Biology subjects

Seal, J. N.

Publications and source records attributed to Seal, J. N..

3 recordsLinked to original sources

bioRxiv2026

Phylosymbiosis and the hologenome in fungus-gardening ants

Hosts and their microbiomes can be extensively integrated so that they behave across evolutionary scales as a single unit or as a hologenome. Hosts and their associated microbiomes can potentially exhibit concordance among their respective phylogenetic histories, a phenomenon known as phylosymbiosis. The obligate symbiosis of fungus-gardening ants represents a complex symbiotic system as there are two macroscopic hosts that have associated microbiomes. Here we apply 16S rRNA gene analysis of microbiomes in combination with phylogenetic analysis of nuclear genes and SNPs (single nucleotide polymomorphisms) of hosts to determine the extent to which phylosymbiosis characterizes the coevolution among ant hosts, fungal symbionts and bacterial microbiomes of five species of fungus-gardening ants. The strongest evidence of phylosymbiosis (i.e., congruent topologies between host phylogenetics and microbiome structure) was found between ants and ant-associated microbiomes. While fungal phylogenies and microbiome dendrograms were correlated, these correlations were not topologically congruent. We conclude that phylosymbiosis is present between the ant hosts and their ant-associated microbiome and this would be the strongest evidence of the hologenome concept within the attine symbiosis.

evolutionary biology↗

bioRxiv2026

Atta Leafcutter Ants are Fine-Scale Bioindicators of Geographic and Seasonal Climate Changes Across the Americas

AimWe develop Atta leafcutter-ants as bioindicators that respond at fine scales to geographic and seasonal climate changes in the Americas, thereby addressing the paucity of versatile insect bioindicator systems capable of monitoring climate in both Southern and Northern Hemispheres. LocationAmerican tropics and sub-tropics from latitudes S33.6{degrees} to N33.2{degrees}, with case studies from Colombia, Mexico, and southern USA. Time Period2012-2024. Taxon StudiedAtta leafcutter-ants. MethodsWe elucidate biogeographic patterns of mating-flight phenology of Atta leafcutter-ants across the entire Atta range from Uruguay/Argentina to the USA, using 2335 records of Atta reproductives from the community database iNaturalist, then ground-truth these patterns by comparison with (i) mating-flight records (n=806) from the Atta literature; and (ii) mating-flight observations (n=836) accumulated by a consortium of experts who have researched Atta for a combined 1000+ work-years. Onset of mating flights can be timed with great precision in Atta populations because mass-mating flights are synchronized and triggered by the first major rainfall of a rainy season. ResultsBiogeographic patterns in climate-dependent mating-flight phenologies recorded at iNaturalist are corroborated by observations accumulated in the literature and by Atta experts. Analyses reveal so-far unknown gradients in mating-flight phenology (e.g., Colombia to USA) that are correlated to geographic climate gradients, and season switches of mating flights from early to late in the year between proximate Atta populations (e.g., 200 kilometers apart), for example in the climatically complex Andean regions of Colombia. Regional differences in Atta mating-flight phenology correspond to temporal differences in rainfall between ecoregions of Colombia. Main ConclusionsAtta ants are tractable insect bioindicators to monitor climate impacts with detailed spatial and temporal resolution across a 9200-kilometer trans-equatorial transect in the Americas. We outline future research directions to explore climate-dependent biology using the continuously growing, and now ground-truthed, information at iNaturalist on Atta mating behavior.

ecology↗

bioRxiv2024

Forage preference in two geographically co-occurring fungus gardening ants: a dietary DNA approach

Traditional methods of forage identification are impractical with non-leafcutting fungus gardening ants, making diet-related ecological and life history questions difficult to study. To address this limitation, we utilized dietary DNA metabarcoding on excavated ant fungus gardens to generate forage diversity metrics for the two co-occurring species Trachymyrmex septentrionalis and Mycetomoellerius turrifex. Ten fungus garden samples from each species were collected from a 60x70 m plot in East Texas. Each of the colonies we sampled was paired with a colony from the other species within 3 m of it. Plant forage diversity was assessed with chloroplast trnL primers, and insect frass forage diversity was assessed with mitochondria COI primers. DNA metabarcoding identified a total of 44 plant taxa across all samples, but performed poorly when characterizing foraged insect frass. Plant beta diversity was significantly different between the gardens of T. septentrionalis and M. turrifex colonies, as well as paired colonies. Colony pairs also had significantly different plant alpha diversity. This indicates that diet preference is likely driven both by ant species-specific plant preference, and colony location-specific plant resource availability. Overall, our results show that dietary DNA techniques are a promising tool for the identification of plant forage in ant fungus gardens, enabling the study of future diet-based ecological and natural history questions.

ecology↗