scholarly journals Glutathione biosynthesis in the aging adult yellow-fever mosquito [Aedes aegypti (Louisville)]

1983 ◽  
Vol 210 (2) ◽  
pp. 289-295 ◽  
Author(s):  
G A Hazelton ◽  
C A Lang
Keyword(s):  
Amino Acid ◽  
Aedes Aegypti ◽  
Life Span ◽  
Yellow Fever ◽  
Time Course ◽  
Adult Life ◽  
Specific Inhibitor ◽  
Yellow Fever Mosquito ◽  
Essential Information ◽  
Glutathione Biosynthesis

Our previous findings [Hazelton & Lang (1978) Fed. Proc. Fed. Am. Soc. Exp. Biol. 37(6), 2378 (abstr.)] demonstrated a senescence-specific decrease in glutathione (GSH) concentration in the yellow-fever mosquito Aedes aegypti (Louisville)]. As a possible mechanism for this change, GSH biosynthesis was investigated in adult mosquitoes of different ages through the life-span. Biosynthesis was measured as the incorporation rate of [14C]glycine or [14C]cystine into glutathione. Essential information to validate the procedure was also obtained on the precursor-amino-acid pool sizes and kinetic parameters such as lag-time and time course of incorporation. Also, synthesis de novo rather than exchange was verified using buthionine sulphoximine, a specific inhibitor of GSH biosynthesis. The synthetic rates with either amino acid precursor varied throughout the adult life-span, but the patterns for both precursors were essentially identical. Biosynthesis was high in the newly emerged adult and decreased 62-70% (P less than 0.005) to a plateau during maturity. From the mature value there was a decrease of 36-41% (P less than 0.005) to a new plateau during senescence. Glutathione biosynthesis and concentration were correlated throughout maturity and senescence (r = 0.982) and thus biosynthesis was proportional to glutathione content. On this basis we concluded that impaired biosynthesis is the major and perhaps sole mechanism for the aging decrease in glutathione content.

scholarly journals AaCAT1 of the Yellow Fever Mosquito, Aedes aegypti

2011 ◽  
Vol 286 (12) ◽  
pp. 10803-10813 ◽  
Author(s):  
Immo A. Hansen ◽  
Dmitri Y. Boudko ◽  
Shin-Hong Shiao ◽  
Dmitri A. Voronov ◽  
Ella A. Meleshkevitch ◽  
...  
Keyword(s):  
Amino Acid ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Fat Body ◽  
Yolk Protein ◽  
Yellow Fever Mosquito ◽  
Signaling System ◽  
Protein Precursor ◽  
Cationic Amino Acid ◽  
Nutrient Signaling

Insect yolk protein precursor gene expression is regulated by nutritional and endocrine signals. A surge of amino acids in the hemolymph of blood-fed female mosquitoes activates a nutrient signaling system in the fat bodies, which subsequently derepresses yolk protein precursor genes and makes them responsive to activation by steroid hormones. Orphan transporters of the SLC7 family were identified as essential upstream components of the nutrient signaling system in the fat body of fruit flies and the yellow fever mosquito, Aedes aegypti. However, the transport function of these proteins was unknown. We report expression and functional characterization of AaCAT1, cloned from the fat body of A. aegypti. Expression of AaCAT1 transcript and protein undergoes dynamic changes during postembryonic development of the mosquito. Transcript expression was especially high in the third and fourth larval stages; however, the AaCAT1 protein was detected only in pupa and adult stages. Functional expression and analysis of AaCAT1 in Xenopus oocytes revealed that it acts as a sodium-independent cationic amino acid transporter, with unique selectivity to l-histidine at neutral pH (K0.5l-His = 0.34 ± 0.07 mm, pH 7.2). Acidification to pH 6.2 dramatically increases AaCAT1-specific His+-induced current. RNAi-mediated silencing of AaCAT1 reduces egg yield of subsequent ovipositions. Our data show that AaCAT1 has notable differences in its transport mechanism when compared with related mammalian cationic amino acid transporters. It may execute histidine-specific transport and signaling in mosquito tissues.

scholarly journals Nutritional Quality during Development Alters Insulin-Like Peptides Expression and Physiology of the Adult Yellow Fever Mosquito, Aedes aegypti

2018 ◽  
Author(s):  
Rana Pooriirouby ◽  
Arvind Sharma ◽  
Joshua Beard ◽  
Jeremiah Reyes ◽  
Andrew Nuss ◽  
...  
Keyword(s):  
Life History ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Insulin Signaling ◽  
Adult Life ◽  
High Carbohydrate Diet ◽  
Yellow Fever Mosquito ◽  
Carbohydrate Diet ◽  
Transcript Levels ◽  
High Carbohydrate

