We acclimated adult males of three Eremias lizards from different latitudes to 28℃,33℃ or 38℃ to examine whether temperature acclimation affects their thermal preference and tolerance and whether thermal preference...We acclimated adult males of three Eremias lizards from different latitudes to 28℃,33℃ or 38℃ to examine whether temperature acclimation affects their thermal preference and tolerance and whether thermal preference and tolerance of these lizards correspond with their latitudinal distributions.Overall,selected body temperature(Tsel)and viable temperature range(VTR)were both highest in E.brenchleyi and lowest in E.multiocellata,with E.argus in between;critical thermal minimum(CTMin)was highest in E.multiocellata and lowest in E.brenchleyi,with E.argus in between;critical thermal maximum(CTMax)was lower in E.multiocellata than in other two species.Lizards acclimated to 28℃ and 38℃ overall selected lower body temperatures than those acclimated to 33℃;lizards acclimated to high temperatures were less tolerant of low temperatures,and vice versa;lizards acclimated to 28℃ were less tolerant of high temperatures but had a wider VTR range than those acclimated to 33℃ and 38℃.Lizards of three species acclimated to the three temperatures always differed from each other in CTMin,but not in Tsel,CTMax and VTR.Our results show that:temperature acclimation plays an important role in influencing thermal preference and tolerance in the three Eremias lizards,although the degrees to which acclimation temperature affects thermal preference and tolerance differ among species;thermal preference rather than tolerance of the three Eremias lizards corresponds with their latitudinal distributions.展开更多
Phenotypic traits are usually correlated with the environment where organism occurs. In this study, the distribution of Eremias velox in the eastern periphery of its range was specified, and its morphological variatio...Phenotypic traits are usually correlated with the environment where organism occurs. In this study, the distribution of Eremias velox in the eastern periphery of its range was specified, and its morphological variation was analyzed. Linear dimensions, pholidosis, coloration and pattern features were compared among 135 specimens from nine populations inhabiting the Balkhash, Ili and Alakol basins, Junggar and Turpan depressions in the territory of Southeast Kazakhstan and Xinjiang, Northwest China. The populations from the Junggar Depression(Kuytun, Shihezi and Urumqi) were characterized by higher mean values of linear characters, the number of scales across the middle of the body and gular, and were similar in the dominant coloration patterns. Small size, dark coloration and almost complete dominance of the striped-type coloration pattern among the specimens from the Alakol Lake islands seem to have an adaptive significance associated with the isolation of the population and type of their habitats. The subspecies Eremias velox roborowskii(endemic to the Turpan Depression) is elevated to species level, as supported by morphological divergence congruent with molecular and geographical data, including its peculiar type of coloration pattern, significantly lower amount of femoral pores and a higher percentage of specimens with one enlarged preanal scale(72.7%). These results together confirm a high degree of variability in morphology for E.veloх in the eastern periphery of its range, reflecting a complex orography and the existence of multiple geographical barriers in this territory.展开更多
The rapid racerunner,Eremias velox,is a widely distributed lizard from the northern Caucasus across entire Central Asia eastward to China.It is increasingly common to accept E.velox as a species complex in its entire ...The rapid racerunner,Eremias velox,is a widely distributed lizard from the northern Caucasus across entire Central Asia eastward to China.It is increasingly common to accept E.velox as a species complex in its entire range.To date,published morphological and molecular systematic hypotheses of this complex are only partially congruent,and its taxonomic status and evolutionary history are still far from clear.The mitochondrial cytochrome b gene and12S rRNA sequences were used to evaluate the taxonomy of this complex,with particular attention to the phylogenetic placement of populations in northwestern China.Examination of the phylogenetic analyses recovers seven distinct,biogeographically discrete,and well-supported clades,revealing genetically identifiable populations corresponding to some previously morphology-defined subspecies.Chinese E.v.roborowskii appears to have split from other Central Asian rapid racerunner lizards well before differentiation occurred among the latter taxa.Specifically,we corroborate that there are two subspecies occurring in China,i.e.,E.v.velox and E.v.roborowskii.We recommend a novel subspecific status for the phenotypically and genetically distinct populations in southern Aral Sea region of Uzbekistan previously assigned to E.v.velox.Finally,each of the three independently evolving lineages from Iranian Plateau should be recognized as three species new to science under the general lineage concept.展开更多
