WorldWideScience

Sample records for aestivation

  1. Differential Gene Expression in the Liver of the African Lungfish, Protopterus annectens, after 6 Months of Aestivation in Air or 1 Day of Arousal from 6 Months of Aestivation

    OpenAIRE

    Hiong, Kum C.; Ip, Yuen K.; Wai P Wong; Shit F Chew

    2015-01-01

    The African lungfish, Protopterus annectens, can undergo aestivation during drought. Aestivation has three phases: induction, maintenance and arousal. The objective of this study was to examine the differential gene expression in the liver of P. annectens after 6 months (the maintenance phase) of aestivation as compared with the freshwater control, or after 1 day of arousal from 6 months aestivation as compared with 6 months of aestivation using suppression subtractive hybridization. During t...

  2. Differential gene expression in the respiratory tree of the sea cucumber Apostichopus japonicus during aestivation.

    Science.gov (United States)

    Zhao, Ye; Yang, Hongsheng; Storey, Kenneth B; Chen, Muyan

    2014-12-01

    Sea cucumbers, Apostichopus japonicus, experience seasonally high water temperatures during the summer months and enter aestivation to survive. Aestivation is characterized by strong metabolic rate depression which is supported by a series of strategies including reorganizing metabolic processes, suppressing cell functions, enhancing cytoprotective mechanisms, and altered gene expression. The respiratory tree tissue of the sea cucumber is an excellent material for studying aestivation, undergoing obvious atrophy during aestivation. The present study analyzed the global gene expression profile of respiratory tree tissue of A. japonicus during aestivation by constructing and screening three libraries representing key stages of aestivation: non-aestivation (NA), deep-aestivation (DA), and arousal from aestivation (AA) using RNA-seq. A total of 1240, 1184 and 303 differentially expressed genes (DEGs) were identified following the criteria of |log2 ratio|≥1 and FDR≤0.001 in comparisons of DA vs. NA, AA vs. NA and DA vs. AA. A set of respiratory tree specific DEGs was identified the first time and, in addition, common DEGs that were responsive to aestivation in both respiratory tree and intestine were identified. Functional analysis of DEGs was further performed by GO enrichment analysis and respiratory tree specific GO terms were screened out and provide interesting hints for further studies of the molecular regulation of aestivation in A. japonicus. PMID:25038515

  3. Signatures of aestivation and migration in Sahelian malaria mosquito populations.

    Science.gov (United States)

    Dao, A; Yaro, A S; Diallo, M; Timbiné, S; Huestis, D L; Kassogué, Y; Traoré, A I; Sanogo, Z L; Samaké, D; Lehmann, T

    2014-12-18

    During the long Sahelian dry season, mosquito vectors of malaria are expected to perish when no larval sites are available; yet, days after the first rains, mosquitoes reappear in large numbers. How these vectors persist over the 3-6-month long dry season has not been resolved, despite extensive research for over a century. Hypotheses for vector persistence include dry-season diapause (aestivation) and long-distance migration (LDM); both are facets of vector biology that have been highly controversial owing to lack of concrete evidence. Here we show that certain species persist by a form of aestivation, while others engage in LDM. Using time-series analyses, the seasonal cycles of Anopheles coluzzii, Anopheles gambiae sensu stricto (s.s.), and Anopheles arabiensis were estimated, and their effects were found to be significant, stable and highly species-specific. Contrary to all expectations, the most complex dynamics occurred during the dry season, when the density of A. coluzzii fluctuated markedly, peaking when migration would seem highly unlikely, whereas A. gambiae s.s. was undetected. The population growth of A. coluzzii followed the first rains closely, consistent with aestivation, whereas the growth phase of both A. gambiae s.s. and A. arabiensis lagged by two months. Such a delay is incompatible with local persistence, but fits LDM. Surviving the long dry season in situ allows A. coluzzii to predominate and form the primary force of malaria transmission. Our results reveal profound ecological divergence between A. coluzzii and A. gambiae s.s., whose standing as distinct species has been challenged, and suggest that climate is one of the selective pressures that led to their speciation. Incorporating vector dormancy and LDM is key to predicting shifts in the range of malaria due to global climate change, and to the elimination of malaria from Africa. PMID:25470038

  4. Global metabolite analysis of the land snail Theba pisana hemolymph during active and aestivated states.

    Science.gov (United States)

    Bose, U; Centurion, E; Hodson, M P; Shaw, P N; Storey, K B; Cummins, S F

    2016-09-01

    The state of metabolic dormancy has fascinated people for hundreds of years, leading to research exploring the identity of natural molecular components that may induce and maintain this state. Many animals lower their metabolism in response to high temperatures and/or arid conditions, a phenomenon called aestivation. The biological significance for this is clear; by strongly suppressing metabolic rate to low levels, animals minimize their exposure to stressful conditions. Understanding blood or hemolymph metabolite changes that occur between active and aestivated animals can provide valuable insights relating to those molecular components that regulate hypometabolism in animals, and how they afford adaptation to their different environmental conditions. In this study, we have investigated the hemolymph metabolite composition from the land snail Theba pisana, a remarkably resilient mollusc that displays an annual aestivation period. Using LC-MS-based metabolomics analysis, we have identified those hemolymph metabolites that show significant changes in relative abundance between active and aestivated states. We show that certain metabolites, including some phospholipids [e.g. LysoPC(14:0)], and amino acids such as l-arginine and l-tyrosine, are present at high levels within aestivated snails. Further investigation of our T. pisana RNA-sequencing data elucidated the entire repertoire of phospholipid-synthesis genes in the snail digestive gland, as a precursor towards future comparative investigation between the genetic components of aestivating and non-aestivating species. In summary, we have identified a large number of metabolites that are elevated in the hemolymph of aestivating snails, supporting their role in protecting against heat or desiccation. PMID:27318654

  5. Differential gene expression in the liver of the African lungfish, Protopterus annectens, after 6 months of aestivation in air or 1 day of arousal from 6 months of aestivation.

    Directory of Open Access Journals (Sweden)

    Kum C Hiong

    Full Text Available The African lungfish, Protopterus annectens, can undergo aestivation during drought. Aestivation has three phases: induction, maintenance and arousal. The objective of this study was to examine the differential gene expression in the liver of P. annectens after 6 months (the maintenance phase of aestivation as compared with the freshwater control, or after 1 day of arousal from 6 months aestivation as compared with 6 months of aestivation using suppression subtractive hybridization. During the maintenance phase of aestivation, the mRNA expression of argininosuccinate synthetase 1 and carbamoyl phosphate synthetase III were up-regulated, indicating an increase in the ornithine-urea cycle capacity to detoxify ammonia to urea. There was also an increase in the expression of betaine homocysteine-S-transferase 1 which could reduce and prevent the accumulation of hepatic homocysteine. On the other hand, the down-regulation of superoxide dismutase 1 expression could signify a decrease in ROS production during the maintenance phase of aestivation. In addition, the maintenance phase was marked by decreases in expressions of genes related to blood coagulation, complement fixation and iron and copper metabolism, which could be strategies used to prevent thrombosis and to conserve energy. Unlike the maintenance phase of aestivation, there were increases in expressions of genes related to nitrogen, carbohydrate and lipid metabolism and fatty acid transport after 1 day of arousal from 6 months aestivation. There were also up-regulation in expressions of genes that were involved in the electron transport system and ATP synthesis, indicating a greater demand for metabolic energy during arousal. Overall, our results signify the importance of sustaining a low rate of waste production and conservation of energy store during the maintenance phase, and the dependence on internal energy store for repair and structural modification during the arousal phase, of

  6. High-throughput sequencing reveals differential expression of miRNAs in intestine from sea cucumber during aestivation.

    Directory of Open Access Journals (Sweden)

    Muyan Chen

    Full Text Available The regulatory role of miRNA in gene expression is an emerging hot new topic in the control of hypometabolism. Sea cucumber aestivation is a complicated physiological process that includes obvious hypometabolism as evidenced by a decrease in the rates of oxygen consumption and ammonia nitrogen excretion, as well as a serious degeneration of the intestine into a very tiny filament. To determine whether miRNAs play regulatory roles in this process, the present study analyzed profiles of miRNA expression in the intestine of the sea cucumber (Apostichopus japonicus, using Solexa deep sequencing technology. We identified 308 sea cucumber miRNAs, including 18 novel miRNAs specific to sea cucumber. Animals sampled during deep aestivation (DA after at least 15 days of continuous torpor, were compared with animals from a non-aestivation (NA state (animals that had passed through aestivation and returned to the active state. We identified 42 differentially expressed miRNAs [RPM (reads per million >10, |FC| (|fold change| ≥ 1, FDR (false discovery rate <0.01] during aestivation, which were validated by two other miRNA profiling methods: miRNA microarray and real-time PCR. Among the most prominent miRNA species, miR-200-3p, miR-2004, miR-2010, miR-22, miR-252a, miR-252a-3p and miR-92 were significantly over-expressed during deep aestivation compared with non-aestivation animals. Preliminary analyses of their putative target genes and GO analysis suggest that these miRNAs could play important roles in global transcriptional depression and cell differentiation during aestivation. High-throughput sequencing data and microarray data have been submitted to GEO database.

  7. RNA-seq dependent transcriptional analysis unveils gene expression profile in the intestine of sea cucumber Apostichopus japonicus during aestivation.

    Science.gov (United States)

    Zhao, Ye; Yang, Hongsheng; Storey, Kenneth B; Chen, Muyan

    2014-06-01

    The seasonal marine, the sea cucumber Apostichopus japonicus (Selenka, 1867), cycles annually between periods of torpor when water temperature is above about 25°C in summer and active life when temperature is below about 18°C. This species is a good candidate model organism for studies of environmentally-induced aestivation in marine invertebrates. Previous studies have examined various aspects of aestivation of A. japonicus, however, knowledge of the molecular regulation underpinning these events is still fragmentary. In the present study, we constructed a global gene expression profile of the intestine tissue of A. japonicus using RNA-seq to identify transcriptional responses associated with transitions between different states: non-aestivation (NA), deep-aestivation (DA), and arousal from aestivation (AA). The analysis identified 1245 differentially expressed genes (DEGs) between DA vs. NA states, 1338 DEGs between AA vs. DA, and 1321 DEGs between AA vs. NA using the criteria |Log2Ratio|≥1 and FDR≤0.001. Of these, 25 of the most significant DEGs were verified by real-time PCR, showing trends in expression patterns that were almost in full concordance between the two techniques. GO analysis revealed that for DA vs. NA, 24 metabolic associated processes were highly enriched (corrected p valuejaponicus and identifies a series of candidate genes and pathways for further research on the molecular mechanisms of aestivation. PMID:24713300

  8. Aestivation and hypoxia-related events share common silent neuron trafficking processes

    Directory of Open Access Journals (Sweden)

    Giusi Giuseppina

    2012-04-01

    Full Text Available Abstract Background The availability of oxygen is a limiting factor for neuronal survival since low levels account not only for the impairment of physiological activities such as sleep-wake cycle, but above all for ischemic-like neurodegenerative disorders. In an attempt to improve our knowledge concerning the type of molecular mechanisms operating during stressful states like those of hypoxic conditions, attention was focused on eventual transcriptional alterations of some key AMPAergic silent neuronal receptor subtypes (GluR1 and GluR2 along with HSPs and HIF-1α during either a normoxic or a hypoxic aestivation of a typical aquatic aestivator, i.e. the lungfish (Protopterus annectens. Results The identification of partial nucleotide fragments codifying for both AMPA receptor subtypes in Protopterus annectens displayed a putative high degree of similarity to that of not only fish but also to those of amphibians, birds and mammals. qPCR and in situ hybridization supplied a very high (p p  Conclusions The distinct transcriptional variations of silent neurons expressing GluR1/2 and HSPs tend to corroborate these factors as determining elements for the physiological success of normoxic and hypoxic aestivation. A distinct switching among these AMPA receptor subtypes during aestivation highlights new potential adaptive strategies operating in key brain regions of the lungfish in relation to oxygen availability. This functional relationship might have therapeutic bearings for hypoxia-related dysfunctions, above all in view of recently identified silent neuron-dependent motor activity ameliorations in mammals.

