Chromosome-level genome and caste transcriptomes for Africa's most widespread social wasp (Belonogaster juncea) reveal unexpected genomic diversity

Scientists have discovered previously unknown microbial species within the guts of wild African lions, shedding light on the hidden diversity of these big cats. This groundbreaking research, conducted by the Wits University in South Africa, involved analyzing 23 fecal samples from 20 lions in Namibia's Etosha National Park. The team reconstructed 318 bacterial and 102 viral genomes from the DNA they found, revealing a wealth of novel species that were not previously identified in international reference databases.

Lead author Carl Belger, who conducted the work for his master's degree, expressed his excitement about the project's significance. He noted that very few studies had explored the gut microbiome of lions before, and the question they aimed to answer was "What does the gut microbiome of lions look like?" The microbiome study was part of a broader ecological research project on Etosha's lions, where researchers collected various samples and fitted tracking collars to the animals for comprehensive data collection.

Microbiome, the community of microorganisms living in a particular environment, plays a crucial role in processes such as digestion, metabolism, and can be linked to an animal's diet, environment, and health. Modern DNA sequencing technology enables researchers to investigate these communities without growing each bacterium in a laboratory.

The computational problem of analyzing microbiome data is likened to sorting through a roomful of jigsaw puzzles with missing, damaged, and duplicated pieces. Bioinformatics methods are used to separate genetic fragments and reconstruct genomes belonging to different organisms.

The researchers were able to reconstruct high-quality bacterial and viral genomes, even for previously unidentified species. However, the classification of these genomes depended on the reference database and classification method used. Adding the newly reconstructed microbial genomes to the reference database improved classification rates significantly from 24.5% to 4.5%.

The study found microbial pathways associated with purine metabolism, which are particularly relevant to an almost entirely carnivorous animal like lions. These pathways enable the breakdown of purines like adenine and guanine to urea, highlighting the importance of microbiota in lion metabolism and health.

Understanding lion ecology, metabolism, and health requires knowledge of the organisms living inside the animals. Establishing wild animal microbiomes provides a baseline against which future changes can be compared. Future studies could explore how microbiomes change between seasons, during pregnancy, or in response to environmental stress.

The findings of this study open up potential conservation applications, as understanding the microbiome of genuinely wild animals will help scientists assess the impact of captivity on these organisms.