Background:The thermoregulatory ability of animals is strongly influenced by the temperature of their environment.Acclimation to cold requires a range of physiological and morphological adjustments.In this study,we te...Background:The thermoregulatory ability of animals is strongly influenced by the temperature of their environment.Acclimation to cold requires a range of physiological and morphological adjustments.In this study,we tested the hypothesis that a small passerine,the Red-billed Leiothrix(Leiothrix lutea),can maintain homeothermy in cold conditions by adjusting the physiology and biochemistry of its tissue and organs and return to its former physiological and biochemical state when moved to a warm temperature.Methods:Phenotypic variation in thermogenic activity of the Red-billed Leiothrixs(Leiothrix lutea)was investigated under warm(35℃),normal(25℃)or cold(15℃)ambient temperature conditions.Oxygen consumption was measured using an open-circuit respirometry system.Mitochondrial state-4 respiration and cytochrome-c oxidase(COX)activity in liver,kidney heart and pectoral muscle were measured with a Clark electrode.Results:Birds acclimated to an ambient temperature of 15℃ for 4 weeks significantly increased their basal metabolic rate(BMR)compared to a control group kept at 25℃.Birds acclimated to 35℃ decreased their BMR,gross energy intake(GEI)and digestible energy intake(DEI).Furthermore,birds acclimated to 15℃ increased state-4 respiration in their pectoral muscles and cytochrome-c oxidase(COX)activity in their liver and pectoral muscle,compared to the 25℃ control group.Birds acclimated to 35℃ also displayed lower state-4 respiration and COX activity in the liver,heart and pectoral muscles,compared to those kept at 25℃.There was a positive correlation between BMR and state-4 respiration,and between BMR and COX activity,in all of the above organs except the liver and heart.Conclusions:Our study illustrates that the morphological,physiological,and enzymatic changes are associated with temperature acclimation in the Red-billed Leiothrix,and supports the notion that the primary means by which small birds meet the energetic challenges of cold conditions is through metabolic adjustments.展开更多
Bacterial diseases affecting corals pose an enormous threat to the health of coral reefs. The relationship between certain bacterial species and coral diseases remain largely unknown. Pigment abnormalities are common ...Bacterial diseases affecting corals pose an enormous threat to the health of coral reefs. The relationship between certain bacterial species and coral diseases remain largely unknown. Pigment abnormalities are common in Porites lutea. Here we used Illumina 16S rRNA gene sequencing to analyze the bacterial communities associated with healthy P. lutea and P. lutea with pigment abnormalities. We observed an increase of alpha diversity of the bacterial community of P. lutea with pigment abnormalities, relative to healthy corals. We then identified changes in the abundance of individual operational taxonomic units(OTUs) between pigmented and healthy corals. We were able to identify eight OTUs associated with pigment abnormalities, which are possibly the causative agents of pigment abnormalities.展开更多
Marginal scleractinian corals growing at their latitudinal limits should be quite sensitive to variations in winter sea surface temperatures(SSTs). An extreme cold event occurring in early 2008 offered a unique opport...Marginal scleractinian corals growing at their latitudinal limits should be quite sensitive to variations in winter sea surface temperatures(SSTs). An extreme cold event occurring in early 2008 offered a unique opportunity to examine the effect of cold-water anomalies on Porites lutea corals and their physiological tolerance and acclimation in the subtropical northern South China Sea(NSCS). Besides in-situ observation, a subsequent aquarium-based experiment was designed for reproducing the chilling process and a 50-year-long Sr/Ca ratio profile from two P. lutea skeletal slabs was analyzed for reconstructed the historical annual minimum SSTs which ceased Porites calcification. The 2008 low-temperature anomaly caused the minimum daily mean SSTs dropped below 13°C in the Daya Bay. The stress symptoms displayed by local P. lutea colonies included polyp retraction, reduced coloration and pale, but none showed tissue sloughing. The ability of P. lutea to survive implied