Tyrosinase is encoded by the Tyr (c or albino) locus and is the key enzyme in pigment biosynthesis. Loss of function of this enzyme caused by gene mutation results in albinism. Most cases of albinism are caused by mis...Tyrosinase is encoded by the Tyr (c or albino) locus and is the key enzyme in pigment biosynthesis. Loss of function of this enzyme caused by gene mutation results in albinism. Most cases of albinism are caused by missense mutations of tyrosinase. Albino mutations in Tyr have been identified in various animals, including human, mouse, rat, rabbit, cattle, cat, and ferret, but not in gerbil. We created two new gerbil strains: MON/Num/a (inbred agouti phenotype) and MON/Num/c (albino phenotype). Here, we report that four nucleotide substitutions in the Tyr gene caused two missense mutations in amino acids in the albino gerbil: a G-to-A mutation at position 204 in exon 1 caused R77H, and A-to-G at position 1392 and G-to-T at position 1393 in exon 5 caused Q473R. The substitution at position 1408 in exon 5 was silent. These missense mutations are conserved in all albino phenotypes we tested. Therefore, we suggest that these mutations are responsible for albinism in gerbil.展开更多
Animal immunity is usually impaired in obesity.We know little about the effect of being overweight or obese on the immune function of wild rodents.The present study is aimed to test the hypothesis that immunity is sup...Animal immunity is usually impaired in obesity.We know little about the effect of being overweight or obese on the immune function of wild rodents.The present study is aimed to test the hypothesis that immunity is suppressed in overweight Mongolian gerbils(Meriones unguiculatus).In the study,16 overweight(body mass:90.8-127.6 g)and 16 lean gerbils(body mass:60.5-77.7 g)were randomly selected from a total of 174 male gerbils(body mass range:55.8-144.7 g).Half of the overweight and lean males were injected with sterile saline;the others were immunochallenged(IC)with phytohaemagglutinin and keyhole limpet hemocyanin to assess cellular and humoral immunity,respectively.Body fat mass,wet and dry spleen mass,leukocyte counts,blood glucose levels and serum leptin levels were significantly higher in the overweight gerbils than in the lean gerbils.However,phytohemagglutinin response indicative of cellular immunity and immunoglobulin G concentrations was significantly lower in the IC overweight gerbils than in the IC lean gerbils.These results indicate that cellular and humoral immunity are impaired in the overweight gerbils.Excessive body fat mass,higher leukocyte counts and serum leptin levels imply that overweight gerbils are in a low grade inflammatory state.展开更多
Kin selection theory predicts that individuals should generally behave less aggressively or more amicably towards relatives than nonkin.However,how individuals treat conspecifics depends on genetic relatedness but als...Kin selection theory predicts that individuals should generally behave less aggressively or more amicably towards relatives than nonkin.However,how individuals treat conspecifics depends on genetic relatedness but also on the ecological context,which influences the benefits and costs of their interactions.In this study,we used microsatellite DNA markers and behavioral tests to examine the influence of kinship and proximity on the social behavior of Mongolian gerbils Meriones unguiculatus living in different social groups,and whether these effects varied with sex and season.We recorded the duration of 4 behavioral categories(investigative,neutral,amicable,and agonistic)during a 10-min pairwise test.We found that genetic relatedness had significant effects on the duration of investigative,neutral,and amicable behavior,but not on agonistic behavior.We also found significant interaction effects of relatedness and distance between burrow systems(i.e.,spatial distance)on investigative,neutral,and amicable behavior,which suggests that the effects of kinship on social behavior were restricted by spatial proximity.The interaction effect between sex and relatedness on amicable behavior showed that male gerbils became more intimate with individuals of the same sex that had higher pairwise relatedness than females.Furthermore,both male and female gerbils enhanced their aggression during the food-hoarding season,but the intensity of these changes was significantly higher in females.Overall,our results suggest that the effects of kinship and spatial proximity on social behavior exhibit sexual or seasonal patterns,thereby implying ecological context-dependent responses to out-group individuals in Mongolian gerbils.展开更多
