The impact of thigmotaxis deprivation on the development of the German cockroach (Blattella germanica)

Yun-Ru Chen; De-Wei Li; Hsin-Ping Wang; Shih-Shun Lin; En-Cheng Yang

doi:10.1016/j.isci.2022.104802

The impact of thigmotaxis deprivation on the development of the German cockroach (Blattella germanica)

iScience. 2022 Jul 20;25(8):104802. doi: 10.1016/j.isci.2022.104802. eCollection 2022 Aug 19.

Authors

Yun-Ru Chen¹, De-Wei Li¹, Hsin-Ping Wang², Shih-Shun Lin², En-Cheng Yang¹

Affiliations

¹ Department of Entomology, National Taiwan University, Taipei, Taiwan, R.O.C.
² Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, R.O.C.

Abstract

Thigmotaxis is required in small animals. In this study, we examined how the shelter angle affects the development of German cockroaches, Blattella germanica. Groups and individual cockroaches showed a strong preference for shelters with an angle of ≤40° after 15 min or 24 h in shelter-selection trials. For cockroaches that developed in 90/180-degree shelters, survival and fecundity were low, and the nymphal stage lasted longer. Post-molting transcriptomes of second- and sixth-instar nymphs were analyzed at 12 h and 2 days post-molting. Upregulation was observed in genes related to ATP metabolism and cellular amide metabolism. Chitin-based cuticle development and postembryonic development-related genes were downregulated. The stress responses of cockroaches that developed in shelters with angles of 90° were similar to those of gregarious cockroaches experiencing social isolation. For German cockroaches, environmental tactile stimuli are crucial to development and homeostasis.

Keywords: Entomology; Molecular mechanism of behavior.