Both copper/zinc superoxide dismutase （SOD; Cu/Zn-SOD, SOD1） cDNA and manganese SOD （Mn-SOD, SOD2） cDNA were cloned for the first time from the three-keeled pond turtle, Chinemys reevesii, using RT-PCR and RACE me...Both copper/zinc superoxide dismutase （SOD; Cu/Zn-SOD, SOD1） cDNA and manganese SOD （Mn-SOD, SOD2） cDNA were cloned for the first time from the three-keeled pond turtle, Chinemys reevesii, using RT-PCR and RACE methods in this work. The SOD1 cDNA was 749 bp long and consisted of a 32-bp 5＇-untranslated region （UTR）, a 249-bp 3＇-UTR, and a 468-bp open reading frame （ORF） encoding a 155-amino-acid protein with 16.0 kDa predicted molecular mass and 5.95 theoretical isoelectric point （p/）. The SOD2 cDNA was 1687 bp long and comprised 94-bp of 5＇-UTR, 912-bp 3＇-UTR and 681-bp ORF encoding a 226-amino-acid protein with 25.0 kDa predicted molecular mass and 8.83 pI. The deduced amino acid sequence of SOD1 showed relatively high similarity （77.4%-87.1%） and identity （65.4%-74.4%） with the published sequences of SOD1 from other vertebrate species, whereas SOD2 protein shared slightly higher similarity （83.6%-95.6%） and identity （76.1%-88.9%） with other reported vertebrates SOD2s. Phylogenetic analysis revealed that the C. reevesii SOD1 and SOD2 were separately clustered together, and were highly conserved during evolution. Both SOD mRNA expression was detected widely in the brain, liver, muscle, kidney, gut, spleen, lung and heart at variable levels. The highest expression of the two SODs was observed in muscle, and followed in brain, liver, kidney, gut and heart, whereas low transcriptional levels were found in spleen and lung. Meanwhile, high activity of SOD 1 was kept in brain, liver, muscle, kidney and heart, and followed in gut, spleen and lung. The activities of SOD2 in brain, liver, muscle, kidney, gut and heart were significantly higher than those in spleen and lung.展开更多
Temperature-dependent sex determination（TSD） is a type of environmental sex determination in which the sex of the embryos depends on the ambient temperature; however,the molecular mechanisms governing this process r...Temperature-dependent sex determination（TSD） is a type of environmental sex determination in which the sex of the embryos depends on the ambient temperature; however,the molecular mechanisms governing this process remain unknown.Aromatase,encoded by the cyp19a1 gene,which converts androgens into estrogens in animals,was considered to be the key gene for TSD.In this study,the 5＇-flanking region of the cyp19a1 gene in Reeves＇ turtle（Mauremys reevesii） was cloned,and the promoter region was identified using the luciferase reporter assay.Then the eggs of Reeves＇ turtle were incubated at different temperatures（26°C： male-biased temperature; 29°C： non-sex-biased temperature and 32°C： female-biased temperature）.During the thermosensitive period,the adrenal kidney gonad complexes（AKG） were sampled.DNA methylation analysis of the AKG samples showed that the promoter region of the cyp19a1 gene was significantly de-methylated in the female-biased temperature regime（P＆lt;0.01）.Quantitative analysis of the cyp19a1 gene and estrogen by q PCR and Elisa assay showed that the expression level of the cyp19a1 gene and estrogen content were both upregulated significantly at the female-biased temperature（P＆lt;0.01）.These results indicated that the de-methylation response of the cyp19a1 gene to incubation temperature,especially at the female-biased temperature,could lead to temperature-specific expression of aromatase and increased estrogen levels,which may further determine gonadal development in Reeves＇ turtle.These findings provide insights into the genetic mechanisms underlying TSD.展开更多
