Maximization of evolutionary trends for placental viviparity in the spadenose shark,Scoliodon taticaudus

1993 ◽  
Vol 38 (1-3) ◽  
pp. 269-294 ◽  
Author(s):  
John P. Wourms
Keyword(s):  
Evolutionary Trends

scholarly journals EVOLUTIONARY TRENDS IN HETEROPTERA

Evolution ◽  
1969 ◽  
Vol 23 (2) ◽  
pp. 357-358
Author(s):  
Herbert H. Ross
Keyword(s):  
Evolutionary Trends

scholarly journals Functional alterations caused by mutations reflect evolutionary trends of SARS-CoV-2

2021 ◽  
Author(s):  
Liang Cheng ◽  
Xudong Han ◽  
Zijun Zhu ◽  
Changlu Qi ◽  
Ping Wang ◽  
...  
Keyword(s):  
Reference Genome ◽  
Sequence Data ◽  
Purifying Selection ◽  
Virus Genome ◽  
Receptor Binding Domain ◽  
Evolutionary Trends ◽  
Synonymous Mutations ◽  
Almost All ◽  
Virus Strains ◽  
New Mutations

Abstract Since the first report of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019, the COVID-19 pandemic has spread rapidly worldwide. Due to the limited virus strains, few key mutations that would be very important with the evolutionary trends of virus genome were observed in early studies. Here, we downloaded 1809 sequence data of SARS-CoV-2 strains from GISAID before April 2020 to identify mutations and functional alterations caused by these mutations. Totally, we identified 1017 nonsynonymous and 512 synonymous mutations with alignment to reference genome NC_045512, none of which were observed in the receptor-binding domain (RBD) of the spike protein. On average, each of the strains could have about 1.75 new mutations each month. The current mutations may have few impacts on antibodies. Although it shows the purifying selection in whole-genome, ORF3a, ORF8 and ORF10 were under positive selection. Only 36 mutations occurred in 1% and more virus strains were further analyzed to reveal linkage disequilibrium (LD) variants and dominant mutations. As a result, we observed five dominant mutations involving three nonsynonymous mutations C28144T, C14408T and A23403G and two synonymous mutations T8782C, and C3037T. These five mutations occurred in almost all strains in April 2020. Besides, we also observed two potential dominant nonsynonymous mutations C1059T and G25563T, which occurred in most of the strains in April 2020. Further functional analysis shows that these mutations decreased protein stability largely, which could lead to a significant reduction of virus virulence. In addition, the A23403G mutation increases the spike-ACE2 interaction and finally leads to the enhancement of its infectivity. All of these proved that the evolution of SARS-CoV-2 is toward the enhancement of infectivity and reduction of virulence.

Evolutionary trends in limbic structures

1983 ◽  
Vol 7 (3) ◽  
pp. 367-374 ◽  
Author(s):  
Heinz Stephan
Keyword(s):  
Evolutionary Trends ◽  
Limbic Structures

scholarly journals Molecular diversity and evolutionary trends of cysteine-rich peptides from the venom glands of Chinese spider Heteropoda venatoria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Luo ◽  
Yiying Ding ◽  
Zhihao Peng ◽  
Kezhi Chen ◽  
Xuewen Zhang ◽  
...  
Keyword(s):  
Expressed Sequence Tags ◽  
Molecular Diversity ◽  
Insect Pests ◽  
Phylogenetic Analyses ◽  
Spider Venom ◽  
Evolutionary Trends ◽  
The Family ◽  
Venom Glands ◽  
Venom Evolution ◽  
Expressed Sequence

AbstractHeteropoda venatoria in the family Sparassidae is highly valued in pantropical countries because the species feed on domestic insect pests. Unlike most other species of Araneomorphae, H. venatoria uses the great speed and strong chelicerae (mouthparts) with toxin glands to capture the insects instead of its web. Therefore, H. venatoria provides unique opportunities for venom evolution research. The venom of H. venatoria was explored by matrix-assisted laser desorption/ionization tandem time-of-flight and analyzing expressed sequence tags. The 154 sequences coding cysteine-rich peptides (CRPs) revealed 24 families based on the phylogenetic analyses of precursors and cysteine frameworks in the putative mature regions. Intriguingly, four kinds of motifs are first described in spider venom. Furthermore, combining the diverse CRPs of H. venatoria with previous spider venom peptidomics data, the structures of precursors and the patterns of cysteine frameworks were analyzed. This work revealed the dynamic evolutionary trends of venom CRPs in H. venatoria: the precursor has evolved an extended mature peptide with more cysteines, and a diminished or even vanished propeptides between the signal and mature peptides; and the CRPs evolved by multiple duplications of an ancestral ICK gene as well as recruitments of non-toxin genes.