Food availability significantly affects an animal＇s energy metabolism, and thus its phenotype, survival, and reproduction. Maternal and offspring responses to food conditions are critical for understanding population...Food availability significantly affects an animal＇s energy metabolism, and thus its phenotype, survival, and reproduction. Maternal and offspring responses to food conditions are critical for understanding population dynamics and life-history evolution of a species. In this study, we conducted food manipulation experiments in field enclosures to identify the effect of food restriction on female reproductive traits and postpartum body condition, as well as on hatchling phenotypes, in a lacertid viviparous lizard from the Inner Mongolian desert steppe of China. Females under low-food availability treatment （LFT） had poorer immune function and body condition compared with those under high-food availability treatment （HFT）. The food availability treatments significantly affected the litter size and litter mass of the females, but not their gestation period in captivity or brood success, or the body size sprint speed, and sex ratio of the neonates. Females from the LFT group had smaller litter sizes and, therefore, lower litter mass than those from the HFT group. These results suggest that female racerunners facing food restriction lay fewer offspring with unchanged body size and locomotor performance, and incur a cost in the form of poor postpartum body condition and immune function. The flexibility of maternal responses to variable food availability represents an important life strategy that could enhance the resistance of lizards to unpredictable environmental change.展开更多
Information on habitat use is critical in sizing protected areas for endangered reptile species. To investigate habitat use, home range, and hibernaculum of the endangered Mongolian Racerunner(Eremias argus), we radio...Information on habitat use is critical in sizing protected areas for endangered reptile species. To investigate habitat use, home range, and hibernaculum of the endangered Mongolian Racerunner(Eremias argus), we radio-tracked 40 specimens in a coastal sand dune in South Korea. Of the 163 locations recorded during the breeding season, 150(92.0%) were in grass sand dunes, and the rest(8.0%), all associated with the same lizard, were in shrub sand dunes. All of the 123 locations recorded during the non-breeding season were in grass sand dunes. No lizards were found in the grasslands abutting the dunes. The four lizards with identifiable hibernation sites were found under an average of 17.8 cm of sand and were all located in grass sand dunes. The lizards moved approximately 5 m daily and used 162 m2of home range(computed by minimum convex polygon, MCP) during the breeding season, and they moved approximately 2 m and used 68 m2of home range during the non-breeding season. However, the mean daily moved distances and MCP home ranges were not statistically significantly different between the seasons or between males and females. Our results suggest that in coastal sand dunes, E. argus uses grass sand dunes as its main habitat throughout the year. This finding could be used to determine the appropriate habitat size and to designate for the conservation of this endangered species.展开更多
Sympatric reptiles are the ideal system for investigating temperature-driven coexistence. Understanding thermally physiological responses of sympatric lizards is necessary to reveal the physiological mechanisms that u...Sympatric reptiles are the ideal system for investigating temperature-driven coexistence. Understanding thermally physiological responses of sympatric lizards is necessary to reveal the physiological mechanisms that underpin the sympatric occurrence of reptiles. In this study, we used three lizard species, Eremias argus, E. multiocellata, and Phrynocephalus przewalskii, which are sympatric in the Inner Mongolia desert steppe, as a study system. By comparing their resting metabolic rates(RMR) and locomotion at different body temperatures, we aimed to better understand their physiological responses to thermal environments, which may explain the sympatric occurrence of these lizards. Our results showed that E. argus had