Juvenile three-keeled pond turtles(Chinemys reevesii) were fed diets supplemented with vitamin C(Vc) at doses of 0(basal diet, Vc0), 100(Vc100), 200(Vc200), 500(Vc500) and 2500(Vc2500) mg/kg diets at 28°C for 4 w...Juvenile three-keeled pond turtles(Chinemys reevesii) were fed diets supplemented with vitamin C(Vc) at doses of 0(basal diet, Vc0), 100(Vc100), 200(Vc200), 500(Vc500) and 2500(Vc2500) mg/kg diets at 28°C for 4 weeks, respectively. Then, the water temperature was gradually reduced to 10°C, and the turtles were induced into hibernation. Liver tissue samples were collected at three time points: start of hibernation(T1), 4 and 6 weeks’ hibernation(T2 and T3). A control group fed with the basal diet was set to parallel the whole treatment process, but reared at 28°C constantly. The results showed that hibernation mildly affected the antioxidant system and the influence varied with hibernating time. Hepatic malondialdehyde content of the Vc100 group was significantly lower than that of the other groups at T1. At T2, hepatic MDA in the groups of Vc500 and Vc2500 decreased significantly, while no clear differences were found among all groups at T3. The activities of antioxidant enzymes showed a positive correlation with dietary Vc dose before hibernation. After hibernation, total antioxidant capability was not affected by Vc. Superoxide dismutase activity became similar in different groups at T2, but decreased in higher Vc groups(≥ 200 mg/kg) at T3. Glutathione peroxidase and glutathione-S-transferase activities decreased significantly with dietary Vc supplementation(≥ 100 mg/kg) at T2, but recovered at T3. The result indicates that under normal rearing condition, low dietary Vc supplementation(< 100 mg/kg) might be beneficial to the antioxidant defense system. The effect of dietary Vc on the antioxidant defense system differed during hibernation.展开更多
A large amount of marine noise pollution from coastal industrial construction and the water transportation industry affects the growth and development of marine life,which is a big issue threatening marine organisms.H...A large amount of marine noise pollution from coastal industrial construction and the water transportation industry affects the growth and development of marine life,which is a big issue threatening marine organisms.However,most studies have focused on vertebrates,such as marine mammals and fishes,and little is known about the effects of noise on invertebrates.Therefore,the impacts of low-frequency noise(100,300,and 500 Hz)on behavioral and physiological responsesof the sea slug(Onchidium reevesii)were investigated.Under laboratory conditions,sea slugs were stimulated with low-frequency noise at 100,300,and 500 Hz for 1 h.Then,hemolymph enzyme activities(glucose,albumin,triglycerides,superoxide dismutase,catalase,and malondialdehyde)were measured,and mRNA expression of the hsp70 gene was detected in hemolymph and the nervous system by quantitative realtime polymerase chain reaction(qRT-PCR)analysis,while expression of the hsp70 protein was analyzed by immunohistochemistry.The results demonstrated that sea slugs were away from the stimulus source under the influence of low-frequency noise compared to the control group.Enzyme activities,as well as hsp70 gene mRNA and protein expression levels,were significantly higher in the noiseexposed groups than those in the control group.Overall,these changes indicate that low-frequency noise caused oxidative stress in sea slugs in vivo,and the oxidative damage gradually increased when the noise frequency was increased from 100 to 500 Hz.展开更多
Previous studies have speculated that tidal rhythm of Onchidium reevesii was linked to its memory ability, which has not been well explained. Mapk1 and egr1 genes are closely related to memory formation in the MAPK si...Previous studies have speculated that tidal rhythm of Onchidium reevesii was linked to its memory ability, which has not been well explained. Mapk1 and egr1 genes are closely related to memory formation in the MAPK signaling pathway that have been extensively studied in vertebrates. These two genes are involved in Long-term potentiation (LTP), which is generally regarded as one of the main molecular mechanisms underlying learning and memory. To investigate the relationship between tidal rhythm of O. reevesii and its memory ability, we studied the molecular mechanism of mapk1 and egr1 genes cooperating with tidal rhythm. The full-length cDNA sequence of mapk1 gene was cloned by RACE method and analyzed by bioinformatics, then qRT-PCR was used to analyze its expression levels in each tissue. A homology analysis and phylogenetic tree reconstruction revealed that O. reevesii is most closely related to the Biomphalaria glabrata. The qRT-PCR showed that mapk1 was expressed in all the tissues, but the highest expression was in the ganglion. We speculated that mapk1 is related to memory