bacteria – AdaptationLab

New paper: Costs and benefits of evolved immune responses

1 October 2021Posted in Achievements, PapersTagged bacteria, beetles, immune function, insect, pathogen, tradeoff

Arun’s paper reporting the detailed costs and benefits of evolved immune priming is now published! In an exciting earlier study, we had found that flour beetles exposed to the pathogen Bacillus thuringiensis adapted rapidly via the evolution of either immune priming or pathogen resistance. The new work – led by Arun (now at Edinburgh University) and Imroze Khan (now at Ashoka University) – aimed to test whether these distinct evolved immune responses were costly for a suite of fitness-related traits, and whether these costs could explain how the responses evolved. While we find that immune priming does impose some fitness costs, increased basal resistance appears to be surprisingly cost-free. As a bonus, we found that the enhanced level of immune priming was also transferred across generations. The project involved a ton of painstaking work and careful analysis, and we are all quite proud of the paper. Give it a read!

New paper: Mistranslation can be good!

20 March 202012 June 2020Posted in PapersTagged bacteria, microbe, mistranslation, stress, translation, tRNA

Our work on ‘useful’ mistakes in bacteria (E. coli) is finally out! Laasya and Parth found that making rebel proteins not encoded by our DNA can be a good thing. In cells that frequently make mistakes, the accumulated ‘junk’ proteins end up triggering a high alert situation. This allows the cells to better deal with various external assaults (like increased temperature, damage to DNA and so on). When everything is normal this isn’t a big deal; in fact the junk makes cells mildly sick. Under stress though, the high alert and error prone cells get the upper hand, leaving behind the more accurate (but less prepared) regular cells. For more: read the paper, and an NCBS news article. And, enjoy this summary cartoon from Pranjal Gupta that was featured on the journal cover!

New paper: Methylobacterium distribution shaped by host rice

10 March 202012 June 2020Posted in PapersTagged bacteria, host-microbe association, Methylobacterium, microbe, microbial distribution, Natural microbes

Bacteria are so small and so ubiquitous that it seems like they should be found everywhere. But recent work shows that much like animals and plants, most bacteria have discrete distributions. We asked: does host association shape bacterial distribution in nature? In Pratibha’s first paper from the lab, we describe how bacteria from the genus Methylobacterium are distributed across nearly 40 different rice landraces from Arunachal Pradesh and Manipur. Collaborating with the labs of Shivaprasad and Radhika at NCBS, we found that bacterial carbon-use phenotypes are largely shaped by the landrace they inhabit. Suprisingly, sugar availability on rice leaves does not correlate with the carbon-use phenotypes, leaving us with many new questions. For more, read the paper. Meanwhile, enjoy this lovely illustration by Pranjal Gupta!

New paper: The little inhabitants of mighty dragon(flies)

11 December 201912 June 2020Posted in PapersTagged bacteria, host-microbe association, insect, microbe, microbiome

Rittik Deb and Ashwin Nair’s paper on the gut bacterial communities of dragonflies is out! We sampled several species of dragonflies from different locations in India, and found that gut bacterial communities varied across host species, location, and season. For some of the dragonflies, we were also able to analyse gut contents, and found that these “generalist predators” eat quite different meals that probably end up introducing distinct bacteria in their guts. So, unlike in most other insects, dragonfly gut bacterial communities seem to be transient and are neutrally assembled (rather than host-selected). Read the paper for more details. Meanwhile, enjoy this beautiful summary of the paper by Pranjal Gupta!