The water flea Daphnia pulex (Cladocera, Daphniidae), a possible model organism to evaluate aspects of freshwater ecosystems

Crustaceana ◽  
2019 ◽  
Vol 92 (11-12) ◽  
pp. 1415-1426
Author(s):  
Juan-Alejandro Norambuena ◽  
Jorge Farías ◽  
Patricio De los Ríos
Keyword(s):  
Phylogenetic Trees ◽  
Daphnia Pulex ◽  
Model Organism ◽  
Freshwater Ecosystems ◽  
Intraspecific Diversity ◽  
Molecular Tools ◽  
Water Flea ◽  
Future Studies ◽  
Molecular Studies

Abstract Daphnia pulex is a freshwater planktonic crustacean, allegedly a cosmopolitan species, which is found in lentic ecosystems. The aim of this study was to conduct a literature review of D. pulex related to its life history and genetic variability, in order to mark a route for future studies. We noted that D. pulex is a model species on which ecological studies have been carried out, as well as molecular studies, in which its molecular diversity has been characterized and such in specimens from different environments: both pristine and under human influence. In particular those studies are highlighted, in which molecular tools have been used to construct phylogenetic trees for study intraspecific differences. Also, in some of these molecular studies, analyses of genetic, inter- and intraspecific diversity have been performed. In addition, analyses of protein expression in D. pulex and related species seem promising in evaluating the detailed role of this species.

scholarly journals Revisiting the past − novel insight into intraspecific molecular diversity and phylogeny of widespread Echinogammarus berilloni

2020 ◽  
pp. 46
Author(s):  
Kamil Hupało
Keyword(s):  
Molecular Diversity ◽  
Model Organism ◽  
Genetic Data ◽  
Intraspecific Diversity ◽  
Future Studies ◽  
Genetic Lineages ◽  
The Past ◽  
High Level ◽  
Taxonomic Studies ◽  
Insight Into

Echinogammarus berilloni (Catta, 1878) is a widespread and euryecious species, inhabiting large parts of Southwestern Europe. Additionally, it is recognized as one of the non-native and invasive species, increasing its range to Central Europe. Even though it is widely used as a model organism in a variety of ecological and ecotoxicological studies, its intraspecific molecular diversity has been overlooked. In this study, the publicly available genetic data reveal high level of intraspecific diversity, supporting presence of up to four phylogenetically distinct genetic lineages. Furthermore, the results indicate that the taxon is not monophyletic. The importance of considering its intraspecific diversity is discussed, highlighting the potential implications for future studies as well as the need for further detailed taxonomic studies.

scholarly journals Introduction and synthesis: plant phylogeny and the origin of major biomes

2004 ◽  
Vol 359 (1450) ◽  
pp. 1455-1464 ◽  
Author(s):  
R. Toby Pennington ◽  
Quentin C. B. Cronk ◽  
James A. Richardson
Keyword(s):  
Phylogenetic Trees ◽  
Environmental Changes ◽  
Sequence Data ◽  
Long Distance ◽  
Future Studies ◽  
Biogeographic Patterns ◽  
Dna Sequence Data ◽  
History Of ◽  
Time Of Origin

Phylogenetic trees based upon DNA sequence data, when calibrated with a dimension of time, allow inference of: (i) the pattern of accumulation of lineages through time; (ii) the time of origin of monophyletic groups; (iii) when lineages arrived in different geographical areas; (iv) the time of origin of biome–specific morphologies. This gives a powerful new view of the history of biomes that in many cases is not provided by the incomplete plant fossil record. Dated plant phylogenies for angiosperm families such as Leguminoaceae (Fabaceae), Melastomataceae sensu stricto , Annonaceae and Rhamnaceae indicate that long–distance, transoceanic dispersal has played an important role in shaping their distributions, and that this can obscure any effect of tectonic history, previously assumed to have been the major cause of their biogeographic patterns. Dispersal from other continents has also been i mportant in the assembly of the Amazonian rainforest flora and the Australian flora. Comparison of dated biogeographic patterns of plants and animals suggests that recent long–distance dispersal might be more prevalent in plants, which has major implications for community assembly and coevolution. Dated plant phylogenies also reveal the role of past environmental changes on the evolution of lineages in species–rich biomes, and show that recent Plio–Pleistocene diversification has contributed substantially to their current species richness. Because of the critical role of fossils and morphological characters in assigning ages to nodes in phylogenetic trees, future studies must include careful morphological consideration of fossils and their extant relatives in a phylogenetic context. Ideal study systems will be based upon DNA sequence data from multiple loci and multiple fossil calibrations. This allows cross–validation both of age estimates from different loci, and from different fossil calibrations. For a more complete view of biome history, future studies should emphasize full taxon sampling in ecologically important groups, and should focus on geographical areas for which few species–level phylogenies are available, such as tropical Africa and Asia. These studies are urgent because understanding the history of biomes can both inform conservation decisions, and help predict the effects of future environmental changes at a time when biodiversity is being impacted on an unprecedented scale.