formation of O. reevesii. Then we used qRT-PCR to detect the expression of mapk1 and egr1 in ganglion of O. reevesi under tidal stimulation. The expression of mapk1 and egr1 at the rising tide points were significantly higher (P < 0.05) than that at the previous one lowest tide points on May 15-21, except the rising tide point on May 20 and May 21 of mapk1. The expression of mapk1 and egr1 genes in the ganglion sampled for 7-day were basically the same as that of the tide change of the same day. The expression of the two genes were upregulated at raising tide and downregulated at the lowest tide, it is presumed that the O. reevesii was affected by the tide for a long time and formed the tide memory.展开更多
We used mitochondrial cytochrome b and ND4 genes and 9 microsatellite loci to determine genetic diversity,population structure,evolutionary history,and migration patterns within the Reeves’butterfly lizard Leiolepis ...We used mitochondrial cytochrome b and ND4 genes and 9 microsatellite loci to determine genetic diversity,population structure,evolutionary history,and migration patterns within the Reeves’butterfly lizard Leiolepis reevesii(Agamidae).Considering molecular-based phylogeographical lineages,we then performed niche equivalency and similarity tests between divergent lineages.Phylogenetic analyses based on mitochondrial DNA(mtDNA)data revealed 2 lineages(A and B)diverging≈0.84 million years ago and,respectively,restricted to the northern and southern portions of the Wuzhishan and Yinggeling mountain ranges.Lineage B contains individuals from southern Hainan;Lineage A includes individuals from all other localities and can be further divided into 3 clusters according to microsatellite data.The null hypothesis that the 2 lineages shared identical niches was rejected in all niche equivalency tests,indicating niche shifts during genetic divergence.Similarity tests provided evidence of niche conservatism,suggesting that the 2 lineages share more characteristics of their niche spaces than randomly expected.The niche similarity and equivalency tests indicated a complex niche pattern in which both lineages share a main portion of their ecological spaces.The climatic niche of Lineage B represented a marginal and specialized fraction of the entire ecological space of the climatic niche of Lineage A,with warmer conditions.Isolation caused by orogenesis and subsequent niche divergence,together with local adaptation,may have led to genetic differentiation and further lineage sorting in L.reevesii.展开更多
During low tide intertidal organisms face severe temperature fluctuations.This situation may be more pronounced in the context of climate change.To investigate the molecular response mechanism of Onchidium reevesii wh...During low tide intertidal organisms face severe temperature fluctuations.This situation may be more pronounced in the context of climate change.To investigate the molecular response mechanism of Onchidium reevesii when stressed by hot and cold temperatures,we cloned its Caspase-3 and Caspase-9 genes and detected their expression characteristics using RT-qPCR.The results showed that the full-length of the cDNA of Caspase-3 consist of 1831 bp,and included an open reading frame(ORF)of 894 bp,a 50UTR of 155 bp and a 30 UTR of 300 bp,and encoding for 297 amino acids.The full-length of the cDNA of Caspase-9 consisted of 2425 bp,and included an ORF of 1373 bp,a 50 UTR of 290 bp,and a 30 UTR of 759 bp,and encoding for 457 amino acids.During the evolution of species the two genes have been greatly conserved.A homology analysis and phylogenetic tree reconstruction revealed that O.reevesii is most closely related to Aplysia californica.The RT-qPCR showed that both genes were expressed in all of the tissues and that expression was highest in the hepatopancreas.It is speculated that these genes play an essential role in the immunity of O.reevesii to certain diseases.Conditions of temperature stress(40�C and 10�C)showed that both heat and cold stresses could induce significant changes in both genes.Compared to the control group,under cold stress conditions the levels of expression of Caspase-3 and Caspase-9 were significantly upregulated(P<0.05)in each experimental group.When exposed to a constant temperature of 10�C,their expression peaked after 1 