  9. Transcriptional changes in epigenetic modifiers associated with gene silencing in the intestine of the sea cucumber, Apostichopus japonicus (Selenka), during aestivation

    Science.gov (United States)

    Wang, Tianming; Yang, Hongsheng; Zhao, Huan; Chen, Muyan; Wang, Bing

    2011-11-01

    The sea cucumber, Apostichopus japonicus, undergoes aestivation to improve survival during periods of high-temperature. During aestivation, the metabolic rate is depressed to reduce the consumption of reserved energy. We evaluated the role of epigenetic modification on global gene silencing during metabolic rate depression in the sea cucumber. We compared the expression of epigenetic modifiers in active and aestivating sea cucumbers. The expression of three genes involved in DNA methylation and chromatin remodeling (DNA (cytosine-5)-methyltransferase 1, Methyl-CpG-binding domain protein 2), and Chromodomain-helicase-DNA-binding protein 5) was significantly higher during aestivation (Days 20 and 40). Similarly, we observed an increase in the expression of genes involved in histone acetylation (Histone deacetylase 3) and Histone-binding protein RBBP4) during the early (Days 5 and 10) and late phases (Days 20 and 40) of aestivation. There was no change in the expression of KAT2B, a histone acetyltransferase. However, the expression of histone methylation associated modifiers (Histone-arginine methyltransferase CARMER and Histone-lysine N-methyltransferase MLL5) was significantly higher after 5 d in the aestivating group. The results suggest that the expression of epigenetic modifiers involved in DNA methylation, chromatin remodeling, histone acetylation, and histone methylation is upregulated during aestivation. We hypothesize that these changes regulate global gene silencing during aestivation in A. japonicus.

  10. Transcriptional changes in epigenetic modifiers associated with gene silencing in the intestine of the sea cucumber,Apostichopus japonicus (Selenka), during aestivation

    Institute of Scientific and Technical Information of China (English)

    WANG Tianming; YANG Hongsheng; ZHAO Huan; CHEN Muyan; WANG Bing

    2011-01-01

    The sea cucumber,Apostichopusjaponicus,undergoes aestivation to improve survival during periods of high-temperature.During aestivation,the metabolic rate is depressed to reduce the consumption of reserved energy.We evaluated the role of epigenetic modification on global gene silencing during metabolic rate depression in the sea cucumber.We compared the expression of epigenetic modifiers in active and aestivating sea cucumbers.The expression of three genes involved in DNA methylation and chromatin remodeling (DNA (cytosine-5)-methyltransferase 1,Methyl-CpG-binding domain protein 2),and Chromodomain-helicase-DNA-binding protein 5) was significantly higher during aestivation (Days 20 and 40).Similarly,we observed an increase in the expression of genes involved in histone acetylation (Histone deacetylase 3) and Histone-binding protein RBBP4) during the early (Days 5 and 10) and late phases (Days 20 and 40) of aestivation.There was no change in the expression of KAT2B,a histone acetyltransferase.However,the expression of histone methylation associated modifiers (Histone-arginine methyltransferase CARMER and Histone-lysine N-methyltransferase MLL5) was significantly higher after 5 d in the aestivating group.The results suggest that the expression of epigenetic modifiers involved in DNA methylation,chromatin remodeling,histone acetylation,and histone methylation is upregulated during aestivation.We hypothesize that these changes regulate global gene silencing during aestivation in A.japonicus.

  11. Synchrotron Reveals Early Triassic Odd Couple: Injured Amphibian and Aestivating Therapsid Share Burrow.

    Directory of Open Access Journals (Sweden)

    Vincent Fernandez

    Full Text Available Fossorialism is a beneficial adaptation for brooding, predator avoidance and protection from extreme climate. The abundance of fossilised burrow casts from the Early Triassic of southern Africa is viewed as a behavioural response by many tetrapods to the harsh conditions following the Permo-Triassic mass-extinction event. However, scarcity of vertebrate remains associated with these burrows leaves many ecological questions unanswered. Synchrotron scanning of a lithified burrow cast from the Early Triassic of the Karoo unveiled a unique mixed-species association: an injured temnospondyl amphibian (Broomistega that sheltered in a burrow occupied by an aestivating therapsid (Thrinaxodon. The discovery of this rare rhinesuchid represents the first occurrence in the fossil record of a temnospondyl in a burrow. The amphibian skeleton shows signs of a crushing trauma with partially healed fractures on several consecutive ribs. The presence of a relatively large intruder in what is interpreted to be a Thrinaxodon burrow implies that the therapsid tolerated the amphibian's presence. Among possible explanations for such unlikely cohabitation, Thrinaxodon aestivation is most plausible, an interpretation supported by the numerous Thrinaxodon specimens fossilised in curled-up postures. Recent advances in synchrotron imaging have enabled visualization of the contents of burrow casts, thus providing a novel tool to elucidate not only anatomy but also ecology and biology of ancient tetrapods.

  12. The interplay of increased urea synthesis and reduced ammonia production in the African lungfish Protopterus aethiopicus during 46 days of aestivation in a mucus cocoon.

    Science.gov (United States)

    Ip, Yuen Kwong; Yeo, Pei Jia; Loong, Ai May; Hiong, Kum Chew; Wong, Wai Peng; Chew, Shit Fun

    2005-12-01

    This study was undertaken to test the hypothesis that the rate of urea synthesis in Protopterus aethiopicus was up-regulated to detoxify ammonia during the initial phase of aestivation in air (day 1-day 12), and that a profound suppression of ammonia production occurred at a later phase of aestivation (day 35-day 46) which eliminated the need to sustain the increased rate of urea synthesis. Fasting apparently led to a greater rate of nitrogenous waste excretion in P. aethiopicus in water, which is an indication of increases in production of endogenous ammonia and urea probably as a result of increased proteolysis and amino acid catabolism for energy production. However, 46 days of fasting had no significant effects on the ammonia or urea contents in the muscle, liver, plasma and brain. In contrast, there were significant decreases in the muscle ammonia content in fish after 12, 34 or 46 days of aestivation in air when compared with fish fasting in water. Ammonia was apparently detoxified to urea because urea contents in the muscle, liver, plasma and brain of P. aethiopicus aestivated for 12, 34 or 46 days were significantly greater than the corresponding fasting control; the greatest increases in urea contents occurred during the initial 12 days. There were also significant increases in activities of some of the hepatic ornithine-urea cycle enzymes from fish aestivated for 12 or 46 days. Therefore, contrary to a previous report on P. aethiopicus, our results demonstrated an increase in the estimated rate of urea synthesis (2.8-fold greater than the day 0 fish) in this lungfish during the initial 12 days of aestivation. However, the estimated rate of urea synthesis decreased significantly during the next 34 days. Between day 35 and day 46 (12 days), urea synthesis apparently decreased to 42% of the day 0 control value, and this is the first report of such a phenomenon in African lungfish undergoing aestivation. On the other hand, the estimated rate of ammonia

  13. Differential gene expression in the brain of the African lungfish, Protopterus annectens, after six days or six months of aestivation in air.

    Directory of Open Access Journals (Sweden)

    Kum C Hiong

    Full Text Available The African lungfish, Protopterus annectens, can undergo aestivation during drought. Aestivation has three phases: induction, maintenance and arousal. The objective of this study was to examine the differential gene expression in the brain of P. annectens during the induction (6 days and maintenance (6 months phases of aestivation as compared with the freshwater control using suppression subtractive hybridization. During the induction phase of aestivation, the mRNA expression of prolactin (prl and growth hormone were up-regulated in the brain of P. annectens, which indicate for the first time the possible induction role of these two hormones in aestivation. Also, the up-regulation of mRNA expression of tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein γ polypeptide and the down-regulation of phosphatidylethanolamine binding protein, suggest that there could be a reduction in biological and neuronal activities in the brain. The mRNA expression of cold inducible RNA-binding protein and glucose regulated protein 58 were also up-regulated in the brain, probably to enhance their cytoprotective effects. Furthermore, the down-regulation of prothymosin α expression suggests that there could be a suppression of transcription and cell proliferation in preparation for the maintenance phase. In general, the induction phase appeared to be characterized by reduction in glycolytic capacity and metabolic activity, suppression of protein synthesis and degradation, and an increase in defense against ammonia toxicity. In contrast, there was a down-regulation in the mRNA expression of prl in the brain of P. annectens during the maintenance phase of aestivation. In addition, there could be an increase in oxidative defense capacity, and up-regulation of transcription, translation, and glycolytic capacities in preparation for arousal. Overall, our results signify the importance of reconstruction of protein structures and regulation of energy

  14. Aestivation induces changes in transcription and translation of coagulation factor II and fibrinogen gamma chain in the liver of the African lungfish Protopterus annectens.

    Science.gov (United States)

    Hiong, Kum C; Tan, Xiang R; Boo, Mel V; Wong, Wai P; Chew, Shit F; Ip, Yuen K

    2015-12-01

    This study aimed to sequence and characterize two pro-coagulant genes, coagulation factor II (f2) and fibrinogen gamma chain (fgg), from the liver of the African lungfish Protopterus annectens, and to determine their hepatic mRNA expression levels during three phases of aestivation. The protein abundance of F2 and Fgg in the liver and plasma was determined by immunoblotting. The results indicated that F2 and Fgg of P. annectens were phylogenetically closer to those of amphibians than those of teleosts. Three days of aestivation resulted in an up-regulation in the hepatic fgg mRNA expression level, while 6 days of aestivation led to a significant increase (3-fold) in the protein abundance of Fgg in the plasma. Hence, there could be an increase in the blood-clotting ability in P. annectens during the induction phase of aestivation. By contrast, the blood-clotting ability in P. annectens might be reduced in response to decreased blood flow and increased possibility of thrombosis during the maintenance phase of aestivation, as 6 months of aestivation led to significant decreases in mRNA expression levels of f2 and fgg in the liver. There could also be a decrease in the export of F2 and Fgg from the liver to the plasma so as to avert thrombosis. Three to 6 days after arousal from 6 months of aestivation, the protein abundance of F2 and Fgg recovered partially in the plasma of P. annectens; a complete recovery of the transcription and translation of f2/F2 in the liver might occur only after refeeding.

  15. Selection of reference genes for qRT-PCR analysis of gene expression in sea cucumber Apostichopus japonicus during aestivation

    Science.gov (United States)

    Zhao, Ye; Chen, Muyan; Wang, Tianming; Sun, Lina; Xu, Dongxue; Yang, Hongsheng

    2014-11-01

    Quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) is a technique that is widely used for gene expression analysis, and its accuracy depends on the expression stability of the internal reference genes used as normalization factors. However, many applications of qRT-PCR used housekeeping genes as internal controls without validation. In this study, the expression stability of eight candidate reference genes in three tissues (intestine, respiratory tree, and muscle) of the sea cucumber Apostichopus japonicus was assessed during normal growth and aestivation using the geNorm, NormFinder, delta CT, and RefFinder algorithms. The results indicate that the reference genes exhibited significantly different expression patterns among the three tissues during aestivation. In general, the β-tubulin (TUBB) gene was relatively stable in the intestine and respiratory tree tissues. The optimal reference gene combination for intestine was 40S ribosomal protein S18 (RPS18), TUBB, and NADH dehydrogenase (NADH); for respiratory tree, it was β-actin (ACTB), TUBB, and succinate dehydrogenase cytochrome B small subunit (SDHC); and for muscle it was α-tubulin (TUBA) and NADH dehydrogenase [ubiquinone] 1 α subcomplex subunit 13 (NDUFA13). These combinations of internal control genes should be considered for use in further studies of gene expression in A. japonicus during aestivation.

