首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 312 毫秒
1.
To investigate the evolutionary relationships among species of Afrotrichloris, Apochiton, Coelachyrum, Dinebra, Eleusine, Leptochloa, and Schoenefeldia of subtribe Eleusininae, a phylogeny based on DNA sequences from nine gene regions (ITS, rps16-trnK, rps3, rps16, rpoC2, rpl32-trnL, ndhF, ndhA, ccsA) is presented. Previous molecular phylogenies indicated that Coelachyrum was polyphyletic and Schoenefeldia was paraphyletic, with Afrotrichloris embedded within it. Apochiton burttii was embedded in the Coelachyrum clade paired with C. longiglume, Coelachyrumpoiflorum was placed outside of Coelachyrum and sister to Eleusine, and Schoenefeldia is paraphyletic, with its two species forming a grade sister to Afrotrichoris. Our molecular phylogeny supports recognition of a new genus, Schoenefeldiella, and a new combination, Schoenfeldiella transiens. In addition, we provide generic emendations for Coelachyrum, which now includes five species including a new combination proposed here, Coelachyrum burttii, and Eleusine, which now includes 11 species.  相似文献   

2.
3.
4.
5.
6.
Potassium can stabilize the formation of chair- or edge-type quadruplex DNA structures and appears to be the only naturally occurring cation that can do so. As quadruplex DNAs may be important in the structure of telomere, centromere, triplet repeat and other DNAs, information about the details of the potassium–quadruplex DNA interactions are of interest. The structures of the 1:1 and the fully saturated, 2:1, potassium–DNA complexes of d(GGTTGGTGTGGTTGG) have been determined using the combination of experimental NMR results and restrained molecular dynamics simulations. The refined structures have been used to model the interactions at the potassium binding sites. Comparison of the 1:1 and 2:1 potassium:DNA structures indicates how potassium binding can determine the folding pattern of the DNA. In each binding site potassium interacts with the carbonyl oxygens of both the loop thymine residues and the guanine residues of the adjacent quartet.  相似文献   

7.
8.
The review on bacteriocins of Gram negative and Gram positive bacteria. Criteria making it possible to regard antagonistic substances as bateriocins or bacteriocin-like substances and on their classification are presented. Examples of bacteriocins naming depending on the taxonomic position of the producer culture are given. Information on the physico-chemical and biological properties of bacteriocins and their purification is presented as well as on detection tools of bacteriocins in microorganisms and evaluation of the producer activity of the bacteriological culture.  相似文献   

9.
10.
Ladakh is India’s link with the exotic past. Popularly known as little Tibet or Western Tibet, Ladakh is one of the richest centres of Buddhist art and culture. It has its own deep-rooted traditions, which have been protected and practised for centuries. The present communication puts on record some of the traditional ladakhi preparations that have been used for hundreds of years. Those described are (1) beverages — chhang and gur gur cha; (2) narcotics — berzeatsink, staspakchek, techepakchiatzen, zimpating, and lingeatzish; and (3) foods — khambir, kholaq, mok mok, and thukpa.  相似文献   

11.
Functions of gelsolin: motility, signaling, apoptosis, cancer   总被引:19,自引:0,他引:19  
Several new members of the gelsolin family have been discovered in the past year. Determination of the structure of gelsolin and identification of lysophosphatidic acid as a negative regulator provide novel functional insights. Gelsolin is an obligate downstream effector of Rac for motility in dermal fibroblasts, regulates phosphoinositide signaling pathways and ion channel function in vivo, and acts as both a regulator and effector of apoptosis.  相似文献   