h(4.32-fold,P<0.05;and 5.58-fold,P<0.05,respectively)and was at its lowest after 12 h(1.93-fold,P<0.05;and 2.35-fold,P<0.05,respectively).Their expression was upregulated after 24 h(2.68-fold,P<0.05;and 4.21-fold,P<0.05,respectively).The expression of both genes showed similar trends.Under heat stress,the expressions of the two genes showed a wave pattern.When exposed to a constant temperature of 40�C,their expression was up-regulated after 1,6,and 24 h,and down-regulated after 3 and 12 h.Except at 24 h,the other experimental groups did not differ significantly(P>0.05)from the control group.When subjected to various stress conditions the two genes displayed different expression patterns,indicating that the species has different strategies for coping with temperature changes.It further indicates that the effect of temperature on the species may play a role through the Caspase-dependent pathway.These may help to better understand the response,at the molecular level,of O.reevesii to conditions of hot and cold stress.展开更多
Home range and habitat use of male Reeves’s pheasant(Syrmaticus reevesii)were studied during winter of 2001~2002 and 2002~2003 in the Dongzhai National Nature Reserve,Henan Province.Results from five individuals of R...Home range and habitat use of male Reeves’s pheasant(Syrmaticus reevesii)were studied during winter of 2001~2002 and 2002~2003 in the Dongzhai National Nature Reserve,Henan Province.Results from five individuals of Reeves’s pheasant with over 30 relocations,indicated that the average size of home range was 10.03±1.17 hm^(2) by Minimum Convex Polygon method,8.60±0.35 hm^(2) by 90%Harmonic Mean Transformation method,and 9.50±1.90 hm^(2) by 95%Fixed Kernel method.It was observed that the winter range is smaller than that in the breeding season.The mean core area of the home range was found to be 1.88±0.37 hm^(2).Although the habitat composition of the core area varied greatly for individuals,a large part of the habitats used were composed of conifer and broadleaf mixed forests,masson pine forests,fir forests,and shrubs.Habitat use within the study area was non-random,while habitats within home ranges were randomly used.Habitat use was dictated by tree diameter at breast height,shrub height and coverage at 2.0 m.The proximity between forests and shrubs were also found to be important in providing refuge for the birds during winter.Recommendations for conservation management include protecting the existing habitats in Dongzhai National Nature Reserve,increasing suitable habitat for Reeves’s Pheasant through artificial plantations(e.g.firs),and restoring some parts of the large shrub area into forests.展开更多
The eggshell of Reeve’s pheasant(Syrmaticus reevesii)collected from the Dongzhai National Nature Reserve in Henan Province,China was studied.By using scanning electron microscopy and inductively coupled plasma(ICP)sp...The eggshell of Reeve’s pheasant(Syrmaticus reevesii)collected from the Dongzhai National Nature Reserve in Henan Province,China was studied.By using scanning electron microscopy and inductively coupled plasma(ICP)spectrometry,the ultrastructure and elemental composition of the eggshell was determined.The study showed that the average thickness of the surface layer of crys-tals,the palisade and cone layer,and the eggshell membrane were 20.8,220.8 and 62.5μm,respectively,accounting for 6.8%,72.6%and 20.6%of the total thickness of the eggshell.There were many vesicular holes in the palisade layer with an average diameter of 0.32±0.08μm(n=30).The function of these holes might be significant to air exchange.The shape of the eggshell pore on the surface layer of crystals is round or elliptical.The fracture surface of the pore is funnel-shaped.Some granules filled the upper part of the eggshell pores.The content of 21 elements in the eggshell of wild and captive Reeve’s pheasants was compared and presented.It indicated that among the elements that made up the eggshell of the wild pheasant,the content of Ca,Mg,P and S was much higher,ω>1 mg/g,withω(Ca)being higher than 40%of the eggshell.The contents of Na,Si,Sr,K and Al wereω=0.1-1 mg/g,while Fe,Zn,Pb,Mn,Cu,V and Ti had lower concentrations(ω=1-100μg/g).Theωof Ni,Cr,Co,Se,Cd were lower than 1μg/g.The elemental composition in the eggshell of the captive Reeve’s pheasant kept in the Dongzhai National Natural Reserve was significantly differ-ent from that of the wild species,with a difference of over 20%on S,Cu,Fe,Al,Mn,Si,Sr,Se and Cr.The lower intake of Fe,Mn,Si and Sr on the one hand and the higher intake of S,Cu,Al and Cr on the other hand might be responsible for the low fertility of captive Reeve’s pheasants in the Dongzhai National Nature Reserve.In order to ensure that the pheasants are receiving the proper amount of nutrition and to improve their breeding success,the amount of certain elements in the food should be adjusted.展开更多