Restricted gene flow may cause positive spatial genetic autocorrelation of animal populations at fine spatial scales. The Mongolian gerbil Meriones unguiculatus is a territorial, social rodent. Territoriality may crea...Restricted gene flow may cause positive spatial genetic autocorrelation of animal populations at fine spatial scales. The Mongolian gerbil Meriones unguiculatus is a territorial, social rodent. Territoriality may create social fences to restrict dispersal or gene flow of Mongolian gerbils to a short distance. Restricted dispersal may differentiate fine-scale spatial genetic structure of populations with increasing distances （i.e., isolation by distance [IBD]）. Competition for mates and inbreeding avoidance may result in equal dispersal propensity and subsequently similar spatial genetic autocorrelation between males and females of monogamous gerbils. We genotyped 327 gerbils, live captured from 26 burrow systems on a 9-ha plot in northcentral Inner Mongolia, China, using seven microsateliite loci. Spatial genetic autocorrelation was positive within 80 m and became negative from 80 m to 200 m, suggesting restricted gene flow. Inter-group genetic and geographic distances were related positively, supporting the IBD model. Live trapping data demonstrated equal dispersal propensities of male and female gerbils. Restricted dispersal and social organization may determine fine-scale spatial population genetic structure of social rodents.展开更多
Mongolian gerbils had high ability to endure both high and cold temperatures.To study the mechanism of high ability for thermal adaptation,gerbils were acclimated to high temperature(30°C)for 8 weeks,and were mea...Mongolian gerbils had high ability to endure both high and cold temperatures.To study the mechanism of high ability for thermal adaptation,gerbils were acclimated to high temperature(30°C)for 8 weeks,and were measured for metabolic fea-tures,body composition as well as mitochondrial content and activities.Lipidomic techniques were used to measure changes in mitochondrial membrane,including potential mitochondrial membrane remodeling during acute thermoregulation in gerbils.Heat acclimated gerbils showed lower basal metabolic rates but no changes in adaptive non-shivering thermogenesis were detected.A significant mitochondrial membrane remodeling with increases in monounsaturated/polyunsaturated free fatty acids ratios was associated with the decrease in metabolic rate.During heat acclimation,mitochondrial cytochrome C oxidase activity was elevated in brown adipose tissue,presumably caused by the increase in membrane unsaturation.Our results indicated that mitochondrial membrane remodeling is an important mechanism during heat acclimation in Mongo-lian gerbils,to reduce the metabolic rate in general while preserving sufficient capability to respond to acute cold.Such a mechanism may allow gerbils to cooperate with wide range of daily and seasonal temperature fluctuations.展开更多
Climatic factors are closely associated with the occurrence of vector‐borne diseases,and they also influence the distribution of vectors.The occurrence of plague is closely related to the population dynamics of fleas...Climatic factors are closely associated with the occurrence of vector‐borne diseases,and they also influence the distribution of vectors.The occurrence of plague is closely related to the population dynamics of fleas and their host animals,as well as climatic conditions.This study focused on Xilingol League,utilizing climatic and flea index data from 2012 to 2021.Spearman correlation and"Boruta"importance analysis were conducted to screen for climatic variables.A generalized additive model(GAM)was employed to investigate the influence of climatic factors and rodent density on the flea index.GAM analysis revealed distinct trends in flea index among different rodent hosts.For Meriones unguiculatus,the flea index declined with increased density and with higher humidity,yet rose with greater lagged sunshine duration.For Spermophilus dauricus,an initial increase in flea index with density was observed,followed by a decrease,and a rise in the index was noted when ground temperatures were low.This study reveals the nonlinear interactions and lag effects among climatic factors,density,and flea index.Climatic factors and density variably influence the flea index of two Yersinia pestis hosts.This research advances the prediction and early warning efforts for plague control,providing a theoretical basis for rodent and flea eradication strategies.展开更多
Animals often interact non-randomly with conspecifics,and association preferences can differ across life-history stages to maximize individuals’fitness.Mongolian gerbils(Meriones unguiculatus)are a social roden...Animals often interact non-randomly with conspecifics,and association preferences can differ across life-history stages to maximize individuals’fitness.Mongolian gerbils(Meriones unguiculatus)are a social rodent that live in highly seasonal habitats and display seasonal fluctuations in population density,growth rate and the size of overlapped home ranges.Nevertheless,whether gerbils modify their social relationships at different life-history stages remains unknown.Here,we used social network analysis to examine whether social associations differ between the sexes and between life-history stages in a wild population of Mongolian gerbils.We quantified social attributes at both group level(assortativity)and individual level(social