Value of the Hydra model system for studying symbiosis

Kovačević, Goran

doi:10.1387/ijdb.123510gk

Cited by 34 publications

(22 citation statements)

References 81 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Exposure of brown and green Hydra to increasing concentration of aluminium was genotoxic as determined by the Comet assay (Kovačević, 2007). The brown were more sensitive to aluminium than green Hydra, showing again a protective role of symbiosis to metals and the evolutionary advantage provided by symbiosis (see in this issue Kovacevic, 2012). Indeed, DNA tail length and intensity changes were stronger in brown than in green Hydra.…”

Section: Dna Integritymentioning

confidence: 73%

“…Moreover, the number of germ cells increased with a concomitant drop in the number of somatic cells. Interestingly, the Chlorella algae symbiosis with H. viridis was also shown to influence regeneration and sexual differentiation in polyps (Habetha et al, 2003; see in this issue Kovacevic, 2012). Under a low feeding regime, asexual growth was reduced in polyps lacking the algae, suggesting increased food assimilation.…”

Section: Reproductionmentioning

confidence: 94%

See 1 more Smart Citation

Hydra, a model system for environmental studies

Quinn¹,

Gagné²,

Blaise³

2012

Int. J. Dev. Biol.

View full text Add to dashboard Cite

Hydra have been extensively used for studying the teratogenic and toxic potential of numerous toxins throughout the years and are more recently growing in popularity to assess the impacts of environmental pollutants. Hydra are an appropriate bioindicator species for use in environmental assessment owing to their easily measurable physical (morphology), biochemical (xenobiotic biotransformation; oxidative stress), behavioural (feeding) and reproductive (sexual and asexual) endpoints. Hydra also possess an unparalleled ability to regenerate, allowing the assessment of teratogenic compounds and the impact of contaminants on stem cells. Importantly, Hydra are ubiquitous throughout freshwater environments and relatively easy to culture making them appropriate for use in small scale bioassay systems. Hydra have been used to assess the environmental impacts of numerous environmental pollutants including metals, organic toxicants (including pharmaceuticals and endocrine disrupting compounds), nanomaterials and industrial and municipal effluents. They have been found to be among the most sensitive animals tested for metals and certain effluents, comparing favourably with more standardised toxicity tests. Despite their lack of use in formalised monitoring programmes, Hydra have been extensively used and are regarded as a model organism in aquatic toxicology.

show abstract

Section: Dna Integritymentioning

confidence: 73%

Section: Reproductionmentioning

confidence: 94%

Hydra, a model system for environmental studies

Quinn¹,

Gagné²,

Blaise³

2012

Int. J. Dev. Biol.

View full text Add to dashboard Cite

show abstract

“…By 24 hours the number will return to uncut control levels but only for the smallest strains of green Hydra. The possible evolutionary significance of this is discussed in Bossert and Dunn (1986) and Kovacevic (2012).…”

Section: Protocol 15 Detection Of Symbiotic Algae In Cells Of Hydra Vmentioning

confidence: 93%

How to use Hydra as a model system to teach biology in the classroom

Bossert¹,

Galliot²

2012

Int. J. Dev. Biol.

