Nivicolous myxomycete assemblages were surveyed on the northwest of the Greater Caucasian ridge in May-June 2010 and 2011 at a north facing transect between 1,700 and 2,920 m elevation of the summit Malaya Khatipara s...Nivicolous myxomycete assemblages were surveyed on the northwest of the Greater Caucasian ridge in May-June 2010 and 2011 at a north facing transect between 1,700 and 2,920 m elevation of the summit Malaya Khatipara situated within the Teberda State Biosphere Reserve.Morphological characters of 396 collections representing 45 taxa(39 species,3 varieties,and 3 forms)of myxomycetes in 8 genera and 5 families were recorded.Many(13)taxa are classified as rare(a species represents<0.5%of all records).Only seven species were found to be widely distributed(present in 50%or more of the 17 studied localities).To confirm the assignment of specimens to morphospecies,we obtained independently from determination 145 partial sequences of the 18S SSU rRNA gene from 35 taxa of Lamproderma,Meriderma,Physarum and Diderma,which turned out to represent 58 genotypes.Most of the taxa represented by more than one sequence had several genotypes,with an average of 1.7 genotypes per taxon.Except for three taxonomically difficult groups of species,partial SSU sequences did well correspond with the respective morphospecies and where similar or identical to sequences of specimens from the European Alps,making this marker a good candidate for barcoding in myxomycetes.Species richness and diversity increased from subalpine crooked-stem birch forests(23 species,2 varieties,H′02.8,E00.88,D00.08)to alpine dwarf shrub communities(34 species and 2 varieties,2 forms,H′03.2,E00.89,D00.05)but decreased again for alpine meadows(27 species and 2 varieties,2 forms,H′03.1,E00.91,D00.06).Species richness and alpha-diversity reached maximum values for ground litter,whereas leaves and stems of living shrubs above ground harboured a more depauperate myxomycete assemblage.展开更多
Acute viral infection causes illness and death.In addition,an infection often results in increased susceptibility to a secondary infection,but the mechanisms behind this susceptibility are poorly understood.Since its ...Acute viral infection causes illness and death.In addition,an infection often results in increased susceptibility to a secondary infection,but the mechanisms behind this susceptibility are poorly understood.Since its initial identification as a marker for resident memory CD8^(+)T cells in barrier tissues,the function and regulation of CD103 integrin(encoded by ITGAE gene)have been extensively investigated.Nonetheless,the function and regulation of the resident CD103^(+)CD8^(+)T cell response to acute viral infection remain unclear.Although TGFβsignaling is essential for CD103 expression,the precise molecular mechanism behind this regulation is elusive.Here,we reveal a TGFβ–SKI–Smad4 pathway that critically and specifically directs resident CD103^(+)CD8^(+)T cell generation for protective immunity against primary and secondary viral infection.We found that resident CD103^(+)CD8^(+)T cells are abundant in both lymphoid and nonlymphoid tissues from uninfected mice.CD103 acts as a costimulation signal to produce an optimal antigenic CD8^(+)T cell response to acute viral infection.There is a reduction in resident CD103^(+)CD8^(+)T cells following primary infection that results in increased susceptibility of the host to secondary infection.Intriguingly,CD103 expression inversely and specifically correlates with SKI proto-oncogene(SKI)expression but not R-Smad2/3 activation.Ectopic expression of SKI restricts CD103 expression in CD8^(+)T cells in vitro and in vivo to hamper viral clearance.Mechanistically,SKI is recruited to the Itgae loci to directly suppress CD103 transcription by regulating histone acetylation in a Smad4-dependent manner.Our study therefore reveals that resident CD103^(+)CD8^(+)T cells dictate protective immunity during primary and secondary infection.Interfering with SKI function may amplify the resident CD103^(+)CD8^(+)T cell response to promote protective immunity.展开更多
Dear Editor, What does the evolutionary origin of a plant protein tell about its subcellular localization？ Naively thinking, one would assume that plant proteins that were originally encoded in the endosymbiont geno...Dear Editor, What does the evolutionary origin of a plant protein tell about its subcellular localization？ Naively thinking, one would assume that plant proteins that were originally encoded in the endosymbiont genome are targeted to the chloroplast. However, published data seem to support only a loose link between evolutionary origin and subcel- lular localization. About half of the Arabidopsis proteins with a detectable cyanobacterial ortholog are targeted to subcellular compartments other than the chloroplast （Martin et al., 2002）. H展开更多
基金supported by the grant RFBR 10-04-00536a to the first author as well as a scientific program“Bioraznoobrazie”from the Russian Academy of Sciencessupported by grants from Greifswald University,sequencing in part by a grant from the Deutsche Forschungsgemeinschaft(SCHN1080/2-1).
