Some days, choosing the right clothes isn't easy. It might be freezing when you leave home, but once the sun's beating down, some early morning sartorial choices might not seem so wise. And if we find diurnal temperature fluctuations stressful, spare a thought for the tiny annual killifish, trapped in its coastal desert ponds; they routinely weather 20°C temperature fluctuations. Jason Podrabsky and George Somero are fascinated by the physiological adaptations that allow creatures to survive and thrive under extreme environmental variations. Curious how the little fish's gene expression patterns change under several thermal conditions, they designed a novel gene chip, coated with 4992 killifish liver genes, to find out how the fish faired after acclimation at 20°, 26° and 37°C, and a daily temperature cycle ranging from 20–37°C over a 2 week period (p. 2237).
Using the custom made gene chip to compare mRNA samples from fish exposed to one of the four temperature regimes, with mRNA from control fish, Podrabsky and Somero found that 540 genes changed their expression patterns significantly, with different patterns in the fish exposed to a daily temperature cycle compared with fish acclimated to constant temperatures.
Grouping the genes according to their cellular functions, Podrabsky found that molecular chaperones, membrane structure and solute transporters were all affected by the temperature treatments, as well as various metabolic genes, cytoskeletal genes, genes involved in protein turnover, immune response and cell growth. Some of the genes which responded to temperature haven't even been assigned functions yet, and Podrabsky is excited by the possibility of discovering new temperature sensitive factors and pathways.
But Podrabsky is most intrigued by a single transcriptional regulator, HMGB1, which decreases its transcriptional levels tenfold as the temperature rises daily. Podrabsky suspects `HMGB1 protein may be... a highly sensitive temperature sensor' by causing a `global change in the rate of transcription'.
- © The Company of Biologists Limited 2004
References
Article navigation
Related articles
Cited by...
More in this TOC section
Similar articles
Other journals from The Company of Biologists
Welcome to JEB’s new Editor Monica Daley
We are pleased to welcome Monica Daley to JEB’s Editorial team. Monica has had a long association with JEB before taking up her new role, overseeing peer review of neuromuscular physiology, terrestrial biomechanics and integrative physiology of locomotion.
In the field with Robyn Hetem
Continuing our fieldwork series, Robyn Hetem reflects on working with species ranging from aardvark to zebra, and the impact COVID-19 has had on fieldwork.
Read & Publish participation continues to grow
“It is particularly encouraging for early career researchers, as it allows them to display their research globally without the need to find costs to cover the open access option.”
Professor Fernando Montealegre-Z (University of Lincoln) shares his experience of publishing Open Access as part of our growing Read & Publish initiative. We now have over 150 institutions in 15 countries and four library consortia taking part – find out more and view our full list of participating institutions.
Nocturnal reef residents have deep-sea-like eyes
Fanny de Busserolles and colleagues from The University of Queensland have discovered that the eyes of nocturnal reef fish have multibank retinas, layers of photoreceptors, similar to the eyes of deep-sea fish that live in dim light conditions.
Mechanisms underlying gut microbiota–host interactions in insects
In their Review, Konstantin Schmidt and Philipp Engel summarise recent findings about the mechanisms involved in gut colonisation and the provisioning of beneficial effects in gut microbiota–insect symbiosis.