被视为恐龙的鸟(英文)

尽管于 2 0世纪 2 0年代在亚洲地表层首次发现长有羽毛的恐龙和著名的“龙骨突位点” ,关于鸟类起源的争论仍没有休止。来自化石的证据表明 ,鸟类在进化分支上应归于兽脚类的特殊分支。本文主要阐明完好无损的化石揭示的鸟和非鸟类恐龙的亲密关系和鸟类羽毛及鸟类出现以前的羽毛的起源证据 。

晚白垩世真兽类Zalamdalestes揭示哺乳动物独特的枢椎及其复杂的进化过程

The typical mammalian neck consisting of seven cervical vertebrae(C1–C7)was established by the Late Permian in the cynodont forerunners of modern mammals.This structure is precisely adapted to facilitate movements of the head during feeding,locomotion,predator evasion,and social interactions.Eutheria,the clade including crown placentals,has a fossil record extending back more than 125 million years revealing significant morphological diversification in the Mesozoic.Yet very little is known concerning the early evolution of eutherian cervical morphology and its functional adaptations.A specimen of Zalambdalestes lechei from the Late Cretaceous of Mongolia boasts exceptional preservation of an almost complete series of cervical vertebrae(C2–C7)revealing a highly modified axis(C2).The significance of this cervical morphology is explored utilizing an integrated approach combining comparative anatomical examination across mammals,muscle reconstruction,geometric morphometrics and virtual range of motion analysis.We compared the shape of the axis in Zalambdalestes to a dataset of 88 mammalian species(monotremes,marsupials,and placentals)using three-dimensional landmark analysis.The results indicate that the unique axis morphology of Zalambdalestes has no close analog among living mammals.Virtual range of motion analysis of the neck strongly implies Zalambdalestes was capable of exerting very forceful head movements and had a high degree of ventral flexion for an animal its size.These findings reveal unexpected complexity in the early evolution of the eutherian cervical morphology and suggest a feeding behavior similar to insectivores specialized in vermivory and defensive behaviors in Zalambdalestes akin to modern spiniferous mammals.

Coprophilous contributions to the phylogeny of Lasiosphaeriaceae and allied taxa within Sordariales(Ascomycota,Fungi)

The phylogenetic relationships of Lasiosphaeriaceae are complicated in that the family is paraphyletic and includes Sordariaceae and Chaetomiaceae,as well as several polyphyletic genera.This study focuses on the phylogenetic relationships of the coprophilous genera,Anopodium,Apodospora,Arnium,Fimetariella and Zygospermella.They are traditionally circumscribed based on ascospore characters,which have proven homoplasious in other genera within the family.Our results based on LSU nrDNA andß–tubulin sequences distinguish four lineages of Lasiosphaeriaceae taxa.Anopodium joins the clade of mor-phologically similar,yellow-pigmented species of Cercophora and Lasiosphaeria.Apodospora is monophyletic and joins a larger group of taxa with unclear affinities to each other,while Arnium is polyphyletic being scattered throughout three of the four major clades of Lasiosphaeriaceae.Fimitariella is represented by a single collection and joins the clade containing Cercophora scortea and Podospora appendiculata.Zygospermella shows affinities to the Lasiosphaeris clade.Based on a combination of morphological and molecular data,Echria stat.nov.is recognized at the genus level for the former Arnium section and two new combinations are proposed:E.gigantospora and E.macrotheca.

Diversity of dictyostelid social amoebae in high latitude habitats of Northern Sweden

The dictyostelid social amoebae(Dictyostelia)occur in terrestrial habitats worldwide.It has been observed previously that their diversity decreases with increasing latitude and altitude.Here we look at dictyostelid diversity in the high latitude habitats of Northern Sweden.Dictyostelids were recovered from soil samples using traditional plating methods and then identified using morphological characters and molecular sequence(small subunit ribosomal RNA)data.In total,nine species were recovered,including two new species,described herein as Dictyostelium barbibulus and Polysphondylium fuscans.The species diversity found here is discussed in relation to previous findings in the area as well as other high-latitude studies,and biogeographical patterns are examined.The total number of species found in Northern Sweden is lower than the numbers recorded for regions further south in Europe,a finding consistent with a latitudinal gradient of species diversity.Our findings highlight the benefit of using molecular data for accurate species identification in Dictyostelia and the need for a continued sampling effort to better understand their diversity and distribution,especially in high latitude habitats.

