Most animals detect ambient light using their cephalic eyes as photosensory organs. However, some animals have different types of photosensors in other parts of their body. The marine gastropod Peronia verruculata possesses several types of extraocular photosensors such as dorsal eyes, dermal photoreceptors, and brain photosensory neurons. In the present study, we identified a pair of follicle-shaped structures expressing Gq-rhodopsin in the lateral lobe of the brain in Peronia. This structure had numerous microvilli and a few cilia in its interior, which is reminiscent of the follicle gland in the lateral lobe of the brain of the pond snail, Lymnaea. Retinal binding protein and retinochrome were localized to the cell bodies of the neurons that constitute this structure. The photoresponses were recorded in an isolated brain by extracellular recording, and the spike frequency increased in a light-intensity-dependent manner. We thus named this structure the follicle photoreceptive organ (FPO). We also found that the FPO was positioned close to the optic nerve projecting from the stalk eye and had nerve connections with the optic nerve. We discuss our findings in the context of the epistellar body of octopus and the parolfactory vesicles of squid, as well as the follicle gland of Lymnaea.
A photosensory structure in the brain of the systellomatophoran gastropod Peronia verruculata
Announcing the 2024 JEB Outstanding Paper Prize shortlist and winner
Every year JEB celebrates early-career researchers through the Outstanding Paper Prize. We recognise the shortlisted ECRS that contributed to 11 remarkable studies published in 2024 and congratulate the winner, Elise Laetz, from University of Groningen. See how else JEB supports and promotes ECRs.
Inside the Intergovernmental Panel on Climate Change with Hans-Otto Pörtner
During the past two decades, Hans-Otto Pörtner has steered climate change policy as a co-Chair of IPCC Working Group II. He tells us about the experience in this Perspective.
Photosynthesis turns symbiotic sea anemone's tentacles toward sun
Snakelocks sea anemones point their tentacles, packed with symbiotic algae, toward the sun so their lodgers can photosynthesize, and now Vengamanaidu Modepalli & colleagues have discovered that photosynthesis by the algae guides their host's tentacles towards the sun.
History of our journals
As our publisher, The Company of Biologists, turns 100 years old, read about JEB’s history and explore the journey of each of our sister journals: Development, Journal of Cell Science, Disease Models & Mechanisms and Biology Open.
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