Artemia Franciscana Embryos Research Articles

Reactivation of ubiquitination in Artemia franciscana embryos during recovery from anoxia-induced quiescence

Encysted gastrulae of Artemia franciscana are known to enter a reversible state of quiescence promoted by anoxia, during which the half-life of cytochrome oxidase is prolonged up to 77-fold. This observation suggests that proteolytic pathways within mitochondria are inhibited, and indeed the suppression of the initial step in ubiquitin-mediated proteolysis under anoxia has been reported. Given that active embryos require efficient degradation of macromolecules, we investigated the reactivation of ubiquitination during recovery from anoxia and aerobic acidosis (elevated CO2 levels under aerobic conditions). During 6 h of recovery from anoxia, the levels of ubiquitin-conjugated proteins rose 6.5-fold, reaching 78 % of the pre-anoxia (control) values. Concomitant with the elevation in ubiquitin conjugates was a sharp decline in AMP level, a rise in ATP level and an alkalization of intracellular pH. Our results suggest that the reinitiation of ubiquitin conjugation is partially dependent on decreasing AMP and/or increasing ATP levels. However, when anoxic embryos were transferred to aerobic acidosis, which promotes a return to control (aerobic) levels of adenylates yet maintains the acidic intracellular pH, 71 % of the total suppression of ubiquitination still remained. This observation reveals a predominant role of intracellular alkalization in the reactivation of ubiquitination during recovery. We suggest that the rapid reversibility of the factors regulating ubiquitin conjugation allows Artemia embryos readily to reinitiate the degradation of proteins via the ubiquitin-mediated pathway during recovery.

Specific Activity of Na⁺ K⁺ ATPase Is Not Altered in Response to Changing Salinities during Early Development of the Brine Shrimp Artemia franciscana

The effects of salinity on the specific activity of ouabain-sensitive Na⁺ K⁺ ATPase were investigated in Artemia franciscana embryos and nauplii. Whole organismal specific activity of the enzyme was measured in organisms exposed to chronic (constant) salinity conditions of 5-, 12-, 32-, or 50-ppt seawater. During emergence and throughout early stage 1 naupliar development, the specific activity of Na⁺ K ⁺ ATPase increased at all external salinities. No significant differences in enzyme activities were observed among the salinity treatments. The pattern and levels of enzyme activity suggest a genetically determined program of enzyme synthesis that is not influenced by the external salinity. The specific activity of the enzyme was also measured after exposure of stage 1 nauplii to acute hypoosmotic and hyperosmotic conditions during both the early and late stages of the observed increase in enzyme activity. The apparent synthesis of Na⁺ K⁺ ATPase was not influenced when stage 1 nauplii were exposed to an abrupt salinity change. These results suggest that, in stage 1 nauplii, this ontogenetic program of enzyme synthesis overrides any acute osmotic stress responses that might involve changes in the total amount of the enzyme. During early naupliar development, modulation of the preexisting enzyme may be a more important mechanism of ion regulation than is modulation of the enzyme's synthesis and degradation.

Respiration of Artemia franciscana embryos after continuous anoxia over 1-year period

Encysted embryos of the brine shrimp, Artemia franciscana, exhibit extraordinary longevity when exposed to continuous anoxia. To explore the metabolic basis of this ability, the post-anoxic respiration of embryos exposed to anoxia for periods exceeding 1 year was measured. Since anoxic metabolism might result in the accumulation of metabolic end products, an O2 debt would be expected. Contrary to that expectation, post-anoxic embryos exhibited a marked depression in respiration rate whether embryos were hydrated under anoxic conditions or were exposed to a previous aerobic incubation and then placed under anoxia. These results, and those of previous studies, suggest that extended anoxia may bring the metabolism of these embryos to a reversible standstill.

Heat dissipation during long-term anoxia inArtemia franciscana embryos: identification and fate of metabolic fuels

