The growth of coarse grains of diamond was observed with graphite as carbon source and Fe80Ni20 alloy powder as catalyst at HPHT in a China-type SPD 6×1670T cubic high-pressure apparatus with highly exact control...The growth of coarse grains of diamond was observed with graphite as carbon source and Fe80Ni20 alloy powder as catalyst at HPHT in a China-type SPD 6×1670T cubic high-pressure apparatus with highly exact control system. To synthesize coarse grains of diamond crystal with high quality,ad-vanced indirect heat assembly,powder catalyst technology and catalyst with optimal granularity were used. Especially the nucleation of diamond and the growth rate were strictly controlled by the opti-mized synthesis craft. At last,diamond crystals (about 0.85 mm) in the perfect hex-octahedron shape were successfully synthesized at ～5.4 GPa and ～1360℃ in 60 min. The characteristic of crystal growth with powder catalyst technology under HPHT was discussed. The results and techniques might be useful for production of coarse grains of diamond.展开更多
Chemical communication plays an important role in kin selection and mate choice in mammals. The covariance of odor-genes of rodents has been documented and kinship odor has been proposed and termed, yet little is know...Chemical communication plays an important role in kin selection and mate choice in mammals. The covariance of odor-genes of rodents has been documented and kinship odor has been proposed and termed, yet little is known of the relationship between genetic relatedness and chemical composition of kinship odors. Giant pandas (Ailuropoda melanoleuca) rely substantially on chemical communication to mediate their social interactions. To examine the relationship between genetic relatedness and compounds in the urine/anogenital gland secretions, we compared the similarities between genetic relatedness and the chemical profiles of anogenital gland secretions and urine via lineage construction and GC-MS (gas chromatography and mass spectrometry). We found that information about kinship odors was present only in the urine of male adults in the mating season but absent in the non-mating season. Adult females and all sub-adults did not have such kinship odors in either mating or non-mating season. Therefore, kinship odor in the panda was contingent on age, sex, and season. This is the first report about the condition-dependent expression of kinship odor, which may have a sig- nificant implication in the practice of panda conservation in relation to chemical communication and sexual selection.展开更多
Captive populations provide a precious genetic resource for endangered animals and a source of individuals for reintroduction to depleted habitats. Therefore, accuracy in determining paternity is of vital importance f...Captive populations provide a precious genetic resource for endangered animals and a source of individuals for reintroduction to depleted habitats. Therefore, accuracy in determining paternity is of vital importance for managing captive populations and in selecting representative individuals of known genetic characteristics for release. In this study, we established a fast and effective method to conduct paternity testing for captive giant pandas in the Wolong population. This technique uses two highly polymor phic microsatellites initially, subsequent use of five less polymorphic markers and then paternity exclusion testing carried out using the giant panda paternity exclusion program we have developed. Our results revealed that (1) both sets of markers success- fully identified the real fathers in 25 cases of paternity testing and (2) the success rate of paternity exclusion varied with the degree of polymorphism of the markers used. Subsequently, we conducted correlation analysis between the success rates of paterni- ty identification with these markers, parameters of genetic diversity and tests of neutrality. We found that the paternity exclusion power of microsatellites was significantly correlated with the number of alleles (Na), expected heterozygosity (HE) and observed homozygosity statistic (FO) (all P < 0.05). From this, we developed a new variable, Na?HE/FO, showing a highly significant positive correlation with the resolution power of microsatellites (P = 0.001). Moreover, the first two highly polymorphic loci gave a 100% success rate of excluding non-paternal males because they yielded higher values of Na?HE/FO than the other five less pol- ymorphic markers. Thus, the Na?HE/FO parameter appears suitable to serve as a criterion for selecting microsatellite markers, which could be used for high-resolution molecular techniques of paternity determination among a range of captive animals besides giant pandas.展开更多
Interspecies somatic nuclear transfer (NT) may provide a new approach for preservation of the endangered rare species. Previous interspecies cloning studies have shown that a nucleus from a quiescent somatic cell supp...Interspecies somatic nuclear transfer (NT) may provide a new approach for preservation of the endangered rare species. Previous interspecies cloning studies have shown that a nucleus from a quiescent somatic cell supports early development of reconstructed embryos in the ooplasm from another species. In this study, we transferred nonqui-escent somatic cells from a giant panda into the perivitelline space of the enucleated rabbit oocytes. After electrofusion (at the rate of 71.6%) and electrical activation, 4.2% of the panda-rabbit reconstructed embryos developed to blastocyst in vitro. For improving the development rate of reconstructed embryos, we used serial NT in this study, i.e. blas-tomeres from reconstructed morulae were transferred into the perivitelline space of the enucleated rabbit oocytes. The fusion rates in the groups of serial I, serial Ⅱ and serial Ⅲ were 79.5%, 84.1% and 78.0%, respectively, having no difference with that of somatic group. And the blastocyst rates in serial NT groups展开更多
基金Supported by the National Natural Science Foundation of China (Grant No.50572032)
文摘The growth of coarse grains of diamond was observed with graphite as carbon source and Fe80Ni20 alloy powder as catalyst at HPHT in a China-type SPD 6×1670T cubic high-pressure apparatus with highly exact control system. To synthesize coarse grains of diamond crystal with high quality,ad-vanced indirect heat assembly,powder catalyst technology and catalyst with optimal granularity were used. Especially the nucleation of diamond and the growth rate were strictly controlled by the opti-mized synthesis craft. At last,diamond crystals (about 0.85 mm) in the perfect hex-octahedron shape were successfully synthesized at ～5.4 GPa and ～1360℃ in 60 min. The characteristic of crystal growth with powder catalyst technology under HPHT was discussed. The results and techniques might be useful for production of coarse grains of diamond.
