Amphioxus is the ancestor of vertebrates 5×108 a ago, it is a typical transitional sample of evolution from invertebrates to vertebrates. Inter simple sequence repeats (ISSRs) and random amplified polymorphic DNA...Amphioxus is the ancestor of vertebrates 5×108 a ago, it is a typical transitional sample of evolution from invertebrates to vertebrates. Inter simple sequence repeats (ISSRs) and random amplified polymorphic DNAs (RAPDs) technologies were applied to detect the genetic variation of 3 bulking samples and individually sampled populations in nowadays Xiamen sea areas (Xiekou, Nanxian and Huangcuo) where the amphioxuses are alive. For the bulking sampled populations, 5 ISSR and 10 RAPD primers generated 357 bands, of which 181 (50.7%) were polymorphic. Nei index and UPGMA statistical analysis indicated that amphioxuses in these 3 areas could be divided into 2 groups. The genetic distance between animals in Nanxian and Huangcuo areas was 0.07 and classified into 1 group, while the population in Xiekou belonged to another group because its genetic distances in Nanxian and Huangcuo were 0.12 and 0.14, respectively. The result was in accordance with the morphological comparison among animals from those areas. For individually sampled population, Shannon's index of genetic diversity was used to partition the diversity of the animals among these 3 sea areas, and the results showed that the indices in populations of Xiekou, Nanxian and Huangcuo, were 0.583, 0.482 and 0.374, respectively. The linear regression equation analysis for amphioxus' genetic diversity versus the environment factors revealed that granularity/sorting coefficient and water depth were the most important factors that affect amphioxus genetic diversity. On the basis of the results, the suggestions for amphioxus resource conservation in Xiamen sea areas are put forward.展开更多
Amphioxus has an important evolutionary position as a result of their phylogenetic position relative to vertebrates. Understanding their chromosomes would provide key points in the study of evolutionary biology and co...Amphioxus has an important evolutionary position as a result of their phylogenetic position relative to vertebrates. Understanding their chromosomes would provide key points in the study of evolutionary biology and comparative genomics. The difficulty in preparing amphioxus chromosomes currently provides a significant hurdle in this research. In the current study, we describe an improved method for metaphase preparation from amphioxus embryos and methodology for preparing metaphase spreads from regenerative somatic cells. Chromosomes of two amphioxus species from Xiamen waters in China are also observed. The diploid chromosome number was found to be 40 in Branchiostoma belcheri, while B. japonicum has 36, confirming the two are distinct species from cytotaxonomic viewpoint.展开更多
In this study, we isolated a polysaccharide from Branchiostoma belcheri （PBB） by enzymatic protein hydrolysis and alcohol precipitation. We investigated the effects of PBB supplementation on DNA oxidation and growth...In this study, we isolated a polysaccharide from Branchiostoma belcheri （PBB） by enzymatic protein hydrolysis and alcohol precipitation. We investigated the effects of PBB supplementation on DNA oxidation and growth of the transplanted tumor cells Sarcoma （S180） in mice. Sixty healthy Kunming mice weighing between 18 and 25 g were randomly assigned to 6 groups, each consisting of 10 animals. All the mice, except for the blank control group, were inoculated with S180 sarcoma cells into the axilla of the left foreleg. PBB was given to mice by gavage at doses of 0 （model control）, 25, 50, or 100 mg/kg b.w. in 0.2 ml saline for 30 days. The fifth group of S180-mice was given cytoxan （50 mg/kg） by peritoneal injection as a positive control group. The animals had free access to food and water. The mice were sacrificed after the final treatment