significantly higher RMR and sprint speed than E. multiocellata, and higher RMR than P. przewalskii. In addition, the optimal temperature that maximized metabolic rates and locomotion for E. argus and E. multiocellata was 36°C, whereas for P. przewalskii it was 39°C. Our study revealed the physiological responses to temperatures that justify the sympatric occurrence of these lizards with different thermal and microhabitat preferences and active body temperatures. Eremias argus and E. multiocellata, which have lower body temperatures than P. przewalskii, depend on higher RMR and locomotion to compensate for their lower body temperatures in field conditions. Our study also highlights the importance of using an integrative approach, combining behavior and physiology, to explore the basis of sympatric occurrence in ectothermic species.展开更多
Phylogeographic studies of Eremias lizards （Lacertidae） in East Asia have been limited, and the impact of major climatic events on their population dynamics remains poorly known. This study aimed to investigate popu...Phylogeographic studies of Eremias lizards （Lacertidae） in East Asia have been limited, and the impact of major climatic events on their population dynamics remains poorly known. This study aimed to investigate population histories and refugia during the Last Glacial Maximum of two sympatric Eremias lizards （E. argus and E. brenchleyi） inhabiting northern China. We sequenced partial mitochondrial DNA from the ND4 gene for 128 individuals of E. argus from nine localities, and 46 individuals of E. brenchleyi from five localities. Forty-four ND4 haplotypes were determined from E. argus samples, and 33 from E. brenchleyi samples. Population expansion events began about 0.0044 Ma in E. argus, and 0.031 Ma in E. brenchleyi. The demographic history of E. brenchleyi indicates a long-lasting population decline since the most recent common ancestor, while that of E. argus indicates a continuous population growth. Among-population structure was significant in both species, and there were multiple refugia across their range. Intermittent gene flow occurred among expanded populations across multiple refugia during warmer phases of the glacial period, and this may explain why the effective population size has remained relatively stable in E. brenchleyi and grown in E. argus.展开更多
The major histocompatibility complex （MHC） is a dynamic genetic region with an essential role in the adaptive immunity of jawed vertebrates. The MHC polymorphism is affected by many processes such as birth-and- deat...The major histocompatibility complex （MHC） is a dynamic genetic region with an essential role in the adaptive immunity of jawed vertebrates. The MHC polymorphism is affected by many processes such as birth-and- death evolution, gene conversion, and concerted evolution. Studies investigating the evolution of MHC class I genes have been biased toward a few particular taxa and model species. However, the investigation of this region in nonavian reptiles is still in its infancy. We present the first characterization of MHC class I genes in a species from the family Lacertidae. We assessed genetic diversity and a role of selection in shaping the diversity of MHC class I exon 4 among 37 individuals of Eremias multiocellata from a population in Lanzhou, China. We generated 67 distinct DNA sequences using cloning and sequencing methods, and identified 36 putative functional variants as well as two putative pseudogene-variants. We found the number of variants within an individual varying between two and seven, indicating that there are at least four MHC class I loci in this species. Gene duplication plays a role in increasing copy numbers of MHC genes and allelic diversity in this species. The class I exon 4 sequences are characteristic of low nucleotide diversity. No signal of recombination is detected, but purifying selection is detected in β2-microglobulin interaction sites and some other silent sites outside of the function-constraint regions. Certain identical alleles are shared by Eremias multiocellata and E. przewalskii and E. brenchleyi, suggesting trans-species polymorphism. The data are compatible with a birth-and-death model of evolution.展开更多