Microcalorimetric measurements of brine shrimp embryos during 6 days of anoxia indicated that heat dissipation was rapidly suppressed to 2.7% of control (aerobic) values over the first 9 h. Energy flow continued to decline slowly to 31 microW.g dry mass-1 (0.4% of control) during the subsequent 5.5 days. Within 2 h after returning anoxic embryos to aerobic conditions, heat dissipation rose to 77% of control rates. The calorimetric/respirometric (CR) ratio across this 2-h recovery period increased steadily from -226 to -346 kJ.mol O2-1). Prior to the anoxic exposures, hydrated embryos were incubated aerobically for 10 h to insure full initiation of carbohydrate metabolism (CR ratio = -484 kJ.mol O2-1). During the 6-day asymptotic approach to a nearly ametabolic state, trehalose and glycogen levels declined 18% and 13%, respectively. The majority of this utilization occurred within the first three days. Thermochemical calculations showed that carbohydrate catabolism accounted for 84% of the total heat dissipation measured over the 6-day anoxic bout; only 3% of the heat could be explained by the catabolism of diguanosine tetraphosphate (Gp4G). Analyses of embryo extracts by high performance liquid chromatography indicated that multiple acid end products were accumulated. Lactate and propionate reached 4.5 mM and 1.0 mM, respectively, but these compounds did not account quantitatively for the amount of carbohydrate utilized. However, the largest chromatographic peak that accumulated under anoxia has not been successfully identified. Fumarate and pyruvate levels decreased as anoxia proceeded. Thus, a perceptible energy flow in Artemia franciscana embryos still remained after 6 days of anoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrest of cytochrome-c oxidase synthesis coordinated with catabolic arrest in dormant Artemia embryos

We have examined cytochrome-c oxidase (COX) biosynthesis in brine shrimp (Artemia franciscana) embryos during preemergence development (PED), as well as its inhibition under anaerobic dormancy, to determine whether transitions in intracellular pH (pHi) have a regulatory influence on anabolic processes. Under control aerobic conditions (embryo pHi greater than or equal to 7.9), incorporation of radiolabeled amino acids shows that substantial biosynthesis of COX occurs during 12 h of PED (500% increase when corrected for enzyme turnover). This anabolic process is blocked under anoxia, a condition known to foster intracellular acidification (pHi less than or equal to 6.8). The arrest of COX synthesis is quantitatively identical when embryos are incubated aerobically during artifical acidification with CO2 (pHi = 6.8). The data suggest that pHi, directly or indirectly, is a regulator of protein synthesis in Artemia embryos during anaerobic dormancy. Previous work has established a fundamental role for pHi in the arrest of carbohydrate catabolism under anoxia. Thus there appears to be a coordinated suppression of energy-producing and energy-utilizing events as Artemia embryos enter quiescence that involves pHi as the common intracellular signal.

Respiration of the Eggs and Parts of Eggs of Aulocara elliotti (Thomas)

Previous articleNext article No AccessRespiration of the Eggs and Parts of Eggs of Aulocara elliotti (Thomas)George RoemhildGeorge Roemhild Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 38, Number 3Jul., 1965 Article DOIhttps://doi.org/10.1086/physzool.38.3.30152833 Views: 2Total views on this site Citations: 11Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). Copyright 1965 University of ChicagoPDF download Crossref reports the following articles citing this article:INNOCENT N. KAMBULE, SHIRLEY A. HANRAHAN, FRANCES D. DUNCAN Metabolic rate in diapause and nondiapause brown locust eggs correlated with embryonic development, Physiological Entomology 36, no.44 (Jul 2011): 299–308.https://doi.org/10.1111/j.1365-3032.2011.00792.xSteven C. Hand, Michael A. Menze, Apu Borcar, Yuvraj Patil, Joseph A. Covi, Julie A. Reynolds, Mehmet Toner Metabolic restructuring during energy-limited states: Insights from Artemia franciscana embryos and other animals, Journal of Insect Physiology 57, no.55 (May 2011): 584–594.https://doi.org/10.1016/j.jinsphys.2011.02.010Julie A. Reynolds, Steven C. Hand Decoupling development and energy flow during embryonic diapause in the cricket, Allonemobius socius, Journal of Experimental Biology 212, no.1313 (Jul 2009): 2065–2074.https://doi.org/10.1242/jeb.027359MICHAEL GUPPY, PHILIP WITHERS Metabolic depression in animals: physiological perspectives and biochemical generalizations, Biological Reviews 74, no.11 (Jan 2007): 1–40.https://doi.org/10.1111/j.1469-185X.1999.tb00180.xG. Romano, A. Ianora, A. Miralto Respiratory physiology in summer diapause embryos of the neustonic copepodAnomalocera patersoni, Marine Biology 127, no.22 (Dec 1996): 229–234.https://doi.org/10.1007/BF00942107G. Romano, A. Ianora, L. Santella, A. Miralto Respiratory metabolism during embryonic subitaneous and diapause development in Pontella mediterranea (Crustacea, Copepoda), Journal of Comparative Physiology B 166, no.33 (Jul 1996): 157–163.https://doi.org/10.1007/BF00263978Sigfrid Ingrisch Oxygen consumption by developing and diapausing eggs of Eupholidoptera smyrnensis (Orthoptera: Tettigoniidae), Journal of Insect Physiology 33, no.1111 (Jan 1987): 861–865.https://doi.org/10.1016/0022-1910(87)90034-5Hans J�rgen Braune Effects of temperature on the rates of oxygen consumption during morphogenesis and diapause in the egg stage of Letopterna dolobrata (Heteroptera, Miridae), Oecologia 25, no.11 (Jan 1976): 77–87.https://doi.org/10.1007/BF00345035Matthias Schaefer An analysis of diapause and resistance in the egg stage of Floronia bucculenta (Araneida: Linyphiidae), Oecologia 25, no.22 (Jan 1976): 155–174.https://doi.org/10.1007/BF00368851Ivar P.S. Agrell, Anders M. Lundquist PHYSIOLOGICAL AND BIOCHEMICAL CHANGES DURING INSECT DEVELOPMENT, (Jan 1973): 159–247.https://doi.org/10.1016/B978-0-12-591601-1.50011-9 George Roemhild Compartmentation in the Eggs of Aulocara elliotti (Thomas), Physiological Zoology 40, no.22 (Sep 2015): 182–188.https://doi.org/10.1086/physzool.40.2.30152453

