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41.
JF Masello RG Choconi M Helmer T Kremberg T Lubjuhn P Quillfeldt 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2009,152(2):176-181
The different leucocyte types are an important part of the immune system. Thus, they have been used in ecological studies to assess immune function and physiological stress in wild birds. It is generally assumed that increased stress and decreased condition are associated with an increase in the ratio of heterophils to lymphocytes, the H/L ratio. We studied leucocyte profiles in relation to body condition in nestling Burrowing Parrots (Cyanoliseus patagonus) in North-eastern Patagonia, Argentina. As in other wild parrots, heterophils were the most numerous leucocyte type, suggesting strong investment into innate immunity. Leucocyte profiles did not change with the age, while nestlings in better body condition increased the number of heterophils. Because the number of lymphocytes was independent of body condition, as a result we observed a positive correlation between body condition and the H/L ratio. The total number of leucocytes relative to erythrocytes increased in nestlings in better body condition, indicating a larger overall investment into immune function in well-nourished nestlings. The observed heterophilic profiles of nestling Burrowing Parrots together with the positive relationship between H/L ratio and body condition may indicate a favoured investment in a robust innate immunity that reduces the risk of infection taking hold in these long-lived birds. 相似文献
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SILVIO ERLER HANS‐JÖRG FERENZ ROBIN F. A. MORITZ HANS‐HINRICH KAATZ 《Biological journal of the Linnean Society. Linnean Society of London》2010,99(2):296-305
In the present study, we present the full sequence of the mitochondrial genome of the African desert locust Schistocerca gregaria gregaria. The size of 15625 bp reported matches very well with mitochondrial genomes of other Orthopteriodea. The mitochondrial genome comprises 13 protein‐coding genes, two ribosomal RNAs and 22 t‐RNAs with two t‐RNA (trnD and trnK) rearrangements that are typical for the taxon Caelifera. We compared the sequence with 12 mitochondrial genes of Schistocerca gregaria flaviventris and Schistocerca americana and used some of these data to construct phylogenetic trees, which confirm the close relationship between the two subspecies S. g. flaviventris and S. g. gregaria. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 296–305. 相似文献
44.
Functional groups (FG) are an useful generalization to investigate environmental change effects on biotic communities. Assigning species to FGs is a contextual task and carries an arbitrary element, regardless of whether the grouping is obtained a priori or by sophisticated numerical methods. Using two grassland community case studies, we show that even simple FG allocation based on growth form, architecture and longevity (plants and mosses), or foraging characteristics (above-ground invertebrates) can be useful to increase our understanding of community processes. For example, the sensitivity of organisms to climate change increases with trophic rank and is higher in disturbed than in undisturbed communities. Complexity of interaction webs (in terms of web connectance), however, is larger in undisturbed than in disturbed communities. A significant and important relationship is likely to exist between anthropogenic disturbances, community complexity and the ecosystem effects of climate change. Trophic interactions may be disrupted much easier by climate changes in disturbed than in undisturbed communities where complexity may be buffering these effects. 相似文献
45.
SUSANNE FEIST-BURKHARDT JÖRG PROSS 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2010,43(1):10-31
Feist‐Burkhardt, S. & Pross, J. 2010: Dinoflagellate cyst biostratigraphy of the Opalinuston Formation (Middle Jurassic) in the Aalenian type area in southwest Germany and north Switzerland. Lethaia, Vol. 43, pp. 10–31. In order to provide a detailed dinoflagellate cyst stratigraphy of the Lower Aalenian Opalinuston Formation from the Aalenian type area, 68 samples from four boreholes and one outcrop section were analysed. The sample localities are Hausen an der Fils and Wittnau in southwest Germany, Weiach in north Switzerland and Mont Russelin in the Swiss Jura Mountains. Dinoflagellate cyst assemblages were recovered from the Late Toarcian Aalensis Zone to the Late Aalenian Murchisonae Zone. The samples yielded rich, well‐preserved and diverse assemblages with 51 dinoflagellate cyst taxa identified in total. The dinoflagellate cyst distribution data obtained from this study allow a high‐resolution biostratigraphical subdivision of the lowermost Middle Jurassic Opalinuston Formation into four palynostratigraphical units. First and last occurrences, acmes and consistent presence of the species Batiacasphaera sp. A, Evansia cf. granochagrinata, Kallosphaeridium praussii, Nannoceratopsis triangulata, Phallocysta? frommernensis and Wallodinium laganum were selected as the criteria for defining these units. The obtained high‐resolution palynostratigraphical scheme provides a basis for establishing and further refining early Middle Jurassic biostratigraphy in the Boreal and Tethyan realms. □Aalenian, biostratigraphy, dinoflagellate cysts, Germany, Jurassic, Switzerland, Toarcian. 相似文献
46.