基金supported by a grant from the National Natural Science Foundation of China (Project No. 31172383)
文摘Both copper/zinc superoxide dismutase （SOD; Cu/Zn-SOD, SOD1） cDNA and manganese SOD （Mn-SOD, SOD2） cDNA were cloned for the first time from the three-keeled pond turtle, Chinemys reevesii, using RT-PCR and RACE methods in this work. The SOD1 cDNA was 749 bp long and consisted of a 32-bp 5＇-untranslated region （UTR）, a 249-bp 3＇-UTR, and a 468-bp open reading frame （ORF） encoding a 155-amino-acid protein with 16.0 kDa predicted molecular mass and 5.95 theoretical isoelectric point （p/）. The SOD2 cDNA was 1687 bp long and comprised 94-bp of 5＇-UTR, 912-bp 3＇-UTR and 681-bp ORF encoding a 226-amino-acid protein with 25.0 kDa predicted molecular mass and 8.83 pI. The deduced amino acid sequence of SOD1 showed relatively high similarity （77.4%-87.1%） and identity （65.4%-74.4%） with the published sequences of SOD1 from other vertebrate species, whereas SOD2 protein shared slightly higher similarity （83.6%-95.6%） and identity （76.1%-88.9%） with other reported vertebrates SOD2s. Phylogenetic analysis revealed that the C. reevesii SOD1 and SOD2 were separately clustered together, and were highly conserved during evolution. Both SOD mRNA expression was detected widely in the brain, liver, muscle, kidney, gut, spleen, lung and heart at variable levels. The highest expression of the two SODs was observed in muscle, and followed in brain, liver, kidney, gut and heart, whereas low transcriptional levels were found in spleen and lung. Meanwhile, high activity of SOD 1 was kept in brain, liver, muscle, kidney and heart, and followed in gut, spleen and lung. The activities of SOD2 in brain, liver, muscle, kidney, gut and heart were significantly higher than those in spleen and lung.
基金supported financially by the National Natural Science Foundation of China(Nos.31401053 and 31471966)Guangdong Provincial Natural Science Foundation of China(No.2015A030313903)+1 种基金GDAS Special Project of Science and Technology Development(2017GDASCX-0107)the Funds for Environment Construction and Capacity Building of GDAS’Research Platform(2016GDASPT-0107)
文摘Temperature-dependent sex determination（TSD） is a type of environmental sex determination in which the sex of the embryos depends on the ambient temperature; however,the molecular mechanisms governing this process remain unknown.Aromatase,encoded by the cyp19a1 gene,which converts androgens into estrogens in animals,was considered to be the key gene for TSD.In this study,the 5＇-flanking region of the cyp19a1 gene in Reeves＇ turtle（Mauremys reevesii） was cloned,and the promoter region was identified using the luciferase reporter assay.Then the eggs of Reeves＇ turtle were incubated at different temperatures（26°C： male-biased temperature; 29°C： non-sex-biased temperature and 32°C： female-biased temperature）.During the thermosensitive period,the adrenal kidney gonad complexes（AKG） were sampled.DNA methylation analysis of the AKG samples showed that the promoter region of the cyp19a1 gene was significantly de-methylated in the female-biased temperature regime（P＆lt;0.01）.Quantitative analysis of the cyp19a1 gene and estrogen by q PCR and Elisa assay showed that the expression level of the cyp19a1 gene and estrogen content were both upregulated significantly at the female-biased temperature（P＆lt;0.01）.These results indicated that the de-methylation response of the cyp19a1 gene to incubation temperature,especially at the female-biased temperature,could lead to temperature-specific expression of aromatase and increased estrogen levels,which may further determine gonadal development in Reeves＇ turtle.These findings provide insights into the genetic mechanisms underlying TSD.