Improving ITS sequence data for identification of plant pathogenic fungi

Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours.These taxa often have complex and poorly understood life cycles,lack observable,discriminatory morphological characters,and may not be amenable to in vitro culturing.As a result,species identification is frequently difficult.Molecular(DNA sequence)data have emerged as crucial information for the taxonomic identification of plant pathogenic fungi,with the nuclear ribosomal internal transcribed spacer(ITS)region being the most popular marker.However,international nucleotide sequence databases are accumulating numerous sequences of compromised or low-resolution taxonomic annotations and substandard technical quality,making their use in the molecular identification of plant pathogenic fungi problematic.Here we report on a concerted effort to identify high-quality reference sequences for various plant pathogenic fungi and to re-annotate incorrectly or insufficiently annotated public ITS sequences from these fungal lineages.A third objective was to enrich the sequences with geographical and ecological metadata.The results-a total of 31,954 changes-are incorporated in and made available through the UNITE database for molecular identification of fungi(http://unite.ut.ee),including standalone FASTA files of sequence data for local BLAST searches,use in the next-generation sequencing analysis platforms QIIME and mothur,and related applications.The present initiative is just a beginning to cover the wide spectrum of plant pathogenic fungi,and we invite all researchers with pertinent expertise to join the annotation effort.

FungalTraits:a user-friendly traits database of fungi and fungus-like stramenopiles

The cryptic lifestyle of most fungi necessitates molecular identification of the guild in environmental studies.Over the past decades,rapid development and affordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats.Yet,in spite of the progress of molecular methods,knowledge about functional properties of the fungal taxa is vague and interpretation of environmental studies in an ecologically meaningful manner remains challenging.In order to facilitate functional assignments and ecological interpretation of environmental studies we introduce a user friendly traits and character database FungalTraits operating at genus and species hypothesis levels.Combining the information from previous efforts such as FUNGuild and FunFun together with involvement of expert knowledge,we reannotated 10,210 and 151 fungal and Stramenopila genera,respectively.This resulted in a stand-alone spreadsheet dataset covering 17 lifestyle related traits of fungal and Stramenopila genera,designed for rapid functional assignments of environmental stud-ies.In order to assign the trait states to fungal species hypotheses,the scientific community of experts manually categorised and assigned available trait information to 697,413 fungal ITS sequences.On the basis of those sequences we were able to summarise trait and host information into 92,623 fungal species hypotheses at 1%dissimilarity threshold.

Correction to:FungalTraits:a user friendly traits database of fungi and fungus-like stramenopiles

Correction to:Fungal Diversity(2020)105:116 https://doi.org/10.1007/s13225-020-00466-2 There were errors in the name of author LászlóG.Nagy and in affiliation no.31 in the original publication.The original article has been corrected.

SHP-1是IL-4诱导的IL-4R在脾脏细胞中表达所必需的

为了探索包含SH-2功能域的蛋白酪氨酸磷酸酶(SH-2-containing protein tyrosine phosphatase1,SHP-1)在IL-4诱导的IL-4受体(IL-4receptor,IL-4R)表达中的作用,用Na3VO4处理野生型(wildtype,WT)实验小鼠的脾脏细胞以及用IL-4刺激可育Motheaten小鼠(viable motheatenmice,mev/mev)的脾脏细胞,并检测IL-4RαmRNA的表达.我们发现IL-4诱导的IL-4RαmRNA表达在经Na3VO4处理后野生型小鼠的脾脏细胞以及用IL-4刺激的mev/mev小鼠的脾脏细胞中降低了.结果表明,IL-4诱导的IL-4RαmRNA表达的降低是由于IL-4R的低水平表达导致的STAT6信号转导缺陷.实验进一步证实,在mev/mev小鼠的脾脏细胞中IL-4Rα蛋白表达的降低是由于细胞组成的改变.在mev/mev小鼠脾脏组织中,表达相对高水平IL-4R的CD4+,CD8+和CD19+的细胞比例显著下降,相反表达低水平IL-4R的Mac-1+和Gr-1+细胞比例明显升高.尽管IL-4R蛋白表达是明显下降的,但在同窝对照小鼠(+/?)和mev/mev小鼠的脾脏细胞中IL-4RαmRNA的表达未发现明显的差异.在B细胞、T细胞和巨噬细胞中也没有显著差异.这提示在巨噬细胞中IL-4R表达细胞类型特异性下调是通过转录后水平的调控来实现的.研究结果提示,在脾脏细胞中SHP-1对于IL-4诱导的IL-4R表达是必需的,并且通过影响血细胞生成而间接地调控相应的功能.

