scholarly journals Morfología de plántulas de Bursera Jacq. ex L. (Burseraceae) y sus implicaciones filogenéticas

2017 ◽  
pp. 5
Author(s):  
Agustina Rosa Andrés-Hernández ◽  
David Espinosa-Organista
Keyword(s):  
Root System ◽  
Phylogenetic Analyses ◽  
Primary Root ◽  
Species Group ◽  
Root Swelling

Characters of seedlings from ten species of the genus Bursera were studied, in order to find additional taxonomic evidence. All species showed phanero-epigeal germination, developing a primary root system (axonomorphous root). Species included in section Bursera have a root swelling at basal level near the collar, and a slim hypocotyl. The cotyledonary leaves were multilobate in the ‘cuajiotes’ species group and three-lobed in species of B. simaruba complex. The species of Bursera sect. Bullockia showed a not swollen primary root system with a slim collar; a striate, lenticelled and swollen hypocotyl, and three-lobed cotyledonary leaves. There are four characters that can be considered important for phylogenetic analyses: (1) protophyll margin type, (2) protophyll venation, (3) form of cotyledonary leaves, and (4) the swolliness of the radicle. Groups like section Bullockia, the ‘cuajiotes’ and ‘mulatos’ are supported upon the distribution of characters.

African Origin of Human T-Lymphotropic Virus Type 2 (HTLV-2) Supported by a Potential New HTLV-2d Subtype in Congolese Bambuti Efe Pygmies

1998 ◽  
Vol 72 (5) ◽  
pp. 4327-4340 ◽  
Author(s):  
Anne-Mieke Vandamme ◽  
Marco Salemi ◽  
Marianne Van Brussel ◽  
Hsin-Fu Liu ◽  
Kristel Van Laethem ◽  
...  
Keyword(s):  
T Cell ◽  
Virus Type ◽  
Phylogenetic Analyses ◽  
Enzyme Linked Immunosorbent Assay ◽  
African Origin ◽  
Entire Genome ◽  
T Lymphotropic Virus ◽  
Tax Protein ◽  
Human T Cell

ABSTRACT We identified a potential new subtype within human T-cell lymphotropic virus type 2 (HTLV-2), HTLV-2d, present in members of an isolated Efe Bambuti Pygmy tribe. Two of 23 Efe Pygmies were HTLV-2 seropositive, with HTLV-2 Western blot and enzyme-linked immunosorbent assay reactivities. From one of them the entire genome of the HTLV-2 strain Efe2 could be amplified and sequenced. In all gene regions analyzed, this strain was the most divergent HTLV-2 strain, differing by 2.4% (tax/rex) to 10.7% (long terminal repeat) from both subtypes HTLV-2a and HTLV-2b, yet major functional elements are conserved. The similarity between the HTLV-2 Efe2 Gag and Env proteins and the corresponding HTLV-2a and -2b proteins is consistent with the observed serological reactivity. In the proximal pX region, one of the two alternative splice acceptor sites is abolished in HTLV-2 Efe2. Another interesting feature of this potential new subtype is that it has a Tax protein of 344 amino acids (aa), which is intermediate in length between the HTLV-2a Tax protein (331 aa) and the HTLV-2b and -2c Tax proteins (356 aa) and similar to the simian T-cell lymphotropic virus type 2 (STLV-2) PP1664 Tax protein. Together these two findings suggest a different phenotype for the HTLV-2 Efe2 strain. Phylogenetic analyses confirmed that the Pygmy Efe2 strain potentially belonged to a new and quite divergent subtype, HTLV-2d. When the STLV-2 bonobo viruses PP1664 and PanP were used as an outgroup, it was clear that the Pygmy HTLV-2 Efe2 strain had the longest independent evolution and that HTLV-2 evolution is consistent with an African origin.

scholarly journals Comprehensive Genome-Wide Association Analysis Reveals the Genetic Basis of Root System Architecture in Soybean

2020 ◽  
Vol 11 ◽  
Author(s):  
Waldiodio Seck ◽  
Davoud Torkamaneh ◽  
François Belzile
Keyword(s):  
Root System ◽  
System Architecture ◽  
Phenotypic Variation ◽  
Genetic Basis ◽  
Genome Wide Association Study ◽  
Primary Root ◽  
Root System Architecture ◽  
Genome Wide Association ◽  
Nucleotide Polymorphisms ◽  
Genome Wide