文摘Juvenile three-keeled pond turtles(Chinemys reevesii) were fed diets supplemented with vitamin C(Vc) at doses of 0(basal diet, Vc0), 100(Vc100), 200(Vc200), 500(Vc500) and 2500(Vc2500) mg/kg diets at 28°C for 4 weeks, respectively. Then, the water temperature was gradually reduced to 10°C, and the turtles were induced into hibernation. Liver tissue samples were collected at three time points: start of hibernation(T1), 4 and 6 weeks’ hibernation(T2 and T3). A control group fed with the basal diet was set to parallel the whole treatment process, but reared at 28°C constantly. The results showed that hibernation mildly affected the antioxidant system and the influence varied with hibernating time. Hepatic malondialdehyde content of the Vc100 group was significantly lower than that of the other groups at T1. At T2, hepatic MDA in the groups of Vc500 and Vc2500 decreased significantly, while no clear differences were found among all groups at T3. The activities of antioxidant enzymes showed a positive correlation with dietary Vc dose before hibernation. After hibernation, total antioxidant capability was not affected by Vc. Superoxide dismutase activity became similar in different groups at T2, but decreased in higher Vc groups(≥ 200 mg/kg) at T3. Glutathione peroxidase and glutathione-S-transferase activities decreased significantly with dietary Vc supplementation(≥ 100 mg/kg) at T2, but recovered at T3. The result indicates that under normal rearing condition, low dietary Vc supplementation(< 100 mg/kg) might be beneficial to the antioxidant defense system. The effect of dietary Vc on the antioxidant defense system differed during hibernation.
基金supported by the Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-culture of Aquaculture Animals(No.A1-3605-21-000202)the Capacity Enhancement of Aquatic Germplasm Resources Research and Support Platform of Shanghai Ocean University(No.A1-3201-20-300206).
文摘A large amount of marine noise pollution from coastal industrial construction and the water transportation industry affects the growth and development of marine life,which is a big issue threatening marine organisms.However,most studies have focused on vertebrates,such as marine mammals and fishes,and little is known about the effects of noise on invertebrates.Therefore,the impacts of low-frequency noise(100,300,and 500 Hz)on behavioral and physiological responsesof the sea slug(Onchidium reevesii)were investigated.Under laboratory conditions,sea slugs were stimulated with low-frequency noise at 100,300,and 500 Hz for 1 h.Then,hemolymph enzyme activities(glucose,albumin,triglycerides,superoxide dismutase,catalase,and malondialdehyde)were measured,and mRNA expression of the hsp70 gene was detected in hemolymph and the nervous system by quantitative realtime polymerase chain reaction(qRT-PCR)analysis,while expression of the hsp70 protein was analyzed by immunohistochemistry.The results demonstrated that sea slugs were away from the stimulus source under the influence of low-frequency noise compared to the control group.Enzyme activities,as well as hsp70 gene mRNA and protein expression levels,were significantly higher in the noiseexposed groups than those in the control group.Overall,these changes indicate that low-frequency noise caused oxidative stress in sea slugs in vivo,and the oxidative damage gradually increased when the noise frequency was increased from 100 to 500 Hz.
基金conducted by supporting from KoreaNational Park Service(KNPS)National Institute of Biological Resource(NIBR) Korea Environmental Industry&Technology Institute(KEITI)
文摘Previous studies have speculated that tidal rhythm of Onchidium reevesii was linked to its memory ability, which has not been well explained. Mapk1 and egr1 genes are closely related to memory formation in the MAPK signaling pathway that have been extensively studied in vertebrates. These two genes are involved in Long-term potentiation (LTP), which is generally regarded as one of the main molecular mechanisms underlying learning and memory. To investigate the relationship between tidal rhythm of O. reevesii and its memory ability, we studied the molecular mechanism of mapk1 and egr1 genes cooperating with tidal rhythm. The full-length cDNA sequence of mapk1 gene was cloned by RACE method and analyzed by bioinformatics, then qRT-PCR was used to analyze its expression levels in each tissue. A homology analysis and phylogenetic tree reconstruction revealed that O. reevesii is most closely related to the Biomphalaria glabrata. The qRT-PCR showed that mapk1 was expressed in all the tissues, but the highest expression was in the ganglion. We speculated that mapk1 is related to memory formation of O. reevesii. Then we used qRT-PCR to detect the expression of mapk1 and egr1 in ganglion of O. reevesi under tidal stimulation. The expression of mapk1 and egr1 at the rising tide points were significantly higher (P < 0.05) than that at the previous one lowest tide points on May 15-21, except the rising tide point on May 20 and May 21 of mapk1. The expression of mapk1 and egr1 genes in the ganglion sampled for 7-day were basically the same as that of the tide change of the same day. The expression of the two genes were upregulated at raising tide and downregulated at the lowest tide, it is presumed that the O. reevesii was affected by the tide for a long time and formed the tide memory.