Nondispersive Protein Bodies in Sieve Elements: A Survey and Review of their Origin, Distribution and Taxonomic Significance

IAWA Journal ◽  
1991 ◽  
Vol 12 (2) ◽  
pp. 143-175 ◽  
Author(s):  
H.-Dietmar Behnke
Keyword(s):  
Electron Microscope ◽  
Protein Bodies ◽  
Evolutionary Trends ◽  
Taxonomic Significance ◽  
Additional Species ◽  
Sieve Elements ◽  
P Protein ◽  
Taxonomic Range ◽  
Characteristic Features

Nondispersive protein bodies present in the sieve elements in addition to dispersive P-protein are characteristic features of many woody dicotyledons; their origin may be nuclear or cytoplasmic. While nuclear nondispersive protein bodies are found in only two families, the Boraginaceae and Myristicaceae, bodies of cytoplasmic origin are present in 39 of the more than 350 families screened. These results were obtained from 228 dicotyledons studied with the electron microscope and data of additional species from the literature. The terminology, origin, form and distribution of nondispersive protein bodies are discussed. Their ultrastructural composition is described as being predominantly spindle-shaped, compound- spherical, rod-shaped and rosette-like. Based on the data accumulated from over 450 species (of about 3000 screened) it is evident that their taxonomic range is confined to a few dicotyledon superorders. Compound-spherical nondispersive protein bodies are characteristic of most of the Malvanae/Violanae; spindle-shaped forms are restricted to the Fabaceae (Rutanae). Rosanae-Proteanae-Myrtanae and the Magnolianae are the only other superorders that contain nondispersive protein bodies in several of their families. Evolutionary trends and possible taxonomic consequences implied in this distribution are discussed.

scholarly journals EVOLUTIONARY TRENDS IN THE FRUITING HEAD OF COMPOSITAE

Evolution ◽  
1950 ◽  
Vol 4 (2) ◽  
pp. 103-109 ◽  
Author(s):  
M. Zohaey
Keyword(s):  
Evolutionary Trends

Ludlow (Silurian) lithistid and hexactinellid sponges, Cape Phillips Formation, Canadian Arctic

1991 ◽  
Vol 28 (12) ◽  
pp. 2042-2061 ◽  
Author(s):  
Tim A. de Freitas
Keyword(s):  
Canadian Arctic ◽  
Evolutionary Trends ◽  
The Family ◽  
Cape Phillips Formation ◽  
Canal Systems ◽  
Structural Simplicity ◽  
Lithistid Sponge ◽  
Hexactinellid Sponges

Abundant hexactinellid and lithistid sponges occur in Ludlow (Silurian) platform slope strata of the Cape Phillips Formation, Canadian Arctic Islands. The following are new: in the Anthaspidellidae Miller, 1889, rhodesispongia simplex n.gen and sp., Climacospongia snowblindella n.sp., and Climacospongia undulata n.sp.; in the Sphaerocladina Schrammen, 1910, Caryospongia tuberosa n.sp.; in the Hexactinellida Schmidt, 1870 Malumispongium? cornwallisi n.sp., of the monospecific superfamily Malumispongium Rigby, 1967. Other previously described sponges recognized in the study assemblage include Hindia sphaeroidalis Duncan, 1879 and Caryospongia juglans Rauff, 1894. These occur in association with abundant Archaeoscyphia sp. in thin, laterally extensive lithistid sponge biostromes which throve on platform slope sediments during the Late Silurian. Based on the dominant dendroclone forms in the skeletons of these and other genera, Anthaspidellidae can be divided informally into two groups: (i) the polyclonids, possessing complex skeletons built of variable dendroclones types, including I-, X-, and Y-shape dendroclones, and accessory spicules, including rhizoclones, chiastoclones, and monactines; and (ii) the monoclonids, possessing simpler parenchymal canal systems and skeletons constructed mainly of I-shaped (amphiarborescent) dendroclones and lacking accessory spicules. The classification, based chiefly on skeletal architecture, suggests two main evolutionary trends in the family. The monoclonids generally maintained structural simplicity, inherited from the probable ancestral monactinellid, whereas the polyclonids evolved a varied and complex skeletal architecture that was more successful.

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