its tolerance of extreme low temperatures. Here we suggest a model on the tolerance of high-latitude Porites under low-temperature stresses, which is when SSTs drop below 18°C, Porites corals contract their tentacles(losing heterotrophic capability), then cease calcification(reducing energy consumption), and meanwhile maintain relatively high levels of zooxanthellae density(sustaining host’s life via photosynthetic capacity of symbiotic zooxanthellae). This study revealed remarkable acclimatization of P. lutea corals to low temperature extremes. This acclimatization is beneficial for Porites corals in the NSCS to expand their living ranges towards the higher-latitude areas and have the potential to be the incipient reef former.展开更多
In the present study,we aimed to investigate a protective role for resveratrol against the effects of immobilization stress on corpora lutea(CL)of mice in early pregnancy.A total of 45 early-pregnant mice were divided...In the present study,we aimed to investigate a protective role for resveratrol against the effects of immobilization stress on corpora lutea(CL)of mice in early pregnancy.A total of 45 early-pregnant mice were divided into no immobilization stress(NIS)group,immobilization stress(IS)group,and immobilization and resveratrol treatment(IS+RES)group(n=15).Mice were immobilized in plastic tubes(50 mL)for 3 h per day during day 1 to 7 of pregnancy.In the IS+RES group,5 mg kg-'d-1 of resveratrol was administered just prior to application of stress.We analyzed apoptotic activity in CL by Western botting analysis(WB),transmission electron microscopy(TEM),and immunohistochemistry(IHC).Serum progesterone levels were examined with radioimmunoassay(RIA).IHC results showed that the intensity of positive staining for Bax was increased,and for BcI-2 was decreased in CL after IS,while resveratrol treatment reversed the positive staining for Bax and Bcl-2.WB revealed that immobilization stress up-regulated the expression of Bax and caspase-9,and down-regulated Bcl-2 expression,while resveratrol treatment attenuated the effects of immobilization stress on the expression of Bax,Bcl-2 and caspase-9.According to our TEM results,apoptosis as defined by chromatin condensation was found in CL after immobilization stress,while resveratrol inhibited the apoptosis.We also demonstrated that immobilization stress decreased progesterone concentrations and ovarian expression of StAR,while resveratrol restored the concentrations of progesterone and expression of StAR back to normal.These results indicated that immobilization stress induced luteal regression while resveratrol inhibited luteal regression,suggesting that resveratrol plays a protective role on corpora lutea of mice during early pregnancy.展开更多
The eight heavy metals Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb have been determined in samples of coral Porites lutea collected from Dafangji Island waters (21°21′N, 111°11′E), Dianbai County, Guangdong Provinc...The eight heavy metals Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb have been determined in samples of coral Porites lutea collected from Dafangji Island waters (21°21′N, 111°11′E), Dianbai County, Guangdong Province, China, by the ICP-MS method. The samples represent the growth of coral in the period of 1982-2001. The results showed that the waters were polluted by the heavy metals Cu, Ni, Zn, and Pb in certain years, but not by other metals. The contamination may have come from industrial sources, including electroplating, metallurgy, mining, and aquatic industries in the coastal areas.; The correlation coefficients among the metals and climatic and economic factors indicate that the metals Ni, Zn, and Cd behave similarly. Copper and Mn are positively correlated, and cobalt is negatively correlated with Cr, Ni, Zn, and Cd. Lead is not correlated with any other metals but is correlated with sea surface water temperature, air temperature, GDP and industrial-agricultural production in Dianbai County. Lead in corals is related to the enhanced pollution level of ocean waters as a result of increased industrial activities.展开更多