  16. DNA methylation levels analysis in four tissues of sea cucumber Apostichopus japonicus based on fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) during aestivation.

    Science.gov (United States)

    Zhao, Ye; Chen, Muyan; Storey, Kenneth B; Sun, Lina; Yang, Hongsheng

    2015-03-01

    DNA methylation plays an important role in regulating transcriptional change in response to environmental stimuli. In the present study, DNA methylation levels of tissues of the sea cucumber Apostichopus japonicus were analyzed by the fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) technique over three stages of the aestivation cycle. Overall, a total of 26,963 fragments were amplified including 9112 methylated fragments among four sea cucumber tissues using 18 pairs of selective primers. Results indicated an average DNA methylation level of 33.79% for A. japonicus. The incidence of DNA methylation was different across tissue types in the non-aestivation stage: intestine (30.16%), respiratory tree (27.61%), muscle (27.94%) and body wall (56.25%). Our results show that hypermethylation accompanied deep-aestivation in A. japonicus, which suggests that DNA methylation may have an important role in regulating global transcriptional suppression during aestivation. Further analysis indicated that the main DNA modification sites were focused on intestine and respiratory tree tissues and that full-methylation but not hemi-methylation levels exhibited significant increases in the deep-aestivation stage. PMID:25461675

  17. High-Throughput Sequencing Reveals Differential Expression of miRNAs in Intestine from Sea Cucumber during Aestivation

    OpenAIRE

    Chen, Muyan; Zhang, Xiumei; LIU, Jianning; Storey, Kenneth B.

    2013-01-01

    The regulatory role of miRNA in gene expression is an emerging hot new topic in the control of hypometabolism. Sea cucumber aestivation is a complicated physiological process that includes obvious hypometabolism as evidenced by a decrease in the rates of oxygen consumption and ammonia nitrogen excretion, as well as a serious degeneration of the intestine into a very tiny filament. To determine whether miRNAs play regulatory roles in this process, the present study analyzed profiles of miRNA e...

  18. Effect of water temperature on digestive enzyme activity and gut mass in sea cucumber Apostichopus japonicus (Selenka), with special reference to aestivation

    Institute of Scientific and Technical Information of China (English)

    GAO Fei; YANG Hongsheng; XU Qiang; WANG Fangyu; LIU Guangbin

    2009-01-01

    The effect of water temperature on gut mass and digestive enzyme activity in sea cucumber Apostichopus japonicus, including relative gut mass (RGM), amylase, lipase, pepsin and trypsin activities were studied at temperatures of 7, 14, 21, and 28°C over a period of 40 days. Results show that RGM significantly decreased after 40 days at 21°C and markedly decreased over the whole experiment period at 28°C; however, no significant effect of duration was observed at 7 or 14°C. At 14°C, trypsin activity significantly decreased over 10 and 20 days, then increased; amylase and trypsin activity significantly decreased after 40 days at 28°C. However, no significant effect of duration was found on amylase, pepsin or trypsin activities in the other temperature treatment groups. At 28°C, lipase activity peaked in 20 days and then markedly decreased to a minimum at the end of the experiment. On the other hand, pepsin activity at 28°C continuously increased over the whole experimental period. Principle component analysis showed that sea cucumbers on day 40 in the 21°C group and in the previous 20 days in the 28°C group were in the prophase of aestivation. At 28°C, sea cucumbers aestivated at 30-40 days after the start of the experiment. It is concluded that the effect of temperature on the digestion of A. japonicus is comparatively weak within a specific range of water temperatures and aestivation behavior is accompanied by significant changes in RGM and digestive enzyme activities.

  19. The division of different stages of aestivation and quantitative analysis of tissue layers thickness of anterior intestine in sea cucumber Apostichopus japonicus%刺参夏眠不同时期划分以及前肠各组织层厚度定量分析

    Institute of Scientific and Technical Information of China (English)

    苏琳; 陈慕雁; 王天明; 刘进; 赵业; 杨红生

    2012-01-01

    Non-aestivation stage sea cucumber as control group, three time points were selected according to aesti-vating degree in sea cucumber (Apostichopus japonicus): initial stage of aestivation, deep aestivation, and the arousal stage of aestivation. The diameter, thickness and different tissue layers thickness of anterior intestine at these three points were measured. As for the submucosa thickness, there was no significant difference between control group and any stage (P > 0.05). As for mucous epithelium and the adventitia, the thickness of the initial stage of aestivation was significantly smaller than those of control group (P < 0.05). At the deep aestivation stage, the thickness of mucous epithelium and muscular layer was significantly smaller than that of control group (P< 0.01). The anterior intestine diameter at the deep aestivation stage was significantly smaller than that of control group (P< 0.01). Calculating the proportion of each layer of the anterior intestine wall thickness, we found that the proportion of mucous epithelium and adventitia was significantly smaller at the initial stage than that of control group (P < 0.05). However, the proportion of submucosa was significantly bigger at the initial stage than that of control group (P < 0.01). The proportion of muscular layer was significantly smaller at the deep aestivation stage than any other stages (P < 0.05).%以非夏眠期刺参(Apostichopus japonicus)为对照组,在刺参夏眠不同程度选取3个时间点,将其分为夏眠初期、深度夏眠期、夏眠解除期3个阶段,采集前肠组织为研究材料,制作石蜡切片,统计不同时期刺参前肠壁厚度、前肠黏膜上皮、黏膜下层、肌肉层和外膜的厚度及直径.结果显示,与对照组相比,夏眠不同时期黏膜下层厚度均无差异(P>0.05),夏眠初期黏膜上皮和外膜显著薄于对照组(P<0.05),深度夏眠期黏膜上皮和肌肉层显著薄于对照组(P<0.01),刺参前肠直径在

  20. 东江支流夏季小型浮游动物群落特征研究%Aestival Characteristics of Small Zooplankton Communities in the Main Tributaries of the Dongjiang River

    Institute of Scientific and Technical Information of China (English)

    彭秋志; 廖剑宇; 伍凯; 刘全儒; 周云龙; 江源; 龚玲

    2013-01-01

    Our goal was to describe the aestival features of small zooplankton communities in the main tributaries of the Dongjiang River and test the possibility of using prominent features derived from the zooplankton community as predictive indicators of water quality. By systematically selecting representative tributaries of the Dongjiang River as case study sites, we randomly sampled small zooplankton (Protozoa and Rotifers) communities along the tributaries in My 2010. The species composition of those zooplankton communities was identified to the genus level, and indices including richness, density, relative density, frequency and diversity were counted. Environmental variables including temperature, dissolved oxygen, electrical conductivity, total phosphorus, total nitrogen, ammonia nitrogen, nitrate nitrogen, permanganate index, and chlorophyll a were also measured. We identified 36 genera, of which 23 belonged to Protozoa and 13 to Rotifers. Those taxa in most cases emerged in low density and low richness in samples. Within a sample, however, often one of the genera was found at a relatively high density, while fewer genera dominated the density and frequency. This implied that small river channels are not suitable for zooplankton growth, whereas diversified habitats resulted in a variety of community composition types. An increased trend from up- to down-stream was found in density, richness and diversity, while at the same time a decreased trend in dominance occurred. Many factors, such as zooplankton origins, available nutrients and flow velocity, could all be influencing the small zooplankton community. Significant correlations between the density of certain special genera and most environmental variables were found, indicating that density might be used as the zooplankton indicator in assessing and monitoring river environmental conditions. On the contrary, the diversity of zooplankton should not be used as a competent indicator in assessment, since there was no

  1. Ecological and physiological aspects of aestivation-diapause in the larvae of twe pyralid stalk borers of maize in Kenya

    NARCIS (Netherlands)

    Scheltes, P.

    1978-01-01

    Stalk borers are highly destructive to a large number of important graminaceous crops all over the world. Some examples of economically important stalk borers and a general description of their life-cycle are mentioned in chapter 1. In the same chapter difficulties in controlling the insects are des

  2. Analysis of fatty acid composition of sea cucumber Apostichopus japonicus using multivariate statistics

    Science.gov (United States)

    Xu, Qinzeng; Gao, Fei; Xu, Qiang; Yang, Hongsheng

    2014-11-01

    Fatty acids (FAs) provide energy and also can be used to trace trophic relationships among organisms. Sea cucumber Apostichopus japonicus goes into a state of aestivation during warm summer months. We examined fatty acid profiles in aestivated and non-aestivated A. japonicus using multivariate analyses (PERMANOVA, MDS, ANOSIM, and SIMPER). The results indicate that the fatty acid profiles of aestivated and non-aestivated sea cucumbers differed significantly. The FAs that were produced by bacteria and brown kelp contributed the most to the differences in the fatty acid composition of aestivated and nonaestivated sea cucumbers. Aestivated sea cucumbers may synthesize FAs from heterotrophic bacteria during early aestivation, and long chain FAs such as eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) that produced from intestinal degradation, are digested during deep aestivation. Specific changes in the fatty acid composition of A. japonicus during aestivation needs more detailed study in the future.

  3. 太阳黑子与毕节地区夏季降水预报%Precipitation forecast considering the aestival solar maculae in BIJIE dirtrict

    Institute of Scientific and Technical Information of China (English)

    张寿荣

    2004-01-01

    利用1月份太阳黑子相对数与夏季降水的相互变化关系,制作第2年夏季降水趋势预报.通过绘制变化曲线进行分析,找出其变化规律,发现当太阳活动达到极值时,尤其是由极低值上升至第3年后的5年内,对第2年夏季降水趋势的短期气候预测效果较好.

  4. 刺参夏眠的研究进展%Research advances in aestivation of sea cucumber Apostichopus japonicus (Selenka): a review

    Institute of Scientific and Technical Information of China (English)

    袁秀堂; 杨红生; 陈慕雁; 高菲

    2007-01-01

    刺参(Apostichopus japonicus(Selenka)),又称仿刺参,属棘皮动物门(Echinodermata),海参纲(Holothuroidea),主要分布于北纬35°到44°的广大西北太平洋沿岸,北起俄罗斯的海参威,经日本海、朝鲜半岛南部到中国黄、渤海。据报道,江苏连云港外的平山岛是该物种在中国分布的最南界。刺参是典型的温带种类,在其生活史中存在着一种重要的生态习性:当夏季海水温度升高到一定范围后,

  5. Leap of faith: voluntary emersion behaviour and physiological adaptations to aerial exposure in a non-aestivating freshwater fish in response to aquatic hypoxia.

    Science.gov (United States)

    Urbina, Mauricio A; Forster, Malcolm E; Glover, Chris N

    2011-05-01

    Lowland stream fauna in areas of intensive agriculture are increasingly under threat from anthropogenic activities leading to eutrophication and subsequent hypoxia. Survival of hypoxic episodes depends upon a combination of behavioural and physiological adaptations. Responses of inanga (Galaxias maculatus: Galaxiidae) to aquatic hypoxia were investigated in the laboratory. Contrary to expectation inanga did not display behaviour that might reduce energy expenditure during oxygen limitation, with swimming activity slightly, but significantly elevated relative to normoxia. Instead, as dissolved oxygen concentrations decreased, the fish moved higher in the water column, increased their swimming speed and exhibited aquatic surface respiration. Physiological changes such as enhanced opercular frequency were also noted. As hypoxia deepened inanga started to leap out of the water, emersing themselves on a floating platform. Once emersed, fish exhibited an enhanced oxygen consumption rate compared to hypoxic fish. Thus inanga appear better adapted to escape hypoxia (a behavioural adaptation) rather than tolerate it (physiological adaptation). The emersion strategy used for inanga in response to severe hypoxia is in agreement with their ability to take up more oxygen from the air than from hypoxic water and therefore may justify the potentially increased risks of desiccation and predation associated with leaving the water. PMID:21316378

  6. Growth, Metabolism and Physiological Response of the Sea Cucumber, Apostichopus japonicus Selenka During Periods of Inactivity

    Institute of Scientific and Technical Information of China (English)

    DU Rongbin; ZANG Yuanqi; TIAN Xiangli; DONG Shuanglin

    2013-01-01

    The growth,metabolism and physiological response of the sea cucumber,Apostichopus japonicus,were investigated during periods of inactivity.The body weight,oxygen consumption rate (OCR),activities of acidic phosphatase (ACP),alkaline phosphatase (AKP),catalase (CAT) and superoxide dismutase (SOD),and content of heat shock protein 70 (Hsp70) in the body wall and coelomic fluid of A.japonicus were measured during starvation,experimental aestivation and aestivation.The results showed that the body weight of sea cucumber in the three treatments decreased significantly during the experimental period (P<0.05).The OCR of sea cucumber reduced in starvation and experimental aestivation treatments,but increased gradually in natural aestivation treatment.The activities of ACP and AKP of sea cucumber decreased gradually in all treatments,whereas those of SOD and CAT as well as Hsp70 content decreased in the starvation and experimental aestivation treatments and increased in natural aestivation treatment.The sea cucumber entered a state of aestivation at 24℃.To some extent,the animals in experimental aestivation were different from those in natural aestivation in metabolism and physiological response.These findings suggested that the aestivation mechanism ofA.japonicus is complex and may not be attributed to the elevated temperature only.

