The role of sex differentiation in social insect caste differentiation

• Applicant: Privatdozent Dr. Jan Oettler
• Subject Area: Evolutionary Cell and Developmental Biology (Zoology) ; Evolution, Anthropology
• Term: from 2017 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 330449926

A highly sought-after question in sociobiology is how queens and workers develop from the same genetic architecture. The developmental trajectories leading to these discrete phenotypes comprise a complex network of input signals (e.g. nutrition, allelic state), mediating hormones (e.g. juvenile hormone, ecdyson), mediating pathways (e.g. target of rapamycin, insulin/insulin-like signaling) and target genes (e.g. core development genes) and the transcriptional regulation thereof (e.g. transcription factors, methylation). How these interact however is largely unclear. We recently presented an intuitive proposal based on correlative observations that highly conserved hub genes responsible for sex differentiation such as the transcription factor doublesex (dsx) gene, played a crucial role in the repeated evolutionary transition to eusociality and caste polyphenism (Klein et al., 2016). studying how the two transcription factors dsx and kr-h2, both well-known for their ability to translate variable input signals into large transcription differences using intermediate-level regulators, act in social insect caste differentiation. Using the emerging model ant Cardiocondyla obscurior, this project aims to resolve the proximate molecular foundation of eusociality.The initial C. obscurior genome grant (2011-2015) basically funded my habilitation and enabled the establishment of several lines of research of my CORE (Cardiocondyla Obscurior REsearch) group (and in the Heinze lab), namely evolutionary novelty and rapid adaptation (Schrader et al., 2014; Schrempf et al., 2015), symbiosis (Klein et al., 2015), aging (Wyschetzki et al., 2015; Oettler and Schrempf, 2016; Wyschetzki et al., 2016), a 3D model of a worker brain, the finding of selenoproteins in male accessory glands and a behavioral gene function study (Bressan et al., 2014; Fuessl et al., 2014; Oettler et al., 2015) and lastly the regulation and evolution of phenotypic plasticity (Schrader et al., 2015; Klein et al., 2016, Oettler et al. submitted (manuscript included in this proposal)). This proposal represents the first step in further development of this rich source of information.

• DFG Programme: Research Grants