From funding to the future

We’re passionate about researching a wide range of organisms at EI, and one particularly interesting group is the cichlid fish, which Tarang Mehta of the Di Palma Group has been focusing on.

Cichlids are fascinating for a multitude of reasons, particularly because they exist in such a rich number of different species that are unique to the lakes in which they reside. More fascinating still is that many of these species, from just a few common ancestors, have been evolving in separate lakes yet developing very similar strategies to coping with life in parallel environments.

Thus, Tarang received an IDS in order to better understand the genomics underlying these incredibly adaptable fish - focusing on one in particular, the soda cichlid (Alcoapia grahami).

Soda cichlids live in a place that most life would try and avoid if at all possible. That place is Lake Magadi, which is ultra-salty, has a pH of 10 and a temperature of around 40°C - all while receiving higher-than-usual UV radiation and fluctuating oxygen levels in the water. Overall, rather inhospitable.

The project, which is continually expanding, therefore aims to compare three species (A. grahami, O. mossambicus and the Nile tilapia) with different tolerances to salt and other conditions of importance for fish farming (aquaculture), in order to find out the genetic secrets that allow the soda cichlids to survive at extreme environments.

From each of the species, various body parts have been collected, including the gill, gut, operculum, liver, whole brain, eye, kidney, heart and gonads.

If you are wondering why, it’s because each of these body parts is regulated differently - and adaptation mechanisms come in all shapes and forms. By analysing and comparing the transcriptome of species, i.e. the specific genes turned on at certain times, we can better understand what is happening (genetically) - and where.

It turns out that one such adaptation that helps the soda cichlids survive in such tricky conditions is how they excrete waste. They have a different urea cycle to most other fish, which normally excrete ammonia. This isn’t possible in alkaline lakes, therefore soda cichlids actually excrete urea - from their gills. They have also adapted to tolerate the low oxygen conditions so well that they can respire using atmospheric oxygen - and can be seen gulping air from the surface of the lake.

The genetic mechanisms behind these adaptations are therefore very interesting to study.

Furthermore, this project has wider significance due to the importance of cichlid fish for food security and socio-economic stability in Africa - a continent with a very high rate of poverty and food insecurity.

The ongoing project into better understanding the genetics of cichlid fish, along with the development of a Tanzania Aquaculture Resolution, is allowing EI to be at the heart of an international collaboration helping to promote and foster better aquaculture practises in Tanzania - a country home to a vast array of cichlid biodiversity.

This project will not only help us better understand how evolutionary processes can shape adaptation to extremes, but also how we can preserve native biodiversity and provide better nutrition and livelihoods for people through sustainable aquaculture programmes.

Cereal rusts are a devastating plant disease also known as the ‘polio of agriculture’. Rusts are parasitic fungi associated with many crop failures and famine throughout history. In particular, ‘stem rust’ - a cereal rust usually found in warmer climates - did not affect the large number of people dependent on wheat for sustenance for many decades.

In 1999, an epidemic caused by a very aggressive form of stem rust on wheat emerged and is currently spreading across Africa, Asia and the Middle East. Its spread poses a significant threat to global food security. Most of the wheat grown around the world is vulnerable to this epidemic. In areas susceptible to disease development, losses are often severe (average 50% to highest 90%) over a large area and individual fields can be totally destroyed.

In temperate climates, the environmental conditions and farming practices have not supported large-scale stem rust epidemics so far. However, climate and epidemiology models predict that stem rust will become widespread as far north as Scotland by 2050. This is supported by recent events where in 2013, Germany experienced its first major outbreak of stem rust in 50 years and Nature published an article in response to an unusually devastating strain being found in Sicily.

Scientists at the Norwich Research Park have developed a cutting edge technology to track cereal rusts: ‘Field Pathogenomics’ – a genomics-driven surveillance method to obtain a genetic fingerprint from samples collected in the field and determine their relation. This information is vital for detecting changes in the rust disease, ensuring breeders, farmers and agronomists have access to the best possible information.

This helps them to be prepared for new outbreaks and effectively manage rusts by breeding new generations of plants which can withstand the disease. Through this IDS funding we are expanding our remit to use our Field Pathogenomics technology to investigate stem rust and get to “know our enemy”. This will help establish the likely global migration routes of stem rust and characterise its future threat.

Although emergent diseases are spreading, we certainly have a better toolkit than ever before when it comes to understanding and responding to them. Further updates will be presented on this research once the grant’s publication is released later in the year.