Water influx via aquaporin directly determines necrotic cell death induced by the Bacillus thuringiensis Cry toxin.

The Bacillus thuringiensis Cry toxin causes swelling and necrosis in insect cells, but the route(s) and significance of the water influx involved in its cytotoxicity are unclear. Here, we assessed the role of aquaporins (AQPs), known as water channels, in Cry toxin intoxication. An AQP inhibitor did not interfere with any known process to form the toxin pore, but it diminished the cell swelling and loss of membrane integrity induced by the Cry toxin.

Insect water-specific aquaporins in developing ovarian follicles of the silk moth Bombyx mori: role in hydration during egg maturation.

Egg formation in terrestrial insects is an absorptive process, accommodated not only by packing proteins and lipids into yolk but also by filling chorions with water. An osmotic swelling of ovarian follicles takes place during oocyte maturation. This study investigated the role of the aquaporin (AQP) water channel in the osmotic uptake of water during oogenesis in the silk moth Bombyx mori Linnaeus, 1758.

Differential distribution of glutamate- and GABA-gated chloride channels in the housefly Musca domestica.

l-Glutamic acid (glutamate) mediates fast inhibitory neurotransmission by affecting glutamate-gated chloride channels (GluCls) in invertebrates. The molecular function and pharmacological properties of GluCls have been well studied, but not much is known about their physiological role and localization in the insect body. The distribution of GluCls in the housefly (Musca domestica L.

Identification and characterisation of a functional aquaporin water channel (Anomala cuprea DRIP) in a coleopteran insect.

Water transport across the plasma membrane depends on the presence of the water channel aquaporin (AQP), which mediates the bulk movement of water through osmotic and pressure gradients. In terrestrial insects, which are solid and/or plant feeders, the entrance and exit of water is primarily executed along the alimentary tract, where the hindgut, particularly the rectum, is the major site of water conservation. A cDNA encoding the homologue of the water-specific Drosophila AQP [Drosophila integral protein (DRIP)] was identified through the RT-PCR of RNA isolated from the rectum of the cupreous chafer larvae, Anomala cuprea, a humus and plant root feeder.

A water-specific aquaporin is expressed in the olfactory organs of the blowfly, Phormia regina.

The high sensitivity and selectivity of perireceptor events in insect olfactory organs requires the concerted action of odorant-binding proteins (OBPs), odorant receptors (ORs), and odorant-degrading enzymes (ODEs). Sensillum lymph in the sensillum cavity is a physiological saline that not only mediates the olfactory signaling pathway described above, but also protects the olfactory neurons against desiccation. The molecular mechanism of how water balance is maintained in the sensillum cavity still remains to be elucidated.

Two water-specific aquaporins at the apical and basal plasma membranes of insect epithelia: molecular basis for water recycling through the cryptonephric rectal complex of lepidopteran larvae.

Larval lepidopteran and coleopteran insects have evolved a specialised cryptonephric system in the hindgut in which water is constantly and rapidly taken up before defecation. In the silkworm, Bombyx mori, the movement of water through the epithelia within the cryptonephric rectal complex is likely facilitated by the two aquaporins, AQP-Bom1 and AQP-Bom3. Both are functionally water-specific and are predominantly expressed in the hindgut (colon and rectum).

Changes in the expression of soluble and integral-membrane trehalases in the midgut during metamorphosis in Bombyx mori.

To elucidate the relationship between soluble trehalase (Treh1) and integral-membrane trehalase (Treh2) in the Bombyx mori midgut, expression profiles for both proteins and mRNAs were examined during metamorphosis by using Western-blotting and quantitative real-time PCR analyses. Two bands of Treh2 (about 74 kDa) were detected in the midgut of 0-day-old 5th (last) instar larvae. Levels of Treh2 decreased as the developing larvae approached spinning (8 days old).

Mating attraction by Stenotus rubrovittatus (Heteroptera: Miridae) females and its relationship to ovarian development.

Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae) causes brown or black marks on rice, Oryza sativa L., grains (pecky rice), and it is becoming of increasing importance in Japan. Attractiveness of adult females or males of S.

Characterization of the carotenoid-binding protein of the Y-gene dominant mutants of Bombyx mori.

Carotenoids play important and diverse roles in insects. Recently, we purified and partially characterized a carotenoid-binding protein (CBP) from the wild type of Bombyx mori. In this report, we utilized immunoblotting, ELISA and immunocytochemistry to further characterize and localize the expression of CBP in the larval midgut and silk gland obtained from the wild type and four naturally occurring mutants linked to carotenoids transport.