In order to evaluate the toxicity of the bisphenol A (BPA) on the growth of zebrafish embryos, fertilized eggs were exposed to the concentration of 2.00, 4.00, 6.00, 8.00, 10.00, 15.00, 18.00, 22.00 and 25.00mg/L BPA ...In order to evaluate the toxicity of the bisphenol A (BPA) on the growth of zebrafish embryos, fertilized eggs were exposed to the concentration of 2.00, 4.00, 6.00, 8.00, 10.00, 15.00, 18.00, 22.00 and 25.00mg/L BPA for 72 h at 26±1℃. The results revealed that the sublethal toxicological endpoints induced by BPA were:delayed hatch> blood balk >cyst>altered axial curvature and tail malformation. The median embryo lethal concentration (LC50) after 24 h was 16.36 mg/L. We concluded that the BPA toxicity on zebrafish embryos were caused before 8h exposure and it was not the result of long-term accumulation. Therefore, BPA maybe cause altered gene expression at the early stage of zebrafish embryos. In the further studies, we will use the technology of genetic chips to look for the toxic mechanism of BPA.展开更多
A series of experiments were conducted to study the major procedures in nuclear transplantation such as oocyte enucleation and activation, electrofusion and developnent of the nuclear transplant embryos in the mouse, ...A series of experiments were conducted to study the major procedures in nuclear transplantation such as oocyte enucleation and activation, electrofusion and developnent of the nuclear transplant embryos in the mouse, rabbits and sheep. The important results are as follows:11. In the mouse, only 35% of the oocytes collected 15～16 h after hCG had a notable first polar body (FPb) and those without FPb were enucleated by removing cytoplasm from the PVS-wider side and the enucleation rate was similar to that in the oocytes with FPb, and the enucleation rate of removing 1/3 cytoplasm was remarkably higher than that of removing 1/4 cytoplasm. 2. Among the three fusion media tested, mannitol and sucrose solutions produced better results than M2 in electrofusion of mouse 2-cell embryos. Under favorable pulse conditions, the osmotic pressure of fusion medium had no motable effect on electrofusion, but as the conditions became so unfavorable that some embryos began to lyse, the fusion rates in hypertonie mannitol solution were significantly higher than those in isotonic or hypotonic solutions. A wide range of pulse strengths (0.31～2.04 by/ cm) and durations(10～1280 μs) were used and 100% of fusion were obtained in many cases. Optimal pulse durations were plotted for field strengths to obtain high fusion rates (96%～ 100%) in mouse2-cell embryos. 3. With one pulse of 0.45 by / cm, satisfactory results of mouse oocyte activation were obtained only when the duration increased to 160 μs or longer. The activation rate increased as the oocytes got older. Some of the oocytes ar. rested at metaphase Ⅲ after electrical stimulation and their proportion to the number of oocytes not activated increased with egg age. 4. 10% and 31% of the nuclear transplant embryos developed to morula or blastocyst stage in sheep and rabbits, respectively, with Chinese-made hormones and chemicals.展开更多
Factors affecting the in vitro germination and growth of Taxus cuspidata embryos were examined. DCR medium was the best among 6 basal media tested; embryos from stage II seeds were the optimal developmental stage for ...Factors affecting the in vitro germination and growth of Taxus cuspidata embryos were examined. DCR medium was the best among 6 basal media tested; embryos from stage II seeds were the optimal developmental stage for in vitro germination; as the seeds approached maturity, germinability of embryos decrease. Embryos cultured in darkness tended to form callus and decrease the frequency of germination; inoculation method obviously affected frequency of embryo germination. Embryos cultured in optimal conditions developed into seedlings in 2 months.展开更多
利用幼畜胚胎体外生产与胚胎移植(Juvenile in vitro embryo transfer,JIVET)技术能够获得大量卵母细胞,缩短世代间隔,加快育种进程。但幼畜卵母细胞形态及代谢与成年动物存在差异,这导致幼畜胚胎发育能力低。目前,对JIVET技术的研究主...利用幼畜胚胎体外生产与胚胎移植(Juvenile in vitro embryo transfer,JIVET)技术能够获得大量卵母细胞,缩短世代间隔,加快育种进程。但幼畜卵母细胞形态及代谢与成年动物存在差异,这导致幼畜胚胎发育能力低。目前,对JIVET技术的研究主要是通过改进激素处理方案及体外培养条件来增加卵母细胞数量并增强卵母细胞发育能力。从供体羔羊的选择、激素处理和卵母细胞的发育等方面对该技术进行了分析。展开更多