  7. 夏眠对刺参(Apostichopus japonicus (Selenka))能量收支的影响%Effects of aestivation on energy budget of sea cucumber Apostichopus japonicus(Selenka)(Echinodermata: Holothuroidea)

    Institute of Scientific and Technical Information of China (English)

    袁秀堂; 杨红生; 王丽丽; 周毅; 张涛; 刘鹰

    2007-01-01

    夏眠是刺参最重要的生理特征;水温升高是其夏眠的主要诱发因子,而夏眠的临界温度与刺参体重密切相关.为揭示刺参夏眠对其能量利用对策的影响,测定了2种体重规格(134.0±13.5)g和(73.6±2.2)g刺参在10、15、20、25 ℃和30 ℃ 5个温度梯度下的能量收支.结果表明,温度和体重及其交互作用对刺参能量的摄入均有显著影响;而温度是影响其摄食能分配的主要因素.研究发现,刺参在非夏眠期、夏眠临界期和完全夏眠期的能量利用对策有所不同:在非夏眠期,刺参摄食能支出的最大组分是粪便能,占摄食能的比例超过50%,其次为呼吸耗能,占19.8%~39.4%,而生长能和排泄能占的比例较小,分别为5.7%~10.7%和2.9%~3.7%;在夏眠临界温度下,呼吸和排泄耗能占摄食能的比例均显著增大(分别为88.3%和13.6%),而生长能所占比例降为负值(-55.3%),刺参表现为负生长;而在夏眠期,刺参的摄食能和排粪能为零,为维持其基本生理活动,不得不动用以往贮存于体内的能量,消耗于呼吸和排泄等生理过程,供维持生命之用.总之,从能量生物学的角度看,夏眠的主要生态学意义在于刺参长时间处于相对高温环境,进而导致摄食受阻条件下的一种能量节约方式.

  8. Relictual physiological ecology in the threatened land snail Codringtonia helenae: A cause for decline in a changing environment?

    Science.gov (United States)

    Giokas, Sinos; Karkoulis, Panayiotis; Pafilis, Panayiotis; Valakos, Efstratios

    2007-11-01

    Land snails often exhibit intra-annual cycles of activity interspersed by periods of dormancy (hibernation/aestivation), accompanied by a range of behavioural and physiological adaptations to ensure their survival under adverse environmental conditions. These adaptations are useful to understand species-specific habitat requirements and to predict their response to environmental changes. We examined the seasonal physiological and biochemical composition patterns of the threatened land snail Codringtonia helenae, endemic to Greece, in relation to its behavioural ecology and climatic conditions. Fuel reserves (glycogen, lipids, proteins) and water were accumulated prior to aestivation, but subsequently were rapidly depleted. LDH exhibited substantial rise during aestivation, suggesting that anaerobic pathways may provide additional energy. The major outcome of our study was the unambiguous discrimination of the four life-cycle periods. Most remarkable was the clear distinction of the aestivation period, with hibernation, the other dormancy period, showing similarity with the two active periods but not with aestivation. We observed disassociation between behavioural and physiological responses and climatic conditions. The physiological responses of C. helenae were effective during hibernation, but only partly compensate the effect of adverse conditions during aestivation, since its aestivating behaviour is occasional and time limited. Perhaps, the behavioural ecology of Codringtonia is relictual and shaped during past environmental conditions. This constitutes an important extinction threat considering the current climatic trends and the deterioration of the habitat of that species due to human activities.

  9. Growth, metabolism and physiological response of the sea cucumber, Apostichopus japonicus Selenka during periods of inactivity

    Science.gov (United States)

    Du, Rongbin; Zang, Yuanqi; Tian, Xiangli; Dong, Shuanglin

    2013-03-01

    The growth, metabolism and physiological response of the sea cucumber, Apostichopus japonicus, were investigated during periods of inactivity. The body weight, oxygen consumption rate (OCR), activities of acidic phosphatase (ACP), alkaline phosphatase (AKP), catalase (CAT) and superoxide dismutase (SOD), and content of heat shock protein 70 (Hsp70) in the body wall and coelomic fluid of A. japonicus were measured during starvation, experimental aestivation and aestivation. The results showed that the body weight of sea cucumber in the three treatments decreased significantly during the experimental period ( P japonicus is complex and may not be attributed to the elevated temperature only.

  10. Differential expression of aquaporin 3 in Triturus italicus from larval to adult epidermal conversion

    Directory of Open Access Journals (Sweden)

    E Brunelli

    2009-06-01

    Full Text Available By using immunohistochemical techniques applied to confocal microscopy, the presence of aquaporin 3 water channel in the epidermis of Triturus italicus (Amphibia, Urodela has been shown. We analysed the expression of aquaporin 3 (AQP3 during the larval, pre-metamorphic and adult phases; we also showed the localization of the water-channel protein AQP3 in free-swimming conditions and during aestivation in parallel with histological analysis of the skin, focusing on the possible relationship between protein expression and terrestrial habitats. Our results indicate that aquaporin is produced as the epidermis modifies during the functional maturation phase starting at the climax. Moreover, our data suggest an increase in enzyme expression in aestivating newts emphasizing the putative functional importance of differential expression related to a distinct phase of the biological cycle.

  11. Railroad crossing structures for spotted turtles: Massachusetts Bay Transportation Authority– Greenbush rail line wildlife crossing demonstration project

    OpenAIRE

    Pelletier, Steven K.; Carlson, Lars; Nein, Daniel; Roy, Robert D.

    2005-01-01

    Loss of access to critical habitats is a key wildlife concern, particularly for species listed for protection by state and federal agencies. Rail corridors pose unique design challenges by virtue of the need to avoid abrupt changes in track curves and grade in the right of way (ROW). Spotted turtles (Clemmys guttata) are particularly vulnerable to habitat fragmentation due to their limited mobility and dependence on a diversity of specific foraging, nesting, and aestivation habitats. Spotted ...

  12. Laboratory Rearing of Laricobius nigrinus (Coleoptera: Derodontidae): A Predator of the Hemlock Woolly Adelgid (Hemiptera: Adelgidae)

    OpenAIRE

    Salom, S. M.; L. T. Kok; Lamb, A B; Jubb, C

    2012-01-01

    Coleopteran species are biological control agents of numerous invasive pests. Laricobius nigrinus (Coleoptera: Derodontidae), a predaceous, univoltine species, spends the summer aestivating but is active for the rest of the year. Laricobius nigrinus possesses many essential attributes for effective biological control of the hemlock woolly adelgid (Hemiptera: Adelgidae). The predator must be reared in large numbers for field releases. We describe some of the studies that led to the successful ...

  13. Pre stimulation by gibberellic acid and the effect of extremely diluted agitated gibberellic acid on wheat stalk growth

    OpenAIRE

    Peter Christina Endler; Harald Lothaller; Waltraud Scherer-Pongratz; Sonja Hribar-Marko

    2012-01-01

    Background: In previous multicentre studies[1,2], the influence of a homeopathic ultra high dilution of gibberellic acid on wheat growth was scrutinized. Data showed that this test dilution slowed down stalk growth when experiments were performed in autumn season. Aim: To test the hypothesis that pre treatment of grains with high concentrations of gibberellic acid will enhance the effect of the ultra high dilution of the plant hormone Methods: Grains of winter wheat (Triticum aestiv...

  14. Use of permethrin as a miticide in the African hedgehog (Atelerix albiventris).

    Science.gov (United States)

    Staley, E C; Staley, E E; Behr, M J

    1994-04-01

    The African hedgehog, Atelerix albiventris (also known as Erinaceous albiventris; 1,2) has recently undergone an increase in popularity as an exotic pet. This popularity (Beatrix Potter not withstanding) is due in part to the small size of the African hedgehog (adults are 4-6 in in length, weighing approximately 1 lb), its lack of hibernation or aestivation if reared under controlled light and temperature, and its general good nature and accommodation to handling. PMID:8197715

  15. Changes in body fluids of the cocooning fossorial frog Cyclorana australis in a seasonally dry environment.

    Science.gov (United States)

    Reynolds, Stephen J; Christian, Keith A; Tracy, Christopher R; Hutley, Lindsay B

    2011-11-01

    We investigated changes in the lymph (equivalent to plasma) and urine of the cocooning frog Cyclorana australis during the dry season in monsoonal northern Australia. Frogs in moist soil for two days were fully hydrated (lymph 220 mOsm kg(-1), urine 49 mOsm kg(-1)). From five weeks onwards the soil was dry (matric potential soil, osmolality increase in C. australis was not severe. Aestivation in a cocoon facilitates survival in shallow burrows, but such a strategy may only be effective in environments with seasonally reliable rainfall. PMID:21777688

  16. Observations of cocooned Hydrobaenus (Diptera: Chironomidae) larvae in Lake Michigan

    Science.gov (United States)

    Tucker, Taaja R.; Hudson, Patrick L.; Riley, Stephen

    2016-01-01

    Larvae of the family Chironomidae have developed a variety of ways to tolerate environmental stress, including the formation of cocoons, which allows larvae to avoid unfavorable temperature conditions, drought, or competition with other chironomids. Summer cocoon formation by younger instars of the genus Hydrobaenus Fries allows persistence through increased temperatures and/or intermittent dry periods in arid regions or temporary habitats, but this behavior was not observed in the Great Lakes until the current study. Cocoon-aestivating Hydrobaenus sp. larvae were found in benthic grab samples collected in 2010–2013 near Sleeping Bear Dunes National Lakeshore in northern Lake Michigan with densities up to 7329/m2. The aestivating species was identified as Hydrobaenus johannseni (Sublette, 1967), and the associated chironomid community was typical for an oligotrophic nearshore system. Hydrobaenus cocoon formation in the Great Lakes was likely previously unnoticed due to the discrepancies between the genus' life history and typical benthos sampling procedures which has consequences for describing chironomid communities where Hydrobaenus is present.