Sox9 is an important member of Sox family which is involved in a variety of developmental processes including sex determination and gonadal differentiation. The cDNA of Sox9 from multiocellated racerunner E. multiocel...Sox9 is an important member of Sox family which is involved in a variety of developmental processes including sex determination and gonadal differentiation. The cDNA of Sox9 from multiocellated racerunner E. multiocellata was cloned using reverse transcription-polymerase chain reaction （RT-PCR） and rapid amplification of cDNA ends （RACE）. The sequence contains a 1497 bp open reading frame, which encodes a 498 amino acid protein with a predicted molecular weight of 55.45 kDa. EmSox9 displays high similarity to those of reptiles, and shows an overall amino acid identity of 〉82%. We also investigated the tissue-specific expression of EmSox9 mRNA by realtime quantitative PCR. Sox9 mRNA is present in brain, heart, liver, kidney, gonads and muscle tissues of adult E. multiocellata, with the highest expression in brain and testis. The results indicate that Sox9 may play important roles in some tissues during E. multiocellata neural and gonadal development.展开更多
Light is essential for embryonic development in many ovipa rous animals including fish,amphibians,and birds.However,light may be harmful for reptile embryos developing underground where they are in complete darkness a...Light is essential for embryonic development in many ovipa rous animals including fish,amphibians,and birds.However,light may be harmful for reptile embryos developing underground where they are in complete darkness and beneath thin eggshells.Nonetheless,how embryonic light conditions affect reptile development and offspring remains largely unknown.Here we incubated eggs in dark and light conditions to determine the effects of light exposure on embryonic development and offspring visual ability,spa tial cognitive ability and growth in a lacertid lizard,Eremias argus.Our experiments demonstrated that light stimulation shortened incubation duration of eggs,but did not affect hatching success,offspring size,visual ability or survival More interestingly,light exposure during incuba tion decreased spa tial cognitive ability and post-hatching growth of offspring On the basis of nega tive effects on offspring growth rates,our study indicates that in squamate reptiles with thin eggshells,light exposure in early development has negative effects on offspring cognitive ability.展开更多
Electrocardiograms (ECG) of Eremias multiocellata were studied at 5-35℃ in body temperature. Electrocardiogram wave intervals (R-R,P-R,QRS,T-P,and R-T) shortened while heart rate increased with the increasing of bod...Electrocardiograms (ECG) of Eremias multiocellata were studied at 5-35℃ in body temperature. Electrocardiogram wave intervals (R-R,P-R,QRS,T-P,and R-T) shortened while heart rate increased with the increasing of body temperature. The average heart rate was 14.6/min at 5℃,whereas it was 201/min at 35℃. The duration of wave intervals of ECG and the heart rate were related significantly to the body temperature (P<0.001). Among the components of a cardiac cycle the cardiac rest period (TP intervals) and the atria-ventricular conduction time (PR interval) were affected mostly by body temperature. In the other hand the ventricular depolarization and repolarization (QRS and R-T intervals) were relatively less affected by the body temperature. The increasing of heart rate with body temperature was mainly caused by the shortening of ECG wave intervals,and the T-P interval (the cardiac rest period) was shortened more noticeably than other intervals.展开更多
基金supported by a grant from Natural Science Foundation of China(Project No.30670281)
文摘We acclimated adult males of three Eremias lizards from different latitudes to 28℃,33℃ or 38℃ to examine whether temperature acclimation affects their thermal preference and tolerance and whether thermal preference and tolerance of these lizards correspond with their latitudinal distributions.Overall,selected body temperature(Tsel)and viable temperature range(VTR)were both highest in E.brenchleyi and lowest in E.multiocellata,with E.argus in between;critical thermal minimum(CTMin)was highest in E.multiocellata and lowest in E.brenchleyi,with E.argus in between;critical thermal maximum(CTMax)was lower in E.multiocellata than in other two species.Lizards acclimated to 28℃ and 38℃ overall selected lower body temperatures than those acclimated to 33℃;lizards acclimated to high temperatures were less tolerant of low temperatures,and vice versa;lizards acclimated to 28℃ were less tolerant of high temperatures but had a wider VTR range than those acclimated to 33℃ and 38℃.Lizards of three species acclimated to the three temperatures always differed from each other in CTMin,but not in Tsel,CTMax and VTR.Our results show that:temperature acclimation plays an important role in influencing thermal preference and tolerance in the three Eremias lizards,although the degrees to which acclimation temperature affects thermal preference and tolerance differ among species;thermal preference rather than tolerance of the three Eremias lizards corresponds with their latitudinal distributions.
