scholarly journals Paramecium Diversity and a New Member of the Paramecium aurelia Species Complex Described from Mexico

Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 197 ◽  
Author(s):  
Alexey Potekhin ◽  
Rosaura Mayén-Estrada
Keyword(s):  
Central America ◽  
Sibling Species ◽  
Species Complex ◽  
Model Organism ◽  
Bacterial Symbionts ◽  
Ideal Model ◽  
Tropical Regions ◽  
Molecular Approaches ◽  
The World ◽  
Paramecium Jenningsi

Paramecium (Ciliophora) is an ideal model organism to study the biogeography of protists. However, many regions of the world, such as Central America, are still neglected in understanding Paramecium diversity. We combined morphological and molecular approaches to identify paramecia isolated from more than 130 samples collected from different waterbodies in several states of Mexico. We found representatives of six Paramecium morphospecies, including the rare species Paramecium jenningsi, and Paramecium putrinum, which is the first report of this species in tropical regions. We also retrieved five species of the Paramecium aurelia complex, and describe one new member of the complex, Paramecium quindecaurelia n. sp., which appears to be a sister species of Paramecium biaurelia. We discuss criteria currently applied for differentiating between sibling species in Paramecium. Additionally, we detected diverse bacterial symbionts in some of the collected ciliates.

scholarly journals Phylogenetic Relationship Between the Endosymbiont “candidatus Riesia Pediculicola” and Its Human Lice Host

2021 ◽  
Author(s):  
alissa hammoud ◽  
Meriem Louni ◽  
Dorothée Missé ◽  
Florence Fenollar ◽  
Oleg Mediannikov
Keyword(s):  
Evolutionary History ◽  
Housekeeping Genes ◽  
Mitochondrial Genes ◽  
Bacterial Symbionts ◽  
Pediculus Humanus ◽  
Molecular Approaches ◽  
Endosymbiotic Bacteria ◽  
Insect Phylogeny ◽  
The World ◽  
Unbalanced Diet

Abstract Background: The human louse is one of the most ancient haematophagous ectoparasites that is related intimately to its host and has been of great concern to public health throughout human history. Previously, Pediculus humanus was classified within six divergent mitochondrial clades (A, D, B, F, C and E). Like all haematophagous lice, P. humanus directly depends on the presence of bacterial symbionts, known as “Candidatus Riesia pediculicola”, to complement their unbalanced diet. In this study, we evaluated the coevolution of human lice around the world and their endosymbiotic bacteria. Using molecular approaches, we targeted lice mitochondrial genes from the six diverged clades and Candidatus R. pediculicola housekeeping genes. Methods: A total of 126 lice were selected for molecular analysis of the cytb gene for lice clade determination. In parallel, four PCR primer pairs were developed targeting three housekeeping genes of Candidatus R. pediculicola: ftsZ, groEL and two regions of the rpoB gene (rpoB-1 and rpoB-2).Results: The endosymbiont phylogeny perfectly mirrored the host insect phylogeny, using the ftsZ and rpoB-2 genes, suggesting a strict vertical transmission and a host-symbiont co-speciation following the evolutionary course of the human louse. Conclusion: Our results unequivocally indicate that lice endosymbiont have experienced a similar co-evolutionary history, and that the human louse clade can be determined by their endosymbiotic bacteria.

The Simulium metallicum species complex (Diptera: Simuliidae) in Latin America: a cytological study

1989 ◽  
Vol 67 (5) ◽  
pp. 1217-1245 ◽  
Author(s):  
Jan Conn ◽  
K. H. Rothfels ◽  
W. S. Procunier ◽  
H. Hirai
Keyword(s):  
Central America ◽  
Sibling Species ◽  
Species Complex ◽  
Chromosome Banding ◽  
Cytological Study ◽  
Onchocerca Volvulus ◽  
Species Status ◽  
Physiological Factors ◽  
The Status ◽  
The Common