  17. Considerações taxonômicas e novas combinações em Ardisia Swartz (Myrsinaceae do sudeste do Brasil Taxonomic considerations and new combinations in Ardisia Swartz (Myrsinaceae from Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Luís Carlos Bernacci

    2000-12-01

    Full Text Available Os tipos de placentação e de pré-floração têm sido utilizados para a distinção dos gêneros Ardisia Swartz, ao qual tem sido atribuído placentação plurisseriada e pré-floração imbricada ou quincuncial, e Stylogyne A.DC., ao qual tem sido atribuído placentação unisseriada e pré-floração contorta. Entretanto, a análise de dez espécies destes gêneros revelou a inconsistência destes caracteres. Também foi constatada a impossibilidade de observar diferenças no tipo de placentação em espécimes com poucos óvulos. Propõe-se, portanto, o restabelecimento da circunscrição de Ardisia, incluindo o gênero Stylogyne, conforme adotado por Miquel, em 1856 e Handro, em 1969. Desta forma, Ardisia ambigua Mart. é o nome válido para S. ambigua (Mart. Mez e Ardisia martiana Miq. o é para S. laevigata (Mart. Mez. Duas novas combinações são necessárias: Ardisia depauperata (Mez Bernacci & Jung-Mendaçolli e Ardisia warmingii (Mez Bernacci & Jung-Mendaçolli.Placentation and aestivation have traditionally been used as diagnostic features to separate the genera Ardisia Swartz and Stylogyne A.DC. While Ardisia has pluriseriate placentation and imbricate or quincuncial aestivation, Stylogyne has uniseriate placentation and contorted aestivation. However, careful examination of ten species of these genera revealed the inconsistency of these characters in the distinction of the two genera. Also, we noticed the impossibility of observation of placentation types in few-ovuled specimens. Therefore, we propose the re-establishment of the circumscription of Ardisia adopted by Miquel, in 1856, and Handro, in 1969 which includes the genus Stylogyne. In this way Ardisia ambigua Mart. is the valid name for S. ambigua (Mart. Mez as Ardisia martiana Miq. is for S. laevigata (Mart. Mez. Two new combinations are necessary: Ardisia depauperata (Mez Bernacci & Jung-Mendaçolli and Ardisia warmingii (Mez Bernacci & Jung-Mendaçolli.

  18. Transcriptome sequencing and characterization for the sea cucumber Apostichopus japonicus (Selenka, 1867.

    Directory of Open Access Journals (Sweden)

    Huixia Du

    Full Text Available BACKGROUND: Sea cucumbers are a special group of marine invertebrates. They occupy a taxonomic position that is believed to be important for understanding the origin and evolution of deuterostomes. Some of them such as Apostichopus japonicus represent commercially important aquaculture species in Asian countries. Many efforts have been devoted to increasing the number of expressed sequence tags (ESTs for A. japonicus, but a comprehensive characterization of its transcriptome remains lacking. Here, we performed the large-scale transcriptome profiling and characterization by pyrosequencing diverse cDNA libraries from A. japonicus. RESULTS: In total, 1,061,078 reads were obtained by 454 sequencing of eight cDNA libraries representing different developmental stages and adult tissues in A. japonicus. These reads were assembled into 29,666 isotigs, which were further clustered into 21,071 isogroups. Nearly 40% of the isogroups showed significant matches to known proteins based on sequence similarity. Gene ontology (GO and KEGG pathway analyses recovered diverse biological functions and processes. Candidate genes that were potentially involved in aestivation were identified. Transcriptome comparison with the sea urchin Strongylocentrotus purpuratus revealed similar patterns of GO term representation. In addition, 4,882 putative orthologous genes were identified, of which 202 were not present in the non-echinoderm organisms. More than 700 simple sequence repeats (SSRs and 54,000 single nucleotide polymorphisms (SNPs were detected in the A. japonicus transcriptome. CONCLUSION: Pyrosequencing was proven to be efficient in rapidly identifying a large set of genes for the sea cucumber A. japonicus. Through the large-scale transcriptome sequencing as well as public EST data integration, we performed a comprehensive characterization of the A. japonicus transcriptome and identified candidate aestivation-related genes. A large number of potential genetic

  19. Pathogenicity of the entomopathogenic fungus Metarhizium anisopliae var. major on different stages of the sunn pest Eurygaster integriceps.

    Science.gov (United States)

    Sedighi, Neda; Abbasipour, Habib; Askary, Hassan; Gorjan, Aziz Sheikhi; Karimi, Jaber

    2013-01-01

    The sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), is the most important insect pest of wheat and barley. The population management of this pest is of major concern to wheat producers. One of the potential control strategies is to use entomopathogenic fungi. This study evaluates the pathogenicity of the fungus Metarhizium anisopliae var. major (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae) on the sunn pest, E. integriceps. Five concentrations of the fungus were utilized, ranging from 1×10(4) to 1×10(8) conidia/mL, accompanied by controls. Fifth instar nymphs and adults (a migratory summer population and a diapausing population) previously exposed to fungi were sown to isolate the fungi, and the growth parameters were analyzed. A direct spray technique was used to expose the isolates to the E. integriceps. The experiment was repeated four times, and mortalities of the insects for all treatments were recorded daily. The results showed that the mortality of infected nymphs was significantly higher than the mortality of control nymphs. Also, the longevity of infected adults was lower than the controls. The results also showed that diapausing adults of the sunn pest were much more susceptible to infection than the summer adults. Estimated LC50 values for the M14 isolate were 1.4 × 10(6), 1.4 ×10 (5) , and 2.3 × 10(3) spores/mL against the aestivation population, the diapausing population, and 5(th) instar nymphs, respectively. Estimated LT50 values using 10(8) spores/mL of the Mm isolate on the aestivation and diapausing populations were 11.9 and 5.11 days, respectively. The results demonstrated that M. anisoplaie was effective on all of stages of E. integriceps. In addition, the nymphal stage was more susceptible than the adults.

  20. The Australian Bogong moth Agrotis infusa: A long-distance nocturnal navigator

    Directory of Open Access Journals (Sweden)

    Eric eWarrant

    2016-04-01

    Full Text Available The nocturnal Bogong moth (Agrotis infusa is an iconic and well-known Australian insect that is also a remarkable nocturnal navigator. Like the Monarch butterflies of North America, Bogong moths make a yearly migration over enormous distances, from southern Queensland, western and northwestern New South Wales (NSW and western Victoria, to the alpine regions of NSW and Victoria. After emerging from their pupae in early spring, adult Bogong moths embark on a long nocturnal journey towards the Australian Alps, a journey that can take many days or even weeks and cover over 1000 km. Once in the Alps (from the end of September, Bogong moths seek out the shelter of selected and isolated high ridge-top caves and rock crevices (typically at elevations above 1800 m. In hundreds of thousands, moths line the interior walls of these cool alpine caves where they hibernate over the summer months (referred to as aestivation. Towards the end of the summer (February and March, the same individuals that arrived months earlier leave the caves and begin their long return trip to their breeding grounds. Once there, moths mate, lay eggs and die. The moths that hatch in the following spring then repeat the migratory cycle afresh. Despite having had no previous experience of the migratory route, these moths find their way to the Alps and locate their aestivation caves that are dotted along the high alpine ridges of southeastern Australia. How naïve moths manage this remarkable migratory feat still remains a mystery, although there are many potential sensory cues along the migratory route that moths might rely on during their journey, including visual, olfactory, mechanical and magnetic cues. Here we review our current knowledge of the Bogong moth, including its natural history, its ecology, its cultural importance to the Australian Aborigines and what we understand about the sensory basis of its long-distance nocturnal migration. From this analysis it becomes clear

  1. Optimization of stocking density for the sea cucumber, Apostichopus japonicus Selenka, under feed-supplement and non-feed-supplement regimes in pond culture

    Science.gov (United States)

    Qin, Chuanxin; Dong, Shuanglin; Tan, Fuyi; Tian, Xiangli; Wang, Fang; Dong, Yunwei; Gao, Qinfeng

    2009-09-01

    Optimal stocking densities were investigated for the sea cucumber Apostichopus japonicus Selenka under feed-supplement and non-feed-supplement regimes in net enclosures for 333 d. Substantial weight loss occurred during the aestivation phase (AE). Decreased growth rates were also observed during the winter phase (WT). In contrast, sea cucumbers showed rapid growth during the spring (SP) and autumn (AU) phases. Feeding regimes considerably influenced the growth performance, i.e., sea cucumbers grew faster under feed-supplement regime than under non-feed-supplement regime ( P < 0.05). The average survival rates of sea cucumbers under feed-supplement regime were higher than those under non-feed-supplement regime for both the autumn phase and spring phase, but the differences were only significant for the latter phase ( P < 0.05). The fitted B-N curves showed that the optimal stocking densities, in terms of net production, were 22.3 ind. m-2 for feed-supplement regime and 14.1 ind. m-2 for non-feed-supplement regime.

  2. On whose shoulders we stand – the pioneering entomological discoveries of Károly Sajó

    Directory of Open Access Journals (Sweden)

    Karoly Vig

    2011-12-01

    Full Text Available The excellence of Károly Sajó as a researcher into Hungary’s natural history has been undeservedly neglected. Yet he did lasting work, especially in entomology, and a number of his discoveries and initiatives were before their time.Born in 1851 in Győr, he received his secondary education there and went to Pest University. He taught in a grammar school in 1877–88 before spending seven years as an entomologist at the National Phylloxera Experimental Station, later the Royal Hungarian State Entomological Station. Pensioned off at his own request in 1895, he moved to Őrszentmiklós, where he continued making entomological observations on his own farm and wrote the bulk of his published materials: almost 500 longer or shorter notes, articles and books, mainly on entomological subjects.Sajó was among the first in the world to publish in 1896 a study of how the weather affects living organisms, entitled Living Barometers. His Sleep in Insects, which appeared in the same year, described his discovery, from 1895 observations of the red turnip beetle, Entomoscelis adonidis (Pallas 1771, of aestivation in insects – in present-day terms diapause.It was a great loss to universal entomology when Sajó ceased publishing about 25 years before his death. His unpublished notes, with his library and correspondence, were destroyed in the World War II. His surviving insect collection is now kept in the Hungarian Natural History Museum, Budapest.

  3. On whose shoulders we stand - the pioneering entomological discoveries of Károly Sajó.

    Science.gov (United States)

    Vig, Károly

    2011-01-01

    The excellence of Károly Sajó as a researcher into Hungary's natural history has been undeservedly neglected. Yet he did lasting work, especially in entomology, and a number of his discoveries and initiatives were before their time.Born in 1851 in Győr, he received his secondary education there and went to Pest University. He taught in a grammar school in 1877-88 before spending seven years as an entomologist at the National Phylloxera Experimental Station, later the Royal Hungarian State Entomological Station. Pensioned off at his own request in 1895, he moved to Őrszentmiklós, where he continued making entomological observations on his own farm and wrote the bulk of his published materials: almost 500 longer or shorter notes, articles and books, mainly on entomological subjects.Sajó was among the first in the world to publish in 1896 a study of how the weather affects living organisms, entitled Living Barometers. His Sleep in Insects, which appeared in the same year, described his discovery, from 1895 observations of the red turnip beetle, Entomoscelis adonidis (Pallas, 1771), of aestivation in insects - in present-day terms diapause.It was a great loss to universal entomology when Sajó ceased publishing about 25 years before his death. His unpublished notes, with his library and correspondence, were destroyed in the World War II. His surviving insect collection is now kept in the Hungarian Natural History Museum, Budapest. PMID:22303108

  4. On whose shoulders we stand – the pioneering entomological discoveries of Károly Sajó *

    Science.gov (United States)

    Vig, Károly

    2011-01-01

    Abstract The excellence of Károly Sajó as a researcher into Hungary’s natural history has been undeservedly neglected. Yet he did lasting work, especially in entomology, and a number of his discoveries and initiatives were before their time. Born in 1851 in Győr, he received his secondary education there and went to Pest University. He taught in a grammar school in 1877–88 before spending seven years as an entomologist at the National Phylloxera Experimental Station, later the Royal Hungarian State Entomological Station. Pensioned off at his own request in 1895, he moved to Őrszentmiklós, where he continued making entomological observations on his own farm and wrote the bulk of his published materials: almost 500 longer or shorter notes, articles and books, mainly on entomological subjects. Sajó was among the first in the world to publish in 1896 a study of how the weather affects living organisms, entitled Living Barometers. His Sleep in Insects, which appeared in the same year, described his discovery, from 1895 observations of the red turnip beetle, Entomoscelis adonidis (Pallas, 1771), of aestivation in insects – in present-day terms diapause. It was a great loss to universal entomology when Sajó ceased publishing about 25 years before his death. His unpublished notes, with his library and correspondence, were destroyed in the World War II. His surviving insect collection is now kept in the Hungarian Natural History Museum, Budapest. PMID:22303108

  5. Ecology of Anopheles dthali Patton in Bandar Abbas District, Hormozgan Province, Southern Iran

    Directory of Open Access Journals (Sweden)

    H Vatandoost

    2007-05-01

    Full Text Available Ecology of Anopheles dthali was studied in Bandar Abbas County, where there is indigenous malaria. Anopheles dthali plays as a secondary malaria vector in the region. It is active throughout the year in mountainous area with two peaks of activity, whereas in coastal area it has one peak. There is no report of hibernation or aestivation for this species in the re¬gion. Precipitin tests on specimens from different parts showed that 15.6-20.8% were positive for human blood. This species usually rests outdoors. It has different larval habitats. Insecticides susceptibility tests on adult females exhibited susceptibil¬ity to all insecticides recommended by WHO. LT50 for the currently used insecticide, lambda-cyhalothrin, is measured less than one minute. The irritability tests to pyrethroid insecticides, showed that permethrin and lambda-cyhalothrin had more irritancy compared to deltamethrin and cyfluthrin. Larval bioassay using malathion, chlorpyrifos, temephos and fenithrothion did not show any sing of resistance to these larvicides at the diagnostic dose. It is recommended that all the decision makers should consider the results of our study for any vector control measures in the region.