Increasing the understanding genetic basis of the variability in root system architecture (RSA) is essential to improve resource-use efficiency in agriculture systems and to develop climate-resilient crop cultivars. Roots being underground, their direct observation and detailed characterization are challenging. Here, were characterized twelve RSA-related traits in a panel of 137 early maturing soybean lines (Canadian soybean core collection) using rhizoboxes and two-dimensional imaging. Significant phenotypic variation (P < 0.001) was observed among these lines for different RSA-related traits. This panel was genotyped with 2.18 million genome-wide single-nucleotide polymorphisms (SNPs) using a combination of genotyping-by-sequencing and whole-genome sequencing. A total of 10 quantitative trait locus (QTL) regions were detected for root total length and primary root diameter through a comprehensive genome-wide association study. These QTL regions explained from 15 to 25% of the phenotypic variation and contained two putative candidate genes with homology to genes previously reported to play a role in RSA in other species. These genes can serve to accelerate future efforts aimed to dissect genetic architecture of RSA and breed more resilient varieties.

scholarly journals Evolutionary Analysis of Cystatins of Early-Emerging Metazoans Reveals a Novel Subtype in Parasitic Cnidarians

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 110
Author(s):  
Pavla Bartošová-Sojková ◽  
Jiří Kyslík ◽  
Gema Alama-Bermejo ◽  
Ashlie Hartigan ◽  
Stephen D. Atkinson ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Gene Organization ◽  
Gene Repertoire ◽  
Evolutionary Analysis ◽  
Ancestral Gene ◽  
Protein Architecture ◽  
Basal Metazoan ◽  
Cystatin Gene ◽  
Evolutionary Aspects

The evolutionary aspects of cystatins are greatly underexplored in early-emerging metazoans. Thus, we surveyed the gene organization, protein architecture, and phylogeny of cystatin homologues mined from 110 genomes and the transcriptomes of 58 basal metazoan species, encompassing free-living and parasite taxa of Porifera, Placozoa, Cnidaria (including Myxozoa), and Ctenophora. We found that the cystatin gene repertoire significantly differs among phyla, with stefins present in most of the investigated lineages but with type 2 cystatins missing in several basal metazoan groups. Similar to liver and intestinal flukes, myxozoan parasites possess atypical stefins with chimeric structure that combine motifs of classical stefins and type 2 cystatins. Other early metazoan taxa regardless of lifestyle have only the classical representation of cystatins and lack multi-domain ones. Our comprehensive phylogenetic analyses revealed that stefins and type 2 cystatins clustered into taxonomically defined clades with multiple independent paralogous groups, which probably arose due to gene duplications. The stefin clade split between the subclades of classical stefins and the atypical stefins of myxozoans and flukes. Atypical stefins represent key evolutionary innovations of the two parasite groups for which their origin might have been linked with ancestral gene chimerization, obligate parasitism, life cycle complexity, genome reduction, and host immunity.

scholarly journals AT-HOOK MOTIF NUCLEAR LOCALISED PROTEIN 18 as a Novel Modulator of Root System Architecture

2020 ◽  
Author(s):  
Marek Šírl ◽  
Tereza Šnajdrová ◽  
Dolores Gutiérrez-Alanís ◽  
Joseph G. Dubrovsky ◽  
Jean Phillipe Vielle-Calzada ◽  
...  
Keyword(s):  
Root System ◽  
System Architecture ◽  
Lateral Root ◽  
Apical Meristem ◽  
Lateral Roots ◽  
Primary Root ◽  
Root System Architecture ◽  
Root Apical Meristem ◽  
Root Initiation ◽  
Lateral Root Initiation

The AT-HOOK MOTIF NUCLEAR LOCALIZED PROTEIN (AHL) gene family encodes embryophyte-specific nuclear proteins with DNA binding activity. They modulate gene expression and affect various developmental processes in plants. We identify AHL18 (At3G60870) as a developmental modulator of root system architecture and growth. AHL18 regulates the length of the proliferation domain and number of dividing cells in the root apical meristem and thereby, cell production. Both primary root growth and lateral root development respond according to AHL18 transcription level. The ahl18 knock-out plants show reduced root systems due to a shorter primary root and a lower number of lateral roots. This change results from a higher number of arrested and non-developing lateral root primordia (LRP) rather than from decreased initiation. Overexpression of AHL18 results in a more extensive root system, longer primary roots, and increased density of lateral root initiation events. Formation of lateral roots is affected during the initiation of LRP and later development. AHL18 regulate root apical meristem activity, lateral root initiation and emergence, which is in accord with localization of its expression.

