Project description:Eusocial insects have evolved the capacity to generate adults with distinct morphological, reproductive and behavioural phenotypes from the same genome. Recent studies suggest that RNA editing might enhance the diversity of gene products at the post-transcriptional level, particularly to induce functional changes in the nervous system. Using head samples from the leaf-cutting ant Acromyrmex echinatior, we compare RNA editomes across eusocial castes, identifying ca. 11,000 RNA editing sites in gynes, large workers and small workers. Those editing sites map to 800 genes functionally enriched for neurotransmission, circadian rhythm, temperature response, RNA splicing and carboxylic acid biosynthesis. Most A. echinatior editing sites are species specific, but 8M-bM-^@M-^S23% are conserved across ant subfamilies and likely to have been important for the evolution of eusociality in ants. The level of editing varies for the same site between castes, suggesting that RNA editing might be a general mechanism that shapes caste behaviour in ants. Analysis of genome-wide RNA editing in three different female castes of the the leaf-cutting ant Acromyrmex echinatior.
Project description:Eusocial insects have evolved the capacity to generate adults with distinct morphological, reproductive and behavioural phenotypes from the same genome. Recent studies suggest that RNA editing might enhance the diversity of gene products at the post-transcriptional level, particularly to induce functional changes in the nervous system. Using head samples from the leaf-cutting ant Acromyrmex echinatior, we compare RNA editomes across eusocial castes, identifying ca. 11,000 RNA editing sites in gynes, large workers and small workers. Those editing sites map to 800 genes functionally enriched for neurotransmission, circadian rhythm, temperature response, RNA splicing and carboxylic acid biosynthesis. Most A. echinatior editing sites are species specific, but 8–23% are conserved across ant subfamilies and likely to have been important for the evolution of eusociality in ants. The level of editing varies for the same site between castes, suggesting that RNA editing might be a general mechanism that shapes caste behaviour in ants.
Project description:Leaf-cutting ants of the genera Acromyrmex and Atta live in mutualistic symbiosis with a basidiomycete fungus (Leucocoprinus gongylophorus), which they cultivate as fungal gardens in underground nest chambers. The ants provide the fungus with a growth substrate consisting of freshly cut leaf fragments. After new leaf fragments are brought into the nest, the ants chew them into smaller pieces and apply droplets of fecal fluid to the leaf pulp before depositing this mixed substrate in the fungus garden and inoculating it with small tufts of mycelium from older parts of the garden. Previous work has shown that the fecal fluid contains a range of digestive enzymes including proteases, amylases, chitinases, cellulases, pectinases, hemicellulases and laccases, and that most of these enzymes are produced by the fungal symbiont in specialized structures called gongylidia that the ants eat. After ingestion, the enzymes apparently pass unharmed through the alimentary channel of the ants and end up in the fecal fluid. Most likely this complex system is an adaptation of the ant-fungus symbiosis to a herbivorous lifestyle, as the ancient ancestors of the ants and the fungus lived as hunter-gatherers and saprotrophs, respectively. The promise of fecal fluid for getting insight into the molecular adaptations that enables the ant-fungus holosymbiont to live as a herbivore, led us to investigate the fecal fluid proteome using LC-MS/MS in order to get a more comprehensive picture of the repertoire of proteins present.
Project description:The leaf-cutter ant Acromyrmex echinatior secretes a protein layer that covers their exoskeleton and physically interacts with biotic and abiotic factors, including their symbiotic bacteria Pseudonocardia. In this study, in order to characterize both the global proteome and the externally-secreted cuticular protein layer of A. echinatior, we utilize a novel, dual-layered proteomic approach. Using diaPASEF, we quantified 4,428 proteins across four early adult stages, uncovering distinct age-dependent protein clusters enriched in muscle development, lipid metabolism, and immune-related responses. We then developed a novel acid-based extraction method to isolate the externally-secreted protein layer, identifying 323 secreted proteins via ddaPASEF acquisition, many of which were temporally upregulated and associated with various functions such as environmental stress response, microbial defense, and cuticle structural maturation. Notably, tropomyosin-family proteins were both highly enriched in the external-secretome and exhibited significant changes across the early adult timepoints, potentially linking these ion-binding molecules to the metal-enrichment processes that takes place during this crucial stage.