12.
13.
14.
15.
The dictyopharid planthopper tribe Aluntiini s.l. is revised and reclassified into two tribes: Aluntiini s.s. and Arjunini Song & Szwedo trib. nov. The tribe Aluntiini s.s. includes five genera: Aluntia Stål, 1866; D endrophora Melichar, 1903 stat. rev. ; Dictyomorpha Melichar, 1912; Indodictyophara Liang & Song, 2012; and Madagascaritia Song & Liang gen. nov. The new tribe Arjunini comprises two genera – Arjuna Muir, 1934 and Pippax Emeljanov, 2008 – both moved from Aluntiini s.l. Four new species – A luntia longicephalica Song & Szwedo sp. nov. , Madagascaritia angusta Song & Liang sp. nov. , Arjuna maai Song & Wang sp. nov. , and Arjuna muiri Song & Wang sp. nov. – are described. A morphologically based phylogenetic analysis is undertaken for Aluntiini, Arjunini, and the representatives of Dictyopharini, Hastini, Orthopagini, and the fossil Worskaitini within Dictyopharinae, all distributed in the Old World. A matrix of 129 characters of the habitus, coloration, head, thorax, and male and female genitalia of the adults was used for the cladistic analysis. The phylogenetic results show that Aluntiini s.l. as placed in Dictyopharidae is well supported, but it is distinctly paraphyletic and should be separated into two unambiguous tribes. A palaeotropical distribution pattern displayed by Aluntiini is suggested. The origin and diversification of Aluntiini are discussed preliminarily. © 2015 The Linnean Society of London  相似文献   

16.
17.
Morphological character analyses indicate that Rhyacichthyidae, Odontobutidae, Eleotridae, and Xenisthmidae are the basal families within the perciform suborder Gobioidei. This study uses DNA sequence data to infer the relationships of genera within these families, as well as determine the placement of more derived gobioids (family Gobiidae) and the identity of the outgroup to Gobioidei. Complete sequences of the mitochondrial ND1, ND2, COI, and cyt b genes (4397 base pairs) are analyzed for representatives of 27 gobioid genera and a variety of perciform and scorpaeniform outgroup candidates; the phylogeny is rooted with a beryciform as a distal outgroup. The single most parsimonious tree that results indicates that, of the outgroups sampled, the perciform family Apogonidae is most closely related to Gobioidei. Gobioidei is monophyletic, and Rhyacichthys aspro is the most basal taxon. The remainder of Gobioidei is resolved into clades corresponding to the families Odontobutidae (plus Milyeringa) and Eleotridae+Xenisthmidae+Gobiidae. Within Eleotridae, the subfamily Butinae (minus Milyeringa) is paraphyletic with respect to Gobiidae, and Eleotrinae is paraphyletic with respect to Xenisthmidae. Other than these groupings, the primary disagreement with the current morphology-based classification is that the molecular data indicate that the troglodytic Milyeringa should be placed in Odontobutidae, not Butinae, although support for this placement is weak. The most basal lineage of Gobioidei is known from the freshwaters of the Indo-Pacific, with marine-dwelling lineages arising several times independently in the group. The phylogeny also indicates that different gobioid lineages are distributed in Asia, Africa, Madagascar and the Neotropics. Five sister pairs of basal gobioid species inhabit Atlantic and Pacific drainages of Panama, with widely varying divergences.  相似文献   

18.
Chronic inflammation induced by Helicobacter pylori infection is a critical factor in the development of peptic ulcer disease and gastric cancer. Central to this inflammation is the initiation of pro‐inflammatory signaling cascades within epithelial cells, in particular those mediated by two sensors of bacterial cell wall components, nucleotide‐binding oligomerization domain‐containing protein 1 (NOD1) and alpha‐protein kinase 1 (ALPK1). H pylori is, however, also highly adept at mitigating inflammation in the host, thereby restricting tissue damage and favoring bacterial persistence. H pylori modulates host immune responses by altering cytokine signaling in epithelial and myeloid cells, which results in increased proliferation of regulatory T cells and downregulation of effector T‐cell responses. H pylori vacuolating cytotoxin A (VacA) has been shown to play an important role in the dampening of immune responses and induction of immune tolerance capable of protecting against asthma. It is also possible to generate protective immune responses by immunization with various H pylori antigens or their epitopes, in combination with an adjuvant, though this for now has only been shown in mouse models. Novel non‐toxic adjuvants, consisting of modified bacterial enterotoxins or nanoparticles, have recently been developed that may not only enhance vaccine efficacy, but also help translate candidate vaccines to the clinic. This review will summarize the main discoveries in the past year regarding host immune responses to H pylori infection, as well as the design of new vaccine approaches against this infection.  相似文献   

19.
《Geobios》1999,32(4):538
  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号