The amino acid and lipophilic profiles of Chilo partellus (Swinhoe) larvae fluctuate with diapause

Abstract

The Chilo partellus (Crambidae: Lepidoptera) larvae undergoes both hibernation and estivation in India. Although, much has been done on reproductive physiological aspects, little is known about biochemical changes happening during hibernation and estivation in C. partellus. Thus, we mapped changes in amino acid and lipophilic profiles of C. partellus larvae while undergoing hibernation and estivation using high-performance liquid chromatography and gas chromatography mass spectroscopy. The studies revealed higher amounts of amino acids namely, serine, glycine, histidine, arginine, proline, tyrosine, and methionine in estivation, while lower in hibernation as compared with nondiapause larvae of C. partellus. Furthermore, the amounts of aspartic acid, glutamic acid, and alanine in hibernation, and threonine, valine, isoleucine, phenylalanine, and leucine in estivation were on par with nondiapause larvae. The lipophilic compounds namely, linoleic acid, stearic acid, eicosanoic acid, and n-pentadecanol were lower in hibernation than estivation and nondiapause larvae of C. partellus. Palmitoleic acid and methyl 3-methoxytetradecanoate contents were higher in hibernation than estivation and nondiapause, while myristic acid and lathosterol contents were higher in estivation than hibernation and nondiapause larvae of C. partellus. Cholesterol content was higher, while squalene and gamma-ergostenol were lower in hibernation and estivation as compared with nondiapause larvae of C. partellus. These findings suggest that certain amino acids may be constituents of heat-shock proteins and help C. partellus during estivation.However, the lipophilic compounds could be helpful in maintaining development during hibernation and estivation in C. partellus.

Diapause in <i>Chilo partellus</i>: A Research Journey

“…The hibernation larvae hoarded low amounts of amino acids as compared to aestivation larvae which might be helpful in maintaining metabolic homeostasis as a result of cold stress. Further, the similar amounts of aspartic acid, glutamic acid and alanine in hibernation and nondiapause, and that of threonine, valine, isoleucine, phenylalanine and leucine in aestivation and nondiapause C. partellus larvae suggest that these amino acids could be specifically required for maintaining the hibernation and aestivation, and post-diapause biological and physiological functions (Tanwar et al, 2021). As cystine has been found to contribute in plant defense against C. partellus (Dhillon and Kumar, 2017), and absence in diapause and presence in the nondiapause larvae suggest that this amino acid is not essential during the non-feeding stage, i.e., diapause.…”

“…The higher total protein content in pupae than the larvae from all the diapause and nondiapause strains of C. partellus, suggest their greater requirement during pupation to support the development of different adult features and organs. The amino acids like serine, glycine, histidine, arginine, proline, tyrosine and methionine were in higher titres in aestivation than hibernation and nondiapause larvae which could be imparting heat-shock tolerance during aestivation (Tanwar et al, 2021). The hibernation larvae hoarded low amounts of amino acids as compared to aestivation larvae which might be helpful in maintaining metabolic homeostasis as a result of cold stress.…”

“…As cystine has been found to contribute in plant defense against C. partellus (Dhillon and Kumar, 2017), and absence in diapause and presence in the nondiapause larvae suggest that this amino acid is not essential during the non-feeding stage, i.e., diapause. The higher amounts of test amino acids in aestivation than hibernation larvae of C. partellus could be to meet the greater energy requirement while dealing with heatshock proteins during aestivation (Tanwar et al, 2021). Total lipid content was found higher in the nondiapause larvae and pupae in comparison to hibernation and aestivation strains of C. partellus, suggesting that the stored lipids are being utilized to maintain the diapause development, which are also left with small amounts to be transferred in the pupae (Tanwar, 2022).…”

“…The total lipid content was significantly higher in the C. partellus larvae at initiation and during hibernation as compared to aestivation, which could be to conserve the energy to support during the hibernation (Tanwar, 2022). The lower linoleic acid, stearic acid, eicosanoic acid and n-pentadecanol contents in hibernation than aestivation and nondiapause larvae of C. partellus suggest that these lipophilic compounds could be required for various metabolic and physiological activities (Tanwar et al, 2021). The higher palmitoleic acid and methyl 3-methoxytetradecanoate contents in hibernation, and higher myristic acid and lathosterol contents in aestivation larvae suggest that these lipophilic compounds impart cold-shock and heatshock tolerance, respectively.…”

Metabolic response of the sea cucumber Apostichopus japonicus during the estivation-arousal cycles

“…In addition, several amino acids are involved in the antioxidant defense system to prevent and repair the deleterious effects from free radicals; for example, tyrosine is an excellent antioxidant inside lipid bilayers and protects cells from oxidative destruction (Moosmann and Behl, 2000); glycine and glutamic acid are integral components of glutathione, which is the major antioxidant molecule of the cell and can effectively scavenge free radicals and other reactive oxygen species and maintain the cellular redox balance (Hensley et al, 2000;Fang et al, 2002); and methionine is easily oxidized to methionine sulfoxide by many reactive species, thus serving to protect other functionally essential residues from oxidative damage (Levine et al, 2010). Furthermore, another investigation of estivating Chilo partellus larvae reported increased amounts of glycine, histidine, arginine, proline, tyrosine, and methionine, which may be constituents of heat-shock proteins to enhance stress tolerance and maintain development (Tanwar et al, 2021). Hence, the elevated levels of the above amino acids in estivating A. japonicus intestines could meet the greater energy requirements for dealing with oxidative stress and heat-shock proteins during torpor.…”