scholarly journals A re-examination of the molecular systematics and phylogeography of taxa of the Peromyscus aztecus species group, with comments on the distribution of P. winkelmanni

Therya ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 331-346
Author(s):  
C. William Kilpatrick ◽  
Nelish Pradhan ◽  
Ryan W Norris
Keyword(s):  
Phylogenetic Analyses ◽  
Distinct Species ◽  
Molecular Study ◽  
Molecular Data ◽  
Species Group ◽  
Cytb Sequence ◽  
Voucher Specimen ◽  
Cranial Measurements ◽  
Mitochondrial Cytochrome B ◽  
Isthmus Of Tehuantepec

The objectives of this study are to examine the available molecular data from the mitochondrial cytochrome-b gene (Cytb) and a concatenated dataset with this gene and two nuclear introns (Adh-1-I2 and Fgb-I7) to reexamine the systematic and phylogeographic conclusions reached by Sullivan et al. (1997) concerning the Peromyscus aztecus species group. The divergence of samples of P. aztecus oaxacensis across the Isthmus of Tehuantepec are further examined and taxonomic revisions are suggested. In addition, this study reviews the sources of data that lead to the conclusion that P. winkelmanni occurred in the Sierra Madre del Sur in Guerrero including a morphometric examination of a reported voucher. Bayesian and maximum likelihood analyses were conducted on a dataset of 31 Cytb sequences of all taxa in the P. aztecus group except for P. a. cordillerae and a concatenated dataset including five individuals of this group. Representative taxa of the P. boylii, P. mexicanus, and P. truei groups were included in both analyses. Body and cranial measurements of the voucher of the P. winkelmanni from Guerrero from which a Cytb sequence is reported to have been obtained was compared with measurements from specimens taken from the vicinity of Dos Aguas, Michoacán, including the type locality. We identified seven instances involving problematic identifications in GenBank. Once these issues were addressed, well-supported monophyletic sister clades of the P. aztecus and P. boylii species groups were recovered from phylogenetic analyses of Cytb sequences (Fig 1). Phylogenetic analyses of the Cytb and the concatenated datasets recover similar topologies that support the relationships of taxa of the aztecus group proposed by an earlier molecular study. Populations of P. a. oaxacensis southeast of the Isthmus of Tehuantepec represent a distinct species. Measurements of the voucher from Guerrero identified as the source of a P. winkelmanni Cytb sequence are smaller than P. winkelmanni for several characters. The divergent populations of P. a. oaxacensis from southeast of the Isthmus of Tehuantepec are recognized as two subspecies of P. cordillerae, P. c. cordillerae and P. c. hondurensis, whereas those northwest of the Isthmus are retained as P. a. oaxacensis. The lack of genetic divergence observed between P. a. evides and P. a. oaxacensis questions whether these two taxa should continue to be recognized as separate subspecies. Northern and southern populations of P. spicilegus demonstrate moderate divergence and additional examination of morphological and molecular differentiation within this taxon is warranted. The distribution of P. winkelmanni should be restricted to the vicinity of Dos Aguas, Michoacán, due to the lack of a voucher specimen that would confirm its reported occurrence in Guerrero.

scholarly journals Phylogenetic analysis of canine parvoviruses from Turkey

2020 ◽  
Vol 76 (01) ◽  
pp. 6334-2020
Author(s):  
ZEYNEP AKKUTAY-YOLDAR ◽  
TAYLAN KOÇ B.
Keyword(s):  
High Mortality ◽  
Phylogenetic Trees ◽  
Clinical Symptoms ◽  
Phylogenetic Analyses ◽  
Canine Parvovirus ◽  
Mortality And Morbidity ◽  
Identity Match ◽  
Genomic Characterization