Abstract： Somatic embryogenesis from lily bulb scales has not been studied in details, although tissue culture methods have been applied to the propagation for decades. The effects of different kinds and concentratio...Abstract： Somatic embryogenesis from lily bulb scales has not been studied in details, although tissue culture methods have been applied to the propagation for decades. The effects of different kinds and concentration of auxins for oriental lily somatic embryogenesis were investigated （Lilium hybrida var. Sorbonne）. 2, 4-dichlorophenoxyacetic acid （2, 4-D）, thidiazuron （TDZ） and α-naphthaleneacetic acid （NAA） media with benzyladenine（6-BA） and lactalbumin hydrolysate （LH） were used for embryogenic callus in the darkness. The best response on embryogenic callus formation was obtained on MS media supplemented 2, 4-D 2.0 mg·L^-1, 6-BA 0.5 mg·L^-1 and LH 300 mg·L^-1. Transfer embryogenic callus to the media with TDZ, 6-BA, kinetin （KT） supplemented 2, 4-D. The highest number of somatic embryos has been produced on medium with 0.5 mg·L^-1 2, 4-D and 0.3 mg·L^-1 KT. Germinated embryos with shoot axes were changed to MS media with 6-BA 0.5 mg·L^-1. The results suggest that in vitro culture of somatic embryogenesis from lily bulb scales can be used for plant regeneration.展开更多
Effects of five incubation temperatures (25℃ ,28℃ ,31℃ ,35℃ and 37℃ for 24hours) and four incubation time periods (0.4,16 and 24 hours at 35℃) on isolated microspore culture of Chinese cabbage were studied. The ...Effects of five incubation temperatures (25℃ ,28℃ ,31℃ ,35℃ and 37℃ for 24hours) and four incubation time periods (0.4,16 and 24 hours at 35℃) on isolated microspore culture of Chinese cabbage were studied. The results showed that cultured microspores of Chinese cabbage developed into embryos at all the incubation temperatues from 28℃ to 37℃ ,but the best response to high temperature occured at 35℃. Among the four kinds of time periods, the highest yield of embryos was obtained at the 24h treatment. Therefore, the isolated microspore culture of Chinese cabbege ran be efficiently carried out at 35℃ for 24 hours.展开更多
The embryo structure of two apomictir lines 296B and SSA-1 has been com-pared in present paper. The apomictic embryo has the same character of lacking (or short) sus-pensor in sorghum,otherwise,the sexual embryo has a...The embryo structure of two apomictir lines 296B and SSA-1 has been com-pared in present paper. The apomictic embryo has the same character of lacking (or short) sus-pensor in sorghum,otherwise,the sexual embryo has a long suspensor in the same species. This character as an index of judgement on apomxis was discussed. The same of unsexual embryos in the lack of suspensor suggested that there were some relationships between non-zagotic embryos.展开更多
Most of model cotton varieties used in tissue culture have glands on both the reproductive and vegetative parts of the plant.These glands contain compounds that are toxic to human and non-ruminant animals.The presence...Most of model cotton varieties used in tissue culture have glands on both the reproductive and vegetative parts of the plant.These glands contain compounds that are toxic to human and non-ruminant animals.The presence of these compounds limits their usage as food and feed.To obtain a glandless cotton variety with high-frequency somatic embryo production ability,27 glandless varieties展开更多
Understanding the mechanism of gastrulation-the early phase in embryonic development where the blastula loses its symmetry and forms organized germ layers（i.e.endoderm,mesoderm,and ectoderm）-has long been a major ch...Understanding the mechanism of gastrulation-the early phase in embryonic development where the blastula loses its symmetry and forms organized germ layers（i.e.endoderm,mesoderm,and ectoderm）-has long been a major challenge to the field of developmental biology.A long standing objective in developmental biology is not only to direct the differentiation of ESCs into specific developmental lineages,but also to organize these differentiated lineages into spatially distinct arrangements resembling the physiological gastrulation.In vivo,research on embryo morphogenesis in lower animals has demonstrated the importance of mechanical forces<sup>[1-3]</sup>.In vitro,experiments of self-sorting utilize pairwise sorting assays where two types of differentiated germ cells are homogeneously mixed<sup>[4]</sup>.It has not been possible to study the or-展开更多