Mesophyll conductance: the leaf corridors for photosynthesis

2020 ◽  
Vol 48 (2) ◽  
pp. 429-439 ◽  
Author(s):  
Jorge Gago ◽  
Danilo M. Daloso ◽  
Marc Carriquí ◽  
Miquel Nadal ◽  
Melanie Morales ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Main Role ◽  
Mesophyll Conductance ◽  
Future Studies ◽  
Cell Structures ◽  
Leaf Tissues ◽  
Change Framework ◽  
Chloroplast Stroma

Besides stomata, the photosynthetic CO2 pathway also involves the transport of CO2 from the sub-stomatal air spaces inside to the carboxylation sites in the chloroplast stroma, where Rubisco is located. This pathway is far to be a simple and direct way, formed by series of consecutive barriers that the CO2 should cross to be finally assimilated in photosynthesis, known as the mesophyll conductance (gm). Therefore, the gm reflects the pathway through different air, water and biophysical barriers within the leaf tissues and cell structures. Currently, it is known that gm can impose the same level of limitation (or even higher depending of the conditions) to photosynthesis than the wider known stomata or biochemistry. In this mini-review, we are focused on each of the gm determinants to summarize the current knowledge on the mechanisms driving gm from anatomical to metabolic and biochemical perspectives. Special attention deserve the latest studies demonstrating the importance of the molecular mechanisms driving anatomical traits as cell wall and the chloroplast surface exposed to the mesophyll airspaces (Sc/S) that significantly constrain gm. However, even considering these recent discoveries, still is poorly understood the mechanisms about signaling pathways linking the environment a/biotic stressors with gm responses. Thus, considering the main role of gm as a major driver of the CO2 availability at the carboxylation sites, future studies into these aspects will help us to understand photosynthesis responses in a global change framework.

Motives for Social Isolation Following a Negative Emotional Episode

2018 ◽  
Vol 77 (3) ◽  
pp. 127-131
Author(s):  
Gérald Delelis ◽  
Véronique Christophe
Keyword(s):  
Social Isolation ◽  
Social Affiliation ◽  
Semantic Categorization ◽  
Future Studies ◽  
Cognitive Regulation ◽  
Emotional Event ◽  
Regulation Strategies ◽  
Emotional Events

Abstract. After experiencing an emotional event, people either seek out others’ presence (social affiliation) or avoid others’ presence (social isolation). The determinants and effects of social affiliation are now well-known, but social psychologists have not yet thoroughly studied social isolation. This study aims to ascertain which motives and corresponding regulation strategies participants report for social isolation following negative emotional events. A group of 96 participants retrieved from memory an actual negative event that led them to temporarily socially isolate themselves and freely listed up to 10 motives for social isolation. Through semantic categorization of the 423 motives reported by the participants, we found that “cognitive clarification” and “keeping one’s distance” – that is, the need for cognitive regulation and the refusal of socioaffective regulation, respectively – were the most commonly and quickly reported motives for social isolation. We discuss the findings in terms of ideas for future studies aimed at clarifying the role of social isolation in health situations.

Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

2012 ◽  
Vol 39 (2) ◽  
pp. 217-233 ◽  
Author(s):  
J. David Archibald
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Phylogenetic Trees ◽  
Charles Darwin ◽  
The Other ◽  
Charles Lyell ◽  
Single Origin ◽  
Molecular Studies ◽  
Richard Owen ◽  
First Time

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

scholarly journals Detection of Rickettsia raoultii in Dermacentor reticulatus and Haemaphysalis inermis ticks in Slovakia

Biologia ◽  
2021 ◽  
Author(s):  
Basma Ouarti ◽  
Basma El Hamzaoui ◽  
Michal Stanko ◽  
Maureen Laroche ◽  
Oleg Mediannikov ◽  
...  
Keyword(s):  
Potential Role ◽  
Animal Health ◽  
Molecular Study ◽  
Dermacentor Reticulatus ◽  
Experimental Models ◽  
Molecular Tools ◽  
Future Studies ◽  
Rickettsia Raoultii ◽  
Pathogenic Agents ◽  
Transmission Models

AbstractTicks are vector arthropods responsible for the transmission of several pathogenic agents that affect both human and animal health worldwide. In this study our objective was to analyse, using molecular tools, the bacterial community of Dermacentor reticulatus and Haemaphysalis inermis ticks collected in south-eastern Slovakia. Using real-time PCR, we identified the presence of Rickettsia spp. DNA at levels of 14/59 (23.72 %) and 29/173 (16.76 %) in D. reticulatus and H. inermis, respectively. In addition, using standard PCR and sequencing, we identified the presence of Rickettsia raoultii DNA in 13 ticks belonging to the two investigated species. Rickettsia raoultii blast results revealed an average identification percentage of 99.62 %. Following the results of this molecular study there is a possibility that D. reticulatus and H. inermis play a potential role in the transmission of R. raoultii. To prove the possibility of validity of this hypothesis, we suggest performing experimental models in future studies. Our results can serve as preliminary data for future transmission models.

scholarly journals “Les copains *dit au revoir”: On Subject–Verb Agreement in L2 French and Cross-Linguistic Influence