Canine parvovirus (CPV) type 2 is the causative agent of acute hemorrhagic enteritis and high mortality in the affected dogs. Numerous studies have been done to understand the origin of the virus and to exhibit new variants and circulating strains. This report describes the detection and genomic characterization of CPV strains from indoor and outdoor dogs in Ankara, Turkey. Samples were sent to our laboratory due to clinical symptoms in puppies. We tested blood and swab samples to determine the presence of canine parvovirus (CPV) in three puppies and two adult dogs by reverse transcription-polymerase chain reaction (RT-PCR) using VP2 (capsid protein) region primers of canine parvoviruses. Following that, to provide molecular characterization data Maximum Likelihood (ML) method was used for phylogenetic analyses. Constructed phylogenetic trees from the aligned nucleotide sequences revealed that our CPV strains demonstrated high genetic similarities, with 100% identity match on nucleotide alignments with each other and classified in CPV-2b genotypes.They have placed on a monophyletic clade as a sister branch with CPV VAC S quantum with 98.9% nucleotide homology. Our findings suggest that CPV-2b is actual and frequently seen variant in Turkey and shows high similarities with other CPV variants and a bit less with FPVs in Turkey and around the world. CPV causes high mortality and morbidity in dogs and to develop effective vaccines for protection of dogs in Turkey where there are few numbers of studies that have been done, field strains should be isolated and characterised.

The Vietnamese population of Megophrys kuatunensis (Amphibia: Megophryidae) represents a new species of Asian horned frog from Vietnam and southern China

Zootaxa ◽  
2017 ◽  
Vol 4344 (3) ◽  
pp. 465 ◽  
Author(s):  
BENJAMIN TAPLEY ◽  
TIMOTHY CUTAJAR ◽  
STEPHEN MAHONY ◽  
CHUNG THANH NGUYEN ◽  
VINH QUANG DAU ◽  
...  
Keyword(s):  
New Species ◽  
Southern China ◽  
Phylogenetic Analyses ◽  
Eastern China ◽  
Taxonomic Status ◽  
Species Group ◽  
Type Specimens ◽  
Vietnamese Population ◽  
Group A ◽  
A New Species

The Asian frog genus Megophrys is a diverse group of morphologically conserved, forest-dwelling frogs. The genus harbours highly localised species diversification and new species continue to be described on a regular basis. We examined the taxonomic status of a population of Megophrys frogs from the Hoang Lien Range in northern Vietnam and southern China previously identified as M. kuatunensis (subgenus Panophrys). Preliminary phylogenetic analyses using a fragment of 16S rDNA places the species in question within the Megophrys (subgenus Panophrys) species group, a primarily Chinese radiation within the genus. On the basis of morphological, molecular and bioacoustic data, we conclude that this population does not represent M. kuatunensis, or any known species in the genus. We herein describe this species of Megophrys as new. Known only from Sa Pa District, Lao Cai Province in Vietnam and Jinping County, Yunnan Province in China, the new species is likely to be threatened by ongoing deforestation in the region. We provide an updated species description of M. kuatunensis based on type specimens, and suggest that M. kuatunensis is likely to be restricted to eastern China.  

DEVELOPMENTAL STUDIES ON EUPHORBIA ESULA L.: MORPHOLOGY OF THE ROOT SYSTEM

1963 ◽  
Vol 41 (5) ◽  
pp. 579-589 ◽  
Author(s):  
M. V. S. Raju ◽  
T. A. Steeves ◽  
R. T. Coupland
Keyword(s):  
Root System ◽  
Lateral Roots ◽  
Primary Root ◽  
Cambial Activity ◽  
Euphorbia Esula ◽  
Developmental Studies ◽  
Limited Growth ◽  
Mode Of Reproduction ◽  
Shoot Buds ◽  
Adverse Conditions

