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bioRxiv · 10.1101/2023.08.22.554244

Conserved switch genes regulate a novel cannibalistic morph after whole genome duplication

Wighard, S.·Sommer, R. J.·Witte, H.
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Abstract

Developmental plasticity facilitates morphological and behavioural novelty, but associated regulatory mechanisms remain elusive. Nematodes have emerged as a powerful model to study developmental plasticity and its evolution. Here, we show the predatory nematode Allodiplogaster sudhausi evolved an additional third mouth morph, concomitant with whole genome duplication (WGD) and a strong increase in body size. The three mouth morphs are induced by different diets; bacteria, fungi and nematodes. CRISPR experiments indicate that regulation of the third morph involves co-option of a conserved developmental switch gene, which through WGD resulted in two mouth-form regulators. Gene dosage studies revealed a diverged role of these developmental switches, with functional redundancy and quantitative effects in the two mouth-form decisions, respectively. The third morph is cannibalistic and kills kin, whereas the other two morphs do not. Thus, the recent evolution of a new morph relies on pre-existing regulatory mechanisms and adds behavioural and social complexity. One-Sentence SummaryExperimental genetics in a nematode reveals a key role for developmental plasticity in the evolution of nutritional diversity

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Wighard, S., Sommer, R. J., Witte, H.. 2023-08-23. Conserved switch genes regulate a novel cannibalistic morph after whole genome duplication. https://doi.org/10.1101/2023.08.22.554244

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