  6. Ecology of Anopheles dthali Patton in Bandar Abbas District, Hormozgan Province, Southern Iran

    Directory of Open Access Journals (Sweden)

    H Vatandoost

    2007-06-01

    Full Text Available Ecology of Anopheles dthali was studied in Bandar Abbas County, where there is indigenous malaria. Anopheles dthali plays as a secondary malaria vector in the region. It is active throughout the year in mountainous area with two peaks of activity, whereas in coastal area it has one peak. There is no report of hibernation or aestivation for this species in the re¬gion. Precipitin tests on specimens from different parts showed that 15.6-20.8% were positive for human blood. This species usually rests outdoors. It has different larval habitats. Insecticides susceptibility tests on adult females exhibited susceptibil¬ity to all insecticides recommended by WHO. LT50 for the currently used insecticide, lambda-cyhalothrin, is measured less than one minute. The irritability tests to pyrethroid insecticides, showed that permethrin and lambda-cyhalothrin had more irritancy compared to deltamethrin and cyfluthrin. Larval bioassay using malathion, chlorpyrifos, temephos and fenithrothion did not show any sing of resistance to these larvicides at the diagnostic dose. It is recommended that all the decision makers should consider the results of our study for any vector control measures in the region.

  7. An Overview of Seasonal Changes in Oxidative Stress and Antioxidant Defence Parameters in Some Invertebrate and Vertebrate Species

    Directory of Open Access Journals (Sweden)

    Gagan Bihari Nityananda Chainy

    2016-01-01

    Full Text Available Antioxidant defence system, a highly conserved biochemical mechanism, protects organisms from harmful effects of reactive oxygen species (ROS, a by-product of metabolism. Both invertebrates and vertebrates are unable to modify environmental physical factors such as photoperiod, temperature, salinity, humidity, oxygen content, and food availability as per their requirement. Therefore, they have evolved mechanisms to modulate their metabolic pathways to cope their physiology with changing environmental challenges for survival. Antioxidant defences are one of such biochemical mechanisms. At low concentration, ROS regulates several physiological processes, whereas at higher concentration they are toxic to organisms because they impair cellular functions by oxidizing biomolecules. Seasonal changes in antioxidant defences make species able to maintain their correct ROS titre to take various physiological functions such as hibernation, aestivation, migration, and reproduction against changing environmental physical parameters. In this paper, we have compiled information available in the literature on seasonal variation in antioxidant defence system in various species of invertebrates and vertebrates. The primary objective was to understand the relationship between varied biological phenomena seen in different animal species and conserved antioxidant defence system with respect to seasons.

  8. Optimization of Stocking Density for the Sea Cucumber,Apostichopus japonicus Selenka, Under Feed-Supplement and Non-Feed-Supplement Regimes in Pond Culture

    Institute of Scientific and Technical Information of China (English)

    QIN Chuanxin; DONG Shuanglin; TAN Fuyi; TIAN Xiangli; WANG Fang; DONG Yunwei; GAO Qinfeng

    2009-01-01

    Optimal stocking densities were investigated for the sea cucumber Apostichopus japonicus Selenka under feed-supplement and non-feed-supplement regimes in net enclosures for 333 d. Substantial weight loss occurred during the aestivation phase (AE).Decreased growth rates were also observed during the winter phase (WT). In contrast, sea cucumbers showed rapid growth during the spring (SP) and autumn (AU) phases. Feeding regimes considerably influenced the growth performance, i.e., sea cucumbers grew faster under feed-supplement regime than under non-feed-supplement regime (P< 0.05). The average survival rates of sea cucumbers under feed-supplement regime were higher than those under non-feed-supplement regime for both the autumn phase and spring phase,but the differences were only significant for the latter phase (P<0.05). The fitted B-N curves showed that the optimal stocking densities, in terms of net production, were 22.3 ind. m-2 for feed-supplement regime and 14.1 ind. m-2 for non-feed-supplement regime.

  9. The importance of cutaneous gas exchange during aerial and aquatic respiration in galaxiids.

    Science.gov (United States)

    Urbina, M A; Meredith, A S; Glover, C N; Forster, M E

    2014-03-01

    The Canterbury mudfish Neochanna burrowsius was found to be a pseudo-aestivating galaxiid with a low metabolic rate and significant cutaneous oxygen uptake (c. 43%) in both air and water. Another galaxiid, inanga Galaxias maculatus, had a higher metabolic rate in both media but the proportion of oxygen uptake met by cutaneous respiration rose significantly from 38 to 63% when the fish were exposed to air. Besides its important role in oxygen uptake, the skin of both species also contributed significantly to excretion of carbon dioxide in air, indicating the critical role of the integument as a respiratory tissue. In air, G. maculatus may increase cutaneous gas exchange to meet metabolic demands owing to the reduced utility of the gills, but as emersed G. maculatus were only able to maintain metabolic rates at c. 67% of that measured in water, this strategy probably only permits short-term survival. By contrast, the low and unchanging metabolic rate in water and air in N. burrowsius is a feature that may facilitate tolerance of long periods of emersion in the desiccating environments they inhabit. PMID:24417441

  10. Habitat use, daily activity periods, and thermal ecology of Ameiva ameiva (Squamata: Teiidae in a caatinga area of northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Eliza M. X. Freire

    2011-12-01

    Full Text Available We studied the use of spatial, temporal, and thermal resources by the Neotropical lizard Ameiva ameiva during rainy and dry seasons in a caatinga (xerophilous open forests environment in northeasternBrazil. Lizards used the vegetation habitats and microhabitats in the ground, but never were seen in the rocky habitat. Adults usually used the arboreal-shrubby habitat, whereas juveniles were sighted more often in the shrubby-herbaceous habitat. Ontogenetic differences in spatial use seem to be linked to different thermal needs between age groups owing to differences in body size. Body temperatures were significantly higher in juveniles than in adults. Most teiid species have elevated body temperatures, usually above 37oC, and are active during the hottest times of day, as was observed for A. ameiva in this study. Seasonality influenced habitat use and daily activity periods of adults, but not body temperatures. We verified annual fluctuations in adult abundance, with a decline of active lizards in the dry season; this phenomenon may be related to aestivation and/or increased mortality rate during the driest months.

  11. Do ice nucleating agents limit the supercooling ability of the land snail Cornu aspersum?

    Science.gov (United States)

    Ansart, A; Nicolai, A; Vernon, P; Madec, L

    2010-01-01

    The supercooling ability of adults and eggs of the partially freezing tolerant land snail Cornu aspersum remains limited to high subzero temperatures (ca. -5 degree C) whatever the conditions, suggesting the presence of ice nucleating agents (INAs). In this study, we investigated the nucleation activity of the digestive tract of adult snails, eggs and their direct environment: food, faeces and soil. The mucous ribbon always present in the distal intestine of adults exhibited a heat-sensitive (i.e. organic) nucleation activity, close to that of the entire snails during dormant states (aestivation and hibernation). However, a microbial nature of these INAs could not be established in inactive snails. The food provided to active snails contained ice nucleating bacteria, which followed the digestive tract to be found in the intestine and in the faeces, but with a decreasing concentration along the transit. Eggshells also presented a heat-sensitive nucleation activity, which could be related to its structure. Moreover, eggs are laid directly in the soil which contained both organic and mineral INAs. This study is the first to demonstrate the implication of organic INAs in the cold hardiness of a terrestrial gastropod. PMID:20818461

  12. Fungal Control of Pathogenic Fungi Isolated From Some Wild Plants in Taif Governorate, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Abou-Zeid, A. M.

    2008-01-01

    Full Text Available Twenty two plants were collected from Taif Governorate and identified as: Aerva lanata, Arnebia hispidissima, Artemisia judaica, Artemisia monosperma, Asphodelus aestives, Avena barbata, Capparis dcidua, Eucalyptus globulus, Euphorbia glomerifera, Foeniculum vulgare, Forsskaolea tenacissima, Juniperus procera, Launaea mucronata, Launaea sonchoides, Medicago sativa, Opuntia ficus, Phagnalon sinaicum, Prunus persica, Pulicaria crispa, Punica granatum, Rumex dentatus and Trichodesma calathiforme. Pathogenic fungi were isolated from some of these plants and identified as Alternaria alternata, Cephalosporium madurae, Cladosporium herbarum, Fusarium oxysporum, Humicola grisea, Penicillium chrysogenum and Ulocladium botrytis. Four antagonistic isolates were tested, 2 from Gliocladium fungus and 2 from Trichoderma fungus. We found that all the four antagonistic isolates (G. deliquescens, G. virens, T. viride and T. hamatum significantly inhibited the radial growth of the pathogenic fungi tested, with different ratios. The results indicated that the antibiotics produced by the antagonists were more effective than the fungus itself and differ with different fungi. Coating plant stems with antagonists or with antagonist extracts reduce the severity of the disease but not prevent it in all tested pathogens.

  13. Application of morphologic burrow architects: lungfish or crayfish?

    Science.gov (United States)

    Hasiotis, Stephen T.; Mitchell, Charles E.; Dubiel, Russell R.

