Biology subjects

Hanus, R.

Publications and source records attributed to Hanus, R..

4 recordsLinked to original sources

bioRxiv2026

Tracking a major evolutionary transition to superorganismality

Major transitions in evolution are associated with the loss of independent reproduction by formerly autonomous units. Termites provide a powerful system for studying this process because they exhibit diverse social systems in which worker developmental and reproductive potential declines with increasing colony-level organismality. However, the evolutionary sequence and developmental genetic basis of these transitions remain unresolved. Here, using comparative developmental transcriptomics across seven termite species that differ in workers' reproductive potential, we reconstructed the evolutionary history of termite social systems. We found that linear caste development, in which workers retain full reproductive potential, represents the ancestral state of termites. Bifurcated caste development, in which workers partially lose reproductive potential early in development, evolved independently multiple times, with two origins subsequently giving rise to superorganisms with unipotent, sterile workers. Ancestral gene regulatory network (GRN) reconstruction revealed that linear caste development evolved through retention of a juvenile-like worker state and co-option of a conserved developmental GRN characterizing hemimetabolous insect nymphal development, in which juvenile hormone, ecdysone and TGF-{beta} signaling pathways play central roles. The convergent evolution of bifurcated caste development repeatedly co-opted the GRN underlying linear caste development, heterochronically shifting its activity to earlier developmental stages. Finally, we found that the evolution of termite superorganisms involved somatization of the worker caste and co-option of a conserved endocrine GRN for terminal differentiation. Together, these findings uncovered repeated routes to reduced workers' reproductive potential through GRN co-option and highlight striking parallels between superorganism evolution in social insects and organismal evolution in metazoans.

evolutionary biology↗

bioRxiv2026

Evolutionary origin of terpenoid biosynthesis in termites

Termites produce the most diverse array of terpenoids among metazoans, comprising over 200 structures. However, their biosynthesis has not yet been elucidated. Here, we identify a gene family which arose through the duplication of geranylgeranyl pyrophosphate synthase in the common ancestor of Neoisoptera, the terpene-producing termite lineage. We functionally characterized several proteins from this family as terpene synthases generating biologically relevant sesqui-and diterpenes. These include the queen pheromone (3R,6E)-nerolidol in Embiratermes neotenicus and the precursor of polycyclic defensive diterpenes (E,E,E)-neocembrene in Nasutitermes takasagoensis. We explore transposable element-mediated genomic mechanisms and selection pressures acting in the evolution of this gene family and report an amino acid site crucial for cyclization capacity as well as the enantiospecificity of the characterized enzymes. We conclude that we have identified an enzyme family underlying the remarkable richness of termite terpenoids, which likely contributed to the ecological success of Neoisoptera.

biochemistry↗

bioRxiv2024

Identification of the trail-following pheromone receptor in termites

Chemical communication is the cornerstone of eusocial insect societies since it mediates the social hierarchy, division of labor, and concerted activities of colony members. The chemistry of social insect pheromones received considerable attention in both major groups of social insects, the eusocial Hymenoptera and termites. By contrast, current knowledge on molecular mechanisms of social insect pheromone detection by odorant receptors (ORs) is limited to hymenopteran social insects and no OR was yet functionally characterized in termites, the oldest eusocial insect clade. Here, we present the first OR deorphanization in termites. We selected four OR sequences from the previously annotated antennal transcriptome of the termite Prorhinotermes simplex (Rhinotermitidae), expressed them in Empty Neuron Drosophila, and functionally characterized using single sensillum recording (SSR) and a panel of termite semiochemicals. In one of the selected ORs, PsimOR14, we succeeded in obtaining strong and reliable responses to the main component of P. simplex trail-following pheromone, the monocyclic diterpene neocembrene. PsimOR14 showed a narrow tuning to neocembrene; only one additional compound out of 67 tested (geranylgeraniol) generated non-negligible responses. Subsequently, we used SSR in P. simplex workers and identified the olfactory sensillum specifically responding to neocembrene, thus likely expressing PsimOR14. We report on homology-based modelling of neocembrene binding by PsimOR14 and show how different ligands impact the receptor dynamicity using molecular dynamics simulations. Finally, we demonstrate that PsimOR14 is significantly more expressed in worker antennae compared to soldiers, which correlates with higher sensitivity of workers to neocembrene.

animal behavior and cognition↗

bioRxiv2024

Extended longevity of termite kings and queens is accompanied by extranuclear localization of telomerase in somatic organs and caste-specific expression of its isoforms

Kings and queens of termites are endowed with an extraordinary longevity coupled with lifelong fecundity. We recently reported that termite kings and queens display a dramatically increased enzymatic activity and abundance of telomerase in their somatic organs when compared to short-lived workers and soldiers. We hypothesized that this telomerase activation may represent a non-canonical pro-longevity function, independent of its canonical role in telomere maintenance. Here, we explore this avenue and investigate whether the presumed non-canonical role of telomerase may be due to alternative splicing of the catalytic telomerase subunit TERT and whether the subcellular localization of TERT isoforms differs among organs and castes in the termite Prorhinotermes simplex. We empirically confirm the expression of four in silico predicted splice variants (psTERT1-A, psTERT1-B, psTERT2-A, psTERT2-B), defined by N-terminal splicing implicating differential localizations, and C-terminal splicing giving rise to full-length and truncated isoforms. We show that the transcript proportions of the psTERT are caste- and tissue-specific and that the extranuclear full-length isoform TERT1-A is relatively enriched in the soma of neotenic kings and queens compared to their gonads and to the soma of workers. We also show that extranuclear TERT protein quantities are significantly higher in the soma of kings and queens compared to workers, namely due to the cytosolic TERT. Independently, we confirm by microscopy the extranuclear TERT localization in somatic organs. We conclude that the presumed pleiotropic action of telomerase combining the canonical nuclear role in telomere maintenance with extranuclear functions is driven by complex TERT splicing.

molecular biology↗