Languages ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 7
Author(s):  
Malin Ågren ◽  
Marie-Eve Michot ◽  
Cyrille Granget ◽  
Sonia Gerolimich ◽  
Pascale Hadermann ◽  
...  
Keyword(s):  
Second Language Acquisition ◽  
Oral Narrative ◽  
Complex Interplay ◽  
Verb Morphology ◽  
Future Studies ◽  
Proficiency Levels ◽  
Verb Agreement ◽  
Significant Difference ◽  
L2 Development

This study focuses on the production of subject–verb (SV) agreement in number in L2 French and investigates the role of cross-linguistic influence (CLI) in this particular morphosyntactic domain. CLI is a well-known phenomenon in Second Language Acquisition (SLA) research but it has rarely been investigated systematically in relation to SV agreement in French. The participants of the study are 114 learners with Italian, German, Dutch and Swedish as L1. The source languages are all inflectional languages but they vary in terms of morphological richness in the verb paradigm, ranging from very poor (Swedish) to very rich (Italian). The participants performed an oral narrative task contrasting singular and plural contexts of SV agreement. Results indicate a significant difference between L1 groups in terms of correct SV agreement but they also show that the overall presence of rich verb morphology in the L1 does not, on its own, result in a more correct SV agreement. It is when comparing learners at two different proficiency levels that we observe differences in the rate of L2 development, which may be explained as an effect of CLI. Overall, results indicate a complex interplay of different factors, where the role of CLI must be further investigated in future studies in relation to L2 French.

Phylogenetic relationships among Halymenia (Halymeniaceae, Rhodophyta) species on the Brazilian coast with description of Halymenia cearensis sp. nov.

Phytotaxa ◽  
2016 ◽  
Vol 280 (3) ◽  
pp. 241 ◽  
Author(s):  
CAROLINA ANGÉLICA ARAÚJO DE AZEVEDO ◽  
VALÉRIA CASSANO ◽  
MARIANA CABRAL OLIVEIRA
Keyword(s):  
Species Diversity ◽  
Phylogenetic Relationships ◽  
Brazilian Coast ◽  
Molecular Tools ◽  
Ecological Data ◽  
Cortical Cells ◽  
Broad Base ◽  
Molecular Studies ◽  
Marine Flora ◽  
Inner Cortex

Phylogenetic relationships and species diversity within the genus Halymenia along the Brazilian coast were investigated through molecular and morphological analyses. Molecular studies included UPA, COI-5P and rbcL markers. A total of five Halymenia species were found: Halymenia cearensis sp. nov., H. ignifera, H. pinnatifida, H. silviae and H. cf. mirabilis. Halymenia cearensis was molecularly distinct from all other Halymenia species included in this study and is morphologically characterized by: cleft, lobate, oblong or obovate blades with broad base; apex irregular in shape; surface with bullations, rugosities, spiny and globular papillae irregularly distributed; abundant and conspicuous ganglionic cells throughout; blades up to 800 µm thick at base; outer cortical cells ellipsoidal or ovoid in shape, higher than broad; and inner cortex cells 4–25 µm in width. Our phylogeny demonstrated that entities attributed to H. floridana and H. elongata occurring in Brazil correspond to two distinct genera, which was also supported by morphological and ecological data. The use of molecular tools was crucial to provide a better understanding of the diversity of Brazilian marine flora.

scholarly journals The Japanese empathy questionnaire (EmQue) for preschool children: Psychometric properties and measurement invariance across gender

2021 ◽  
pp. 016502542110228
Author(s):  
Reina Takamatsu ◽  
Yung-Ting Tsou ◽  
Takashi Kusumi ◽  
Carolien Rieffe
Keyword(s):  
Preschool Children ◽  
Measurement Invariance ◽  
Japanese Version ◽  
Developmental Models ◽  
Future Studies ◽  
Human Motivation ◽  
Confirmatory Factor ◽  
High Measurement ◽  
Gender Groups

Empathy is assumed to be a universal human motivation to act altruistically toward others. Developmental models of empathy explaining when and how children acquire the capacity to empathize have been proposed. However, the existing knowledge is largely built upon studies conducted in the Western context. To fill this gap, a cross-culturally validated measure of empathy for children is needed. The purpose of this study was to assess the Japanese version of the Empathy Questionnaire (EmQue), a parent-reported measure of empathy in preschool children, including its construct validity, measurement invariance across genders, and reliability. A total of 550 children aged 1–6 years participated in this study ( M age = 4.17 years, SD = 1.21). Their mothers completed the Japanese EmQue. Confirmatory factor analysis confirmed the hypothesized three-factor structure (emotional contagion, attention to others’ feelings, and prosocial actions) in the 13-item Japanese EmQue. The internal consistencies of the three scales were high. Measurement invariance across gender groups was also supported. Overall, the results demonstrate that the Japanese EmQue is a reliable and valid measure of the empathy of Japanese preschool children. It can serve as a tool in future studies to elucidate the role of culture in shaping empathy in early childhood.

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