Vacuolar protein sorting 4 is required for silkworm metamorphosis

Abstract

Vacuolar protein sorting 4 (Vps4) not only functions with its positive regulator vacuolar protein sorting 20‐associated 1 (Vta1) in the multivesicular body (MVB) pathway but also participates alone in MVB‐unrelated cellular processes. However, its physiological roles at the organism level remain rarely explored. We previously identified their respective homologues Bombyx mori Vps4 (BmVps4) and BmVta1 from the silkworm, a model organism for insect research. In this study, we performed fluorescence quantitative real‐time PCR and Western blot to globally characterize the transcription and protein expression profiles of BmVps4 and BmVta1 during silkworm development and in different silkworm tissues and organs. The results showed that they were significantly up‐regulated in metamorphosis, adulthood and embryogenesis relative to larval stages, and displayed a roughly similar tissue‐and‐organ specificity for transcriptions in silkworm larvae. Importantly, BmVps4 was down‐regulated during the early period of the fifth instar, reaching the lowest level of transcription on Day 6, then up‐regulated from Day 7 to the wandering, spinning and pupal stages, and down‐regulated again in adulthood. Moreover, knocking down BmVps4 by RNA interference significantly inhibited silk gland growth, shortened spinning time, prolonged pupation, reduced pupal size and weight, and increased moth wing defects. Together, our data demonstrate the critical and broad requirements for BmVps4 in silkworm metamorphosis.

Hydrogen sulfide treatment retrieves the inhibition of growth and development characteristics in silkworm (Bombyx mori) via phosphoacetyl glucosamine mutase gene knock down

“…RNA interference technology has also been applied in silkworm research (Xia et al, 2017, 2019; Wang & Wu, 2020). Yu et al (2016) have shown that the expression of BmD6DES was the highest at low temperature (0°C) and 6–36 h after fungal infection.…”

“…The glycolysis pathway is an important energy metabolism pathway in the body, PGM can convert glucose 1-phosphate into glucose 6-phosphate, which provides a raw material for the glycolysis pathway (Kim et al, 2003;Tsukamoto et al, 2013). In RNA interference technology has also been applied in silkworm research (Xia et al, 2017(Xia et al, , 2019Wang & Wu, 2020). Yu et al (2016) have shown that the expression of BmD6DES was the highest at low temperature (0°C) and 6-36 h after fungal infection.…”

Bombyx mori Vps13d is a key gene affecting silk yield

“…Correlational research indicated that beyond MVB formation and endocytosis, ESCRT complexes have crucial functions in cytokinesis, and mitophagy [ 18 – 21 ]. Knocking down BmVps4 resulted in silkworm metamorphosis reduction, including inhibiting silk gland growth, shortening spinning time, prolonging pupation, reducing the pupal size, and weight [ 22 ]. According to results of the bioinformatics analysis, BmVps13d belongs to this signal pathway and may have a similar function with BmVps4 in B .…”

Bombyx mori U‐shaped regulates the melanization cascade and immune response via binding with the Lozenge protein

“…Although RNAi success rate is low in several insect species, including silkworm, in the present study, application of RNAi efficiently suppressed silkworm U-shaped in larvae. Previously, this method has also been proved successful to knockdown partial genes, such as Vps4 (Xia et al, 2019), Kr-h1 (Zhu et al, 2020) and SGF1 (Liu et al, 2016). Recently, You et al (2020) improved the RNAi susceptibility of silkworm larvae by overexpressing RNAi's core machinery .…”