基金supported by the Ministry of Education and Sciences of Kazakhstan (Grant No. 1850/GF4)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDPA20050201)+1 种基金the Ministry of Science and Technology of the People’s Republic of China (Grant No. 2015DFR30790)the National Natural Science Foundation of China (Grant No. 31672270)
文摘Phenotypic traits are usually correlated with the environment where organism occurs. In this study, the distribution of Eremias velox in the eastern periphery of its range was specified, and its morphological variation was analyzed. Linear dimensions, pholidosis, coloration and pattern features were compared among 135 specimens from nine populations inhabiting the Balkhash, Ili and Alakol basins, Junggar and Turpan depressions in the territory of Southeast Kazakhstan and Xinjiang, Northwest China. The populations from the Junggar Depression(Kuytun, Shihezi and Urumqi) were characterized by higher mean values of linear characters, the number of scales across the middle of the body and gular, and were similar in the dominant coloration patterns. Small size, dark coloration and almost complete dominance of the striped-type coloration pattern among the specimens from the Alakol Lake islands seem to have an adaptive significance associated with the isolation of the population and type of their habitats. The subspecies Eremias velox roborowskii(endemic to the Turpan Depression) is elevated to species level, as supported by morphological divergence congruent with molecular and geographical data, including its peculiar type of coloration pattern, significantly lower amount of femoral pores and a higher percentage of specimens with one enlarged preanal scale(72.7%). These results together confirm a high degree of variability in morphology for E.veloх in the eastern periphery of its range, reflecting a complex orography and the existence of multiple geographical barriers in this territory.
基金supported by the National Natural Science Foundation of China (31272281)Knowledge Innovation Program of the Chinese Academy of Sciences (KSCX2-EW-Q-6)Projects of the Bureau of International Co-operation of the Chinese Academy of Sciences (No. 1136, 1327, 1441)
文摘The rapid racerunner,Eremias velox,is a widely distributed lizard from the northern Caucasus across entire Central Asia eastward to China.It is increasingly common to accept E.velox as a species complex in its entire range.To date,published morphological and molecular systematic hypotheses of this complex are only partially congruent,and its taxonomic status and evolutionary history are still far from clear.The mitochondrial cytochrome b gene and12S rRNA sequences were used to evaluate the taxonomy of this complex,with particular attention to the phylogenetic placement of populations in northwestern China.Examination of the phylogenetic analyses recovers seven distinct,biogeographically discrete,and well-supported clades,revealing genetically identifiable populations corresponding to some previously morphology-defined subspecies.Chinese E.v.roborowskii appears to have split from other Central Asian rapid racerunner lizards well before differentiation occurred among the latter taxa.Specifically,we corroborate that there are two subspecies occurring in China,i.e.,E.v.velox and E.v.roborowskii.We recommend a novel subspecific status for the phenotypically and genetically distinct populations in southern Aral Sea region of Uzbekistan previously assigned to E.v.velox.Finally,each of the three independently evolving lineages from Iranian Plateau should be recognized as three species new to science under the general lineage concept.
基金supported by the grant from the National Natural Science Fund for Distinguished Young Scholars(31525006)
文摘Food availability significantly affects an animal＇s energy metabolism, and thus its phenotype, survival, and reproduction. Maternal and offspring responses to food conditions are critical for understanding population dynamics and life-history evolution of a species. In this study, we conducted food manipulation experiments in field enclosures to identify the effect of food restriction on female reproductive traits and postpartum body condition, as well as on hatchling phenotypes, in a lacertid viviparous lizard from the Inner Mongolian desert steppe of China. Females under low-food availability treatment （LFT） had poorer immune function and body condition compared with those under high-food availability treatment （HFT）. The food availability treatments significantly affected the litter size and litter mass of the females, but not their gestation period in captivity or brood success, or the body size sprint speed, and sex ratio of the neonates. Females from the LFT group had smaller litter sizes and, therefore, lower litter mass than those from the HFT group. These results suggest that female racerunners facing food restriction lay fewer offspring with unchanged body size and locomotor performance, and incur a cost in the form of poor postpartum body condition and immune function. The flexibility of maternal responses to variable food availability represents an important life strategy that could enhance the resistance of lizards to unpredictable environmental change.
