Adaptation Lab

Welcome to Deepa Agashe’s lab at the National Centre for Biological Sciences (NCBS), Bangalore!

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Gaurav describes new ant species

While collecting ants for his MSc thesis project on ant communities in the Andaman Islands, Gaurav Agavekar found two species of ants from the genus Tetramorium that turned out to be new to science. Along with Evan Economo’s lab at OIST Japan, he recently described these species in a paper in PeerJ. The new species – T. krishnani and T. jarawa – are named in honor of the late Prof KS Krishnan (NCBS), and the indigenous Jarawa people of the Andaman Islands. Read more about the work here.

Aparna wins award at SPEEC-Up 2017

SPEEC-Up 2017 was the first iteration of what we hope will be an annual 3-minute talk competition for students of ecology, evolution and conservation in Bangalore. The event was a lot of fun, and a great way to get introduced to a wide range of work from our neighbours. I am truly happy to have had a chance to listen to so many cool talks.

We had three competitors from the lab- Kruttika, Aparna and Rittik all gave great talks about their respective work with insect gut microbes. We’re very happy that Aparna won a runner-up prize for her talk on beetle gut microbes! Here she is, accepting her award (with joint winner Vignesh).

Aparna_SpeecUp

Open postdoctoral position

I am recruiting a postdoctoral fellow to analyze bacterial communities associated with flour beetles. The postdoctoral fellow will work with a team of researchers towards the following goals:

  • Quantify the repeatability of ecological and evolutionary changes in the gut microbiome of an insect adapting to a new diet
  • Determine the metabolic and genetic basis of the microbiome changes
  • Test the importance of inter-species associations in driving microbiome changes

The position is fully funded through a grant from the Wellcome Trust-DBT India Alliance, and will begin from January 2018 for a maximum of 5 years.

  • A background in evolutionary biology, ecology, or microbiology is essential
  • Experience with handling anaerobic microbes would be beneficial
  • Experience with coding or mathematical modeling would be beneficial
  • The ability and motivation to think and work independently is important

To apply, please write to me with the following details:

  • Your CV
  • A short paragraph (~300 words) summarizing your research interests and career goals
  • Contact information for 2 people who can write a letter of recommendation for you
  • A 1-page summary of any paper from our lab. Include your criticisms and any questions that arise from the work

Summer travel

The conference season is suddenly upon us! The lab will be out in full force this year since many of the first people to join the lab have cool results to report. Everyone has received various competitive grants to help support their travel, which is superb news! We are all looking forward to good feedback and hearing about the latest in evolutionary biology from across the world. Do come and chat if you spot us.

Kruttika and Aparna are off to the Evolution meeting in Portland, Oregon. Aparna is supported by a DST travel grant.

Mrudula, Saurabh, Gaurav and I will be at the SMBE meeting in Austin, Texas. Mrudula has a DBT travel grant, Gaurav has a DST travel grant, and Saurabh has a CSIR travel fellowship.

After SMBE, Mrudula and I will hop over to the GRC on Microbial Population Biology in New Hampshire.

Meanwhile, Saurabh will spend some time visiting labs in Boston and then attend the MBL Workshop on Molecular Evolution at Woods Hole. Saurabh has received funding support from MBL as well as CSIR.

In August, Mrudula, Gaurav and Saurabh will join me in Barcelona, Spain, to teach in the School of Molecular and Theoretical Biology.

Finally, to wrap up the summer: Aparna, Kruttika and I will participate in the ESEB meeting in Groningen, Netherlands. Aparna has received an ESEB travel award to attend this meeting.

New paper on the evolutionary implications of stress-induced mutations

Recently I wrote a Primer (a short tutorial/introduction for a subject of broad interest) to accompany a new paper in PLoS Biology demonstrating stress-specific mutation spectra in E. coli (Maharjan and Ferenci 2017). Stress-induced mutagenesis (SIM) is a fascinating phenomenon, whereby some organisms show a transient increase in mutation rates when exposed to stresses such as starvation. However, the evolutionary implications of this phenomenon have been controversial, and I give a brief introduction to this debate (and potential ways forward) in my Primer. In their paper, Maharjan and Ferenci show that not all stresses induce mutagensis, but each stress produces a unique distribution of mutational types. These results suggest that stress-specific mutation spectra may influence evolutionary trajectories in a stress-specific manner. This remains to be explicitly tested, but we are now a little bit closer to understanding the evolutionary consequences of SIM.

The Primer and the related paper are available online, if you would like to know more.

On insect-bacterial associations

Aparna, Kruttika and I recently wrote a short review article on insect bacterial associations, that was featured in the March 2017 newsletter of the Indian Society of Cell Biology. We’d like to share it here since it might be of general interest. Enjoy!

A PARTNERSHIP STORY: INSECT-BACTERIAL ASSOCIATIONS

Aparna Agarwal, Kruttika Phalnikar and Deepa Agashe

National Centre for Biological Sciences (NCBS), Bangalore

The world around us is full of microbes that influence both biotic and abiotic components of ecosystems. For instance, nitrogen-fixing bacteria enrich the soil1, and algae in marine ecosystems provide sustenance to a variety of organisms2,3. On the other hand, pathogenic bacteria cause diseases across trophic levels, changing the environment around them dramatically. Such interactions have been extensively studied for a long period of time. However, non-pathogenic host-bacterial associations also influence host physiology and even host behaviour4,5. For example, in mice, differences in gut bacterial communities determine utilization of specific dietary components and the propensity for diseases like obesity and diabetes6,7. Gut bacteria are also linked to several neurological disorders such as depression and anxiety8. Such dependence of animal hosts on their gut microbes is not limited to humans, but extends across the tree of life.

Continue reading

Announcing the SPEEC Up competition

On 31 Aug 2017, NCBS will host a one-day competition for 3-minute talks in Ecology, Evolution and Conservation. The event is jointly organized by multiple institutes in Bangalore to encourage cross-talk within local ecology circles.

If you have an interesting story from your work, consider competing! You can find more details here.

Goodbye Imroze!

We said a fond farewell to Imroze Khan, the first postdoc from the lab. Over the last 4 years or so, Imroze initiated and led work on the ecology and evolution of insect immune function. He is now an Assistant Professor at Ashoka University, where he will continue to work with insect life history and immune function.

New paper: A link between early inflammation, immune function and ageing

All organisms age. One prominent hypothesis suggests that infections experienced early in life accelerate ageing. In collaboration with Jens Rolff, Imroze tested this idea in mealworm beetles (Tenebrio molitor). He found that young beetles injected with bacterial cell components mounted an immune response that damaged their vital organs – Malpighian tubules, equivalent to kidneys – and resulted in faster ageing. Experimental down-regulation of phenoloxidase (a key component of the immune response) via RNAi allowed beetles to live longer. Similarly, older beetles infected with a live pathogen also lived longer if their immune response was suppressed. Thus, inflammation induced by immune responses may generally accelerate ageing in various contexts. These results suggest that natural selection is nearly blind to immune self-harm because its effects are felt later in life, after peak reproduction. Similar mechanisms may operate in other organisms, as ageing is a feature of most multi-cellular organisms including humans.

Read the early online version of the paper here.