differentiation and degree,closeness and betweenness centrality);these attributes reflect individuals’social preferences and their potential influence on others in the network.We found that both male and female gerbils established fewer inter-group social connections during the food-hoarding season than during the breeding season,revealing constraints on sociality.Similarly,during the food-hoarding season,degree centrality and social differentiation increased significantly whereas closeness and betweenness centrality decreased significantly.Together,these results suggest that gerbils have relatively more partners and preferred associations and decreased influence over others in the network during the food-hoarding season.In addition,we found no significant difference in any of the social attribute between males and females,but there was a significant interaction effect between sex and season on degree,closeness and betweenness centrality.Our results demonstrate that Mongolian gerbils adjust their association strategies to adapt to the changes of life history.Such adjustments may balance the costs/benefits associated with survival and reproduction.展开更多
Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China.The Mongolian gerbil(Meriones unguiculatus)is a dominant pest rodent which is distributed across the semi-desert grasslands o...Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China.The Mongolian gerbil(Meriones unguiculatus)is a dominant pest rodent which is distributed across the semi-desert grasslands of Inner Mongolia,China.In 2009,we studied the contraceptive effect of levonorgestrel-quinestrol(EP-1),concentration 50 ppm,on a wild Mongolian gerbil population.The one-off contraceptive treatment was compared with a control group using a semi-monthly live trapping method in the Ordos Semi-desert Grassland Region of Inner Mongolia.The results show that juveniles were not recruited in spring in the treatment group.Ratios of juveniles in the control and treatment groups showed significant semi-monthly differences from spring to summer(one-way ANOVA,F_(2,14)=7.53,P<0.05).Between both groups,annual fluctuations of juvenile and total population densities were significantly different respectively(F_(2,14)=4.64,P<0.05;F_(2,18)=7.72,P<0.05).The contraceptive EP-1 delayed the normal reproductive pattern of Mongolian gerbil populations.This suppressed birth rates of gerbil populations,reduced their densities,and changed their age structures.The period of EP-1 baiting should be extended but it could be an ideal method for controlling Mongolian gerbil populations during each breeding season.展开更多
文摘Tyrosinase is encoded by the Tyr (c or albino) locus and is the key enzyme in pigment biosynthesis. Loss of function of this enzyme caused by gene mutation results in albinism. Most cases of albinism are caused by missense mutations of tyrosinase. Albino mutations in Tyr have been identified in various animals, including human, mouse, rat, rabbit, cattle, cat, and ferret, but not in gerbil. We created two new gerbil strains: MON/Num/a (inbred agouti phenotype) and MON/Num/c (albino phenotype). Here, we report that four nucleotide substitutions in the Tyr gene caused two missense mutations in amino acids in the albino gerbil: a G-to-A mutation at position 204 in exon 1 caused R77H, and A-to-G at position 1392 and G-to-T at position 1393 in exon 5 caused Q473R. The substitution at position 1408 in exon 5 was silent. These missense mutations are conserved in all albino phenotypes we tested. Therefore, we suggest that these mutations are responsible for albinism in gerbil.
基金This study was supported by grants to DHW from the National Science and Technology Ministry Project(No.2007BC109103)the National Natural Science Foundation of China(30625009).
文摘Animal immunity is usually impaired in obesity.We know little about the effect of being overweight or obese on the immune function of wild rodents.The present study is aimed to test the hypothesis that immunity is suppressed in overweight Mongolian gerbils(Meriones unguiculatus).In the study,16 overweight(body mass:90.8-127.6 g)and 16 lean gerbils(body mass:60.5-77.7 g)were randomly selected from a total of 174 male gerbils(body mass range:55.8-144.7 g).Half of the overweight and lean males were injected with sterile saline;the others were immunochallenged(IC)with phytohaemagglutinin and keyhole limpet hemocyanin to assess cellular and humoral immunity,respectively.Body fat mass,wet and dry spleen mass,leukocyte counts,blood glucose levels and serum leptin levels were significantly higher in the overweight gerbils than in the lean gerbils.However,phytohemagglutinin response indicative of cellular immunity and immunoglobulin G concentrations was significantly lower in the IC overweight gerbils than in the IC lean gerbils.These results indicate that cellular and humoral immunity are impaired in the overweight gerbils.Excessive body fat mass,higher leukocyte counts and serum leptin levels imply that overweight gerbils are in a low grade inflammatory state.