ADAM H. PORTER HANSJÜRG GEIGER 《Biological journal of the Linnean Society. Linnean Society of London》1995,54(4):329-348
We used hierarchical and pairwise F-statistics to describe genetic differentiation and infer gene flow (M) on local and regional scales within and among parapatric European butterfly taxa in the Pieris napi (L.) group. Within-population allozyme variability is consistently high, and local effective population sizes are inferred to be in the thousands of individuals. The pairwise analysis yields an average neighbourhood area of radius 3.5 km. Among populations within most regions, differentiation is low and M > 2 effective individuals population-1generation-1. Pairwise comparisons within the brilannica group show a disjunction indicating that it is out of equilibrium, perhaps as a result of secondary contact between highland and lowland groups. Comparison between meridionalis groups on mainland Italy and Corsica yields M > 12; this is surely loo high and lack of equilibrium resulting from initial colonization is suspected. The hierarchical analysis indicates that 23 ≤0020M≤ 88 among the taxa napi, bryoniae and meridionalis that meet in hybrid zones; no effective gene flow barrier exists among them. This high estimate could also result from recent primary contact, but such a genetic barrier should produce the ‘edge effects' seen in population genetic simulations, and no evidence of this was found among geographically close samples of napi and bryoniae populations from Switzerland. Studies of gene flow among geographic regions are greatly limited by the equilibrium assumption, though studies of local differentiation are much less so. Population studies of gene flow on local scales at regional boundaries provide limited means of testing the equilibrium assumption, and both regional and local analyses provide testable predictions about local population structure. When the equilibrium assumption is not upheld, local patterns at regional boundaries can provide historical information about primary vs. secondary contact. 相似文献
47.
KLARA BJÖRG JAKOBSDÓTTIR þÓRA DÖGG JÖRUNDSDÓTTIR SIGURLAUG SKÍRNISDÓTTIR SIGRÍÐUR HJÖRLEIFSDÓTTIR GUÐMUNDUR Ó. HREGGVIÐSSON ANNA KRISTÍN DANÍELSDÓTTIR CHRISTOPHE PAMPOULIE 《Molecular ecology resources》2006,6(2):337-339
Nine out of 22 microsatellite primers tested were successfully amplified on three samples of cod Gadus morhua L. (two contemporary and one archived otolith samples). All loci were polymorphic (5–23 alleles/locus). The average observed heterozygosity across loci and samples was 0.625, ranging from 0.294 to 0.895 at each locus. All loci were under Hardy–Weinberg equilibrium, except PGmo56 that showed significant excess of heterozygotes in all studied samples. The isolated loci were suitable for degraded DNA and therefore useful for conducting a long‐term temporal study with DNA obtained from archived otoliths of cod. 相似文献
48.