Ranking higher taxa using divergence times:a case study in Dothideomycetes

The current classification system for the recognition of taxonomic ranks among fungi,especially at highranking level,is subjective.With the development of molecular approaches and the availability of fossil calibration data,the use of divergence times as a universally standardized criterion for ranking taxa has now become possible.We can therefore date the origin of Ascomycota lineages by using molecular clock methods and establish the divergence times for the orders and families of Dothideomycetes.We chose Dothideomycetes,the largest class of the phylum Ascomycota,which contains 32 orders,to establish ages at which points orders have split;and Pleosporales,the largest order of Dothideomycetes with 55 families,to establish family divergence times.We have assembled a multi-gene data set(LSU,SSU,TEF1 and RPB2)from 391 taxa representing most family groups of Dothideomycetes and utilized fossil calibration points solely from within the ascomycetes and a Bayesian approach to establish divergence times of Dothideomycetes lineages.Two separated datasets were analysed:(i)272 taxa representing 32 orders of Dothideomycetes were included for the order level analysis,and(ii)191 taxa representing 55 families of Pleosporales were included for the family level analysis.Our results indicate that divergence times(crown age)for most orders(20 out of 32,or 63%)are between 100 and 220 Mya,while divergence times for most families(39 out of 55,or 71%)are between 20 and 100 Mya.We believe that divergence times can provide additional evidence to support establishment of higher level taxa,such as families,orders and classes.Taking advantage of this added approach,we can strive towards establishing a standardized taxonomic system both within and outside Fungi.In this study we found that molecular dating coupled with phylogenetic inferences provides no support for the taxonomic status of two currently recognized orders,namely Bezerromycetales and Wiesneriomycetales and these are treated as synonyms of Tubeufiales while Asterotexiales is treated as a synonym of Asterinales.In addition,we provide an updated phylogenetic assessment of Dothideomycetes previously published as the Families of Dothideomycetes in 2013 with a further ten orders and 35 families.

人类的面孔如何从鱼形祖先演化而来？

面孔,即脊椎动物头部的正面,对动物机体的运作和人类社会生活有重要意义,面孔的演化长久以来吸引着学界和大众的兴趣,是备受关注的经典科学问题.最近数十年来,演化基因组学、演化发育生物学和古生物学等领域的一系列进展,使得学界对脊椎动物面孔基本构架和面部各器官的演化有了许多新的认识.本文对脊椎动物从鱼到人的面孔演化进行了梳理,重点介绍了近年来在头部和颌骨的起源与演化、耳鼻眼演化、牙齿演化以及人类面部特征形成等领域的一批新知.回顾面孔演化历程,人类面孔许多社会属性的生理基础都可以清楚地追溯到我们与其他脊椎动物的共同祖先中.

A comparative genomic framework for the fish-tetrapod transition

The evolution of tetrapods(land vertebrates)from lobe-finned fishes,nearly 400 million years ago,was a hugely important event.For one thing,if these ancient fishes had not found a way to adapt to life out of the water,we humans would not exist.To investigate this event we can look at the fossil record,but that only tells us about changes in the skeleton.

Fungal diversity notes 709–839: taxonomic and phylogenetic contributions to fungal taxa with an emphasis on fungi on Rosaceae

