scholarly journals Adaptación e incertidumbre ambiental

2019 ◽  
Author(s):  
Manuel Serra ◽  
María José Carmona ◽  
Eduardo Moisés García-Roger ◽  
Raquel Ortells
Keyword(s):  
Life Cycle ◽  
Biological Diversity ◽  
Evolutionary Ecology ◽  
Complex Life Cycle ◽  
Model Organisms ◽  
Uncertain Environments ◽  
Sexual And Asexual Reproduction ◽  
The Face ◽  
Survival And Reproduction ◽  
Inland Water Bodies

Studying evolution in the face of environmental uncertainty is crucial to understand biological diversity, because diversifying life strategies is key to survival and reproduction in uncertain environments. Rotifers are planktonic microinvertebrates that live in inland water bodies. Their complex life cycle combines sexual and asexual reproduction and, together with their small size and short generation times, makes them excellent model organisms in evolutionary ecology studies. Here we present field population and laboratory experimental evolution studies which show that these organisms can adapt by locally diversifying their life cycle to face unpredictable fluctuations in their environment.

Evolutionary Ecology of Odonata: A Complex Life Cycle Perspective

2012 ◽  
Vol 57 (1) ◽  
pp. 249-265 ◽  
Author(s):  
Robby Stoks ◽  
Alex Córdoba-Aguilar
Keyword(s):  
Life Cycle ◽  
Evolutionary Ecology ◽  
Complex Life Cycle ◽  
Life Cycle Perspective

Temporal effects and changes in the parasitic community of Prochilodus lineatus (Valenciennes, 1837) (Characiformes: Prochilodontidae) in a floodplain

2022 ◽  
Vol 96 ◽  
Author(s):  
Atsler Luana Lehun ◽  
Lidiany Doreto Cavalcanti ◽  
Maria de los Angeles Perez Lizama ◽  
João Otávio Santos Silva ◽  
Guilherme Pomaro Casali ◽  
...  
Keyword(s):  
Life Cycle ◽  
Environmental Changes ◽  
Complex Life Cycle ◽  
Fish Length ◽  
Intermediate Hosts ◽  
Prochilodus Lineatus ◽  
Length Relationship ◽  
Significant Difference ◽  
Upper Paraná River Floodplain ◽  
The Face

Abstract The construction of dams causes several impacts on aquatic environments, altering the flow of rivers, environmental variables, and all biota present, including parasites. Little is known about how the parasitic community can be influenced in the long term by environmental changes. In this study, it was expected that the impacts caused by environmental disturbances will be directly reflected by the composition of the parasite populations. We evaluated the change in the structure of the Prochilodus lineatus endoparasite community between two periods sampled 15 years apart in the upper Paraná River floodplain. There was a significant difference in the weight–length relationship of P. lineatus between these periods and a total of 15 species of parasites were found: 11 species in Period 1 and nine species in Period 2 and five species occurred in both periods. The species richness and diversity were higher in Period 1, and we observed that the correlation of descriptors (richness, diversity and evenness) increased with fish length in this period. In both periods, digeneans numerically dominated the parasitic community, and we verified changes in the composition of parasites between periods. Both the host and the parasites were possibly affected by the environmental impacts resulting from the construction of dams over time, and it is noteworthy that complex life cycle parasites such as Digenea and Acanthocephala require intermediate hosts to complete their life cycle, and the population responds to fluctuations in the face of modified environments.

scholarly journals Do cave orb spiders show unique behavioural adaptations to subterranean life? A review of the evidence

Behaviour ◽  
2019 ◽  
Vol 156 (10) ◽  
pp. 969-996 ◽  
Author(s):  
Thomas Hesselberg ◽  
Daniel Simonsen ◽  
Carlos Juan
Keyword(s):  
Life Cycle ◽  
Life Stage ◽  
Current Data ◽  
Complex Life Cycle ◽  
Model Organisms ◽  
Surface Phase ◽  
Cave Environment ◽  
Surface Dwelling ◽  
Behavioural Adaptations

Abstract Interest for subterranean biology has risen sharply in recent years due to the simplicity of the cave environment. However, most studies have focussed on morphology with few studies looking at behaviour. The cave orb spiders show some unique behavioural adaptations compared to other orb spiders, including rudimentary orb webs, off-web foraging and a complex life cycle with a surface phase. Here, we compare these behavioural adaptations in the European Meta menardi and Meta bourneti to similar behaviours in surface-dwelling orb spiders. We find that current data suggest (1) an extreme reduction in the number of frame threads, (2) evidence of capturing non-flying prey, but not necessarily evidence for off-web foraging and (3) dispersal through a surface-dwelling life stage, but with data lacking on the role of ballooning and their return to caves. We conclude that Meta spiders have potential as model organisms for studies on behavioural adaptations and flexibility.

Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

1989 ◽  
Vol 47 ◽  
pp. 962-963
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan
Keyword(s):  
Nervous System ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
The Social ◽  
Social And Economic Development ◽  
Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

The glycomes of Caenorhabditis elegans and other model organisms

2002 ◽  
Vol 69 ◽  
pp. 117-134 ◽  
Author(s):  
Stuart M. Haslam ◽  
David Gems ◽  
Howard R. Morris ◽  
Anne Dell
Keyword(s):  
Caenorhabditis Elegans ◽  
Current Knowledge ◽  
Structural Data ◽  
Model Organisms ◽  
Entire Genome ◽  
C Elegans ◽  
The Face ◽  
Area Of Concern ◽  
Nematode Worm

There is no doubt that the immense amount of information that is being generated by the initial sequencing and secondary interrogation of various genomes will change the face of glycobiological research. However, a major area of concern is that detailed structural knowledge of the ultimate products of genes that are identified as being involved in glycoconjugate biosynthesis is still limited. This is illustrated clearly by the nematode worm Caenorhabditis elegans, which was the first multicellular organism to have its entire genome sequenced. To date, only limited structural data on the glycosylated molecules of this organism have been reported. Our laboratory is addressing this problem by performing detailed MS structural characterization of the N-linked glycans of C. elegans; high-mannose structures dominate, with only minor amounts of complex-type structures. Novel, highly fucosylated truncated structures are also present which are difucosylated on the proximal N-acetylglucosamine of the chitobiose core as well as containing unusual Fucα1–2Gal1–2Man as peripheral structures. The implications of these results in terms of the identification of ligands for genomically predicted lectins and potential glycosyltransferases are discussed in this chapter. Current knowledge on the glycomes of other model organisms such as Dictyostelium discoideum, Saccharomyces cerevisiae and Drosophila melanogaster is also discussed briefly.

scholarly journals The ATXN2 Orthologs CID3 and CID4, Act Redundantly to In-Fluence Developmental Pathways throughout the Life Cycle of Arabidopsis thaliana

2021 ◽  
Vol 22 (6) ◽  
pp. 3068
Author(s):  
Zaira M. López-Juárez ◽  
Laura Aguilar-Henonin ◽  
Plinio Guzmán
Keyword(s):  
Arabidopsis Thaliana ◽  
Life Cycle ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Leaf Growth ◽  
Transcriptome Profiling ◽  
Developmental Pathways ◽  
Model Organisms ◽  
Key Factors

RNA-binding proteins (RBPs) are key elements involved in post-transcriptional regulation. Ataxin-2 (ATXN2) is an evolutionarily conserved RBP protein, whose function has been studied in several model organisms, from Saccharomyces cerevisiae to the Homo sapiens. ATXN2 interacts with poly(A) binding proteins (PABP) and binds to specific sequences at the 3′UTR of target mRNAs to stabilize them. CTC-Interacting Domain3 (CID3) and CID4 are two ATXN2 orthologs present in plant genomes whose function is unknown. In the present study, phenotypical and transcriptome profiling were used to examine the role of CID3 and CID4 in Arabidopsis thaliana. We found that they act redundantly to influence pathways throughout the life cycle. cid3cid4 double mutant showed a delay in flowering time and a reduced rosette size. Transcriptome profiling revealed that key factors that promote floral transition and floral meristem identity were downregulated in cid3cid4 whereas the flowering repressor FLOWERING LOCUS C (FLC) was upregulated. Expression of key factors in the photoperiodic regulation of flowering and circadian clock pathways, were also altered in cid3cid4, as well as the expression of several transcription factors and miRNAs encoding genes involved in leaf growth dynamics. These findings reveal that ATXN2 orthologs may have a role in developmental pathways throughout the life cycle of plants.