and blood was quickly collected. Spontaneous and oxidized DNA damage of peripheral lymphocytes induced by H2O2 were analyzed by SCGE. O6-methyl-guanine （O6-MeG） was measured by high-performance capillary zone electrophoresis. The average tumor weights （0.856-1.118 g） of the three PBB groups were significantly lower than that of the model control group （1.836 g） （p〈0.05）. The tumor inhibition ratios of the PBB groups were 39.1%-53.4% and similar to the cytoxan positive group （57.5%）. There were no significant differences in spontaneous DNA damage in peripheral lymphocytes among the groups. The oxidative DNA damage induced by 10 μmol/L H2O2 in the 50 and 100 mg/kg b.w. groups were 246.1 AU and 221.7 AU, respectively, both of which were significantly lower than that in the model group （289.0 AU; p〈0.05）. The plasma concentrations of O6-MeG in the 25, 50, and 100 mg/kg supplemented groups were 2.09 μmol/L, 1.86 μmol/L, and 1.63 lamol/L, respectively, all of which were significantly lower than that of the model group （2.67 μmol/L; p〈0.05）. These results indicated that PBB may have antioxidative activity and thus reduce oxidation-in展开更多
GATA factors are evolutionarily conserved and play crucial roles during embryonic development in both vertebrates and invertebrates. Vertebrate GATAs can be divided into two subgroups, the GATAI/2/3 and the GATA4/5/6 ...GATA factors are evolutionarily conserved and play crucial roles during embryonic development in both vertebrates and invertebrates. Vertebrate GATAs can be divided into two subgroups, the GATAI/2/3 and the GATA4/5/6 classes. Through genomic analysis, we have identified three GATA factors, representing the GATA1/2/3 and GATA4/5/6 subfamilies respectively, and one GATA like protein in the genome of the basal chordate amphioxus （Branchiostoma floridae, cephalochordata）. Partial sequence of GATA123 in the amphioxus Branchiostoma belcheri （BbGATA123） was cloned and its expression pattern during early embryonic development was studied. Expression of BbGATA123 is first detected in the mesendoderm during gastrulation. Interestingly, in the late neurula and early larva stages, it is expressed strongly in the cerebral vesicle and the mid gut region. Its expression is compared to Otx, a gene known crucial for the development of anterior structures. Our observations suggest that GATA123, together with Otx, might play an important role in the development of amphioxus cerebral vesicle, the counterpart of the vertebrate brain.展开更多
脊椎动物活化的(蛋白)激酶C受体1(receptor for activated C-kinase1,RACK1)在胚胎发育过程中起着至关重要的作用.克隆了RACK1基因在青岛文昌鱼(Branchiostoma belcheri)中的同源基因AmphiRACK1,对其进行了系统的进化学分析,并研究了该...脊椎动物活化的(蛋白)激酶C受体1(receptor for activated C-kinase1,RACK1)在胚胎发育过程中起着至关重要的作用.克隆了RACK1基因在青岛文昌鱼(Branchiostoma belcheri)中的同源基因AmphiRACK1,对其进行了系统的进化学分析,并研究了该基因在正常胚胎发育过程中和经LiCl处理胚胎发育中的时空表达图式.系统进化学分析结果表明,文昌鱼RACK1位于脊椎动物进化枝的基部.在正常胚胎发育中,AmphiRACK1基因在脑泡、神经管和体节中都有明显的表达.在经LiCl处理的胚胎中,该基因在体节中的分节型表达变模糊,表达下调;在脑泡和神经管中的表达下调甚至消失.此外,在成体文昌鱼的轮器、鳃血管、肝盲囊和肠上皮以及精巢中都检测到AmphiRACK1基因不同程度的表达.展开更多
Objective: To determine the ability of oysters to trap and maintain viable Cryptosporidium oocysts, and the feasibility of Cryptosporidium multiplication in oysters’ organs. Methods: Seventy oysters were raised in ex...Objective: To determine the ability of oysters to trap and maintain viable Cryptosporidium oocysts, and the feasibility of Cryptosporidium multiplication in oysters’ organs. Methods: Seventy oysters were raised in experimentally seeded natural seawater for up to 3 months, with weekly oocysts inoculations. Cryptosporidium oocysts, viable and non-viable, as well as other stages were detected using two immunofluorescence vital staining techniques(SporoGlo and Merifluor~) with confocal microscopy. Viability rate at various times after inoculations were calculated. Results: Cryptosporidium oocysts were found most concentrated in oysters’ digestive organs than in gill and water inside the oysters. Oocysts