Title

Role for calcium in the development of ovarial patency in Heliothis virescens

Abstract

Insect oocytes sequester nutritive proteins from the hemolymph under the regulation by juvenile hormone (JH), in a process called patency. Here, a pharmacological approach was used to decipher the role for calcium in ovarial patency in the moth, Heliothis virescens.

Follicular epithelial cells were exposed in calcium-free or calcium-containing media to JH I, JH II or JH III alone, or in combination with various inhibitors of signal transduction. Protein kinase inhibitors, Na+/K+-ATPase inhibitor, ouabain, an inhibitor of voltage-dependent calcium channels in plasma membrane, ω-Conotoxin MVII, endoplasmic reticulum (ER) Ca2+-ATPase inhibitor, thapsigargin, ER inositol 1,4,5-triphosphate receptor (IP3R) inhibitor, 2-ABP and ER ryanodine receptor (RyR) inhibitor, ryanodine, were used.

The results of our study suggest that JH II evokes patency via protein kinase C-dependent signaling pathway, and activation of Na+/K+-ATPase, similar to JH III. Response to JH II and JH III predominantly relies upon external and internal calcium stores, using voltage-dependent calcium channels, IP3Rs and RyRs. In contrast, regulation of patency by JH I appears to be largely calcium independent, and the calcium-dependent component of the signaling pathway likely does not use IP3Rs, but RyRs only. The JH II, JH III and calcium-dependent component of JH I signaling pathway probably utilize calcium/calmodulin-dependent kinase II for activation of Na+/K+-ATPase.

Department(s)

Environmental Plant Science and Natural Resource

Document Type

Article

DOI

https://doi.org/10.1016/j.jinsphys.2007.10.005

Keywords

juvenile hormone, signal transduction, oocyte maturation, tobacco budworm, Na+/K+-ATPase

Publication Date

2008

Recommended Citation

Pszczolkowski, Maciej A., Emily Olson, Crystal Rhine, and Sonny B. Ramaswamy. "Role for calcium in the development of ovarial patency in Heliothis virescens." Journal of insect physiology 54, no. 2 (2008): 358-366.

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