Functional characterization of TGF-β receptor Saxophone in the red flour beetle Tribolium castaneum

On-Demand

Presenting Author(s)

Jingjing Li (she/her/hers)

Graduate research assistant
University of Missouri
Columbia, Missouri

Co-Author(s)

LY

Letong Yin

University of Missouri
Columbia, Missouri
QS

Qisheng Song

University of Missouri
Columbia, Missouri

The transforming growth factor-β (TGF-β) superfamily is comprised of a large group of proteins, including TGF-β isoforms, bone morphogenetic proteins and activins, with equally conserved cell-surface receptors and signaling co-receptors. TGF-β signaling in insects controls a variety of physiological events, including growth, development, diapause, and caste determination. However, the underlying mechanism remains unclear. In this study, we used the red flour beetle, Tribolium castaneum, as a model species to investigate how the TGF-β receptor Saxophone (Sax) mediates insect growth and development. Developmental and tissue-specific distribution profiles indicated Sax was constitutively expressed in various tissues during the development with less expression in the 6^thinstar larvae and prepupae. The pupation and eclosion rates decreased in a dose-dependent manner after Sax RNAi. When 100 ng dsSax was injected into the 6^th instar larvae, most of the treated larvae were able to pupate but failed to emerge as adults. At the dose of 200 ng dsSax, only 50% of larvae were able to pupate successfully. Further investigation revealed that the expression of 20E receptor genes EcR and USP, and 20E downstream gene BrC, were suppressed after silencing Sax, leading to lethality in pupae and adults. These results indicated that TGF-β receptor gene Sax is essential in the growth and development of T. castaneum.