基金We are grateful to all the members of the Animal Physiological Ecology Group for helpful discussions.We also thank Mr Bin Wu,Plant Protection Station of Taipusiqi,for help with the field work.We are grateful to Dr Michael Cant for his help revising the manuscript.This study was financially support from the National Natural Science Foundation of China(No.31372211)for W.L.and from the Chinese Academy of Sciences(KSCX2-EW-N-005)for D-H.W.
文摘Kin selection theory predicts that individuals should generally behave less aggressively or more amicably towards relatives than nonkin.However,how individuals treat conspecifics depends on genetic relatedness but also on the ecological context,which influences the benefits and costs of their interactions.In this study,we used microsatellite DNA markers and behavioral tests to examine the influence of kinship and proximity on the social behavior of Mongolian gerbils Meriones unguiculatus living in different social groups,and whether these effects varied with sex and season.We recorded the duration of 4 behavioral categories(investigative,neutral,amicable,and agonistic)during a 10-min pairwise test.We found that genetic relatedness had significant effects on the duration of investigative,neutral,and amicable behavior,but not on agonistic behavior.We also found significant interaction effects of relatedness and distance between burrow systems(i.e.,spatial distance)on investigative,neutral,and amicable behavior,which suggests that the effects of kinship on social behavior were restricted by spatial proximity.The interaction effect between sex and relatedness on amicable behavior showed that male gerbils became more intimate with individuals of the same sex that had higher pairwise relatedness than females.Furthermore,both male and female gerbils enhanced their aggression during the food-hoarding season,but the intensity of these changes was significantly higher in females.Overall,our results suggest that the effects of kinship and spatial proximity on social behavior exhibit sexual or seasonal patterns,thereby implying ecological context-dependent responses to out-group individuals in Mongolian gerbils.
文摘Restricted gene flow may cause positive spatial genetic autocorrelation of animal populations at fine spatial scales. The Mongolian gerbil Meriones unguiculatus is a territorial, social rodent. Territoriality may create social fences to restrict dispersal or gene flow of Mongolian gerbils to a short distance. Restricted dispersal may differentiate fine-scale spatial genetic structure of populations with increasing distances （i.e., isolation by distance [IBD]）. Competition for mates and inbreeding avoidance may result in equal dispersal propensity and subsequently similar spatial genetic autocorrelation between males and females of monogamous gerbils. We genotyped 327 gerbils, live captured from 26 burrow systems on a 9-ha plot in northcentral Inner Mongolia, China, using seven microsateliite loci. Spatial genetic autocorrelation was positive within 80 m and became negative from 80 m to 200 m, suggesting restricted gene flow. Inter-group genetic and geographic distances were related positively, supporting the IBD model. Live trapping data demonstrated equal dispersal propensities of male and female gerbils. Restricted dispersal and social organization may determine fine-scale spatial population genetic structure of social rodents.
基金supported by the National Natural Science Foundation of China(No.32330012 and 32270508)to DHW.
文摘Mongolian gerbils had high ability to endure both high and cold temperatures.To study the mechanism of high ability for thermal adaptation,gerbils were acclimated to high temperature(30°C)for 8 weeks,and were measured for metabolic fea-tures,body composition as well as mitochondrial content and activities.Lipidomic techniques were used to measure changes in mitochondrial membrane,including potential mitochondrial membrane remodeling during acute thermoregulation in gerbils.Heat acclimated gerbils showed lower basal metabolic rates but no changes in adaptive non-shivering thermogenesis were detected.A significant mitochondrial membrane remodeling with increases in monounsaturated/polyunsaturated free fatty acids ratios was associated with the decrease in metabolic rate.During heat acclimation,mitochondrial cytochrome C oxidase activity was elevated in brown adipose tissue,presumably caused by the increase in membrane unsaturation.Our results indicated that mitochondrial membrane remodeling is an important mechanism during heat acclimation in Mongo-lian gerbils,to reduce the metabolic rate in general while preserving sufficient capability to respond to acute cold.Such a mechanism may allow gerbils to cooperate with wide range of daily and seasonal temperature fluctuations.