A Porites lutea core from Yongshu Reef of Nansha Islands covering 50 years growth history was ana-ly/ed for oxygen isotopic composition with monthly and seasonally resolution. The calibration of the δ18O with the ins...A Porites lutea core from Yongshu Reef of Nansha Islands covering 50 years growth history was ana-ly/ed for oxygen isotopic composition with monthly and seasonally resolution. The calibration of the δ18O with the instrumental temperature indicated that the coral δ18O is a good indicator for sea surface temperature (SST) and air temperature (t). It can be used to reconstruct the SST and air temperature of the Yongshu Reef sea area. In addition, the coral δ18O provides signatures for the intensity of the East Asia monsoon and it is a record for the activities of El Nino events. With the calibrated SST and air temperature formulas, the most recent fifty years SST and air temperature were reconstructed based on the coral δ18O, thus back up the understanding of the climate of Nansha Islands to 1950. far beyond the limit of the instrumental recording since September 1988. It was found that, in general, increasing 1℃ air temperature results in 0.24‰decrease in skeletal δ18O.展开更多
Relationship between insulin-like growth factor-l receptor (IGF-IR) and luteinizing hormone receptor (LHR) mRNA expression as well as their regulation was determined in rat corpora lutea (CL) . In the CL of estrous cy...Relationship between insulin-like growth factor-l receptor (IGF-IR) and luteinizing hormone receptor (LHR) mRNA expression as well as their regulation was determined in rat corpora lutea (CL) . In the CL of estrous cycle rat, LHR mRNA positive CL expressed high level of mRNA of IGF-IR. While the expression of LHR mRNA decreased on estrus, the CL still expressed relatively high level of IGF-IR mRNA. In pseudopregnant rat CL, the expression level of LHR mRNA was low on day 1, the most intense signals were detected on day 8, the signals of LHR mRNA became undetectable on day 14. In contrast to LHR expression, the high level of IGF-IR mRNA was observed in pseudopregnant CL of day 1, and thereafter its signals were detected from day 2 to day 14. Pregnant rat CL expressed both LHR and IGF-IR mRNAs. IGF-I stimulated LHR expression in CL. PGF2ainhibited expression of IGF-IR and LHR. PGE2 negated the inhibiting effects of PGF2α. These data suggest that IGF-I may be involved in regulating CL function, and maintaining CL structure through changes in expression of its receptors. Inhibited expression of IGF-IR by PGF2α may be part of mechanisms for regression of CL.展开更多
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.31470472 and 31971420)the National Undergraduate “Innovation” Projectthe “Xinmiao” Project in Zhejiang Province
文摘Background:The thermoregulatory ability of animals is strongly influenced by the temperature of their environment.Acclimation to cold requires a range of physiological and morphological adjustments.In this study,we tested the hypothesis that a small passerine,the Red-billed Leiothrix(Leiothrix lutea),can maintain homeothermy in cold conditions by adjusting the physiology and biochemistry of its tissue and organs and return to its former physiological and biochemical state when moved to a warm temperature.Methods:Phenotypic variation in thermogenic activity of the Red-billed Leiothrixs(Leiothrix lutea)was investigated under warm(35℃),normal(25℃)or cold(15℃)ambient temperature conditions.Oxygen consumption was measured using an open-circuit respirometry system.Mitochondrial state-4 respiration and cytochrome-c oxidase(COX)activity in liver,kidney heart and pectoral muscle were measured with a Clark electrode.Results:Birds acclimated to an ambient temperature of 15℃ for 4 weeks significantly increased their basal metabolic rate(BMR)compared to a control group kept at 25℃.Birds acclimated to 35℃ decreased their BMR,gross energy intake(GEI)and digestible energy intake(DEI).Furthermore,birds acclimated to 15℃ increased state-4 respiration in their pectoral muscles and cytochrome-c oxidase(COX)activity in their liver and pectoral muscle,compared to the 25℃ control group.Birds acclimated to 35℃ also displayed lower state-4 respiration and COX activity in the liver,heart and pectoral muscles,compared to those kept at 25℃.There was a positive correlation between BMR and state-4 respiration,and between BMR and COX activity,in all of the above organs except the liver and heart.Conclusions:Our study illustrates that the morphological,physiological,and enzymatic changes are associated with temperature acclimation in the Red-billed Leiothrix,and supports the notion that the primary means by which small birds meet the energetic challenges of cold conditions is through metabolic adjustments.
