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51.
Data on investigation of hand sceletal bones carried out in eight genera of three families of bats were subjected to comparative-anatomical and functional analysis. Quantitatively, the hand sceletal bones of Chiroptera preserve constructive pattern general for the hand of terrestrial mammalians Pentadactilus. It has rudiments of the prefirst (Pp) and the seventh (Pm) rays. The latter is situated on the volar surface of the base Mc5. Scaphoid, semilunar and central carnal bones of Chiroptera, like those of Mototremata, some Marsupialia, Insectivorona and Carnivora merge together into one large bone--os lunatum. At the same time, the hand of Chiropter is a highly specialized structure, that is evident from the presence of articular restricotrs of anterior sagging of the wrist, crests and grooves directing movements in a strictly definite plane, from fan-like spreading and bringing together the rays, from very long metacarpal bones and proximal phalanges, from reduction of distal phalangs of the 3d and 5th fingers. Thus, the hand of Chiroptera is a unique example of combination of primitive, initial for pentadactule plantigrades wrist with signs of narrow specialization resembling, to some extent, those of Ungulata; only in Ungulata those signs developed on the base of digitigrades wrist. 相似文献
52.
Giorgio Manzi Elena Santandrea Pietro Passarello 《American journal of physical anthropology》1997,102(4):469-479
Different socioeconomic strata of Roman imperial age are represented by two large dental samples recovered from archaeological excavations near Rome, Italy. Teeth are investigated for crown dimensions and morphological variants. One sample, comprising 1,465 permanent teeth, represents the rural town of Lucus Feroniae (LFR) and is mainly composed of slaves and war veterans. The other, comprising 734 teeth from the Isola Sacra necropolis at Portus Romae (NIS), represents the “middle class” segment of an urban population. Both series show small dental dimensions and fit at the lower end of the trend toward dental reduction in Europe from the Upper Paleolithic to the historical times. The urban sample is less variable metrically and less sexually dimorphic than the rural one. The analysis of discrete crown traits shows absence of rare phenotypic variants in both series. The urban sample is also less variable in this last respect, suggesting that the gene pool of this particular “stratum” of the NIS population was more homogeneous than that of LFR. The occurrence of enamel hypoplasia indicates that metabolic stress during growth and development was similar in LFR and NIS. The overall set of available data is evaluated in the light of the history of the two Roman sites and the composition of each population. Am J Phys Anthropol 102:469–479, 1997. © 1997 Wiley-Liss, Inc. 相似文献
53.
Global warming is predicted to impact the prevalence and severity of infectious diseases. However, empirical data supporting this statement usually stem from experiments in which parasite fitness and disease outcome are measured directly after temperature increase. This might exclude the possibility of parasite adaptation. To incorporate the adaptive response of parasites into predictions of disease severity in a warmer world, we undertook an experimental evolution assay in which a fungal parasite of phytoplankton was maintained at elevated or control temperatures for six months, corresponding to 100–200 parasite generations. Host cultures were maintained at the respective temperatures and provided as substrate, but were not under parasite pressure. A reciprocal infection experiment conducted after six-month serial passages revealed no evidence of parasite adaptation. In fact, parasite fitness at elevated temperatures was inferior in parasite populations reared at elevated temperatures compared with those maintained under control temperature. However, this effect was reversed after parasites were returned to control temperatures for a few (approx. 10) generations. The absence of parasite adaptation to elevated temperatures suggests that, in phytoplankton–fungus systems, disease outcome under global warming will be largely determined by both host and parasite thermal ecology. 相似文献
54.
Binding of hepatitis C virus envelope protein E2 to CD81 up-regulates matrix metalloproteinase-2 in human hepatic stellate cells 总被引:9,自引:0,他引:9
Mazzocca A Sciammetta SC Carloni V Cosmi L Annunziato F Harada T Abrignani S Pinzani M 《The Journal of biological chemistry》2005,280(12):11329-11339
The hepatitis C virus (HCV) envelope E2 glycoprotein is a key molecule regulating the interaction of HCV with cell surface proteins. E2 binds the major extracellular loop of human CD81, a tetraspanin expressed on various cell types including hepatocytes and B lymphocytes. Regardless, information on the biological functions originating from this interaction are largely unknown. Since human hepatic stellate cells (HSC) express high levels of CD81 at the cell surface, we investigated the E2/CD81 interaction in human HSC and the possible effects arising from this interaction. Matrix metalloproteinase-2 (MMP-2; gelatinase A), a major enzyme involved in the degradation of normal hepatic extracellular matrix, was up-regulated following the interaction between E2 and CD81. In particular, by employing zymography and Western blot, we observed that E2 binding to CD81 induces a time-dependent increase in the synthesis and activity of MMP-2. This effect was abolished by preincubating HSC with an anti-CD81 neutralizing antibody. Similar effects were detected in NIH3T3 mouse fibroblasts transfected with human CD81 with identical time course features. In addition, E2/CD81 interaction in human HSC induced the up-regulation of MMP-2 by increasing activator protein-2/DNA binding activity via ERK/MAPK phosphorylation. Finally, suppression of CD81 by RNA interference in human HSC abolished the described effects of E2 on these cells, indicating that CD81 is essential for the activation of the signaling pathway leading to the up-regulation of MMP-2. These results suggest that HSC may represent a potential target for HCV. The interaction of HCV envelope with CD81 on the surface of human HSC induces an increased expression of MMP-2. Increased degradation of the normal hepatic extracellular matrix in areas where HCV is concentrated may favor inflammatory infiltration and further parenchymal damage. 相似文献
55.