Eleven members of the Simulium metallicum complex from Central America and South America are described using the polytene chromosome banding pattern of S. metallicum A as standard. The members are B from Mexico and Guatemala, C from Colombia, D and E from Venezuela, F from Panama, G from Costa Rica, H from Mexico, Guatemala, and Panama, I from Mexico and Guatemala, and J and K from Panama. A cytophylogeny separates the members into three lineages. H, I, J, and K form one lineage, separated from the standard by eight rearrangement steps. D and E form a second lineage on the basis of six fixed inversions in common. Three floating inversions characterize the common progenitor of C and G, which together form a third lineage. B is independently derived from the standard and separated from it by seven rearrangement steps. F is very close to A. Six cytotypes (A, B, H, I, J, and K) appear cytologically to be reproductively isolated and are considered sibling species. One cytotype, E, is a sibling species by virtue of cytological criteria, and possible ecological and physiological factors. The remaining four members (C, D, F, and G) are cytotypes requiring additional evidence to confirm sibling species status. Sibling A is provisionally considered to represent S. metallicum s.s.; sibling H may be S. horacioi Okazawa &Onishi. The status of members within the complex as vectors of Onchocerca volvulus is discussed.

scholarly journals First record of Amatitlania nigrofasciata (Günther, 1867) (Cichliformes: Cichlidae) as introduced species in natural freshwaters of Colombia

Check List ◽  
2016 ◽  
Vol 12 (4) ◽  
pp. 1932 ◽  
Author(s):  
Guido A. Herrera-R ◽  
Miguel A. Murcia-Castillo ◽  
Saúl Prada-Pedreros
Keyword(s):  
Introduced Species ◽  
Central America ◽  
River Basin ◽  
Fish Species ◽  
First Record ◽  
Ornamental Fish ◽  
Tropical Regions ◽  
Country Level ◽  
The World ◽  
Amatitlania Nigrofasciata

Amatitlania nigrofasciata is a small fresh­water fish species native to Central America. Is a popular ornamental fish that has been traded and cultivated for the aquarium industry, introduced into temperate and tropical regions across the world. Two specimens of A. nigrofasciata were collected from two small creeks draining into the Guavio River, upper Meta River in Mambita, Ubalá, Cundinamarca, Colombia in the Piedmont Orinoco ecoregion. This is the first record of A. nigrofasciata in natural freshwaters of Colombia and the Orinoco River basin. Diagnostic characters of species and updated distribution at country level are provided.

scholarly journals Edible Insects and Global Food Security

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 472
Author(s):  
Fabio Verneau ◽  
Mario Amato ◽  
Francesco La La Barbera
Keyword(s):  
Food Security ◽  
Central America ◽  
Mediterranean Basin ◽  
Edible Insects ◽  
African Continent ◽  
Global Food Security ◽  
The World ◽  
The Mediterranean ◽  
Global Food ◽  
The Mediterranean Basin

Starting in 2008 and lasting up until 2011, the crisis in agricultural and, in particular, cereal prices triggered a period of riots that spread from the Mediterranean basin to the rest of the world, reaching from Asia to Central America and the African continent. [...]

scholarly journals Remarkable Species Diversity of the Leafhopper Genus Xestocephalus (Hemiptera: Cicadellidae: Aphrodinae) in Thailand

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 514
Author(s):  
Zonglei Liang ◽  
Christopher H. Dietrich ◽  
Wu Dai
Keyword(s):  
New Species ◽  
Species Diversity ◽  
Single Species ◽  
Comparative Morphology ◽  
Malaise Trap ◽  
Field Sampling ◽  
Tropical Regions ◽  
Trap Field ◽  
The World ◽  
First Time