基金The China-Indonesia Maritime Cooperation Fund Project "China-Indonesia Bitung Ecological Station Establishment"the National Natural Science Foundation of China under contract No.41506180the Public Science and Technology Research Funds Projects of Ocean under contract No.201505009
文摘Bacterial diseases affecting corals pose an enormous threat to the health of coral reefs. The relationship between certain bacterial species and coral diseases remain largely unknown. Pigment abnormalities are common in Porites lutea. Here we used Illumina 16S rRNA gene sequencing to analyze the bacterial communities associated with healthy P. lutea and P. lutea with pigment abnormalities. We observed an increase of alpha diversity of the bacterial community of P. lutea with pigment abnormalities, relative to healthy corals. We then identified changes in the abundance of individual operational taxonomic units(OTUs) between pigmented and healthy corals. We were able to identify eight OTUs associated with pigment abnormalities, which are possibly the causative agents of pigment abnormalities.
基金The National Basic Research Program(973 Program)of China under contract Nos 2013CB956103 and 2013CB956104the National Natural Science Foundation of China under contract Nos 41306109,41476038 and 41676049the Youth Innovation Promotion Association CAS under contract No.2015284
文摘Marginal scleractinian corals growing at their latitudinal limits should be quite sensitive to variations in winter sea surface temperatures(SSTs). An extreme cold event occurring in early 2008 offered a unique opportunity to examine the effect of cold-water anomalies on Porites lutea corals and their physiological tolerance and acclimation in the subtropical northern South China Sea(NSCS). Besides in-situ observation, a subsequent aquarium-based experiment was designed for reproducing the chilling process and a 50-year-long Sr/Ca ratio profile from two P. lutea skeletal slabs was analyzed for reconstructed the historical annual minimum SSTs which ceased Porites calcification. The 2008 low-temperature anomaly caused the minimum daily mean SSTs dropped below 13°C in the Daya Bay. The stress symptoms displayed by local P. lutea colonies included polyp retraction, reduced coloration and pale, but none showed tissue sloughing. The ability of P. lutea to survive implied its tolerance of extreme low temperatures. Here we suggest a model on the tolerance of high-latitude Porites under low-temperature stresses, which is when SSTs drop below 18°C, Porites corals contract their tentacles(losing heterotrophic capability), then cease calcification(reducing energy consumption), and meanwhile maintain relatively high levels of zooxanthellae density(sustaining host’s life via photosynthetic capacity of symbiotic zooxanthellae). This study revealed remarkable acclimatization of P. lutea corals to low temperature extremes. This acclimatization is beneficial for Porites corals in the NSCS to expand their living ranges towards the higher-latitude areas and have the potential to be the incipient reef former.
基金The authors wish to thank Prof.Emeritus Reinhold J.Hutz,PhD of the Department of Biological Sciences,University of Wisconsin-Milwaukee,USA,for his editing and helpful adviceThis work was supported by the National Natural Science Foundation of China(31501956 and 31572403).
文摘In the present study,we aimed to investigate a protective role for resveratrol against the effects of immobilization stress on corpora lutea(CL)of mice in early pregnancy.A total of 45 early-pregnant mice were divided into no immobilization stress(NIS)group,immobilization stress(IS)group,and immobilization and resveratrol treatment(IS+RES)group(n=15).Mice were immobilized in plastic tubes(50 mL)for 3 h per day during day 1 to 7 of pregnancy.In the IS+RES group,5 mg kg-'d-1 of resveratrol was administered just prior to application of stress.We analyzed apoptotic activity in CL by Western botting analysis(WB),transmission electron microscopy(TEM),and immunohistochemistry(IHC).Serum progesterone levels were examined with radioimmunoassay(RIA).IHC results showed that the intensity of positive staining for Bax was increased,and for BcI-2 was decreased in CL after IS,while resveratrol treatment reversed the positive staining for Bax and Bcl-2.WB revealed that immobilization stress up-regulated the expression of Bax and caspase-9,and down-regulated Bcl-2 expression,while resveratrol treatment attenuated the effects of immobilization stress on the expression of Bax,Bcl-2 and caspase-9.According to our TEM results,apoptosis as defined by chromatin condensation was found in CL after immobilization stress,while resveratrol inhibited the apoptosis.We also demonstrated that immobilization stress decreased progesterone concentrations and ovarian expression of StAR,while resveratrol restored the concentrations of progesterone and expression of StAR back to normal.These results indicated that immobilization stress induced luteal regression while resveratrol inhibited luteal regression,suggesting that resveratrol plays a protective role on corpora lutea of mice during early pregnancy.
