scholarly journals Starvation Responses Throughout the Caenorhabditiselegans Life Cycle

Genetics ◽  
2020 ◽  
Vol 216 (4) ◽  
pp. 837-878
Author(s):  
L. Ryan Baugh ◽  
Patrick J. Hu
Keyword(s):  
Life Cycle ◽  
Epigenetic Inheritance ◽  
Egg Laying ◽  
Food Sources ◽  
Adult Health ◽  
Adaptive Responses ◽  
Comprehensive Overview ◽  
C Elegans ◽  
Maternal Provisioning ◽  
In The Wild

Caenorhabditis elegans survives on ephemeral food sources in the wild, and the species has a variety of adaptive responses to starvation. These features of its life history make the worm a powerful model for studying developmental, behavioral, and metabolic starvation responses. Starvation resistance is fundamental to life in the wild, and it is relevant to aging and common diseases such as cancer and diabetes. Worms respond to acute starvation at different times in the life cycle by arresting development and altering gene expression and metabolism. They also anticipate starvation during early larval development, engaging an alternative developmental program resulting in dauer diapause. By arresting development, these responses postpone growth and reproduction until feeding resumes. A common set of signaling pathways mediates systemic regulation of development in each context but with important distinctions. Several aspects of behavior, including feeding, foraging, taxis, egg laying, sleep, and associative learning, are also affected by starvation. A variety of conserved signaling, gene regulatory, and metabolic mechanisms support adaptation to starvation. Early life starvation can have persistent effects on adults and their descendants. With its short generation time, C. elegans is an ideal model for studying maternal provisioning, transgenerational epigenetic inheritance, and developmental origins of adult health and disease in humans. This review provides a comprehensive overview of starvation responses throughout the C. elegans life cycle.

scholarly journals Inter-generational consequences for growing Caenorhabditis elegans in liquid

2019 ◽  
Vol 374 (1770) ◽  
pp. 20180125 ◽  
Author(s):  
Itamar Lev ◽  
Roberta Bril ◽  
Yunan Liu ◽  
Lucila Inés Ceré ◽  
Oded Rechavi
Keyword(s):  
Caenorhabditis Elegans ◽  
Early Life ◽  
Epigenetic Inheritance ◽  
Evolutionary Medicine ◽  
C Elegans ◽  
Generational Effects ◽  
Large Populations ◽  
Two Generations ◽  
Generational Changes ◽  
In The Wild

In recent years, studies in Caenorhabditis elegans nematodes have shown that different stresses can generate multigenerational changes. Here, we show that worms that grow in liquid media, and also their plate-grown progeny, are different from worms whose ancestors were grown on plates. It has been suggested that C. elegans might encounter liquid environments in nature, although actual observations in the wild are few and far between. By contrast, in the laboratory, growing worms in liquid is commonplace, and often used as an alternative to growing worms on agar plates, to control the composition of the worms' diet, to starve (and synchronize) worms or to grow large populations for biochemical assays. We found that plate-grown descendants of M9 liquid medium-grown worms were longer than control worms, and the heritable effects were already apparent very early in development. We tested for the involvement of different known epigenetic inheritance mechanisms, but could not find a single mutant in which these inter-generational effects are cancelled. While we found that growing in liquid always leads to inter-generational changes in the worms’ size, trans-generational effects were found to be variable, and in some cases, the effects were gone after one to two generations. These results demonstrate that standard cultivation conditions in early life can dramatically change the worms' physiology in adulthood, and can also affect the next generations. This article is part of the theme issue ‘Developing differences: early-life effects and evolutionary medicine’.

RNAi pathways in the recognition of foreign RNA: antiviral responses and host–parasite interactions in nematodes

2013 ◽  
Vol 41 (4) ◽  
pp. 876-880 ◽  
Author(s):  
Peter Sarkies ◽  
Eric A. Miska
Keyword(s):  
Life Cycle ◽  
Food Sources ◽  
Rnai Pathway ◽  
Parasitic Nematodes ◽  
Antiviral Responses ◽  
In The Wild ◽  
Amplification Mechanism ◽  
Sense And Respond ◽  
Molecular Components ◽  
Host Parasite

The nematode Caenorhabditis elegans was the first animal for which RNAi (RNA interference) in response to exogenous triggers was shown experimentally and subsequently the molecular components of the RNAi pathway have been characterized in some detail. However, the function of RNAi in the life cycle of nematodes in the wild is still unclear. In the present article, we argue that RNAi could be used in nematodes as a mechanism to sense and respond to foreign RNA that the animal might be exposed to either through viral infection or through ingestion of food sources. This could be of potential importance to the life cycle of parasitic nematodes as they ingest RNA from different hosts at different points during their life cycle. We postulate that RNA ingested from the host could be used by the parasite to regulate its own genes, through the amplification mechanism intrinsic to the nematode RNAi pathway.