文摘Nivicolous myxomycete assemblages were surveyed on the northwest of the Greater Caucasian ridge in May-June 2010 and 2011 at a north facing transect between 1,700 and 2,920 m elevation of the summit Malaya Khatipara situated within the Teberda State Biosphere Reserve.Morphological characters of 396 collections representing 45 taxa(39 species,3 varieties,and 3 forms)of myxomycetes in 8 genera and 5 families were recorded.Many(13)taxa are classified as rare(a species represents<0.5%of all records).Only seven species were found to be widely distributed(present in 50%or more of the 17 studied localities).To confirm the assignment of specimens to morphospecies,we obtained independently from determination 145 partial sequences of the 18S SSU rRNA gene from 35 taxa of Lamproderma,Meriderma,Physarum and Diderma,which turned out to represent 58 genotypes.Most of the taxa represented by more than one sequence had several genotypes,with an average of 1.7 genotypes per taxon.Except for three taxonomically difficult groups of species,partial SSU sequences did well correspond with the respective morphospecies and where similar or identical to sequences of specimens from the European Alps,making this marker a good candidate for barcoding in myxomycetes.Species richness and diversity increased from subalpine crooked-stem birch forests(23 species,2 varieties,H′02.8,E00.88,D00.08)to alpine dwarf shrub communities(34 species and 2 varieties,2 forms,H′03.2,E00.89,D00.05)but decreased again for alpine meadows(27 species and 2 varieties,2 forms,H′03.1,E00.91,D00.06).Species richness and alpha-diversity reached maximum values for ground litter,whereas leaves and stems of living shrubs above ground harboured a more depauperate myxomycete assemblage.
基金This work was supported by NIH funding(R01Al143894,R01Al138337)for J.K.W.the NIH(Al123193)+1 种基金the National Multiple Sclerosis Society(RG-1802-30483)the Yang Family Biomedical Scholars Award for Y.Y.W.
文摘Acute viral infection causes illness and death.In addition,an infection often results in increased susceptibility to a secondary infection,but the mechanisms behind this susceptibility are poorly understood.Since its initial identification as a marker for resident memory CD8^(+)T cells in barrier tissues,the function and regulation of CD103 integrin(encoded by ITGAE gene)have been extensively investigated.Nonetheless,the function and regulation of the resident CD103^(+)CD8^(+)T cell response to acute viral infection remain unclear.Although TGFβsignaling is essential for CD103 expression,the precise molecular mechanism behind this regulation is elusive.Here,we reveal a TGFβ–SKI–Smad4 pathway that critically and specifically directs resident CD103^(+)CD8^(+)T cell generation for protective immunity against primary and secondary viral infection.We found that resident CD103^(+)CD8^(+)T cells are abundant in both lymphoid and nonlymphoid tissues from uninfected mice.CD103 acts as a costimulation signal to produce an optimal antigenic CD8^(+)T cell response to acute viral infection.There is a reduction in resident CD103^(+)CD8^(+)T cells following primary infection that results in increased susceptibility of the host to secondary infection.Intriguingly,CD103 expression inversely and specifically correlates with SKI proto-oncogene(SKI)expression but not R-Smad2/3 activation.Ectopic expression of SKI restricts CD103 expression in CD8^(+)T cells in vitro and in vivo to hamper viral clearance.Mechanistically,SKI is recruited to the Itgae loci to directly suppress CD103 transcription by regulating histone acetylation in a Smad4-dependent manner.Our study therefore reveals that resident CD103^(+)CD8^(+)T cells dictate protective immunity during primary and secondary infection.Interfering with SKI function may amplify the resident CD103^(+)CD8^(+)T cell response to promote protective immunity.
文摘Dear Editor, What does the evolutionary origin of a plant protein tell about its subcellular localization？ Naively thinking, one would assume that plant proteins that were originally encoded in the endosymbiont genome are targeted to the chloroplast. However, published data seem to support only a loose link between evolutionary origin and subcel- lular localization. About half of the Arabidopsis proteins with a detectable cyanobacterial ortholog are targeted to subcellular compartments other than the chloroplast （Martin et al., 2002）. H