To investigate the expression of Prominin-1(Prom-1)in mouse uterus during peri-implantation.In situ hybridization and immunohistochemical staining were used to detect the mRNA and protein expression level of Prom-1 in...To investigate the expression of Prominin-1(Prom-1)in mouse uterus during peri-implantation.In situ hybridization and immunohistochemical staining were used to detect the mRNA and protein expression level of Prom-1 in mice uterus in early pregnancy,pseudopregnancy,estrous cycle,treated with hormone,delayed implantation and activation models.The results showed that Prom-1 was gradually weakened in uterine luminal epithelium(LE)and glandular epithelium(GE)during days 1-4 of pregnancy.During days 5-8,Prom-1 was strongly expressed in GE,and signal of Prom-1 protein was detected in matrix and decidua around the embryo.Similar to pregnancy,Prom-1 was strongly expressed in LE and GE on the 1st day and weakly expressed on the 4th day of pseudopregnancy.In addition,Prom-1 was highly expressed in LE and GE on estrus.Expression of Prom-1 was observed in the LE and the GE of delayed-implantation uterus.In activated-implantation animal model,Prom-1 was strongly expressed in the GE.In the hormone-treated model,Prom-1 expression levels were higher in the uterus of the 17β-estradiol-treated group than those in the control group.These results indicated that Prom-1 might promote the proliferation of mouse endometrial epithelium and participate in the establishment of uterine receptivity.Meanwhile,the expression of Prom-1 was up-regulated by the 17β-estradiol,indicating that Prom-1 might involve in the process of decidua development regulated by uterine glands,and Prom-1 might play an important role in mice early pregnancy.展开更多
文摘In order to evaluate the toxicity of the bisphenol A (BPA) on the growth of zebrafish embryos, fertilized eggs were exposed to the concentration of 2.00, 4.00, 6.00, 8.00, 10.00, 15.00, 18.00, 22.00 and 25.00mg/L BPA for 72 h at 26±1℃. The results revealed that the sublethal toxicological endpoints induced by BPA were:delayed hatch> blood balk >cyst>altered axial curvature and tail malformation. The median embryo lethal concentration (LC50) after 24 h was 16.36 mg/L. We concluded that the BPA toxicity on zebrafish embryos were caused before 8h exposure and it was not the result of long-term accumulation. Therefore, BPA maybe cause altered gene expression at the early stage of zebrafish embryos. In the further studies, we will use the technology of genetic chips to look for the toxic mechanism of BPA.
文摘A series of experiments were conducted to study the major procedures in nuclear transplantation such as oocyte enucleation and activation, electrofusion and developnent of the nuclear transplant embryos in the mouse, rabbits and sheep. The important results are as follows:11. In the mouse, only 35% of the oocytes collected 15～16 h after hCG had a notable first polar body (FPb) and those without FPb were enucleated by removing cytoplasm from the PVS-wider side and the enucleation rate was similar to that in the oocytes with FPb, and the enucleation rate of removing 1/3 cytoplasm was remarkably higher than that of removing 1/4 cytoplasm. 2. Among the three fusion media tested, mannitol and sucrose solutions produced better results than M2 in electrofusion of mouse 2-cell embryos. Under favorable pulse conditions, the osmotic pressure of fusion medium had no motable effect on electrofusion, but as the conditions became so unfavorable that some embryos began to lyse, the fusion rates in hypertonie mannitol solution were significantly higher than those in isotonic or hypotonic solutions. A wide range of pulse strengths (0.31～2.04 by/ cm) and durations(10～1280 μs) were used and 100% of fusion were obtained in many cases. Optimal pulse durations were plotted for field strengths to obtain high fusion rates (96%～ 100%) in mouse2-cell embryos. 3. With one pulse of 0.45 by / cm, satisfactory results of mouse oocyte activation were obtained only when the duration increased to 160 μs or longer. The activation rate increased as the oocytes got older. Some of the oocytes ar. rested at metaphase Ⅲ after electrical stimulation and their proportion to the number of oocytes not activated increased with egg age. 4. 10% and 31% of the nuclear transplant embryos developed to morula or blastocyst stage in sheep and rabbits, respectively, with Chinese-made hormones and chemicals.
文摘Factors affecting the in vitro germination and growth of Taxus cuspidata embryos were examined. DCR medium was the best among 6 basal media tested; embryos from stage II seeds were the optimal developmental stage for in vitro germination; as the seeds approached maturity, germinability of embryos decrease. Embryos cultured in darkness tended to form callus and decrease the frequency of germination; inoculation method obviously affected frequency of embryo germination. Embryos cultured in optimal conditions developed into seedlings in 2 months.