scholarly journals The C. elegans female state: Decoupling the transcriptomic effects of aging and sperm-status

2016 ◽  
Author(s):  
David Angeles-Albores ◽  
Daniel H. W. Leighton ◽  
Tiffany Tsou ◽  
Tiffany H. Khaw ◽  
Igor Antoshechkin ◽  
...  
Keyword(s):  
Life Cycle ◽  
Neuronal Development ◽  
Global Gene Expression ◽  
Egg Laying ◽  
Biological Aging ◽  
Wild Type ◽  
Time Points ◽  
C Elegans ◽  
Development And Differentiation ◽  
Effects Of Aging

AbstractUnderstanding genome and gene function in a whole organism requires us to fully comprehend the life cycle and the physiology of the organism in question. Although C. elegans is traditionally thought of as a hermaphrodite, XX animals exhaust their sperm and become endogenous females after 3days of egg-laying. Themolecular physiology of this state has not been as intensely studied as other parts of the life cycle, despite documented changes in behavior and metabolism that occur at this stage. To study the female state of C. elegans, we measured the transcriptomes of 1st day adult hermaphrodites; endogenous, 6th day adult females; and at the same time points, mutant fog-2(lf) worms that have a feminized germline phenotype. At these time points, we could separate the effects of biological aging from the transition into the female state. fog-2(lf) mutants partially phenocopy 6 day adult wild-type animals and exhibit fewer differentially expressed genes as they age throughout these 6 days. Therefore, fog-2 is epistatic to age as assessed by this transcriptomic phenotype, which indicates that both factors act on sperm status to mediate entry into the female state. These changes are enriched in transcription factors canonically associated with neuronal development and differentiation. Our data provide a high-quality picture of the changes that happen in global gene expression throughout the period of early aging in the worm.

How do histone modifications contribute to transgenerational epigenetic inheritance in C. elegans?

2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe
Keyword(s):  
Histone Modifications ◽  
Molecular Mechanisms ◽  
Epigenetic Inheritance ◽  
Nematode Caenorhabditis Elegans ◽  
Histone Methyltransferases ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Recent Developments ◽  
Gene Regulatory

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.

scholarly journals Observations on some biological aspects of Cicadatra persica (Cicadidae: Hemiptera) in apple fruit orchards in Erneh, Syria

2012 ◽  
Vol 44 (3) ◽  
pp. 12 ◽  
Author(s):  
Marah Ahmad Dardar ◽  
Hamzeh Mouhammad Ramadan Belal ◽  
Abedlnabi Mouhammad Basheer
Keyword(s):  
Life Cycle ◽  
Adult Emergence ◽  
Apple Fruit ◽  
Egg Laying ◽  
Egg Development ◽  
Successful Method ◽  
Biological Aspects ◽  
Fruit Orchards

<em>Cicadatra persica</em> Kirkaldy, 1909 (Hemiptera: Cicadidae) is regarded as a potential constraint to the productivity of apple fruit orchards in Erneh (33&deg;21&rsquo;N, 35&deg;52&rsquo;E), near Damascus, Syria. However, no research has been conducted on this pest. This study examined adult emergence, egg laying, and hatching periods. Adults emerged in early June, with an emergence peak in the fourth week of June 2011, and started laying eggs in mid-June. Egg development was approximately 40 days, with the first eggs hatching on 1<sup>st</sup> August 2011 and the final hatch on 17<sup>th</sup> August 2011. The simple and relatively successful method of monitoring egg development reported here may be useful for studying the nymphal ecology and life cycle of this species.

scholarly journals Dietary Choline Intake: Current State of Knowledge Across the Life Cycle

Nutrients ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1513 ◽  
Author(s):  
Alejandra Wiedeman ◽  
Susan Barr ◽  
Timothy Green ◽  
Zhaoming Xu ◽  
Sheila Innis ◽  
...  
Keyword(s):  
Life Cycle ◽  
Current Knowledge ◽  
Water Soluble ◽  
Food Sources ◽  
Soluble Form ◽  
Dietary Recommendations ◽  
Current State ◽  
Dietary Nutrient ◽  
Choline Intake ◽  
Dietary Choline

Choline, an essential dietary nutrient for humans, is required for the synthesis of the neurotransmitter, acetylcholine, the methyl group donor, betaine, and phospholipids; and therefore, choline is involved in a broad range of critical physiological functions across all stages of the life cycle. The current dietary recommendations for choline have been established as Adequate Intakes (AIs) for total choline; however, dietary choline is present in multiple different forms that are both water-soluble (e.g., free choline, phosphocholine, and glycerophosphocholine) and lipid-soluble (e.g., phosphatidylcholine and sphingomyelin). Interestingly, the different dietary choline forms consumed during infancy differ from those in adulthood. This can be explained by the primary food source, where the majority of choline present in human milk is in the water-soluble form, versus lipid-soluble forms for foods consumed later on. This review summarizes the current knowledge on dietary recommendations and assessment methods, and dietary choline intake from food sources across the life cycle.