The Output of First Stage Larvae by Cats Infested with Aelurostrongylus abstrusus

1968 ◽  
Vol 42 (3-4) ◽  
pp. 295-298 ◽  
Author(s):  
J. M. Hamilton ◽  
A. W. McCaw
Keyword(s):  
Life Cycle ◽  
Great Britain ◽  
Intermediate Host ◽  
World Wide ◽  
Wide Distribution ◽  
Clinical Disease ◽  
Complex Life Cycle ◽  
Patent Period ◽  
Aelurostrongylus Abstrusus

Aelurostrongylus abstrusus, the lungworm of the cat, has a world wide distribution and has been reported from countries as far apart as America, Great Britain and Palestine. It has a complex life cycle insofar as a molluscan intermediate host is essential and it is possible that auxiliary hosts also play an important part. In Britain, the incidence of active infestation of cats with the parasite has been recorded as 19·4% (Lewis, 1927) and 6·6% (Hamilton, 1966) but the latter author found that, generally, the clinical disease produced by the parasite was of a mild nature. It is known that the average patent period of the infestation in the cat is 8–13 weeks and it seems likely that, in that time, a considerable number of first stage larvae would be evacuated. Information on that point is not available and the object of the following experiment was to ascertain the number of larvae produced by cats during the course of a typical infestation.

Autonomy and integration in complex parasite life cycles

Parasitology ◽  
2016 ◽  
Vol 143 (14) ◽  
pp. 1824-1846 ◽  
Author(s):  
DANIEL P. BENESH
Keyword(s):  
Life Cycle ◽  
Holistic Approach ◽  
Life Cycles ◽  
Complex Life Cycle ◽  
Functional Specialization ◽  
Life Stages ◽  
Free Living ◽  
New Host ◽  
Complex Life Cycles ◽  
Life Cycle Stages

SUMMARYComplex life cycles are common in free-living and parasitic organisms alike. The adaptive decoupling hypothesis postulates that separate life cycle stages have a degree of developmental and genetic autonomy, allowing them to be independently optimized for dissimilar, competing tasks. That is, complex life cycles evolved to facilitate functional specialization. Here, I review the connections between the different stages in parasite life cycles. I first examine evolutionary connections between life stages, such as the genetic coupling of parasite performance in consecutive hosts, the interspecific correlations between traits expressed in different hosts, and the developmental and functional obstacles to stage loss. Then, I evaluate how environmental factors link life stages through carryover effects, where stressful larval conditions impact parasites even after transmission to a new host. There is evidence for both autonomy and integration across stages, so the relevant question becomes how integrated are parasite life cycles and through what mechanisms? By highlighting how genetics, development, selection and the environment can lead to interdependencies among successive life stages, I wish to promote a holistic approach to studying complex life cycle parasites and emphasize that what happens in one stage is potentially highly relevant for later stages.

scholarly journals Probing Plasmodium falciparum sexual commitment at the single-cell level

2018 ◽  
Vol 3 ◽  
pp. 70 ◽  
Author(s):  
Nicolas M.B. Brancucci ◽  
Mariana De Niz ◽  
Timothy J. Straub ◽  
Deepali Ravel ◽  
Lauriane Sollelis ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Life Cycle ◽  
Single Cell ◽  
Transcriptional Profiling ◽  
Quantitative Imaging ◽  
Complex Life Cycle ◽  
Major Transitions ◽  
Transcriptional Signature ◽  
Life Cycle Stages ◽  
Parasite Populations

Background: Malaria parasites go through major transitions during their complex life cycle, yet the underlying differentiation pathways remain obscure. Here we apply single cell transcriptomics to unravel the program inducing sexual differentiation in Plasmodium falciparum. Parasites have to make this essential life-cycle decision in preparation for human-to-mosquito transmission. Methods: By combining transcriptional profiling with quantitative imaging and genetics, we defined a transcriptional signature in sexually committed cells. Results: We found this transcriptional signature to be distinct from general changes in parasite metabolism that can be observed in response to commitment-inducing conditions. Conclusions: This proof-of-concept study provides a template to capture transcriptional diversity in parasite populations containing complex mixtures of different life-cycle stages and developmental programs, with important implications for our understanding of parasite biology and the ongoing malaria elimination campaign.

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