% of the glandular zone of the oviducal gland.
Sperm bundles were observed in the deeper recesses of the baffle zone during the maturation process, and during capsule extrusion,
sperm were detected near the lumen. The terminal zone was composed of two types of gland tubules: serous (producing protein
fibres) and mucous glands (producing sulfated acid mucins). 相似文献
999.
Zhang X de Chickera SN Willert C Economopoulos V Noad J Rohani R Wang AY Levings MK Scheid E Foley R Foster PJ Dekaban GA 《Cytotherapy》2011,13(10):1234-1248
BACKGROUND AIMS. The use of dendritic cells (DC) as an adjuvant in cell-based immunotherapeutic cancer vaccines is a growing field of interest. A reliable and non-invasive method to track the fate of autologous DC following their administration to patients is required in order to confirm that clinically sufficient numbers are reaching the lymph node (LN). We demonstrate that an immunocompromised mouse model can be used to conduct translational studies employing cellular magnetic resonance imaging (MRI). Such studies can provide clinically relevant information regarding the migration potential of clinical-grade DC used in cancer immunotherapies. METHODS. Human monocyte-derived dendritic cells (mo-DC) were generated from negatively selected monocytes obtained from either healthy donors or cancer patients. DC were labeled with superparamagnetic iron oxide (SPIO) nanoparticles in order to track them in vivo in a CB17scid mouse model using cellular MRI. SPIO did not have any adverse effects on DC phenotype or function, independent of donor type. Cellular MRI readily detected migration of SPIO-loaded DC in CB17scid mice. No differences in migration were observed between DC obtained from healthy donors and those obtained from donors undergoing autologous stem cell transplant for cancer therapy. CONCLUSIONS. Cellular MRI provided semi-quantitative image data that corresponded with data obtained by digital morphometry, validating cellular MRI's potential to assess DC migration in DC-based cancer immunotherapy clinical trials. 相似文献
1000.
Franke MF Robins JM Mugabo J Kaigamba F Cain LE Fleming JG Murray MB 《PLoS medicine》2011,8(5):e1001029