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141.
Petra Dieker Claudia Drees Thomas Schmitt Thorsten Assmann 《Conservation Genetics》2013,14(1):231-236
The burnet moth Zygaena anthyllidis, endemic to the high elevations of the Pyrenees, is vulnerable to land-use. In order to identify conservation priorities based on an assessment of genetic diversity within populations and gene flow among populations, we examined Z. anthyllidis’ genetic variability and differentiation based on allozyme electrophoresis from seven populations scattered across its entire range. In comparison to other mountain Lepidoptera, the populations studied exhibit a low level of genetic diversity. Remarkable between-population differentiation (F ST = 0.053), the presence of private alleles, and the lack of significant isolation-by-distance pattern characterises the genetic make-up of the species. We interpreted the pattern of genetic differentiation as a consequence of low dispersal power in combination with insufficient landscape connectivity. Ongoing land-use change might reinforce genetic differentiation due to habitat fragmentation and additionally affect negatively allozyme variability at shifting range margins, i.e. the capacity to adapt to changing environments. We therefore suggest creating a network of suitable habitats at the landscape scale to facilitate genetic exchange and to conserve the species’ overall genetic variability. 相似文献
142.
James Curlin Kimberly Schmitt Leila Remling-Mulder Ryan Moriarty Mark Stenglein Shelby O'Connor Preston Marx Ramesh Akkina 《Journal of medical primatology》2020,49(1):40-43
HIV-1 evolved from its progenitor SIV strains, but details are lacking on its adaptation to the human host. We followed the evolution of SIVcpz in humanized mice to mimic cross-species transmission. Increasing viral loads, CD4+ T-cell decline, and non-synonymous mutations were seen in the entire genome reflecting viral adaptation. 相似文献
143.
Kimberly Schmitt James Curlin Leila Remling-Mulder Ryan Moriarty Kelly Goff Shelby O’Connor Mark Stenglein Preston Marx Ramesh Akkina 《Journal of medical primatology》2020,49(5):284-287
HIV-1 evolved from SIV during cross-species transmission events, though viral genetic changes are not well understood. Here, we studied the evolution of SIVcpzLB715 into HIV-1 Group M using humanized mice. High viral loads, rapid CD4+ T-cell decline, and non-synonymous substitutions were identified throughout the viral genome suggesting viral adaptation. 相似文献
144.
145.
Sylvain Hanein Mathilde Garcia Lucas Fares-Taie Valérie Serre Yves De Keyzer Thierry Delaveau Isabelle Perrault Nathalie Delphin Sylvie Gerber Alain Schmitt Jean-Marc Masse Arnold Munnich Josseline Kaplan Frédéric Devaux Jean-Michel Rozet 《Biochimica et Biophysica Acta (BBA)/General Subjects》2013
Background
Hereditary optic neuropathies (HONs) are a heterogeneous group of disorders that affect retinal ganglion cells (RGCs) and axons that form the optic nerve. Leber's Hereditary Optic Neuropathy and the autosomal dominant optic atrophy related to OPA1 mutations are the most common forms. Nonsyndromic autosomal recessive optic neuropathies are rare and their existence has been long debated. We recently identified the first gene responsible for these conditions, TMEM126A. This gene is highly expressed in retinal cellular compartments enriched in mitochondria and supposed to encode a mitochondrial transmembrane protein of unknown function.Methods
A specific polyclonal antibody targeting the TMEM126A protein has been generated. Quantitative fluorescent in situ hybridization, cellular fractionation, mitochondrial membrane association study, mitochondrial sub compartmentalization analysis by both proteolysis assays and transmission electron microscopy, and expression analysis of truncated TMEM126A constructs by immunofluorescence confocal microscopy were carried out.Results
TMEM126A mRNAs are strongly enriched in the vicinity of mitochondria and encode an inner mitochondrial membrane associated cristae protein. Moreover, the second transmembrane domain of TMEM126A is required for its mitochondrial localization.Conclusions
TMEM126A is a mitochondrial located mRNA (MLR) that may be translated in the mitochondrial surface and the protein is subsequently imported to the inner membrane. These data constitute the first step toward a better understanding of the mechanism of action of TMEM126A in RGCs and support the importance of mitochondrial dysfunction in the pathogenesis of HON.General significance
Local translation of nuclearly encoded mitochondrial mRNAs might be a mechanism for rapid onsite supply of mitochondrial membrane proteins. 相似文献146.