基金Financially supported jointly by the Innovation Project Funds of theChinese Academy of Sciences (KZCX2-SW-118, KZCX3-SW-120), theNKPBR Project Fund (2001CCB00100), and the SKLLQG Fund (No.0324).
文摘The eight heavy metals Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb have been determined in samples of coral Porites lutea collected from Dafangji Island waters (21°21′N, 111°11′E), Dianbai County, Guangdong Province, China, by the ICP-MS method. The samples represent the growth of coral in the period of 1982-2001. The results showed that the waters were polluted by the heavy metals Cu, Ni, Zn, and Pb in certain years, but not by other metals. The contamination may have come from industrial sources, including electroplating, metallurgy, mining, and aquatic industries in the coastal areas.; The correlation coefficients among the metals and climatic and economic factors indicate that the metals Ni, Zn, and Cd behave similarly. Copper and Mn are positively correlated, and cobalt is negatively correlated with Cr, Ni, Zn, and Cd. Lead is not correlated with any other metals but is correlated with sea surface water temperature, air temperature, GDP and industrial-agricultural production in Dianbai County. Lead in corals is related to the enhanced pollution level of ocean waters as a result of increased industrial activities.
基金This work was supported partially by the State Key Project of the Nineth Five-Year Plan (Grant No. 95-926-03-01) the National Natu- ral Science Foundation of China (Grant No. 49902014) and the Open Laboratory of Marginal Sea Geology and Paleoenvironm
文摘A Porites lutea core from Yongshu Reef of Nansha Islands covering 50 years growth history was ana-ly/ed for oxygen isotopic composition with monthly and seasonally resolution. The calibration of the δ18O with the instrumental temperature indicated that the coral δ18O is a good indicator for sea surface temperature (SST) and air temperature (t). It can be used to reconstruct the SST and air temperature of the Yongshu Reef sea area. In addition, the coral δ18O provides signatures for the intensity of the East Asia monsoon and it is a record for the activities of El Nino events. With the calibrated SST and air temperature formulas, the most recent fifty years SST and air temperature were reconstructed based on the coral δ18O, thus back up the understanding of the climate of Nansha Islands to 1950. far beyond the limit of the instrumental recording since September 1988. It was found that, in general, increasing 1℃ air temperature results in 0.24‰decrease in skeletal δ18O.
文摘Relationship between insulin-like growth factor-l receptor (IGF-IR) and luteinizing hormone receptor (LHR) mRNA expression as well as their regulation was determined in rat corpora lutea (CL) . In the CL of estrous cycle rat, LHR mRNA positive CL expressed high level of mRNA of IGF-IR. While the expression of LHR mRNA decreased on estrus, the CL still expressed relatively high level of IGF-IR mRNA. In pseudopregnant rat CL, the expression level of LHR mRNA was low on day 1, the most intense signals were detected on day 8, the signals of LHR mRNA became undetectable on day 14. In contrast to LHR expression, the high level of IGF-IR mRNA was observed in pseudopregnant CL of day 1, and thereafter its signals were detected from day 2 to day 14. Pregnant rat CL expressed both LHR and IGF-IR mRNAs. IGF-I stimulated LHR expression in CL. PGF2ainhibited expression of IGF-IR and LHR. PGE2 negated the inhibiting effects of PGF2α. These data suggest that IGF-I may be involved in regulating CL function, and maintaining CL structure through changes in expression of its receptors. Inhibited expression of IGF-IR by PGF2α may be part of mechanisms for regression of CL.