View full text Add to dashboard Cite

As scientists it is our duty to fight against obscurantism and loss of rational thinking if we want politicians and citizens to freely make the most intelligent choices for the future generations. With that aim, the scientific education and training of young students is an obvious and urgent necessity. We claim here that Hydra provides a highly versatile but cheap model organism to study biology at any age. Teachers of biology have the unenviable task of motivating young people, who with many other motivations that are quite valid, nevertheless must be guided along a path congruent with a 'syllabus' or a 'curriculum' . The biology of Hydra spans the history of biology as an experimental science from Trembley's first manipulations designed to determine if the green polyp he found was plant or animal to the dissection of the molecular cascades underpinning, regeneration, wound healing, stemness, aging and cancer. It is described here in terms designed to elicit its wider use in classrooms. Simple lessons are outlined in sufficient detail for beginners to enter the world of 'Hydra biology' . Protocols start with the simplest observations to experiments that have been pretested with students in the USA and in Europe. The lessons are practical and can be used to bring 'life' , but also rational thinking into the study of life for the teachers of students from elementary school through early university. KEY WORDS: ecology, evolution and developmental biology education, science policy, authentic assessment, inquiry-based learning, student portfolio How the authors met the Hydra model systemIn the USA, Patricia Bossert taught Biology on Long Island for 35 years, making Hydra her accomplice for many of those years. Initially trained as a classroom teacher, she decided to go back to academic studies after 15 years of teaching and, with the support of her family (husband, mother and two young sons), she performed a PhD in Ecology and Evolution in the laboratory of Lawrence B. Slobodkin at Stony Brook University. During this period she gained a deeper appreciation of the amazing potential of Hydra to address ecological and evolutionary issues experimentally (Bossert and Dunn, 1986;Slobodkin and Bossert, 1991) as well as its outstanding value for stimulating the curiosity of even the youngest students while also providing a challenging model for older students to perform authentic investigations. Thanks to her original approach that combined ecology and evolution with molecular strategies, several of them obtained prizes in national and international scientific competitions. This led her to be recruited by Stony Brook University as an expert for mentoring teachers to do research using Hydra; focusing on students from families of lower socio-economic Int. J. Dev. Biol. 56: 637-652 (2012) doi: 10.1387/ijdb.123523pb www.intjdevbiol.com *Address correspondence to: Brigitte Galliot. Department of Genetics and Evolution, University of Geneva, Switzerland. e-mail: brigitte.galliot@unige.ch Abbreviations used in this pa...

show abstract

“…Green hydra (H. viridissima) are special among hydra because they form stable symbioses with photosynthetic algae (zoochlorellae belonging to different species; Kovacevic 2012). The algae provide their hosts with photosynthates in the form of maltose (Kovacevic 2012), which helps green hydra to survive periods of low food availability (e.g. Cook and Kelty 1982).…”

Section: Animals and Culture Conditionsmentioning

confidence: 99%

Life history trade‐offs and stress tolerance in green hydra (Hydra viridissima Pallas 1766): the importance of nutritional status and perceived population density

Tökölyi

Rosa

Bradács

et al. 2014

Ecological Research

View full text Add to dashboard Cite

Life history trade-offs and stress tolerance in green hydra (Hydra viridissima Pallas 1766): the importance of nutritional status and perceived population density Abstract Clonally reproducing animals, such as freshwater hydra, can achieve very quick population growth, potentially resulting in high density when dispersal is limited. The reproductive value of any offspring produced clonally in such a high density population is low because of the strong competition for food. Therefore, animals experiencing such conditions should allocate their resources to self-maintenance, to increase survival chances. Increased allocation to self-maintenance in turn should enable animals to withstand higher levels of genotoxic stress. To test this prediction, we exposed green hydra (Hydra viridissima Pallas 1766) to a perceived high density (by keeping them in crowded culture medium) or low density (fresh culture medium) without altering food availability. We also manipulated nutritional status (by starving animals for different time periods) and previous exposure to mild stress in a full factorial experimental design. At the end of the experiment we exposed animals to a high concentration of hydrogen-peroxide and scored stress tolerance. We found that stress tolerance is greatly elevated in animals perceiving high density, confirming our prediction. Stress tolerance decreased in animals starved for a few days, suggesting that the ability to maintain an elevated stress tolerance function has nutritional costs and is possible only when resource availability is high. On the other hand, previous exposure to mild stress had a small effect on the ability to tolerate subsequent exposure to stress, and only in the low density treatment group. Thus, stress tolerance in hydra is dynamically modulated in response to social, environmental and nutritional cues.

show abstract

Value of the Hydra model system for studying symbiosis

Cited by 34 publications

References 81 publications

Hydra, a model system for environmental studies

Hydra, a model system for environmental studies

How to use Hydra as a model system to teach biology in the classroom

Life history trade‐offs and stress tolerance in green hydra (Hydra viridissima Pallas 1766): the importance of nutritional status and perceived population density

Contact Info

Product

Resources

About