文摘利用幼畜胚胎体外生产与胚胎移植(Juvenile in vitro embryo transfer,JIVET)技术能够获得大量卵母细胞,缩短世代间隔,加快育种进程。但幼畜卵母细胞形态及代谢与成年动物存在差异,这导致幼畜胚胎发育能力低。目前,对JIVET技术的研究主要是通过改进激素处理方案及体外培养条件来增加卵母细胞数量并增强卵母细胞发育能力。从供体羔羊的选择、激素处理和卵母细胞的发育等方面对该技术进行了分析。
文摘Abstract： Somatic embryogenesis from lily bulb scales has not been studied in details, although tissue culture methods have been applied to the propagation for decades. The effects of different kinds and concentration of auxins for oriental lily somatic embryogenesis were investigated （Lilium hybrida var. Sorbonne）. 2, 4-dichlorophenoxyacetic acid （2, 4-D）, thidiazuron （TDZ） and α-naphthaleneacetic acid （NAA） media with benzyladenine（6-BA） and lactalbumin hydrolysate （LH） were used for embryogenic callus in the darkness. The best response on embryogenic callus formation was obtained on MS media supplemented 2, 4-D 2.0 mg·L^-1, 6-BA 0.5 mg·L^-1 and LH 300 mg·L^-1. Transfer embryogenic callus to the media with TDZ, 6-BA, kinetin （KT） supplemented 2, 4-D. The highest number of somatic embryos has been produced on medium with 0.5 mg·L^-1 2, 4-D and 0.3 mg·L^-1 KT. Germinated embryos with shoot axes were changed to MS media with 6-BA 0.5 mg·L^-1. The results suggest that in vitro culture of somatic embryogenesis from lily bulb scales can be used for plant regeneration.
文摘Effects of five incubation temperatures (25℃ ,28℃ ,31℃ ,35℃ and 37℃ for 24hours) and four incubation time periods (0.4,16 and 24 hours at 35℃) on isolated microspore culture of Chinese cabbage were studied. The results showed that cultured microspores of Chinese cabbage developed into embryos at all the incubation temperatues from 28℃ to 37℃ ,but the best response to high temperature occured at 35℃. Among the four kinds of time periods, the highest yield of embryos was obtained at the 24h treatment. Therefore, the isolated microspore culture of Chinese cabbege ran be efficiently carried out at 35℃ for 24 hours.
文摘The embryo structure of two apomictir lines 296B and SSA-1 has been com-pared in present paper. The apomictic embryo has the same character of lacking (or short) sus-pensor in sorghum,otherwise,the sexual embryo has a long suspensor in the same species. This character as an index of judgement on apomxis was discussed. The same of unsexual embryos in the lack of suspensor suggested that there were some relationships between non-zagotic embryos.
文摘Most of model cotton varieties used in tissue culture have glands on both the reproductive and vegetative parts of the plant.These glands contain compounds that are toxic to human and non-ruminant animals.The presence of these compounds limits their usage as food and feed.To obtain a glandless cotton variety with high-frequency somatic embryo production ability,27 glandless varieties
基金supported by the funds from Huazhong University of Science and TechnologyUS NIH grant GM072744
文摘Understanding the mechanism of gastrulation-the early phase in embryonic development where the blastula loses its symmetry and forms organized germ layers（i.e.endoderm,mesoderm,and ectoderm）-has long been a major challenge to the field of developmental biology.A long standing objective in developmental biology is not only to direct the differentiation of ESCs into specific developmental lineages,but also to organize these differentiated lineages into spatially distinct arrangements resembling the physiological gastrulation.In vivo,research on embryo morphogenesis in lower animals has demonstrated the importance of mechanical forces<sup>[1-3]</sup>.In vitro,experiments of self-sorting utilize pairwise sorting assays where two types of differentiated germ cells are homogeneously mixed<sup>[4]</sup>.It has not been possible to study the or-
基金Supported by the National Natural Science Foundation of China(31472097)
文摘To investigate the expression of Prominin-1(Prom-1)in mouse uterus during peri-implantation.In situ hybridization and immunohistochemical staining were used to detect the mRNA and protein expression level of Prom-1 in mice uterus in early pregnancy,pseudopregnancy,estrous cycle,treated with hormone,delayed implantation and activation models.The results showed that Prom-1 was gradually weakened in uterine luminal epithelium(LE)and glandular epithelium(GE)during days 1-4 of pregnancy.During days 5-8,Prom-1 was strongly expressed in GE,and signal of Prom-1 protein was detected in matrix and decidua around the embryo.Similar to pregnancy,Prom-1 was strongly expressed in LE and GE on the 1st day and weakly expressed on the 4th day of pseudopregnancy.In addition,Prom-1 was highly expressed in LE and GE on estrus.Expression of Prom-1 was observed in the LE and the GE of delayed-implantation uterus.In activated-implantation animal model,Prom-1 was strongly expressed in the GE.In the hormone-treated model,Prom-1 expression levels were higher in the uterus of the 17β-estradiol-treated group than those in the control group.These results indicated that Prom-1 might promote the proliferation of mouse endometrial epithelium and participate in the establishment of uterine receptivity.Meanwhile,the expression of Prom-1 was up-regulated by the 17β-estradiol,indicating that Prom-1 might involve in the process of decidua development regulated by uterine glands,and Prom-1 might play an important role in mice early pregnancy.