Cellular and subcellular distribution of PBP72/74, a peptide-binding protein that plays a role in antigen processing 总被引:10,自引:0,他引:10
A M VanBuskirk D C DeNagel L E Guagliardi F M Brodsky S K Pierce 《Journal of immunology (Baltimore, Md. : 1950)》1991,146(2):500-506
A 72/74-kDa peptide binding protein (PBP72/74) was previously described which plays a role in the processing and/or presentation of Ag, possibly by facilitating the association of processed Ag with the MHC class II molecules. PBP72/74 was recently shown to be related to the 70-kDa family of heat shock proteins (hsp70), whose members show the general characteristic of binding to denatured or inappropriately folded proteins. Here we describe the cellular and subcellular distribution of PBP72/74. By flow cytometry with PBP72/74-specific rabbit antisera, PBP72/74 is detected on the surfaces of mouse Ig+ B cells and MAC-1+ macrophages. PBP72/74 74 was not detected on the surfaces of Thy-1+ T cells or NK1.1+ NK cells. The cell surface expression of PBP72/74 does not require MHC class II expression. Indeed, the Ia- variant B cell lymphoma cell line, M12.C3, expresses PBP72/74 at levels equivalent to that of the Ia+ parent cell line, M12.4.1, from which it was derived. Furthermore, the fibroblast L cell line, DAP.3, shows no cell surface expression of PBP72/74, nor do DAP.3 lines transfected with and expressing genes encoding the alpha- and beta-chain of the I-Ad and I-Ed molecules. Moreover, treatment of B cells with either IL-4 or LPS, which increases Ia expression severalfold, does not affect PBP72/74 expression. Thus, PBP72/74 cell surface expression appears to be a property of B cells and macrophages, independent of Ia expression. In addition, the B cell surface expression of PBP72/74 is not altered by stress in the form of heat shock. Thus, PBP72/74 appears to be a constitutive noninducible member of the hsp70 family. By immunoelectron microscopy, PBP72/74 is detected in approximately 36% of early endocytic vesicles into which surface Ig is internalized after binding to anti-Ig antibodies. This compartment was previously shown to contain class II en route to the cell surface associated with invariant chain and the proteases cathepsin B and D and is suggested to be a subcellular site of antigen processing. PBP72/74 is also found associated with the plasma membrane, endoplasmic reticulum, and membranes proximal to the Golgi stacks. The cellular and subcellular distribution of PBP72/74 is consistent with its playing a role in the processing of presentation of Ag with the MHC class II molecules. 相似文献
49.
Immunofluorescence studies of neurofilaments in the rat and human peripheral and central nervous system
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Localization of antisera to neurofilament antigens derived from rat peripheral nerve was carried out in tissues of rat and human peripheral and central nervous systems by indirect immunofluorescence. Unfixed and chloroform-methanol-fixed frozen sections of tissues were incubated in purified IgG of the experimental rabbit antisera and subsequently exposed to goat anti-rabbit IgG conjugated with fluorescein isothiocyanate. Control studies were conducted on identical tissue preparations incubated in the same concentrations of nonspecific rabbit IgG or in experimental rabbit IgG absorbed with extracts of rat peripheral nerve containing neurofilament antigen. Extensive immunofluorescence was observed in rat and human peripheral and central nervous systems. The distribution and configuration of immunofluorescence corresponded to neurofilament-rich structural components of these tissues. Prominent immunofluorescence was also noted in neuronal cell bodies of spinal sensory ganglia, especially in perikarya of the large neuronal type. Immunofluorescence of the central nervous system was located predominantly in myelinated axons of the white matter in cerebrum, cerebellum, brain stem, and spinal cord. Less intense immunofluorescence was also seen in neuronal perikarya and in short thin linear processes of grey matter. 相似文献
50.
A deficiency of vitamin B6 is a plausible molecular basis of the retinopathy of patients with diabetes mellitus 总被引:1,自引:0,他引:1
J M Ellis K Folkers M Minadeo R VanBuskirk L J Xia H Tamagawa 《Biochemical and biophysical research communications》1991,179(1):615-619
Eighteen patients with diabetes mellitus, some of whom had variously retinopathy, pregnancy, and the carpal tunnel syndrome, and were variously treated with steroids and vitamin B6, have been overviewed for periods of 8 months to 28 years. We have established an association of a deficiency of vitamin B6 with diabetes by monitoring the specific activity of the erythrocyte glutamic oxaloacetic transaminase and again by the association with the carpal tunnel syndrome (C.T.S.). It has been known for a decade that C.T.S. is caused by a B6 deficiency. The absence of retinopathy in vitamin B6-treated diabetic patients over periods of 8 months - 28 years appears monumental. These observations are like discovery and constitute a basis for a new protocol to establish the apparent relationship of a deficiency of vitamin B6 as a molecular cause of diabetic neuropathy. Blindness and vision are so important that the strength or weakness of the observations are not important; the conduct of a new protocol is important. 相似文献