基金This work was supported by the National Natural Science Foundation of China(31971414 and 31470471)the Finance Science and Technology Project of Hainan Province(ZDYF2018219)。
文摘We used mitochondrial cytochrome b and ND4 genes and 9 microsatellite loci to determine genetic diversity,population structure,evolutionary history,and migration patterns within the Reeves’butterfly lizard Leiolepis reevesii(Agamidae).Considering molecular-based phylogeographical lineages,we then performed niche equivalency and similarity tests between divergent lineages.Phylogenetic analyses based on mitochondrial DNA(mtDNA)data revealed 2 lineages(A and B)diverging≈0.84 million years ago and,respectively,restricted to the northern and southern portions of the Wuzhishan and Yinggeling mountain ranges.Lineage B contains individuals from southern Hainan;Lineage A includes individuals from all other localities and can be further divided into 3 clusters according to microsatellite data.The null hypothesis that the 2 lineages shared identical niches was rejected in all niche equivalency tests,indicating niche shifts during genetic divergence.Similarity tests provided evidence of niche conservatism,suggesting that the 2 lineages share more characteristics of their niche spaces than randomly expected.The niche similarity and equivalency tests indicated a complex niche pattern in which both lineages share a main portion of their ecological spaces.The climatic niche of Lineage B represented a marginal and specialized fraction of the entire ecological space of the climatic niche of Lineage A,with warmer conditions.Isolation caused by orogenesis and subsequent niche divergence,together with local adaptation,may have led to genetic differentiation and further lineage sorting in L.reevesii.
基金This work was supported by the Construction Project of the Double First-class Disciplines of Fisheries.
文摘During low tide intertidal organisms face severe temperature fluctuations.This situation may be more pronounced in the context of climate change.To investigate the molecular response mechanism of Onchidium reevesii when stressed by hot and cold temperatures,we cloned its Caspase-3 and Caspase-9 genes and detected their expression characteristics using RT-qPCR.The results showed that the full-length of the cDNA of Caspase-3 consist of 1831 bp,and included an open reading frame(ORF)of 894 bp,a 50UTR of 155 bp and a 30 UTR of 300 bp,and encoding for 297 amino acids.The full-length of the cDNA of Caspase-9 consisted of 2425 bp,and included an ORF of 1373 bp,a 50 UTR of 290 bp,and a 30 UTR of 759 bp,and encoding for 457 amino acids.During the evolution of species the two genes have been greatly conserved.A homology analysis and phylogenetic tree reconstruction revealed that O.reevesii is most closely related to Aplysia californica.The RT-qPCR showed that both genes were expressed in all of the tissues and that expression was highest in the hepatopancreas.It is speculated that these genes play an essential role in the immunity of O.reevesii to certain diseases.Conditions of temperature stress(40�C and 10�C)showed that both heat and cold stresses could induce significant changes in both genes.Compared to the control group,under cold stress conditions the levels of expression of Caspase-3 and Caspase-9 were significantly upregulated(P<0.05)in each experimental group.When exposed to a constant temperature of 10�C,their expression peaked after 1 h(4.32-fold,P<0.05;and 5.58-fold,P<0.05,respectively)and was at its lowest after 12 h(1.93-fold,P<0.05;and 2.35-fold,P<0.05,respectively).Their expression was upregulated after 24 h(2.68-fold,P<0.05;and 4.21-fold,P<0.05,respectively).The expression of both genes showed similar trends.Under heat stress,the expressions of the two genes showed a wave pattern.When exposed to a constant temperature of 40�C,their expression was up-regulated after 1,6,and 24 h,and down-regulated after 3 and 12 h.Except at 24 h,the other experimental groups did not differ significantly(P>0.05)from the control group.When subjected to various stress conditions the two genes displayed different expression patterns,indicating that the species has different strategies for coping with temperature changes.It further indicates that the effect of temperature on the species may play a role through the Caspase-dependent pathway.These may help to better understand the response,at the molecular level,of O.reevesii to conditions of hot and cold stress.