Mosquitoes have distinct developmental and adult life history, and the vectorial capacity of females has been shown to be affected by the larval nutritional environment. However, little is known about the effect of developmental nutrition on insulin-signaling and nutrients storage. In this study, we used Aedes aegypti, the yellow fever mosquito, to determine whether larval nutrition affects insulin gene expression. We also determined the traits regulated by insulin signaling, such as stored-nutrients levels and fecundity. We raised mosquito larvae on two different diets, containing either high protein or high carbohydrates. Development on a high-carbohydrate diet resulted in several life-history phenotypes indicative of suboptimal conditions, including increased developmental time and decreased fecundity. Additionally, our data showed that insulin transcript levels are affected by a high-carbohydrate diet during development. Females, not males, reared on high-carbohydrate diets had much higher transcript levels of insulin-like peptide 3 (ILP3), a mosquito equivalent of human insulin, and these females more readily stored sugar from the meal into lipids. We also found that AaILP4, not AaILP3, transcript levels were much higher in the males after a sugar meal, suggesting sex-specific differences in insulin-signaling pathway. Our findings suggest a conserved mechanism of carbohydrate-mediated hyperinsulinemia in animals.

scholarly journals SLC7 amino acid transporters of the yellow fever mosquito Aedes aegypti and their role in fat body TOR signaling and reproduction

2012 ◽  
Vol 58 (4) ◽  
pp. 513-522 ◽  
Author(s):  
Victoria K. Carpenter ◽  
Lisa L. Drake ◽  
Sarah E. Aguirre ◽  
David P. Price ◽  
Stacy D. Rodriguez ◽  
...  
Keyword(s):  
Amino Acid ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Fat Body ◽  
Amino Acid Transporters ◽  
Yellow Fever Mosquito ◽  
Tor Signaling

scholarly journals Glutathione S-transferase activities in the yellow-fever mosquito [Aedes aegypti (Louisville)] during growth and aging

1983 ◽  
Vol 210 (2) ◽  
pp. 281-287 ◽  
Author(s):  
G A Hazelton ◽  
C A Lang
Keyword(s):  
Aedes Aegypti ◽  
Life Span ◽  
Yellow Fever ◽  
Kinetic Properties ◽  
Yellow Fever Mosquito ◽  
Glutathione S Transferase ◽  
Entire Life ◽  
Old Adult ◽  
Growth And Aging

Our previous findings [Hazelton & Lang (1978) Fed. Proc. Fed. Am. Soc. Exp. Biol. 37(6), 2378 (abstr.)] demonstrated aging-specific changes in glutathione concentrations in the yellow-fever mosquito [Aedes aegypti (Louisville)]. A possible mechanism could be increased utilization via glutathione S-transferase. Thus glutathione S-transferase activities were measured in mosquito samples from the entire life span, including growth, maturity and senescence. Methods were validated for the quantitative determination of transferase activities with 1,2-dichloro-4-nitrobenzene (DCNB) and 1-chloro-3,4-dinitrobenzene (CDNB) as second substrates. Marked changes occurred during the life span, and the profiles for both DCNB and CDNB activities were identical. The activities increased throughout larval development and reached a maximum in the metamorphosis stage. The activities decreased at the end of metamorphosis in the 5-day-old adult, reached a plateau during maturity (5-20 days), and then decreased 31% (P less than 0.007) during senescence (after 33 days). This senescence-specific decrease occurred in both sexes and was localized in the abdominal region. Further kinetic analyses indicated that the lower enzyme activities were most likely due to lower amounts of active enzyme rather than a change in kinetic properties. These findings indicate that the capacity for GSH utilization via glutathione S-transferase is diminished with aging. This does not explain our previously observed decreases in GSH, but the results suggest that GSH-linked detoxification would be impaired during senescence.

scholarly journals Nutritional Quality during Development Alters Insulin-Like Peptides’ Expression and Physiology of the Adult Yellow Fever Mosquito, Aedes aegypti

Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 110 ◽  
Author(s):  
Rana Pooraiiouby ◽  
Arvind Sharma ◽  
Joshua Beard ◽  
Jeremiah Reyes ◽  
Andrew Nuss ◽  
...  
Keyword(s):  
Life History ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Insulin Signaling ◽  
Adult Life ◽  
High Carbohydrate Diet ◽  
Yellow Fever Mosquito ◽  
Carbohydrate Diet ◽  
Transcript Levels ◽  
High Carbohydrate

Mosquitoes have distinct developmental and adult life history, and the vectorial capacity of females has been shown to be affected by the larval nutritional environment. However, little is known about the effect of developmental nutrition on insulin-signaling and nutrient storage. In this study, we used Aedes aegypti, the yellow fever mosquito, to determine whether larval nutrition affects insulin gene expression. We also determined the traits regulated by insulin signaling, such as stored-nutrient levels and fecundity. We raised mosquito larvae on two different diets, containing either high protein or high carbohydrates. Development on a high-carbohydrate diet resulted in several life-history phenotypes indicative of suboptimal conditions, including increased developmental time and decreased fecundity. Additionally, our data showed that insulin transcript levels are affected by a high-carbohydrate diet during development. Females, not males, reared on high-carbohydrate diets had much higher transcript levels of insulin-like peptide 3 (ILP3), a mosquito equivalent of human insulin, and these females more readily converted sugar meals into lipids. We also found that AaILP4, not AaILP3, transcript levels were much higher in the males after a sugar meal, suggesting sex-specific differences in the insulin-signaling pathway. Our findings suggest a conserved mechanism of carbohydrate-mediated hyperinsulinemia in animals.

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