56.
Carlo Peretto Julie Arnaud Jacopo Moggi-Cecchi Giorgio Manzi Sébastien Nomade Alison Pereira Christophe Falguères Jean-Jacques Bahain Dominique Grimaud-Hervé Claudio Berto Benedetto Sala Giuseppe Lembo Brunella Muttillo Rosalia Gallotti Ursula Thun Hohenstein Carmela Vaccaro Mauro Coltorti Marta Arzarello 《PloS one》2015,10(10)
Isernia La Pineta (south-central Italy, Molise) is one of the most important archaeological localities of the Middle Pleistocene in Western Europe. It is an extensive open-air site with abundant lithic industry and faunal remains distributed across four stratified archaeosurfaces that have been found in two sectors of the excavation (3c, 3a, 3s10 in sect. I; 3a in sect. II). The prehistoric attendance was close to a wet environment, with a series of small waterfalls and lakes associated to calcareous tufa deposits. An isolated human deciduous incisor (labelled IS42) was discovered in 2014 within the archaeological level 3 coll (overlying layer 3a) that, according to new 40Ar/39Ar measurements, is dated to about 583–561 ka, i.e. to the end of marine isotope stage (MIS) 15. Thus, the tooth is currently the oldest human fossil specimen in Italy; it is an important addition to the scanty European fossil record of the Middle Pleistocene, being associated with a lithic assemblage of local raw materials (flint and limestone) characterized by the absence of handaxes and reduction strategies primarily aimed at the production of small/medium-sized flakes. The faunal assemblage is dominated by ungulates often bearing cut marks. Combining chronology with the archaeological evidence, Isernia La Pineta exhibits a delay in the appearance of handaxes with respect to other European Palaeolithic sites of the Middle Pleistocene. Interestingly, this observation matches the persistence of archaic morphological features shown by the human calvarium from the Middle Pleistocene site of Ceprano, not far from Isernia (south-central Italy, Latium). In this perspective, our analysis is aimed to evaluate morphological features occurring in IS42. 相似文献
57.
Background
Horizontal gene transfer (HGT) is the stable transmission of genetic material between organisms by means other than vertical inheritance. HGT has an important role in the evolution of prokaryotes but is relatively rare in eukaryotes. HGT has been shown to contribute to virulence in eukaryotic pathogens. We studied the importance of HGT in plant pathogenic fungi by identifying horizontally transferred genes in the genomes of three members of the genus Colletotrichum.Results
We identified eleven HGT events from bacteria into members of the genus Colletotrichum or their ancestors. The HGT events include genes involved in amino acid, lipid and sugar metabolism as well as lytic enzymes. Additionally, the putative minimal dates of transference were calculated using a time calibrated phylogenetic tree. This analysis reveals a constant flux of genes from bacteria to fungi throughout the evolution of subphylum Pezizomycotina.Conclusions
Genes that are typically transferred by HGT are those that are constantly subject to gene duplication and gene loss. The functions of some of these genes suggest roles in niche adaptation and virulence. We found no evidence of a burst of HGT events coinciding with major geological events. In contrast, HGT appears to be a constant, albeit rare phenomenon in the Pezizomycotina, occurring at a steady rate during their evolution.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-16-2) contains supplementary material, which is available to authorized users. 相似文献58.
Pierre-Arthur Moreau Stéphane Welti Branislav Perić Patricia Jargeat Sophie Manzi Alfredo Vizzini 《Mycological Progress》2013,12(1):109-119
A new ectomycorrhizal species, Alpova komoviana, is described from several collections from Montenegro (south-eastern Europe), in association with Alnus incana ssp. incana (Betulaceae). Its interesting basal position in the strictly Alnus-associated Alpova lineage is discussed through morphology and phylogenetic analyses based on ITS, gpd and rpb2 nuclear DNA. ITS sequences of two other taxa are included in the analysis: Alpova rubescens and A. rubescens var. obscuratus; their identity and systematic positions are discussed. 相似文献
59.
Úrzula Franco-Enzástiga Guadalupe García Janet Murbartián Rodrigo González-Barrios Ana B. Salinas-Abarca Beatriz Sánchez-Hernández Diana Tavares-Ferreira Luis A. Herrera Paulino Barragán-Iglesias Rodolfo Delgado-Lezama Theodore J. Price Vinicio Granados-Soto 《Journal of neurochemistry》2021,156(6):897-916
60.
Juliette Rochet Pierre-Arthur Moreau Sophie Manzi Monique Gardes 《BMC evolutionary biology》2011,11(1):40