Aquatic silk proteins in Chironomus: A review

Abstract

Silk proteins secreted by salivary glands in the dipteran insect, Chironomus play a significant role as proteinaceous adhesives for construction of underwater housing nests by larvae. To date, only three Chironomus species, C. tentans Fabricius, C. pallidivittatus Malloch and C. riparius Meigen have been explored for characterization of their aquatic silk protein. Genes coding for silk proteins are located on specific chromosomal 'puffs' called Balbiani rings as well as non-Balbiani ring regions. Expression of these genes is closely regulated by developmental and hormonal alterations and environmental factors. Furthermore, pilot studies have postulated that silk proteins probably occur in diverse size classes grouped into large (~1000 kDa), intermediate (100-200 kDa) and small (≤100 kDa). Barring few preliminary reports that date back to the 1990s, the physical and bioproperties of silk from chironomid midges remain largely unknown, leading to paucity of updated information. This review was therefore aimed to compile existing literature database and to highlight the wide possibilities for commercialization of midge larval silk as a novel biopolymer.

Changes in Microbiota Composition Along the Metamorphosis Developmental Stages of Chironomus transvaalensis

“…These egg masses are embedded in a gelatinous matrix that is composed of glycoprotein and chitin ( Halpern et al, 2003 ; Laviad et al, 2016 ). The first instar larva feeds on the egg mass remnants and then swims toward the bottom of the water habitat, where it constructs a silken tube ( Thorat and Nath, 2018 ). The larva passes through four instars before it transforms into a pupa, from which a flying adult emerges into the air ( Armitage et al, 1995 ; Thorat and Nath, 2013 ).…”

Insects With Survival Kits for Desiccation Tolerance Under Extreme Water Deficits

“…Some beetles exhibit bimodal activity patterns in order to escape the hottest hours of the day whereas others display fog-basking for moisture absorption from the surroundings (Bedick et al, 2006; Chown et al, 2011). Other striking evidences for aridity protection, come from niche construction behaviors such as the housing nests of chironomid midges, termite nests, domiciles of some thrips and insect galls (Kikawada et al, 2005; Gilberta, 2014; Zukowski and Su, 2017; Thorat and Nath, 2018). The cuticle is the first portal of water loss in insects and the differential desiccation tolerance patterns in C. ramosus vs. D. melanogaster and P. vanderplanki vs. Paraborniella tonnoiri (Diptera: Chironomidae) have been attributed to striking differences in their cuticular thickness (Nakahara et al, 2008; Thorat et al, 2017).…”

Comparative Microbiota Composition Across Developmental Stages of Natural and Laboratory-Reared Chironomus circumdatus Populations From India

“…A single egg mass contains hundreds of eggs that are embedded in a glycoprotein and chitin gelatinous matrix (Halpern et al, 2003;. The first larval instars feed on the egg mass remains and then swim toward the bottom of the water body where they build a silken tube (Thorat and Nath, 2018). The larval foraging zone is limited to the tube entrance (Halpern et al, 2002).…”