    1993-01-01

    A methodology for trace fossil identification using burrowing signatures is tested by evaluating ancient and modern lungfish and crayfish burrows and comparing them to previously undescribed burrows in a stratigraphic interval thought to contain both lungfish and crayfish burrows. Permian burrows that bear skeletal remains of the lungfish Gnathorhiza, from museum collections, were evaluated to identify unique burrow morphologies that could be used to distinguish lungfish from crayfish burrows when fossil remains are absent. The lungfish burrows were evaluated for details of the burrowing mechanism preserved in the burrow morphologies together forming burrowing signatures and were compared to new burrows in the Chinle Formation of western Colorado to test the methodology of using burrow signatures to identify unknown burrows. Permian lungfish aestivation burrows show simple, nearly vertical, unbranched architectures and relatively smooth surficial morphologies with characteristic quasi‐horizontal striae on the burrow walls and vertical striae on the bulbous terminus. Burrow lengths do not exceed 0.5 m. In contrast, modern and ancient crayfish burrows exhibit simple to highly complex architectures with highly textured surficial morphologies. Burrow lengths may reach 4 to 5 m. Burrow morphologies unlike those identified in Gnathorhiza aestivation burrows were found in four burrow groups from museum collections. Two of these groups exhibit simple architectures and horizontal striae that were greater in sinuosity and magnitude, respectively. One of these burrows contains the remains of Lysorophus, but the burrow surface reveals no reliable surficial characteristics. It is not clear whether Lysorophus truly burrowed or merely occupied a pre‐existing structure. The other two groups exhibit surficial morphologies similar to those found on modern and ancient crayfish burrows and may provide evidence of freshwater crayfish in the Permian. Burrows from the Upper Triassic

  14. Annual changes of immune enzymes in coelome fluid of sea cucumber, Apostichopus japonicus%刺参体腔液几种免疫指标的周年变化

    Institute of Scientific and Technical Information of China (English)

    王方雨; 杨红生; 高菲; 刘广斌

    2009-01-01

    In view of eco-immunology, immune enzymes in coelome fluid of sea cucumber, Apostichopus japonicus, were investigated from July in 2006 to June in 2007. The data showed that turing points of enzyme changes were in September, October, January, February, April and May. The results showed that immune characters in coelomic fluid ofA. japonicus might not solely be attributed to temperature and salinity. These data were complex and interesting. Considering the life characters ofA. japonicus, the significant changes of enzymes activity might be associated with growth, reproduction, aestivation, and environment.%为了调查刺参(Apostichopus japonicus)免疫机能的周年变化,初步探索刺参免疫的规律,于2006年7月至2007年6月对刺参体腔液几种免疫指标进行了周年测定.结果显示,周年内刺参体腔液内几种酶类显著变化的转折点为9月、10月,1月,2月、4月和5月.刺参体腔液几种酶类活性变化与温度和盐度等环境因素并不存在相关关系,因此推测这些显著变化并不是单一的温度、盐度等环境因素作用的结果,综合分析,其变化原因可能与刺参的夏眠、生理及繁殖等因素的作用有关.

  15. What parts of the US mainland are climatically suitable for invasive alien pythons spreading from Everglades National Park?

    Science.gov (United States)

    Rodda, G.H.; Jarnevich, C.S.; Reed, R.N.

    2009-01-01

    The Burmese Python (Python molurus bivittatus) is now well established in southern Florida and spreading northward. The factors likely to limit this spread are unknown, but presumably include climate or are correlated with climate. We compiled monthly rainfall and temperature statistics from 149 stations located near the edge of the python's native range in Asia (Pakistan east to China and south to Indonesia). The southern and eastern native range limits extend to saltwater, leaving unresolved the species' climatic tolerances in those areas. The northern and western limits are associated with cold and aridity respectively. We plotted mean monthly rainfall against mean monthly temperature for the 149 native range weather stations to identify the climate conditions inhabited by pythons in their native range, and mapped areas of the coterminous United States with the same climate today and projected for the year 2100. We accounted for both dry-season aestivation and winter hibernation (under two scenarios of hibernation duration). The potential distribution was relatively insensitive to choice of scenario for hibernation duration. US areas climatically matched at present ranged up the coasts and across the south from Delaware to Oregon, and included most of California, Texas, Oklahoma, Arkansas, Louisiana, Mississippi, Alabama, Florida, Georgia, and South and North Carolina. By the year 2100, projected areas of potential suitable climate extend northward beyond the current limit to include parts of the states of Washington, Colorado, Illinois, Indiana, Ohio, West Virginia, Pennsylvania, New Jersey, and New York. Thus a substantial portion of the mainland US is potentially vulnerable to this ostensibly tropical invader. ?? 2008 Springer Science+Business Media B.V.

  16. Genome-wide transcriptional analysis of genes associated with acute desiccation stress in Anopheles gambiae.

    Directory of Open Access Journals (Sweden)

    Mei-Hui Wang

    Full Text Available Malaria transmission in sub-Saharan Africa varies seasonally in intensity. Outbreaks of malaria occur after the beginning of the rainy season, whereas, during the dry season, reports of the disease are less frequent. Anopheles gambiae mosquitoes, the main malaria vector, are observed all year long but their densities are low during the dry season that generally lasts several months. Aestivation, seasonal migration, and local adaptation have been suggested as mechanisms that enable mosquito populations to persist through the dry season. Studies of chromosomal inversions have shown that inversions 2La, 2Rb, 2Rc, 2Rd, and 2Ru are associated with various physiological changes that confer aridity resistance. However, little is known about how phenotypic plasticity responds to seasonally dry conditions. This study examined the effects of desiccation stress on transcriptional regulation in An. gambiae. We exposed female An. gambiae G3 mosquitoes to acute desiccation and conducted a genome-wide analysis of their transcriptomes using the Affymetrix Plasmodium/Anopheles Genome Array. The transcription of 248 genes (1.7% of all transcripts was significantly affected in all experimental conditions, including 96 with increased expression and 152 with decreased expression. In general, the data indicate a reduction in the metabolic rate of mosquitoes exposed to desiccation. Transcripts accumulated at higher levels during desiccation are associated with oxygen radical detoxification, DNA repair and stress responses. The proportion of transcripts within 2La and 2Rs (2Rb, 2Rc, 2Rd, and 2Ru (67/248, or 27% is similar to the percentage of transcripts located within these inversions (31%. These data may be useful in efforts to elucidate the role of chromosomal inversions in aridity tolerance. The scope of application of the anopheline genome demonstrates that examining transcriptional activity in relation to genotypic adaptations greatly expands the number of

  17. 中原地区玉米富氮低氧储藏试验%Experiment on corn storage with nitrogen- rich and hypoxia in central plains region of China

    Institute of Scientific and Technical Information of China (English)

    王毅; 冀圣江; 孟彬; 刘强; 司建中; 汪福友; 吕秉霖; 张海涛

    2012-01-01

    Controlled nitrogen storage has advantages of killing and preventing insects, preventing mildew and stopping heating, delaying the speed of grain quality into inferior grade, avoiding or reducing chemical pollutions and resistances to drugs of insects. For the sake of guaranteeing corn to aestivate safely, the test of controlled nitrogen storage was performed in high & large warehouse by the techniques of controlled temperature, automatic detection of insects and electronic measuring temperature. Especially, some PVC pipes were inserted inner warehouse near the wall and some special places which can dredge the air flow all around in the warehouse to optimize airflow distributed evenly. The experiment got a good effectiveness that assuring safe storage of corn, which gathered experience about corn storage with nitrogen -rich and hypoxia in central plains region of China.%氮气气调储藏具有不用化学药剂达到杀虫防虫、防霉止热、延缓粮食品质变化和避免或减少化学污染、害虫抗药性的产生等特点。为确保玉米安全度夏,在高大平房仓运用控温、虫害自动检测、电子测温等技术开展氮气储粮试验。特别是在仓内四周及特别部位插入的PVC导气管优化了气流均匀分布。实现了玉米的安全储藏,为中原地区玉米富氮低氧储藏积累了经验。

  18. Torpor in mammals: types, species and patterns%哺乳动物的蛰眠:类型、物种分布与模式

    Institute of Scientific and Technical Information of China (English)

    杨明; 王德华

    2011-01-01

    哺乳动物的蛰眠(包括冬眠、夏眠和日蛰眠等)是最具吸引力的生命现象之一,是动物应对寒冷、食物短缺、干旱等不良环境条件的适应策略之一.冬眠生理学(生态学)研究具有重要的理论和实际意义.国际学术界在该领域发展比较迅速,国内发展相对缓慢.本文从哺乳动物蛰眠的季节和持续时间、蛰眠期间所利用能量的来源和贮存方式、启动蛰眠的信号来源等方面综述了哺乳动物蛰眠的类型;介绍了蛰眠的哺乳动物物种的系统学分布;并对温带或北极动物的冬眠和冬眠阵及其各阶段的体温和代谢率变化特征、日温剧烈波动环境下的冬眠特征以及日眠和日眠阵等方面进行了概括介绍,以期能促进国内相关领域的发展.%Torpor ( including hibernation, aestivation, and daily torpor) in mammals is one of the most attractive physiological phenomena in life science.Some mammal species use torpor to survive harsh environments such as cold, food shortage and drought.Physiological and/or ecological research into torpor of mammals has potential implications in biomedicine in situations such as trauma treatment, organ transplantation and spaceflight.This review briefly introduces several aspects of torpor in mammals: 1 ) Types of torpor in mammals according to the season and duration of mammalian torpor, the source and storage form of the fuel used in torpor, and the signals initiating torpor.2) The systematic distribution of the mammal species utilized torpors.3 ) The general properties in body temperature and metabolic rate which occurr in hibernation and hibernation bouts of mammals in temperate and arctic zone, and in the tropics where the diurnal hibemacula temperatures fluctuate acutely.We also introduce the patterns of other kinds of torpor, such as daily torpor.

  19. Ornithine-urea cycle and urea synthesis in African lungfishes, Protopterus aethiopicus and Protopterus annectens, exposed to terrestrial conditions for six days.

    Science.gov (United States)

    Loong, Ai May; Hiong, Kum Chew; Lee, Serene Min Lin; Wong, Wai Peng; Chew, Shit Fun; Ip, Yuen Kwong

    2005-05-01

    The objectives of this study were (1) to determine the type of carbamoyl phosphate synthetase (CPS) present, and the compartmentalization of arginase, in the livers of the African lungfishes, Protopterus aethiopicus and Protopterus annectens, and (2) to elucidate if these two lungfishes were capable of increasing the rates of urea synthesis and capacities of the ornithine-urea cycle (OUC) during 6 days of aerial exposure without undergoing aestivation. Like another African lungfish, Protopterus dolloi, reported elsewhere, the CPS activities from the livers of P. aethiopicus and P. annectens had properties similar to that of the marine ray (Taeniura lymma), but dissimilar to that of the mouse (Mus musculus). Hence, they possessed CPS III, and not CPS I as reported previously. CPS III was present exclusively in the liver mitochondria of both lungfishes, but the majority of the arginase activities were present in the cytosolic fractions of their livers. Glutamine synthetase (GS) activity was also detected in the hepatic mitochondria of both specimens. Therefore, our results suggest that the evolution of CPS III to CPS I might not have occurred before the evolution of extant lungfishes as suggested previously, prompting an examination of the current view on the evolution of CPS and OUC in vertebrates. Aerial exposure led to significant decreases in rates of ammonia excretion in P. aethiopicus and P. annectens, but there were no accumulations of ammonia in their tissues. However, urea contents in their tissues increased significantly after 6 days of aerial exposure. The estimated rates of urea synthesis in P. aethiopicus and P. annectens increased 1.2- and 1.47-fold, respectively, which were smaller than that in P. dolloi (8.6-fold) reported elsewhere. In addition, unlike P. dolloi, 6 days of aerial exposure had no significant effects on the hepatic CPS III activities of P. aethiopicus and P. annectens. In contrast, aerial exposure induced relatively greater degrees of

  20. Drastic Population Size Change in Two Populations of the Golden-Striped Salamander over a Forty-Year Period—Are Eucalypt Plantations to Blame?

    Directory of Open Access Journals (Sweden)

    Jan W. Arntzen

    2015-07-01

    Full Text Available Over the last half century the Iberian peninsula has seen the large scale planting of exotic gum trees (Eucalyptus sp. therewith reducing space for native wildlife. An additional effect of the gum tree plantations may be the lowering of the water table in adjacent streams, to which amphibian species with a larval niche in the running sections of small streams would be especially susceptible. In northwestern Iberia that niche is occupied by the Golden-striped salamander, Chioglossa lusitanica. I here report on the demographic trends of two C. lusitanica populations over a forty-year period, in two areas of one mountain range near Porto in northwestern Portugal. In both areas advantage was taken of the migration pattern of C. lusitanica to sites for aestivation and breeding in summer and fall. The area of the Silveirinhos brook was transformed in a plantation of gum trees shortly after the research started, while the area of Poço do Inferno remained virtually unaffected. At Silveirinhos the adult C. lusitanica population declined by one or two orders of magnitude, from ca. 1500 individuals to less than 50 at present. Demographic models that operate under a uniform larval mortality yielded population sizes that are compatible with field observations, including the late onset of the decline at 14 or more years after the planting of the gum trees and the near-extinction at year 32. An alternative reason for the relatively recent population collapse of C. lusitanica may have been disease, but no sick individuals or corpses have become available for clinical investigation. Conversely, the control population at Poço do Inferno increased in size by a factor of five or more. These data support the hypothesis that gum tree plantations have a strong negative effect on C. lusitanica. The population size increase at Poço do Inferno is probably attributable to the installation of wastewater treatment in the adjacent town of Valongo, with a discharge in the

  1. Paleoenvironmental and paleoclimatic significance of freshwater bivalves in the Upper Jurassic Morrison Formation, Western Interior, USA

    Science.gov (United States)

    Good, Steven C.