Xestocephalus Van Duzee is among the most common and widespread genera of Cicadellidae in the temperate and tropical regions of the world. In the present study, 205 specimens of the genus Xestocephalus were collected in Thailand, whereas only a single species of the genus was recorded previously using Malaise trap field sampling, studied by comparative morphology. Seventeen species were recognized, including twelve new species: X. binarius sp. nov., X. chrysanthemum sp. nov., X. cowboyocreus sp. nov., X. densprint sp. nov., X. dimiprocessus sp. nov., X. exproiecturus sp. nov., X. gracilus sp. nov., X. limpidissimus sp. nov., X. malleus sp. nov., X. nonattribus sp. nov., X. recipinams sp. nov., and X. tenusis Liang sp. nov. Four species were recorded in Thailand for the first time: Xestocephalus abyssinicus Heller and Linnavuori, Xestocephalus asper Linnavuori, Xestocephalus ishidae Matsumura, and Xestocephalus toroensis Matsumura. Detailed morphological descriptions of all 17 species are given; photographs of external habitus and male genitalia of the species from Thailand are provided. A checklist of species of the genus is also given, and a key to all Thailand Xestocephalus species is also provided.

scholarly journals High Diversity in Urban Areas: How Comprehensive Sampling Reveals High Ant Species Richness within One of the Most Urbanized Regions of the World

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 358
Author(s):  
François Brassard ◽  
Chi-Man Leong ◽  
Hoi-Hou Chan ◽  
Benoit Guénard
Keyword(s):  
Exotic Species ◽  
Urban Areas ◽  
Urban Landscapes ◽  
Dual Roles ◽  
Ant Communities ◽  
Continuous Increase ◽  
Tropical Regions ◽  
The World ◽  
Ant Diversity ◽  
The Vertical Distribution

The continuous increase in urbanization has been perceived as a major threat for biodiversity, particularly within tropical regions. Urban areas, however, may still provide opportunities for conservation. In this study focused on Macao (China), one of the most densely populated regions on Earth, we used a comprehensive approach, targeting all the vertical strata inhabited by ants, to document the diversity of both native and exotic species, and to produce an updated checklist. We then compared these results with 112 studies on urban ants to illustrate the dual roles of cities in sustaining ant diversity and supporting the spread of exotic species. Our study provides the first assessment on the vertical distribution of urban ant communities, allowing the detection of 55 new records in Macao, for a total of 155 ant species (11.5% being exotic); one of the highest species counts reported for a city globally. Overall, our results contrast with the dominant paradigm that urban landscapes have limited conservation value but supports the hypothesis that cities act as gateways for exotic species. Ultimately, we argue for a more comprehensive understanding of ants within cities around the world to understand native and exotic patterns of diversity.

scholarly journals Myxococcus xanthus as a Model Organism for Peptidoglycan Assembly and Bacterial Morphogenesis

2021 ◽  
Vol 9 (5) ◽  
pp. 916
Author(s):  
Huan Zhang ◽  
Srutha Venkatesan ◽  
Beiyan Nan
Keyword(s):  
De Novo ◽  
Myxococcus Xanthus ◽  
Model Organism ◽  
Life Stages ◽  
Negative Bacterium ◽  
Ideal Model ◽  
Daughter Cells ◽  
Bacterial Division ◽  
Cell Shapes ◽  
Rare Opportunity

A fundamental question in biology is how cell shapes are genetically encoded and enzymatically generated. Prevalent shapes among walled bacteria include spheres and rods. These shapes are chiefly determined by the peptidoglycan (PG) cell wall. Bacterial division results in two daughter cells, whose shapes are predetermined by the mother. This makes it difficult to explore the origin of cell shapes in healthy bacteria. In this review, we argue that the Gram-negative bacterium Myxococcus xanthus is an ideal model for understanding PG assembly and bacterial morphogenesis, because it forms rods and spheres at different life stages. Rod-shaped vegetative cells of M. xanthus can thoroughly degrade their PG and form spherical spores. As these spores germinate, cells rebuild their PG and reestablish rod shape without preexisting templates. Such a unique sphere-to-rod transition provides a rare opportunity to visualize de novo PG assembly and rod-like morphogenesis in a well-established model organism.