基金supported by the Korean Ministry of Environment as "The Eco-Technopia 21 Project (#052-091-080)"
文摘Information on habitat use is critical in sizing protected areas for endangered reptile species. To investigate habitat use, home range, and hibernaculum of the endangered Mongolian Racerunner(Eremias argus), we radio-tracked 40 specimens in a coastal sand dune in South Korea. Of the 163 locations recorded during the breeding season, 150(92.0%) were in grass sand dunes, and the rest(8.0%), all associated with the same lizard, were in shrub sand dunes. All of the 123 locations recorded during the non-breeding season were in grass sand dunes. No lizards were found in the grasslands abutting the dunes. The four lizards with identifiable hibernation sites were found under an average of 17.8 cm of sand and were all located in grass sand dunes. The lizards moved approximately 5 m daily and used 162 m2of home range(computed by minimum convex polygon, MCP) during the breeding season, and they moved approximately 2 m and used 68 m2of home range during the non-breeding season. However, the mean daily moved distances and MCP home ranges were not statistically significantly different between the seasons or between males and females. Our results suggest that in coastal sand dunes, E. argus uses grass sand dunes as its main habitat throughout the year. This finding could be used to determine the appropriate habitat size and to designate for the conservation of this endangered species.
基金Animal Ethics Committees at the Institute of Zoology, Chinese Academy of Sciences approved the ethics and protocol (IOZ14001) for the collection, handling, and husbandry of the study animalsBI J. H. (No.31660615) and SUN B. J. (No. 31870391 and 31500324) are supported by grants from the National Natural Science Foundation of China
文摘Sympatric reptiles are the ideal system for investigating temperature-driven coexistence. Understanding thermally physiological responses of sympatric lizards is necessary to reveal the physiological mechanisms that underpin the sympatric occurrence of reptiles. In this study, we used three lizard species, Eremias argus, E. multiocellata, and Phrynocephalus przewalskii, which are sympatric in the Inner Mongolia desert steppe, as a study system. By comparing their resting metabolic rates(RMR) and locomotion at different body temperatures, we aimed to better understand their physiological responses to thermal environments, which may explain the sympatric occurrence of these lizards. Our results showed that E. argus had significantly higher RMR and sprint speed than E. multiocellata, and higher RMR than P. przewalskii. In addition, the optimal temperature that maximized metabolic rates and locomotion for E. argus and E. multiocellata was 36°C, whereas for P. przewalskii it was 39°C. Our study revealed the physiological responses to temperatures that justify the sympatric occurrence of these lizards with different thermal and microhabitat preferences and active body temperatures. Eremias argus and E. multiocellata, which have lower body temperatures than P. przewalskii, depend on higher RMR and locomotion to compensate for their lower body temperatures in field conditions. Our study also highlights the importance of using an integrative approach, combining behavior and physiology, to explore the basis of sympatric occurrence in ectothermic species.
基金supported by grants from Chinese Ministry of Education (20070319006)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Phylogeographic studies of Eremias lizards （Lacertidae） in East Asia have been limited, and the impact of major climatic events on their population dynamics remains poorly known. This study aimed to investigate population histories and refugia during the Last Glacial Maximum of two sympatric Eremias lizards （E. argus and E. brenchleyi） inhabiting northern China. We sequenced partial mitochondrial DNA from the ND4 gene for 128 individuals of E. argus from nine localities, and 46 individuals of E. brenchleyi from five localities. Forty-four ND4 haplotypes were determined from E. argus samples, and 33 from E. brenchleyi samples. Population expansion events began about 0.0044 Ma in E. argus, and 0.031 Ma in E. brenchleyi. The demographic history of E. brenchleyi indicates a long-lasting population decline since the most recent common ancestor, while that of E. argus indicates a continuous population growth. Among-population structure was significant in both species, and there were multiple refugia across their range. Intermittent gene flow occurred among expanded populations across multiple refugia during warmer phases of the glacial period, and this may explain why the effective population size has remained relatively stable in E. brenchleyi and grown in E. argus.
