The Zoological Society of Japan, Hokkaido Branch 610th Branch Lecture
The 610th Annual Meeting of the Zoological Society of Japan, Hokkaido Branch
Date and Time: January 20, 2026 (Tue) 17:00 -
Location: Hokkaido University, Faculty of Science, Building No. 5, 8th Floor, Room 813
Speaker: Dr. Naoki Okamoto (Transborder Medical Research Center, University of Tsukuba)
Title: Mechanisms of internal calcium regulation in insects lacking “bones”
Abstract: Calcium is an essential mineral that supports the foundation of diverse biological activities, such as muscle contraction and neural activity. In vertebrates, endocrine factors such as parathyroid hormone (PTH) control “bone,” a massive calcium reservoir, to maintain blood calcium homeostasis. Meanwhile, in invertebrates lacking “bone,” it remained unclear what kind of endocrine system is responsible for systemic calcium homeostasis. In this study, using the fruit fly Drosophila melanogaster, which is rich in molecular genetic tools, we searched for novel hormones that regulate calcium homeostasis. As a result, we found that the neurosecretory peptide hormone Capa functions as a regulatory factor for hemolymph calcium. Furthermore, analysis of the mechanism of action of Capa revealed the existence of an organ specialized for calcium storage even in Drosophila. That is, it was demonstrated that an endocrine system centered around a calcium reservoir exists in insects lacking “bone.” This endocrine system plays a role in supplementing hemolymph calcium when dietary calcium is deficient, which closely resembles the function of PTH in vertebrates.
In this lecture, I will introduce our research approach toward the identification of novel endocrine factors in Drosophila and the elucidation of their mechanisms of action, based on the latest research findings, and also discuss future research prospects.
References
Okamoto N*, Mizuno Y, Watanabe A, Kohsaka H & Niwa R*, Neuroendocrine control of calcium mobilization in the fruit fly. Nature, (2025). DOI: 10.1038/s41586-025-09670-z
Caretaker:
Yusuke Tomina (Research Institute for Electronic Science, Hokkaido University)
tomina[a]es.hokudai.ac.jp
Please change [a] to @.
----------Up to this point----------
Zoological Society of Japan, Hokkaido Branch
General Affairs Secretary
Hidenari Mizushima
Sable (provided by Naotaka Minami, former director of the Asahikawa City Science Museum and Museum)