Respiratory Metabolism during Embryogenesis of Gryllus veletis (Alexander and Bigelow) (Orthoptera: Gryllidae)

Previous articleNext article No AccessRespiratory Metabolism during Embryogenesis of Gryllus veletis (Alexander and Bigelow) (Orthoptera: Gryllidae)R. RakshpalR. Rakshpal Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 35, Number 1Jan., 1962 Article DOIhttps://doi.org/10.1086/physzool.35.1.30152712 Views: 5Total views on this site Citations: 11Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). Copyright 1962 University of ChicagoPDF download Crossref reports the following articles citing this article:Suhrid Ghosh, Anna Körte, Giulia Serafini, Vinca Yadav, Jonathan Rodenfels Developmental energetics: Energy expenditure, budgets and metabolism during animal embryogenesis, Seminars in Cell & Developmental Biology 145 (Mar 2022).https://doi.org/10.1016/j.semcdb.2022.03.009B. Chen, R. Ma, D. Ding, L. Wei, L. Kang Aerobic respiration by haemocyanin in the embryo of the migratory locust, Insect Molecular Biology 26, no.44 (Apr 2017): 461–468.https://doi.org/10.1111/imb.12310B. Chen, R. Ma, G. Ma, X. Guo, X. Tong, G. Tang, L. Kang Haemocyanin is essential for embryonic development and survival in the migratory locust, Insect Molecular Biology 24, no.55 (May 2015): 517–527.https://doi.org/10.1111/imb.12177James L. Maino and Michael R. Kearney Ontogenetic and Interspecific Metabolic Scaling in Insects., The American Naturalist 184, no.66 (Jul 2015): 695–701.https://doi.org/10.1086/678401Julie A. Reynolds, Steven C. Hand Decoupling development and energy flow during embryonic diapause in the cricket, Allonemobius socius, Journal of Experimental Biology 212, no.1313 (Jul 2009): 2065–2074.https://doi.org/10.1242/jeb.027359Julie A. Reynolds, Steven C. Hand Embryonic diapause highlighted by differential expression of mRNAs for ecdysteroidogenesis, transcription and lipid sparing in the cricket Allonemobius socius, Journal of Experimental Biology 212, no.1313 (Jul 2009): 2075–2084.https://doi.org/10.1242/jeb.027367 Julie A. Reynolds and Steven C. Hand Differences in Isolated Mitochondria Are Insufficient to Account for Respiratory Depression during Diapause in Artemia franciscana Embryos J. A. Reynolds and S. C. Hand, Physiological and Biochemical Zoology 77, no.33 (Jul 2015): 366–377.https://doi.org/10.1086/420950G. Romano, A. Ianora, L. Santella, A. Miralto Respiratory metabolism during embryonic subitaneous and diapause development in Pontella mediterranea (Crustacea, Copepoda), Journal of Comparative Physiology B 166, no.33 (Jul 1996): 157–163.https://doi.org/10.1007/BF00263978Sinzo Masaki, Thomas J. Walker Cricket Life Cycles, (Jan 1987): 349–423.https://doi.org/10.1007/978-1-4615-6986-2_11 Mekkara Mandaravally Madhavan Respiratory Metabolism and Energy Sources during Embryogenesis of the Aquatic Hemipteran, Sphaerodema molestum (Duf.), Physiological Zoology 48, no.33 (Sep 2015): 263–268.https://doi.org/10.1086/physzool.48.3.30160948R. Rakshpal Respiratory metabolism during embryogenesis of a diapause species of field cricket, Gryllus pennsylvanicus Burmeister (Orthoptera, Gryllidae), Journal of Insect Physiology 8, no.33 (May 1962): 217–221.https://doi.org/10.1016/0022-1910(62)90023-9