基金supported by the Science and Technology Project for Outstanding Youths in Life Science (KSCX2-EW-Q-6) from the Chinese Academy of SciencesNational Natural Science Foundation of China (31272281)
文摘The major histocompatibility complex （MHC） is a dynamic genetic region with an essential role in the adaptive immunity of jawed vertebrates. The MHC polymorphism is affected by many processes such as birth-and- death evolution, gene conversion, and concerted evolution. Studies investigating the evolution of MHC class I genes have been biased toward a few particular taxa and model species. However, the investigation of this region in nonavian reptiles is still in its infancy. We present the first characterization of MHC class I genes in a species from the family Lacertidae. We assessed genetic diversity and a role of selection in shaping the diversity of MHC class I exon 4 among 37 individuals of Eremias multiocellata from a population in Lanzhou, China. We generated 67 distinct DNA sequences using cloning and sequencing methods, and identified 36 putative functional variants as well as two putative pseudogene-variants. We found the number of variants within an individual varying between two and seven, indicating that there are at least four MHC class I loci in this species. Gene duplication plays a role in increasing copy numbers of MHC genes and allelic diversity in this species. The class I exon 4 sequences are characteristic of low nucleotide diversity. No signal of recombination is detected, but purifying selection is detected in β2-microglobulin interaction sites and some other silent sites outside of the function-constraint regions. Certain identical alleles are shared by Eremias multiocellata and E. przewalskii and E. brenchleyi, suggesting trans-species polymorphism. The data are compatible with a birth-and-death model of evolution.
基金supported by the National Natural Science Foundation of China (No. 30670263)
文摘Sox9 is an important member of Sox family which is involved in a variety of developmental processes including sex determination and gonadal differentiation. The cDNA of Sox9 from multiocellated racerunner E. multiocellata was cloned using reverse transcription-polymerase chain reaction （RT-PCR） and rapid amplification of cDNA ends （RACE）. The sequence contains a 1497 bp open reading frame, which encodes a 498 amino acid protein with a predicted molecular weight of 55.45 kDa. EmSox9 displays high similarity to those of reptiles, and shows an overall amino acid identity of 〉82%. We also investigated the tissue-specific expression of EmSox9 mRNA by realtime quantitative PCR. Sox9 mRNA is present in brain, heart, liver, kidney, gonads and muscle tissues of adult E. multiocellata, with the highest expression in brain and testis. The results indicate that Sox9 may play important roles in some tissues during E. multiocellata neural and gonadal development.
基金We thank Tingting WANG,Yige CHEN and Peng CAO for assistance.AIll procedures were performed under the approval(IOZ14001)from the Animal Ethics Comittee at the Institute of Zoology,Chinese Academy of Sciences Funding was provided by National Natural Science Foundation of China(31500324 for Baojun SUN and 31801977 for Shuran LI).
文摘Light is essential for embryonic development in many ovipa rous animals including fish,amphibians,and birds.However,light may be harmful for reptile embryos developing underground where they are in complete darkness and beneath thin eggshells.Nonetheless,how embryonic light conditions affect reptile development and offspring remains largely unknown.Here we incubated eggs in dark and light conditions to determine the effects of light exposure on embryonic development and offspring visual ability,spa tial cognitive ability and growth in a lacertid lizard,Eremias argus.Our experiments demonstrated that light stimulation shortened incubation duration of eggs,but did not affect hatching success,offspring size,visual ability or survival More interestingly,light exposure during incuba tion decreased spa tial cognitive ability and post-hatching growth of offspring On the basis of nega tive effects on offspring growth rates,our study indicates that in squamate reptiles with thin eggshells,light exposure in early development has negative effects on offspring cognitive ability.
文摘Electrocardiograms (ECG) of Eremias multiocellata were studied at 5-35℃ in body temperature. Electrocardiogram wave intervals (R-R,P-R,QRS,T-P,and R-T) shortened while heart rate increased with the increasing of body temperature. The average heart rate was 14.6/min at 5℃,whereas it was 201/min at 35℃. The duration of wave intervals of ECG and the heart rate were related significantly to the body temperature (P<0.001). Among the components of a cardiac cycle the cardiac rest period (TP intervals) and the atria-ventricular conduction time (PR interval) were affected mostly by body temperature. In the other hand the ventricular depolarization and repolarization (QRS and R-T intervals) were relatively less affected by the body temperature. The increasing of heart rate with body temperature was mainly caused by the shortening of ECG wave intervals,and the T-P interval (the cardiac rest period) was shortened more noticeably than other intervals.
