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Li Y, Yin L, Guo R, Du Y, Wang B, Liu L, Li Z, Liu W, Zhang G, An S, Yin X, Su L. Juvenile Hormone Involved in the Defensive Behaviors of Soldiers in Termite Reticulitermes aculabialis. Insects 2024; 15:130. [PMID: 38392549 PMCID: PMC10889337 DOI: 10.3390/insects15020130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 02/08/2024] [Accepted: 02/09/2024] [Indexed: 02/24/2024]
Abstract
Eusocial insects have evolved specific defensive strategies to protect their colonies. In termite colonies, soldiers perform a colony-level defense by displaying mechanical biting, head-banging and mandible opening-closing behaviors. However, few studies have been reported on the factors modulating defensive behaviors in termites. Owing to JH (juvenile hormone) being involved in soldier differentiation, JH was speculated to affect defensive behaviors in termite soldiers. To determine the effect of JH on the defensive behaviors of termite soldiers, we performed a JHA-feeding and RaSsp1-silencing experiment and then tested the changes in defense-related behaviors, alarm pheromones and key JH signaling genes. The observed result was that after feeding workers with JHA, soldiers displayed the following: (1) decreased biting events and increased head-banging events; (2) a reduced expression of RaSsp1 and increased expression of Met (methoprene-tolerant, the nuclear receptor of JH) and Kr-h1 (the JH-inducible transcription factor Krüppel homolog 1); and (3) a decreased concentration of alarm pheromones, including α-pinene, β-pinene and limonene (+, -). Further study showed that soldiers silenced for RaSsp1 also exhibited (1) decreased biting events and increased head-banging events and (2) increased expression of Met and Kr-h1. In addition, soldiers stimulated by the alarm pheromone limonene displayed an increase in the frequency of mandible opening-closing and biting behavior. All of these results show that JHA influenced the defensive behaviors of termite soldiers, possibly via downregulating RaSsp1 expression, up-regulating Met and Kr-h1 and stimulating the secretion of alarm pheromones, suggesting that the JH pathway plays important roles in modulating social behaviors in termite colonies.
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Affiliation(s)
- Yiying Li
- College of Life Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Letong Yin
- College of Life Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Ruiyao Guo
- College of Life Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Yunliang Du
- College of Life Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Bo Wang
- College of Life Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Long Liu
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Zhenya Li
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Wei Liu
- College of Life Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Guozhi Zhang
- College of Life Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Shiheng An
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Xinming Yin
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Lijuan Su
- College of Life Science, Henan Agricultural University, Zhengzhou 450002, China
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