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Yvonne Meyer-Lucht Celine Otten Thomas Püttker Renata Pardini Jean Paul Metzger Simone Sommer 《Conservation Genetics》2010,11(5):2001-2013
The adaptive potential of a species to a changing environment and in disease defence is primarily based on genetic variation.
Immune genes, such as genes of the major histocompatibility complex (MHC), may thereby be of particular importance. In marsupials,
however, there is very little knowledge about natural levels and functional importance of MHC polymorphism, despite their
key role in the mammalian evolution. In a previous study, we discovered remarkable differences in the MHC class II diversity
between two species of mouse opossums (Gracilinanus microtarsus, Marmosops incanus) from the Brazilian Atlantic forest, which is one of the most endangered hotspots for biodiversity conservation. Since the
main forces in generating MHC diversity are assumed to be pathogens, we investigated in this study gastrointestinal parasite
burden and functional associations between the individual MHC constitution and parasite load. We tested two contrasting scenarios,
which might explain differences in MHC diversity between species. We predicted that a species with low MHC diversity would
either be under relaxed selection pressure by low parasite diversity (‘Evolutionary equilibrium’ scenario), or there was a recent loss in MHC diversity leading to a lack of resistance alleles and increased parasite burden
(‘Unbalanced situation’ scenario). In both species it became apparent that the MHC class II is functionally important in defence against gastrointestinal
helminths, which was shown here for the first time in marsupials. On the population level, parasite diversity did not markedly
differ between the two host species. However, we did observe considerable differences in the individual parasite load (parasite
prevalence and infection intensity): while M. incanus revealed low MHC DAB diversity and high parasite load, G. microtarsus showed a tenfold higher population wide MHC DAB diversity and lower parasite burden. These results support the second scenario
of an unbalanced situation. 相似文献
74.
Jewell MC Frere CH Prentis PJ Lambrides CJ Godwin ID 《American journal of botany》2010,97(10):e99-e101
? Premise of the study: Cynodon species are multiple-use grasses that display varying levels of adaptation to biotic and abiotic stress. Previously identified EST-SSR primers were characterized and multiplexed to assess the level of genetic diversity present within a collection of almost 1200 Cynodon accessions from across Australia. ? Methods and Results: Two multiplex reactions were developed comprising a total of 16 EST-SSR markers. All SSR markers amplified across different Cynodon species and different levels of ploidy. The number of alleles ranged from one to eight per locus and the total number of alleles for the germplasm collection was 79. ? Conclusions: The 16 markers show sufficient variation for the characterization of Cynodon core collections and analysis of population genetic diversity in Cynodon grasses. 相似文献
75.
Raul Herrera Catherine Krier Celine Lalanne ElHadji Maodo Ba Alexia Stokes Franck Salin Thierry Fourcaud Stéphane Claverol Christophe Plomion 《BMC plant biology》2010,10(1):217
Background
Plants are subjected to continuous stimuli from the environment and have evolved an ability to respond through various growth and development processes. Phototropism and gravitropism responses enable the plant to reorient with regard to light and gravity. 相似文献76.
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Tran BQ Hernandez C Waridel P Potts A Barblan J Lisacek F Quadroni M 《Journal of proteome research》2011,10(2):800-811
In the vast majority of bottom-up proteomics studies, protein digestion is performed using only mammalian trypsin. Although it is clearly the best enzyme available, the sole use of trypsin rarely leads to complete sequence coverage, even for abundant proteins. It is commonly assumed that this is because many tryptic peptides are either too short or too long to be identified by RPLC-MS/MS. We show through in silico analysis that 20-30% of the total sequence of three proteomes (Schizosaccharomyces pombe, Saccharomyces cerevisiae, and Homo sapiens) is expected to be covered by Large post-Trypsin Peptides (LpTPs) with M(r) above 3000 Da. We then established size exclusion chromatography to fractionate complex yeast tryptic digests into pools of peptides based on size. We found that secondary digestion of LpTPs followed by LC-MS/MS analysis leads to a significant increase in identified proteins and a 32-50% relative increase in average sequence coverage compared to trypsin digestion alone. Application of the developed strategy to analyze the phosphoproteomes of S. pombe and of a human cell line identified a significant fraction of novel phosphosites. Overall our data indicate that specific targeting of LpTPs can complement standard bottom-up workflows to reveal a largely neglected portion of the proteome. 相似文献
79.
A novel class of Pseudoautosomal region 1 deletions downstream of SHOX is associated with Leri-Weill dyschondrosteosis 总被引:1,自引:0,他引:1 下载免费PDF全文
80.
Of the several types of polarized cells, the neuron is one of the most dramatic examples. It extends two distinctive processes, axon and dendrite. Polarization in neurons enables the two processes to play their functionally different roles, sending and receiving electrical signals in a vectorial fashion. While a catalog of structural, molecular, and functional differences between axon and dendrite is accumulating, the mechanisms involved in establishment of neuronal polarity are not well understood. Neuronal polarity formation begins with the elongation of one process as an axon in a symmetric cell phase. In this review, we describe recent advances in the understanding of several cellular events in the early development of axon and dendrite. We also discuss the involvement of the Rho family small GTPases, their upstream and downstream molecules, and collapsin response mediator protein-2 (CRMP-2) in the regulation of neuronal polarity. 相似文献