The significance of Euphorbia esula L. as a weed is related to its capacity to persist under adverse conditions and to its mode of reproduction. In both these properties, the root system plays an important role. The root system is initially established by seedlings. The seedling has a vigorous primary root with extensive longitudinal growth and considerable cambial activity. Such a root has been designated a "long" root. By contrast, the first lateral roots produced on the primary root have limited growth and no cambial activity. These roots have been termed "short" roots. Thus, the seedling exhibits a "heterorhizic" pattern. Lateral long roots also arise on the primary root of seedlings but their origin is delayed until cambial activity has begun. Such lateral long roots arise much earlier on seedlings growing in denuded areas than on those growing in areas covered by dense vegetation. The mature root system is described in terms of horizontal and vertical long roots, which make up the conspicuous framework of the system, and of the short roots which they produce. Long roots produce shoot-buds and the origin of these structures is delayed until cambial activity has started. Short roots do not give rise to shoot-buds. Cambial activity in long roots appears to be connected with bud production and its absence in short roots probably underlies their inability to produce buds.L'importance de Euphorbia esula L. comme mauvaise herbe est connexé a son capacité de persister dans les situations hostiles et à sa methode de reproduction. Dans ces deux caractéristiques, le système des racines a une signification profunde. Initialement le système des racines s'établit dans le semis. Le semis a une racine primaire très forte avec beaucoup de croissance longitudinale et avec une activité considérable du cambium. Une racine de cette espèce s'appelle une "longue" racine (long root). Par contre, les premières racines latérales que poussent sur la racine primaire ont croissance limité et aucun activité du cambium. Ces racines s'appellent les "courtes" racines (short roots). De cette façon, le semis montre un dessin "heterorhizique" (heterorhizic). Les longues racines latérales ont aussi leur origine sur la racine primaire du semis, mais l'origine est retardé jusqu'au commencement de l'activité du cambium. Les racines de cette espèce apparaissent beaucoup plus tôt sur les semis qui sont situés en terre sans autre végétation, que sur ceux qui sont situés au milieu des autres plantes. Le système adulte des racines se décrit sous forme des longues racines de l'espèce horizontale et verticale, lesquelles constituent la charpente bien visible du système, et des courtes racines que sont produites par les longues racines. Les longues racines produisent les bourgeons, mais l'origine des bourgeons est retardé jusqu'au commencement de l'activité du cambium dans les racines. Les courtes racines ne produisent pas les bourgeons. Il paraît que l'activité du cambium dans les longues racines soit corrélative avec l'initiation des bourgeons et l'absence du cambium dans les courtes racines explique probablement leur incapacité à produire les bourgeons.

Oogonial biometry and phylogenetic analyses of the Pythium vexans species group from woody agricultural hosts in South Africa reveal distinct groups within this taxon

2011 ◽  
Vol 115 (2) ◽  
pp. 157-168 ◽  
Author(s):  
Christoffel F.J. Spies ◽  
Mark Mazzola ◽  
Wilhelm J. Botha ◽  
Marieta Van Der Rijst ◽  
Lizel Mostert ◽  
...  
Keyword(s):  
South Africa ◽  
Phylogenetic Analyses ◽  
Species Group ◽  
Pythium Vexans

The Akodon boliviensis species group (Rodentia: Cricetidae: Sigmodontinae) in Argentina: species limits and distribution, with the description of a new entity

Zootaxa ◽  
2010 ◽  
Vol 2409 (1) ◽  
pp. 1 ◽  
Author(s):  
J. PABLO JAYAT ◽  
PABLO E. ORTIZ ◽  
JORGE SALAZAR-BRAVO ◽  
ULYSES F. J. PARDIÑAS ◽  
GUILLERMO D’ELÍA
Keyword(s):  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Species Group ◽  
Species Limits ◽  
Northwestern Argentina ◽  
Semiarid Environments ◽  
Central Argentina ◽  
The Andes ◽  
Mountain System ◽  
Living Species

Akodon, with about 42 living species, is the most diverse genus of the subfamily Sigmodontinae. The Akodon boliviensis species group includes small-bodied, morphologically similar forms inhabiting Altiplano grasslands and grassland/forest ecotones of the eastern slope of the Andes, from central Peru to central Argentina. Northwestern Argentina contains the largest diversity of species of the group; the taxonomic treatment of these species has been based largely on unsupported and some weakly based opinions as underscored by recurrent changes. Based on morphologic and molecular data we assessed species limits among Argentinean populations of the Akodon boliviensis species group. We conclude that four species of the A. boliviensis species group inhabit northwestern Argentina. These are: A. boliviensis; A. caenosus (under which we synonymyze A. aliquantulus); A. spegazzinii (of which the nominal forms alterus, leucolimnaeus, and tucumanensis are junior synonyms); and A. sylvanus. Additionally, we described here a new species of the A. boliviensis species group, Akodon polopi, which inhabits central Argentina. This is the only species of the A. boliviensis species group inhabiting the Sierras Grandes range (ca. 2000 m), mountain system of medium height, isolated (ca., 600 km) from the main Andean chain by low elevation arid and semiarid environments. Additionally, our phylogenetic analyses suggests that the Akodon varius species group is polyphyletic.

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