The nature and perception of environmental cues that orchestrate the pelago-benthic life cycle in the sponge Amphimedon queenslandica: molecular and behavioural perspectives

Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?

The Condor ◽

10.1093/condor/102.1.35 ◽

2000 ◽

Vol 102 (1) ◽

pp. 35-51 ◽

Cited By ~ 27

Author(s):

Jerry D. Jacobs ◽

John C. Wingfield

Keyword(s):

Life History ◽

Life Cycle ◽

Control Systems ◽

Life Cycles ◽

Environmental Cues ◽

Endocrine Control ◽

Theoretical Approaches ◽

Life Cycle Stages ◽

Wide Range ◽

Breeding Seasons

Abstract Most organisms live in seasonal environments that fluctuate on a predictable schedule and sometimes unpredictably. Individuals must, therefore, adjust so as to maximize their survival and reproductive success over a wide range of environmental conditions. In birds, as in other vertebrates, endocrine secretions regulate morphological, physiological, and behavioral changes in anticipation of future events. The individual thus prepares for predictable fluctuations in its environment by changing life-cycle stages. We have applied finite-state machine theory to define and compare different life-history cycles. The ability of birds to respond to predictable and unpredictable regimes of environmental variation may be constrained by the adaptability of their endocrine control systems. We have applied several theoretical approaches to natural history data of birds to compare the complexity of life cycles, the degree of plasticity of timing of stages within the cycle, and to determine whether endocrine control mechanisms influence the way birds respond to their environments. The interactions of environmental cues on the timing of life-history stages are not uniform in all populations. Taking the reproductive life-history stage as an example, arctic birds that have short breeding seasons in severe environments appear to use one reliable environmental cue to time reproduction and they ignore other factors. Birds having longer breeding seasons exhibit greater plasticity of onset and termination and appear to integrate several environmental cues. Theoretical approaches may allow us to predict how individuals respond to their environment at the proximate level and, conversely, predict how constraints imposed by endocrine control systems may limit the complexity of life cycles.

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Systems Biology Approach to Model the Life Cycle ofTrypanosoma cruzi

10.1101/025510 ◽

2015 ◽

Author(s):

Alejandra Carrea ◽

Luis Diambra

Keyword(s):

Life Cycle ◽

Systems Biology ◽

Network Architecture ◽

Regulatory Networks ◽

Developmental Stages ◽

Environmental Cues ◽

Cell Fates ◽

Gene Regulatory ◽

Cell Phenotypes ◽

Optimisation Procedure

Due to recent advances in reprogramming cell phenotypes, many efforts have been dedicated to developing reverse engineering procedures for the identification of gene regulatory networks that emulate dynamical properties associated with the cell fates of a given biological system. In this work, we propose a systems biology approach for the reconstruction of the gene regulatory network underlying the dynamics of theTrypanosoma cruzi's life cycle. By means of an optimisation procedure, we embedded the steady state maintenance, and the known phenotypic transitions between these steady states in response to environmental cues, into the dynamics of a gene network model. In the resulting network architecture we identified a small subnetwork, formed by seven interconnected nodes, that controls the parasite's life cycle. The present approach could be useful for better understanding other single cell organisms with multiple developmental stages.

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Biology of the mayfly Leptophlebia cupida (Say) (Ephemeroptera: Leptophlebiidae)

Canadian Journal of Zoology ◽

10.1139/z79-131 ◽

1979 ◽

Vol 57 (5) ◽

pp. 1026-1045 ◽

Cited By ~ 34

Author(s):

Hugh F. Clifford ◽

Hal Hamilton ◽

Brian A. Killins

Keyword(s):

Life Cycle ◽

Average Particle Size ◽

Laboratory Data ◽

Fixed Number ◽

Environmental Cues ◽

Average Particle ◽

Water Stream ◽

Potential Fecundity ◽

Relative Contribution ◽

Total Potential

Leptophlebia cupida (Say) is a widely distributed and extensively reported mayfly species of North America. In the Bigoray River, a brown-water stream of Alberta, Canada, L. cupida is a univoltine species. The rate of progressing through the life cycle, i.e. predicted instar intervals, was found to be better correlated with the amount of cumulative degree days (water temperature) that the nymphs receive than with the cumulative calendar days of the life cycle. Leptophlebia subimagoes had a higher total potential fecundity per unit body size than any of the other Bigoray River mayflies.Nymphs are fine particle detritivores, ingesting about 96% detritus and 4% diatoms. Average particle size ingested was 38 μm. In the laboratory at 20 °C, there were 34 nymphal instars; but there is probably no fixed number of nymphal instars, the 34th being just one of several instars in which the nymphs, given the proper environmental cues, might transform. The first nine instars are figured.Using mainly laboratory data, we investigated the relative contribution that small individuals (< 1.5 mm) make to cohort production. This theoretical exercise indicated that the error which occurs in cohort production estimates by not adequately sampling the small individuals could be less than 10%.

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Transcriptome profiling of the demosponge Amphimedon queenslandica reveals genome-wide events that accompany major life cycle transitions

BMC Genomics ◽

10.1186/1471-2164-13-209 ◽

2012 ◽

Vol 13 (1) ◽

pp. 209 ◽

Cited By ~ 37

Author(s):

Cecilia Conaco ◽

Pierre Neveu ◽

Hongjun Zhou ◽

Mary Arcila ◽

Sandie M Degnan ◽

...