Description of Three Pristionchus Species (Nematoda: Diplogastridae) from Japan that Form a Cryptic Species Complex with the Model Organism P. pacificus

2012 ◽  
Vol 29 (6) ◽  
pp. 403 ◽  
Author(s):  
Natsumi Kanzaki ◽  
Erik J. Ragsdale ◽  
Matthias Herrmann ◽  
Werner E. Mayer ◽  
Ralf J. Sommer
Keyword(s):  
Cryptic Species ◽  
Species Complex ◽  
Model Organism ◽  
Cryptic Species Complex

UNICEF in Central America

1960 ◽  
Vol 329 (1) ◽  
pp. 69-77
Author(s):  
Alice C. Shaffer
Keyword(s):  
United Nations ◽  
Central America ◽  
International Organizations ◽  
Central American ◽  
The World ◽  
Working Together ◽  
Integrated Programs ◽  
Regional Basis ◽  
The United Nations

Central America has been one of the pioneer areas for the United Nations Children's Fund assisted pro grams. When the United Nations Children's Fund, under a broadened mandate from the United Nations, shifted the emphasis of its aid from emergency to long term and from war-torn countries to those economically less developed, Cen tral American governments immediately requested its assist ance to strengthen and extend services to children and mothers. As one of the first areas in the world to aim at the eradication of malaria and to have engaged in an inten sive campaign against malnutrition on a regional basis, the Central American experiences in these fields have become known, watched, and studied by people from many countries. Against this background, international and bilateral organi zations are working together with governments as they broaden the scope and the extent of their programs. Ten years of co-operative action have highlighted the need for train ing of personnel, both professional and auxiliary. This period has also made clear the value of more integrated programs with wider collaboration both within the ministries of government and between the international organizations.

The Development of the United Nations Law Concerning Peace-Keeping Operations

1992 ◽  
Vol 5 (2) ◽  
pp. 273-281
Author(s):  
Robert Siekmann
Keyword(s):  
Cold War ◽  
Soviet Union ◽  
United Nations ◽  
Central America ◽  
The Soviet Union ◽  
The World ◽  
New Thinking ◽  
The United Nations ◽  
The Moment ◽  
The Cold War

Especially as a consequence of the termination of the Cold War, the détente in the relations between East en West (Gorbachev's ‘new thinking’ in foreign policy matters) and, finally, the disappearance of the Soviet Union, the number of UN peace-keeping operations substantially increased in recent years. One could even speak of a ‘proliferation’. Until 1988 the number of operations was twelve (seven peace-keeping forces: UNEF ‘I’ and ‘II’, ONUC, UNHCYP, UNSF (West New Guinea), UNDOF AND UNIFIL; and five military observer missions: UNTSO, UNMOGIP, UNOGIL, UNYOM and UNIPOM). Now, three forces and seven observer missions can be added. The forces are MINURSO (West Sahara), UNTAC (Cambodia) and UNPROFOR (Yugoslavia); the observer groups: UNGOMAP (Afghanistan/Pakistan), UNIIMOG (Iran/Iraq), UNAVEM ‘I’ and ‘II’ (Angola), ONUCA (Central America), UNIKOM (Iraq/Kuwait) and ONUSAL (El Salvador). UNTAG (Namibia), which was established in 1978, could not become operational until 1989 as a result of the new political circumstances in the world. So, a total of twenty-three operations have been undertaken, of which almost fifty percent was established in the last five years, whereas the other half was the result of decisions taken by the United Nations in the preceding forty years (UNTSO dates back to 1949). In the meantime, some ‘classic’ operations are being continued (UNTSO, UNMOGIP, UNFICYP, UNDOF, and UNIFIL), whereas some ‘modern’ operations already have been terminated as planned (UNTAG, UNGOMAP, UNIIMOG, UNAVEM ‘I’ and ‘II’, and ONUCA). At the moment (July 1992) eleven operations are in action – the greatest number in the UN history ever.

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