Elise P. Salerno Sofia M. Shea Walter C. Olson Gina R. Petroni Mark E. Smolkin Chantel McSkimming Kimberly A. Chianese-Bullock Craig L. Slingluff Jr. 《Cancer immunology, immunotherapy : CII》2013,62(7):1149-1159
We conducted a randomized clinical trial in 45 patients with resected AJCC stage IIB-IV melanoma to characterize cellular and molecular events at sites of immunization with incomplete Freund’s adjuvant (IFA) alone, or a melanoma vaccine in IFA. At a primary vaccine site, all patients received a multi-peptide melanoma vaccine in IFA. At a replicate vaccine site, which was biopsied, group 1 received IFA only; group 2 received vaccine in IFA. Lymphocytes isolated from replicate vaccine site microenvironments (VSME) were compared to time-matched peripheral blood mononuclear cells (PBMC) in ELISpot and flow cytometry assays. Compared to PBMC, the VSME had fewer naïve and greater proportions of effector memory CD8+ T cells (TCD8). The vast majority of TCD8 within the VSME were activated (CD69+), with a concentration of antigen-specific (tetramerpos) cells in the VSME, particularly in vaccine sites with peptide (group 2). CXCR3+ lymphocytes were concentrated in the VSME of all patients, suggesting IFA-induced chemokine recruitment. TCD8 expression of retention integrins αEβ7 and α1β1 was elevated in VSME, with the highest levels observed in antigen-specific cells in VSME containing peptide (group 2). TCD8 retained in the VSME of both groups were strikingly dysfunctional, with minimal IFN-γ production in response to peptide stimulation and few tetramerpos cells producing IFN-γ. These data suggest that vaccine-induced selective retention and dysfunction of antigen-specific TCD8 within VSME may represent a significant mechanism underlying transient immune responses and low clinical response rates to peptide vaccines administered in IFA. 相似文献
147.
148.
Sea stars are able to make firm but temporary attachments to various substrata by secretions released by their tube feet. After tube foot detachment, the adhesive secretions remain on the substratum as a footprint. Proteins presumably play a key role in sea star adhesion, as evidenced by the removal of footprints from surfaces after a treatment with trypsin. However, until now, characterisation was hampered by their high insolubility. In this study, a non-hydrolytic method was used to render most of the proteins constituting the adhesive footprints soluble. After analysis by SDS-PAGE, the proteins separated into about 25 bands, which ranged from 25 to 450 kDa in apparent molecular weight. Using mass spectrometry and a homology-database search, it was shown that several of the proteins are known intracellular proteins, presumably resulting from contamination of footprint material with tube foot epidermal cells. However, 11 protein bands, comprising the most abundant proteins, were not identified and might correspond to novel adhesive proteins. They were named ‘Sea star footprint proteins’ (Sfps). Tandem mass spectrometry analysis of the protein bands yielded 43 de novo-generated peptide sequences. Most of them were shared by several, if not all, Sfps. Polyclonal antibodies were raised against one of the peptides (HEASGEYYR from Sfp-115) and were used in immunoblotting. They specifically labelled Sfp-115 and other bands with lower apparent molecular weights. The different results suggest that all Sfps might belong to a single family of related proteins sharing similar motifs or, alternatively, they are the products of polymerization and/or degradation processes. 相似文献
149.
Background and Aims
Below-ground translocated carbon (C) released as rhizodeposits is an important driver for microbial mobilization of nitrogen (N) for plants. We investigated how a limited substrate supply due to reduced photoassimilation alters the allocation of recently assimilated C in plant and soil pools under legume and non-legume species.Methods
A non-legume (Lolium perenne) and a legume (Medicago sativa) were labelled with 15N before the plants were clipped or shaded, and labelled twice with 13CO2 thereafter. Ten days after clipping and shading, the 15N and 13C in shoots, roots, soil, dissolved organic nitrogen (DON) and carbon (DOC) and in microbial biomass, as well as the 13C in soil CO2 were analyzed.Results
After clipping, about 50 % more 13C was allocated to regrowing shoots, resulting in a lower translocation to roots compared to the unclipped control. Clipping also reduced the total soil CO2 efflux under both species and the 13C recovery of soil CO2 under L. perenne. The 15N recovery increased in the shoots of M. sativa after clipping, because storage compounds were remobilized from the roots and/or the N uptake from the soil increased. After shading, the assimilated 13C was preferentially retained in the shoots of both species. This caused a decreased 13C recovery in the roots of M. sativa. Similarly, the total soil CO2 efflux under M. sativa decreased more than 50 % after shading. The 15N recovery in plant and soil pools showed that shading has no effect on the N uptake and N remobilization for L. perenne, but, the 15N recovery increased in the shoot of M. sativa.Conclusions
The experiment showed that the dominating effect on C and N allocation after clipping is the need of C and N for shoot regrowth, whereas the dominating effect after shading is the reduced substrate supply for growth and respiration. Only slight differences could be observed between L. perenne and M. sativa in the C and N distribution after clipping or shading. 相似文献150.