Keyword(s):

Life Cycle ◽

Transcriptome Profiling ◽

Major Life ◽

Genome Wide ◽

Amphimedon Queenslandica

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Glucose inhibits the shoot bud formation in the moss Bryum billarderi

Open Life Sciences ◽

10.2478/s11535-012-0056-x ◽

2012 ◽

Vol 7 (4) ◽

pp. 648-654

Author(s):

Arturo Zavala ◽

Netzahualcoyotl Pérez ◽

Analilia Becerra ◽

Miguel López

Keyword(s):

Life Cycle ◽

Abiotic Stresses ◽

Vascular Plants ◽

Environmental Cues ◽

Bud Formation ◽

Shoot Bud ◽

Signalling Molecules ◽

Induction Process ◽

Signalling Molecule ◽

Bud Induction

AbstractPlant development is controlled by certain factors such as nutrient availability, environmental cues and the presence of signalling molecules. It has been proposed that phytohormones interact with sugars to modulate important processes in vascular plants. Cytokinins are key hormones because they regulate a large number of metabolic events, and sugars act as regulatory signals at several points in the life cycle. Bryum bilarderi Schwägr is a moss that was isolated by our group in the central highlands of Mexico and has demonstrated the ability to tolerate abiotic stresses. To study the effect of cytokinins and their interaction with glucose in bud induction, different concentrations of cytokinins with glucose were tested. One micromolar N-6-benzylaminopurine provided the best results for bud induction, but when 100 mM glucose was added, bud formation was inhibited. This glucose concentration also favoured the spread of the protonemal colony. These data demonstrate that N-6-benzylaminopurine is more effective than kinetin in inducing buds, and that glucose plays an important role as an inhibitory signalling molecule for the bud induction process that is mediated by cytokinins in the moss B. billarderi.

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Joint temporal trends in river thermal and hydrological conditions can threaten the downstream migration of the critically endangered European eel

Scientific Reports ◽

10.1038/s41598-021-96302-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Elorri Arevalo ◽

Hilaire Drouineau ◽

Stéphane Tétard ◽

Caroline M. F. Durif ◽

Ola H. Diserud ◽

...

Keyword(s):

Life Cycle ◽

Water Temperature ◽

Environmental Changes ◽

Temporal Trends ◽

Downstream Migration ◽

Critically Endangered ◽

Environmental Cues ◽

European Eel ◽

High Discharge ◽

Silver Eels

AbstractClimate change is modifying the hydrological and thermal regimes of rivers worldwide, threatening the triggering of organisms’ key life-cycle processes. European eel (Anguilla anguilla) is a critically endangered fish species that migrates over several thousand kilometres between its rearing habitats in continental waters of Europe and North Africa and its spawning area in the Sargasso Sea. Downstream migration of adult eels occurs during periods of decreasing river water temperature associated with high discharge but changes in these environmental cues may affected eel migratory conditions. An innovative multivariate method was developed to analyse long-term datasets of daily water temperature, discharge and eel passage in two European rivers. Over the past 50 years, water temperature and discharge increased in both rivers during the downstream migration period from August to November. Silver eels preferentially migrated at temperatures between 10 and 20 °C combined with high discharge. Environmental changes have resulted in the migration of silver eels under warmer water temperatures. This example illustrates how the changes in environmental cues have led to a growing mismatch between the migratory conditions preferentially selected and those actually used, which may threaten the completion of the eel’s life cycle and ultimately the persistence of this already critically endangered species.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156791 ◽

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).

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A freeze-fracture-etched study of the physarum polycephalum plasma membrane during early formation of the macroplasmodial stage

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100147570 ◽

1993 ◽

Vol 51 ◽

pp. 346-347

Author(s):

Randolph W. Taylor ◽

Henrie Treadwell

Keyword(s):

Plasma Membrane ◽

Life Cycle ◽

Growth Phase ◽

Filter Paper ◽

Physarum Polycephalum ◽

Freeze Fracture ◽

Petri Dish ◽

Wire Screen ◽

Wide Mouth ◽

Sterile Filter

The plasma membrane of the Slime Mold, Physarum polycephalum, process unique morphological distinctions at different stages of the life cycle. Investigations of the plasma membrane of P. polycephalum, particularly, the arrangements of the intramembranous particles has provided useful information concerning possible changes occurring in higher organisms. In this report Freeze-fracture-etched techniques were used to investigate 3 hours post-fusion of the macroplasmodia stage of the P. polycephalum plasma membrane.Microplasmodia of Physarum polycephalum (M3C), axenically maintained, were collected in mid-expotential growth phase by centrifugation. Aliquots of microplasmodia were spread in 3 cm circles with a wide mouth pipette onto sterile filter paper which was supported on a wire screen contained in a petri dish. The cells were starved for 2 hrs at 24°C. After starvation, the cells were feed semidefined medium supplemented with hemin and incubated at 24°C. Three hours after incubation, samples were collected randomly from the petri plates, placed in plancettes and frozen with a propane-nitrogen jet freezer.

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