She’s got nerve: roles of octopamine in insect female reproduction

Abstract

The biogenic monoamine octopamine (OA) is a crucial regulator of invertebrate physiology and behavior. Since its discovery in the 1950s in octopus salivary glands, OA has been implicated in many biological processes among diverse invertebrate lineages. It can act as a neurotransmitter, neuromodulator and neurohormone in a variety of biological contexts, and can mediate processes including feeding, sleep, locomotion, flight, learning, memory, and aggression. Here, we focus on the roles of OA in female reproduction in insects. OA is produced in the octopaminergic neurons that innervate the female reproductive tract (RT). It exerts its effects by binding to receptors throughout the RT to generate tissue- and region-specific outcomes. OA signaling regulates oogenesis, ovulation, sperm storage, and reproductive behaviors in response to the female’s internal state and external conditions. Mating profoundly changes a female’s physiology and behavior. The female’s OA signaling system interacts with, and is modified by, male molecules transferred during mating to elicit a subset of the post-mating changes. Since the role of OA in female reproduction is best characterized in the fruit fly Drosophila melanogaster, we focus our discussion on this species but include discussion of OA in other insect species whenever relevant. We conclude by proposing areas for future research to further the understanding of OA’s involvement in female reproduction in insects.

Keywords:

• Octopamine
• reproduction
• fertility
• insect

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Acknowledgements

The authors are delighted to contribute this article to an issue in honor of Dr. Sokolowski’s milestone birthday. Dr. Sokolowski has been pivotal to, and a patient and inspirational tutor for, our interest in neural mechanisms and their evolution. We wish her all the best. The authors thank Drs. Nilay Yapici and Alexandra Amaro, and two anonymous reviewers, for helpful comments on the manuscript. Last but not least, we thank the readers of this review for their interest in the topic and this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

We thank NIH grants R01- and R37-HD038921 (to MFW) and R01-HD059060 (to MFW and A.G. Clark) for support.