基金the National Natural Science Foundation of China (Grant Nos. 30470233, 30170169 and 30230080)Research Fund for the Doctoral Program of Higher Education (Grant No. 98002717)China Wildlife Conservation Associa-tion (Grant Nos. 96035 and WH0309)
文摘Chemical communication plays an important role in kin selection and mate choice in mammals. The covariance of odor-genes of rodents has been documented and kinship odor has been proposed and termed, yet little is known of the relationship between genetic relatedness and chemical composition of kinship odors. Giant pandas (Ailuropoda melanoleuca) rely substantially on chemical communication to mediate their social interactions. To examine the relationship between genetic relatedness and compounds in the urine/anogenital gland secretions, we compared the similarities between genetic relatedness and the chemical profiles of anogenital gland secretions and urine via lineage construction and GC-MS (gas chromatography and mass spectrometry). We found that information about kinship odors was present only in the urine of male adults in the mating season but absent in the non-mating season. Adult females and all sub-adults did not have such kinship odors in either mating or non-mating season. Therefore, kinship odor in the panda was contingent on age, sex, and season. This is the first report about the condition-dependent expression of kinship odor, which may have a sig- nificant implication in the practice of panda conservation in relation to chemical communication and sexual selection.
基金supported by the National Basic Research Program of China (2007CB411600)a special grant from the State Forestry Administration of China (2130206)the Fundamen-tal Research Funds for the Central Universities of China
文摘Captive populations provide a precious genetic resource for endangered animals and a source of individuals for reintroduction to depleted habitats. Therefore, accuracy in determining paternity is of vital importance for managing captive populations and in selecting representative individuals of known genetic characteristics for release. In this study, we established a fast and effective method to conduct paternity testing for captive giant pandas in the Wolong population. This technique uses two highly polymor phic microsatellites initially, subsequent use of five less polymorphic markers and then paternity exclusion testing carried out using the giant panda paternity exclusion program we have developed. Our results revealed that (1) both sets of markers success- fully identified the real fathers in 25 cases of paternity testing and (2) the success rate of paternity exclusion varied with the degree of polymorphism of the markers used. Subsequently, we conducted correlation analysis between the success rates of paterni- ty identification with these markers, parameters of genetic diversity and tests of neutrality. We found that the paternity exclusion power of microsatellites was significantly correlated with the number of alleles (Na), expected heterozygosity (HE) and observed homozygosity statistic (FO) (all P < 0.05). From this, we developed a new variable, Na?HE/FO, showing a highly significant positive correlation with the resolution power of microsatellites (P = 0.001). Moreover, the first two highly polymorphic loci gave a 100% success rate of excluding non-paternal males because they yielded higher values of Na?HE/FO than the other five less pol- ymorphic markers. Thus, the Na?HE/FO parameter appears suitable to serve as a criterion for selecting microsatellite markers, which could be used for high-resolution molecular techniques of paternity determination among a range of captive animals besides giant pandas.
基金This work was supported by the Climbing Project of the Ministry of Sciences and Technology of China (Grant No.97021109-2)the Important Project of Knowledge Innovation of Chinese Academy of Sciences (Grant No. KSCX1-05-01).
文摘Interspecies somatic nuclear transfer (NT) may provide a new approach for preservation of the endangered rare species. Previous interspecies cloning studies have shown that a nucleus from a quiescent somatic cell supports early development of reconstructed embryos in the ooplasm from another species. In this study, we transferred nonqui-escent somatic cells from a giant panda into the perivitelline space of the enucleated rabbit oocytes. After electrofusion (at the rate of 71.6%) and electrical activation, 4.2% of the panda-rabbit reconstructed embryos developed to blastocyst in vitro. For improving the development rate of reconstructed embryos, we used serial NT in this study, i.e. blas-tomeres from reconstructed morulae were transferred into the perivitelline space of the enucleated rabbit oocytes. The fusion rates in the groups of serial I, serial Ⅱ and serial Ⅲ were 79.5%, 84.1% and 78.0%, respectively, having no difference with that of somatic group. And the blastocyst rates in serial NT groups