This paper is the seventh in the Fungal Diversity Notes series,where 131 taxa accommodated in 28 families are mainly described from Rosa(Rosaceae)and a few other hosts.Novel fungal taxa are described in the present study,including 17 new genera,93 new species,four combinations,a sexual record for a species and new host records for 16 species.Bhatiellae,Cycasicola,Dactylidina,Embarria,Hawksworthiana,Italica,Melanocucurbitaria,Melanodiplodia,Monoseptella,Uzbekistanica,Neoconiothyrium,Neopaucispora,Pararoussoella,Paraxylaria,Marjia,Sporormurispora and Xenomassariosphaeria are introduced as new ascomycete genera.We also introduce the new species Absidia jindoensis,Alternaria doliconidium,A.hampshirensis,Angustimassarina rosarum,Astragalicola vasilyevae,Backusella locustae,Bartalinia rosicola,Bhatiellae rosae,Broomella rosae,Castanediella camelliae,Coelodictyosporium rosarum,Comoclathris rosae,C.rosarum,Comoclathris rosigena,Coniochaeta baysunika,C.rosae,Cycasicola goaensis,Dactylidina shoemakeri,Dematiopleospora donetzica,D.rosicola,D.salsolae,Diaporthe rosae,D.rosicola,Endoconidioma rosaehissaricae,Epicoccum rosae,Hawksworthiana clematidicola,H.lonicerae,Italica achilleae,Keissleriella phragmiticola,K.rosacearum,K.rosae,K.rosarum,Lophiostoma rosae,Marjia tianschanica,M.uzbekistanica,Melanocucurbitaria uzbekistanica,Melanodiplodia tianschanica,Monoseptella rosae,Mucor fluvius,Muriformistrickeria rosae,Murilentithecium rosae,Neoascochyta rosicola,Neoconiothyrium rosae,Neopaucispora rosaecae,Neosetophoma rosarum,N.rosae,N.rosigena,Neostagonospora artemisiae,Ophiobolus artemisiicola,Paraconiothyrium rosae,Paraphaeosphaeria rosae,P.rosicola,Pararoussoella rosarum,Parathyridaria rosae,Paraxylaria rosacearum,Penicillium acidum,P.aquaticum,Phragmocamarosporium rosae,Pleospora rosae,P.rosae-caninae,Poaceicola agrostina,P.arundinicola,P.rosae,Populocrescentia ammophilae,P.rosae,Pseudocamarosporium pteleae,P.ulmi-minoris,Pseudocercospora rosae,Pseudopithomyces rosae,Pseudostrickeria rosae,Sclerostagonospora lathyri,S.rosae,S.rosicola,Seimatosporium rosigenum,S.rosicola,Seiridium rosarum,Setoseptoria arundelensis,S.englandensis,S.lulworthcovensis,Sigarispora agrostidis,S.caryophyllacearum,S.junci,S.medicaginicola,S.rosicola,S.scrophulariae,S.thymi,Sporormurispora atraphaxidis,S.pruni,Suttonomyces rosae,Umbelopsis sinsidoensis,Uzbekistanica rosaehissaricae,U.yakutkhanika,Wojnowicia rosicola,Xenomassariosphaeria rosae.New host records are provided for Amandinea punctata,Angustimassarina quercicola,Diaporthe rhusicola,D.eres,D.foeniculina,D.rudis,Diplodia seriata,Dothiorella iberica,Lasiodiplodia theobromae,Lecidella elaeochroma,Muriformistrickeria rubi,Neofusicoccum australe,Paraphaeosphaeria michotii,Pleurophoma pleurospora,Sigarispora caulium and Teichospora rubriostiolata.The new combinations are Dactylidina dactylidis(=Allophaeosphaeria dactylidis),Embarria clematidis(=Allophaeosphaeria clematidis),Hawksworthiana alliariae(=Dematiopleospora alliariae)and Italica luzulae(=Dematiopleospora luzulae).This study also provides some insights into the diversity of fungi on Rosa species and especially those on Rosa spines that resulted in the characterisation of eight new genera,45 new species,and nine new host records.We also collected taxa from Rosa stems and there was 31%(20/65)overlap with taxa found on stems with that on spines.Because of the limited and non-targeted sampling for comparison with collections from spines and stems of the same host and location,it is not possible to say that the fungi on spines of Rosa differ from those on stems.The study however,does illustrate how spines are interesting substrates with high fungal biodiversity.This may be because of their hard structure resulting in slow decay and hence are suitable substrates leading to fungal colonisation.All data presented herein are based on morphological examination of specimens,coupled with phylogenetic sequence data to better integrate taxa into appropriate taxonomic ranks and infer their evolutionary relationships.

SH-2-containing protein tyro-sine phosphatase 1 is required for IL-4-induced IL-4R expression in spleen cells

To investigate the role of SH-2-containing pro- tein tyrosine phosphatase 1, SHP-1, in IL-4-induced IL-4 receptor (IL-4R) expression, we examined IL-4 receptor α-chain (IL-4Rα) mRNA expression in Na3VO4-treated wild type (WT) spleen cells and measured IL-4R mRNA in IL-4-stimulated spleen cells of viable motheaten mice (mev/mev). It is found that IL-4-induced IL-4R mRNA ex- pression was impaired in Na3VO4-treated WT spleen cells and IL-4-stimulated mev/mev spleen cells. Here we show that the impaired IL-4-induced IL-4Rα mRNA expression was due to reduced expression of IL-4R that led to impaired STAT6 signaling. We further demonstrate that reduction of IL-4Rα protein expression in mev/mev spleen cells was due to alteration in cell compositions. In mev/mev spleen, the per- centages of CD4+, CD8+, and CD19+ cells expressing rela- tively high levels of IL-4R were reduced dramatically while the percentages of Mac-1+ and Gr-1+ cells with relative low levels of IL-4R increased greatly. Despite the profound effect of reduced expression of IL-4R protein, the IL-4Rα mRNA expression was comparable in spleen cells of littermate con- trol mice (+/?) and mev/mev mice and no differences were found in B cells, T cells, and macrophages, suggesting cell type-specific downregulation of IL-4R expression in macro- phages through a posttranscriptional mechanism. Our study suggests that SHP-1 is required for IL-4-meidated function and indirectly regulates IL-4-meidated function in spleen cells by affecting hematopoiesis.