scholarly journals Learning a non-neutral conditioned stimulus: place preference in the crab Neohelice granulata

2020 ◽  
Author(s):  
Martín Klappenbach ◽  
Candela Medina ◽  
Ramiro Freudenthal
Keyword(s):  
Conditioned Stimulus ◽  
Food Pellet ◽  
Place Preference ◽  
Food Sources ◽  
Long Term Memory ◽  
Target Area ◽  
Neohelice Granulata ◽  
Preference Task ◽  
In The Wild ◽  
First Time

AbstractIn the wild, being able to recognize and remember specific locations related to food sources and the associated attributes of landmarks is a cognitive trait important for survival. In the present work we show that the crab Neohelice granulata can be trained to associate a specific environment with an appetitive reward in a conditioned place preference task. After a single training trial, when the crabs were presented with a food pellet in the target quadrant of the training arena, they were able to form a long-term memory related to the event. This memory was evident at least 24 h after training and was protein-synthesis dependent. Importantly, the target area of the arena proved to be a non-neutral environment, given that animals initially avoided the target quadrant. In the present work we introduce for the first time an associative one-trial memory paradigm including a conditioned stimulus with a clear valence performed in a crustacean.

scholarly journals Luqin-like RYamide peptides regulate food-evoked responses in C. elegans

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Hayao Ohno ◽  
Morikatsu Yoshida ◽  
Takahiro Sato ◽  
Johji Kato ◽  
Mikiya Miyazato ◽  
...  
Keyword(s):  
Critical Role ◽  
Egg Laying ◽  
Serotonergic Neuron ◽  
Pacemaker Neurons ◽  
C Elegans ◽  
Peptide Signaling ◽  
Multiple Organs ◽  
Locomotory Behavior ◽  
Control Food ◽  
And Control

Peptide signaling controls many processes involving coordinated actions of multiple organs, such as hormone-mediated appetite regulation. However, the extent to which the mode of action of peptide signaling is conserved in different animals is largely unknown, because many peptides and receptors remain orphan and many undiscovered peptides still exist. Here, we identify two novel Caenorhabditis elegans neuropeptides, LURY-1-1 and LURY-1-2, as endogenous ligands for the neuropeptide receptor-22 (NPR-22). Both peptides derive from the same precursor that is orthologous to invertebrate luqin/arginine-tyrosine-NH2 (RYamide) proneuropeptides. LURY-1 peptides are secreted from two classes of pharyngeal neurons and control food-related processes: feeding, lifespan, egg-laying, and locomotory behavior. We propose that LURY-1 peptides transmit food signals to NPR-22 expressed in feeding pacemaker neurons and a serotonergic neuron. Our results identified a critical role for luqin-like RYamides in feeding-related processes and suggested that peptide-mediated negative feedback is important for satiety regulation in C. elegans.

scholarly journals Biology and Nutritional Indexes of Spodoptera frugiperda (Lepidoptera: Noctuidae) in Saccharine Sorghum

2019 ◽  
Vol 11 (4) ◽  
pp. 126
Author(s):  
Lauren M. Barcelos ◽  
Fabrício O. Fernandes ◽  
Caroline Lopes ◽  
Beatriz M. Emygdio ◽  
Ricardo Valgas ◽  
...  
Keyword(s):  
Life Cycle ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Biological Data ◽  
Egg Laying ◽  
Grain Production ◽  
Current Analysis ◽  
Suitable Host ◽  
Significant Difference ◽  
Lepidoptera Noctuidae

Saccharine sorghum has been analyzed as a supplementary prime matter for ethanol production, especially during the sugarcane off-season period. However, it has proven to be highly susceptible to insect attacks during the cultivation cycle. The fall armyworm should be emphasized due to its voracity and high damage capacity enhanced by feeding-caused decrease in photosynthetic area. Current analysis studies the biology and determines the nutritional indexes of Spodoptera frugiperda in saccharine sorghum. Cultivars of saccharine sorghum BRS 506, BRS 509 and BRS 511were evaluated. Duration and survival of the egg, caterpillar, pre-pupal and pupal phases were determined, coupled to weight of pupae and caterpillar, life span, fecundity and pre-egg laying period. Although S. frugiperda completed its life cycle on cultivars BRS 506 and BRS 511, egg-laying and egg feasibility rates were low, whereas insects did not lay eggs on cultivar BRS 509. There was no significant difference in feeding intake by S. frugiperda among these three sorghum cultivars. Results suggest that saccharine sorghum is not a suitable host for S. frugiperda. Biological data reveal that the three saccharine sorghum cultivars are recommended for the grain production system since the number of specimens of the next generation is low or null.

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