基金Funding was provided by the National Natural Sciences Foundation of China (No.30070117 and 30330050)State Key Basic Research Program Plan (G2000046805).
文摘Home range and habitat use of male Reeves’s pheasant(Syrmaticus reevesii)were studied during winter of 2001~2002 and 2002~2003 in the Dongzhai National Nature Reserve,Henan Province.Results from five individuals of Reeves’s pheasant with over 30 relocations,indicated that the average size of home range was 10.03±1.17 hm^(2) by Minimum Convex Polygon method,8.60±0.35 hm^(2) by 90%Harmonic Mean Transformation method,and 9.50±1.90 hm^(2) by 95%Fixed Kernel method.It was observed that the winter range is smaller than that in the breeding season.The mean core area of the home range was found to be 1.88±0.37 hm^(2).Although the habitat composition of the core area varied greatly for individuals,a large part of the habitats used were composed of conifer and broadleaf mixed forests,masson pine forests,fir forests,and shrubs.Habitat use within the study area was non-random,while habitats within home ranges were randomly used.Habitat use was dictated by tree diameter at breast height,shrub height and coverage at 2.0 m.The proximity between forests and shrubs were also found to be important in providing refuge for the birds during winter.Recommendations for conservation management include protecting the existing habitats in Dongzhai National Nature Reserve,increasing suitable habitat for Reeves’s Pheasant through artificial plantations(e.g.firs),and restoring some parts of the large shrub area into forests.
文摘The eggshell of Reeve’s pheasant(Syrmaticus reevesii)collected from the Dongzhai National Nature Reserve in Henan Province,China was studied.By using scanning electron microscopy and inductively coupled plasma(ICP)spectrometry,the ultrastructure and elemental composition of the eggshell was determined.The study showed that the average thickness of the surface layer of crys-tals,the palisade and cone layer,and the eggshell membrane were 20.8,220.8 and 62.5μm,respectively,accounting for 6.8%,72.6%and 20.6%of the total thickness of the eggshell.There were many vesicular holes in the palisade layer with an average diameter of 0.32±0.08μm(n=30).The function of these holes might be significant to air exchange.The shape of the eggshell pore on the surface layer of crystals is round or elliptical.The fracture surface of the pore is funnel-shaped.Some granules filled the upper part of the eggshell pores.The content of 21 elements in the eggshell of wild and captive Reeve’s pheasants was compared and presented.It indicated that among the elements that made up the eggshell of the wild pheasant,the content of Ca,Mg,P and S was much higher,ω>1 mg/g,withω(Ca)being higher than 40%of the eggshell.The contents of Na,Si,Sr,K and Al wereω=0.1-1 mg/g,while Fe,Zn,Pb,Mn,Cu,V and Ti had lower concentrations(ω=1-100μg/g).Theωof Ni,Cr,Co,Se,Cd were lower than 1μg/g.The elemental composition in the eggshell of the captive Reeve’s pheasant kept in the Dongzhai National Natural Reserve was significantly differ-ent from that of the wild species,with a difference of over 20%on S,Cu,Fe,Al,Mn,Si,Sr,Se and Cr.The lower intake of Fe,Mn,Si and Sr on the one hand and the higher intake of S,Cu,Al and Cr on the other hand might be responsible for the low fertility of captive Reeve’s pheasants in the Dongzhai National Nature Reserve.In order to ensure that the pheasants are receiving the proper amount of nutrition and to improve their breeding success,the amount of certain elements in the food should be adjusted.