    2004-05-01

    Freshwater unionid bivalves are spatially and temporally distributed throughout the Morrison depositional basin, and locally dominate the biomass of many aquatic depositional environments. Two bivalve assemblages are identified. Within-channel assemblages are death assemblages that have been transported and may represent mixed assemblages from multiple communities. These assemblages are predominately disarticulated, in current stable orientations, and composed of higher stream velocity ecophenotypes (medium size, lanceolate form, and very thick shells). The floodplain-pond assemblages are disturbed neighborhood assemblages in the mudstones inhabited during life. The bivalves are predominately articulated, variable in size, and composed of low stream velocity ecophenotypes (large maximum sizes, ovate shell shapes, and thinner shells). The glochidial parasitic larval stage of unionid bivalves provides an effective means of dispersing species throughout drainage basins. These larvae attach to fish and are carried through the fluvial drainage where the larvae detach and establish new bivalve communities. Preliminary paleobiogeographic analyses are drawn at the genus level because of the need to reevaluate bivalve species of the Morrison. Unio spp. and Vetulonaia spp. are widespread throughout the Morrison depositional basin, but Hadrodon spp. are restricted to the eastern portion of the Colorado Plateau during Salt Wash Member deposition, suggesting that Salt Wash drainage was isolated from other contemporaneous regions of the basin. Bivalves from five localities in the Morrison Formation were thin-sectioned for growth band analysis. Growth bands of modern unionid bivalves are produced when the valves are forced to close. Closure can produce annual growth bands in response to seasonal variation, such as temperature-induced hibernation, or precipitation-induced aestivation or turbidity. Pseudoannual growth bands form from non-cyclical events such as predation attacks or

  2. Variaciones en la estacionalidad de polen y esporas fúngicas en la atmósfera de la ciudad de La Plata (Argentina Seasonal variation of pollen and fungal spores in the atmosphere of Plata city (Argentina

    Directory of Open Access Journals (Sweden)

    Daniela S Nitiu

    2011-12-01

    fungal component, spores from Oomycota, Zygomycota, Myxomycota Ascomycota, and Basidiomycota were identified. These bioaerosols were present throughout the year in high concentrations being more abundant in spring - summer time. Imperfect Fungi mitospores were dominant in the cloud exceeding 44% of the Spore Index. The major peak was in february due to Cladosporium spores. We identified two seasonal periods in which, high concentrations of pollen and fungal spores occurred simultaneously. The first takes place in spring and consists of elements of Platanus, Fraxinus and Aspergillus / Penicillium and the second peak is aestival and involves Ambrosia, Alternaria and Cladosporium.

  3. Metabolic depression in animals: physiological perspectives and biochemical generalizations.

    Science.gov (United States)

    Guppy, M; Withers, P

    1999-02-01

    metabolic rate occurs in hibernating (or aestivating) mammals and birds during torpor, e.g. to less than 0.01 of pre-torpor metabolic rate, but there is often no intrinsic metabolic depression in addition to that reduction in metabolic rate due to readjustment of thermoregulatory control and a decrease in body temperature with a concommitant Q10 effect. There may be a modest intrinsic metabolic depression for some species in shallow torpor (to approx. 0.86) and a more substantial metabolic depression for deep torpor (approx. 0.6), but any energy saving accruing from this intrinsic depression is small compared to the substantial savings accrued from the readjustment of thermoregulation and the Q10 effect. Secondly, a more extreme pattern of metabolic depression (to oxygen and for osmobiotic, anhydrobiotic or cryobiotic animals there is an alteration of the ionic/osmotic balance or state of body water. Some normally aerobic animals can tolerate anoxia for considerable periods, and their duration of tolerance is inversely related to their magnitude of metabolic depression; anaerobic metabolic rate can be less than 0.005 of resting. The metabolic rate of anhydrobiotic animals is often so low as to be unmeasurable, if not zero. Thus, anhydrobiosis is the ultimate strategy for eggs or other stages of the life cycle to survive extended periods of environmental stress. Thirdly, a pattern of absence of metabolism when normally hydrated (as opposed to anhydrobiotic or cryobiotic) is apparently unique to diapaused eggs of the brine-shrimp (Artemia spp., an anostracan crustacean) during anoxia. The apparent complete metabolic depression of anoxic yet hydrated cysts (and extreme metabolic depression of normoxic, hypoxic, or osmobiotic, yet hydrated cysts), is an obvious exception to the above patterns. (ABST PMID:10396183

  4. Study on Natural Distribution and Biological Characteristics of Lycium ruthenicum in Yanqi Basin%焉耆盆地黑果枸杞自然分布特点及其生物特性研究

    Institute of Scientific and Technical Information of China (English)

    何文革; 那松曹克图; 吾其尔; 吴春焕; 赵洁; 王瑛; 李玉霞

    2015-01-01

    对新疆焉耆盆地黑果枸杞的自然分布及其生物特性进行了研究,结果表明:黑果枸杞是典型的根蘖类无性系植物,并兼具有性和无性两套繁殖系统,其自然分布涵盖了焉耆盆地平原荒漠和低地草甸2类8个亚类的草地类型,占盆地10个亚类草地类型的80%,并在农区广泛分布,为焉耆盆地的广布种;其根系由水平根和地下垂直茎以及季节性分生存在的不定根组成;其有性繁育系统为异交型,并具花的色泽变化和“两花两果”特性;其无性繁育由水平根以根蘖克隆的形式繁殖;其单体群落中看似独立的植株个体,却是由地下由水平根相连的一个有机“整体”,并具有相同的遗传基因;其植株具有夏眠及被掩埋后仍能存活并变性的特性。%Natural distribution and biological characteristics of Lycium ruthenicum in Xinjiang Yanqi Basin was studied.The results showed that Lycium ruthenicum was typical clonal plant which belonged to root sucker class,and had two sets of reproductive system,sexual and asexual.Its natural distribution covered 2 classes and 8 subclasses of the desert plains of Yanqi Basin and lowland meadow grassland types,accounting for 80%of the 10 subgenera grassland types in basin,and widely distributed in rural areas in Yanqi Basin.The root was composed of horizontal root and vertical underground stem and adventitious root which meristematic existed seasonal.The sexual breeding system were outcrossing,with flowers color change and "two flowers of two fruit" characteristics,the asexual breeding system reproduction by cloning root suckers with horizontal root.The monomer seemed independent individual plants in the community,but connected by underground horizontal root of an organic"whole",and had the same genetic. Plant with properties that after aestivation and buried still could survive and degeneration.

  5. Possible Effects of Sea Level Rise in the Future on the Coral Reef in Weizhou Island%未来海平面上升对涠洲岛珊瑚礁的可能影响

    Institute of Scientific and Technical Information of China (English)

    汤超莲; 周雄; 郑兆勇; 莫少华; 唐旺先

    2013-01-01

    Based on historical records of rainfall, salinity, PH, sea level, Max wave height and ecological surveys (Reef Check), we analyzed the effects of climate change and sea level rise on the coral reef in Weizhou Island. Our results suggest that 1) The rainfall, water salinity and PH are in the coral growth suitable range in Weizhou Island with an average annual rainfall of 1388mm, water salinity of 32.1 and PH of between 8.0 and 8.23; 2) Once-in-a-century hydrological extrema obtained from P- formulaⅢ are that, annual rainfall 2313mm, Max sea level 514cm and Max wave height 6.1m;3) the skeletal extension rate of Porites coral is 6~8mm/a, heigher than sea level rise rate (2.2mm/a) in Weizhou Island. The maximum tide range is 450~500cm, when the minimum tide occurs in the aestival daytime, coral bleaching will ascend in frequency. 4) If 512cm of maximum tide hight and 580cm of maximum wave height both occur when the sea level rise 30cm in the future, the corel reef in Weizhou Island will not be destroyed thoroughly.%  根据涠洲岛珊瑚样品资料和涠洲岛海洋站实测雨量、盐度、pH、潮位、最大波高及珊瑚普查历史资料,分析气候变化、海平面上升对涠洲岛珊瑚礁的可能影响.结果显示:1)涠洲岛的多年平均雨量为1388 mm,多年平均盐度为32.1,目前海水pH值为8.0~8.23,均在珊瑚生长合适范围内;2)用P-Ⅲ型算式得出涠洲岛的水文要素百年一遇极值为:年雨量2313 mm,最高潮位514 cm,最大波高6.1 m;3)涠洲岛珊瑚生长率(6~8 mm/a)大于海平面上升率(2.2 mm/a),涠洲岛最大潮差为450~500 cm,夏季白天遇低潮时,会增加珊瑚白化概率;4)若未来海平面上升30 cm,遇上512 cm高潮位与580 cm最大波高,不会对涠洲岛珊瑚礁造成毁灭性破坏.

  6. Effects of high-temperature stress on several immune enzyme activi-ties ofApostichopus japonicus thermotolerant and normal species%高温胁迫对刺参耐高温群体和普通群体主要免疫酶活力的影响

    Institute of Scientific and Technical Information of China (English)

    刘石林; 茹小尚; 徐勤增; 柏雨岑; 李静; 张立斌; 杨红生

    2016-01-01

    以定向选育的刺参(Apostichopus japonicus)耐高温品系子三代(F3组)和未经选育的普通刺参(C组)1龄幼参[(13.6±1.8) g/头]为研究对象,在室内模拟池塘夏季高温环境,比较了两个群体在25℃、27℃、29℃、31℃、32℃和33℃6个温度梯度下体壁抗氧化酶(SOD、CAT和T-AOC)、水解酶(ACP和AKP)和溶菌酶(LSZ)活力的差异。结果表明,在抗氧化酶活力方面, F3和C组刺参SOD活力均随温度的升高呈先升高后降低的趋势,且当温度为31℃和32℃时F3组SOD活力显著高于C组(P<0.05); F3组CAT活力在实验温度范围内均高于C组,且当温度为27~31℃和33℃时差异显著(P<0.05); F3组T-AOC活力在各温度下均显著高于C组(P<0.05)。在水解酶活力方面, F3组的ACP活力在各温度下均高于C组,且除31℃外,其余温度下均差异显著(P<0.05); F3组AKP活力在25℃、27℃和31℃下显著高于C组(P<0.05),其余温度下差异不显著。F3和C组LSZ活力均随水温的上升呈先升高后降低的趋势,且在27~31℃范围内F3组LSZ活力显著高于C组(P<0.05)。结果表明,经过定向选育的耐高温品系F3对高温的耐受能力获得了提高,实验结果为耐高温刺参良种选育提供了理论依据。%Temperature has a significant effect on the growth, reproduction, distribution and abundance of sea cu-cumbers (Apostichopus japonicus). The suitable temperature range for this species is 5–20℃, and the optimum growth range is 10–16℃, which fluctuates depending on size. When the water temperature exceeds the optimal range,A. japonicus stops feeding and goes into aestivation. In recent years, as global warming has intensified, slow growth, malformation and high mortality of marine animals have been observed frequently because of high temperatures. High seawater temperatures during summer 2013 resulted in significant economic losses in theA. japonicus aquaculture industry in China. Therefore