基金supported by the Major Program of National Natural Science Foundation of China(32090023).
文摘Climatic factors are closely associated with the occurrence of vector‐borne diseases,and they also influence the distribution of vectors.The occurrence of plague is closely related to the population dynamics of fleas and their host animals,as well as climatic conditions.This study focused on Xilingol League,utilizing climatic and flea index data from 2012 to 2021.Spearman correlation and"Boruta"importance analysis were conducted to screen for climatic variables.A generalized additive model(GAM)was employed to investigate the influence of climatic factors and rodent density on the flea index.GAM analysis revealed distinct trends in flea index among different rodent hosts.For Meriones unguiculatus,the flea index declined with increased density and with higher humidity,yet rose with greater lagged sunshine duration.For Spermophilus dauricus,an initial increase in flea index with density was observed,followed by a decrease,and a rise in the index was noted when ground temperatures were low.This study reveals the nonlinear interactions and lag effects among climatic factors,density,and flea index.Climatic factors and density variably influence the flea index of two Yersinia pestis hosts.This research advances the prediction and early warning efforts for plague control,providing a theoretical basis for rodent and flea eradication strategies.
基金supported by the National Natural Science Foundation of China(No.31372211)to WLthe Chinese Academy of Sciences(KSCX2-EW-N-005)to DHW.
文摘Animals often interact non-randomly with conspecifics,and association preferences can differ across life-history stages to maximize individuals’fitness.Mongolian gerbils(Meriones unguiculatus)are a social rodent that live in highly seasonal habitats and display seasonal fluctuations in population density,growth rate and the size of overlapped home ranges.Nevertheless,whether gerbils modify their social relationships at different life-history stages remains unknown.Here,we used social network analysis to examine whether social associations differ between the sexes and between life-history stages in a wild population of Mongolian gerbils.We quantified social attributes at both group level(assortativity)and individual level(social differentiation and degree,closeness and betweenness centrality);these attributes reflect individuals’social preferences and their potential influence on others in the network.We found that both male and female gerbils established fewer inter-group social connections during the food-hoarding season than during the breeding season,revealing constraints on sociality.Similarly,during the food-hoarding season,degree centrality and social differentiation increased significantly whereas closeness and betweenness centrality decreased significantly.Together,these results suggest that gerbils have relatively more partners and preferred associations and decreased influence over others in the network during the food-hoarding season.In addition,we found no significant difference in any of the social attribute between males and females,but there was a significant interaction effect between sex and season on degree,closeness and betweenness centrality.Our results demonstrate that Mongolian gerbils adjust their association strategies to adapt to the changes of life history.Such adjustments may balance the costs/benefits associated with survival and reproduction.
基金supported by National Key Basic Research and Development Program of China(No.2007CB109105).
文摘Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China.The Mongolian gerbil(Meriones unguiculatus)is a dominant pest rodent which is distributed across the semi-desert grasslands of Inner Mongolia,China.In 2009,we studied the contraceptive effect of levonorgestrel-quinestrol(EP-1),concentration 50 ppm,on a wild Mongolian gerbil population.The one-off contraceptive treatment was compared with a control group using a semi-monthly live trapping method in the Ordos Semi-desert Grassland Region of Inner Mongolia.The results show that juveniles were not recruited in spring in the treatment group.Ratios of juveniles in the control and treatment groups showed significant semi-monthly differences from spring to summer(one-way ANOVA,F_(2,14)=7.53,P<0.05).Between both groups,annual fluctuations of juvenile and total population densities were significantly different respectively(F_(2,14)=4.64,P<0.05;F_(2,18)=7.72,P<0.05).The contraceptive EP-1 delayed the normal reproductive pattern of Mongolian gerbil populations.This suppressed birth rates of gerbil populations,reduced their densities,and changed their age structures.The period of EP-1 baiting should be extended but it could be an ideal method for controlling Mongolian gerbil populations during each breeding season.