numbers were 857.33 at 24 h after inoculation and strikingly decreased to 243.00 and 126.67 oocysts at 72 h and 7 days, respectively. The oocysts in oyster were also less viable over time; 70%, 60% and 30% viable at 24 hrs, 72 hrs and 7days after inoculation, respectively. At 77 days, the number of oocysts was very low and none was found at 84 days onwards. Although some oocysts were ruptured with released sporozoites, there was no evidence throughout the study of sporozoites multiplication to indicate that oyster is a biological host. Despite the significant reduction in oocysts number after 7 days of inoculation, the remained viable oocysts can still cause cryptosporidiosis. Conclusion: The findings confirm that Cryptosporidium parvum does not multiply in oyster, and is therefore not a biological host. Nevertheless, the results suggest that oyster can be an effective transmission vehicle for Cryptosporidium oocysts, especially within 24-72 h of contamination, with viable oocysts present at up to 7 days post infection. Unless consuming well-cooked oyster dishes, eating raw oyster remains a public health concern and at least 3 days of depuration in clean sea water prior to consumption is recommended.展开更多
Amphioxus, also called lancelet or cephalochordate, is a promising model organism owning to its particularly evolu- tionary position, simple genome content and comparable body plan to that of vertebrates （Holland et ...Amphioxus, also called lancelet or cephalochordate, is a promising model organism owning to its particularly evolu- tionary position, simple genome content and comparable body plan to that of vertebrates （Holland et aL, 2004; Bertrand and Escriva, 2011）. However, use of amphioxus as a model or- ganism has been limited for many years because of lack of an efficient genomic modification method. Recently, several revolutionary gene targeting methods that could induce directed mutations, insertions and deletions at intended target sites, have been developed （Gaj et al., 2013）.展开更多
A full length amphioxus cDNA, encoding a novel phosducin-like protein （Amphi-PhLP）, was identified for the first time from the gut cDNA library of Branchiostoma belcheri. It is comprised of 1 550 bp and an open read...A full length amphioxus cDNA, encoding a novel phosducin-like protein （Amphi-PhLP）, was identified for the first time from the gut cDNA library of Branchiostoma belcheri. It is comprised of 1 550 bp and an open reading frame （ORF） of 241 amino acids, with a predicted molecular mass of approximately 28 kDa. In situ hybridization histochemistry revealed a tissue-specific expression pattern of Amphi-PhLP with the high levels in the ovary, and at a lower level in the hind grit and testis, hepatic caecum, gill, endostyle, and epipbaryngeal groove, while it was absent in the muscle, neural tube and notochord. In the Chinese Hamster Ovary （CHO） cells transfected with the expression plasmid pEGFP-NI/Amphi-PhLP, the fusion protein was targeted in the cytoplasm of CHO cells, suggesting that Amphi-PhLP is a cytosolic protein. This work may provide a framework for further understanding of the physiological function of Amphi-PhLP in B. belcheri.展开更多
基金supported by the Science and Technology ofFujian Province under contract No.2001J033.
文摘Amphioxus is the ancestor of vertebrates 5×108 a ago, it is a typical transitional sample of evolution from invertebrates to vertebrates. Inter simple sequence repeats (ISSRs) and random amplified polymorphic DNAs (RAPDs) technologies were applied to detect the genetic variation of 3 bulking samples and individually sampled populations in nowadays Xiamen sea areas (Xiekou, Nanxian and Huangcuo) where the amphioxuses are alive. For the bulking sampled populations, 5 ISSR and 10 RAPD primers generated 357 bands, of which 181 (50.7%) were polymorphic. Nei index and UPGMA statistical analysis indicated that amphioxuses in these 3 areas could be divided into 2 groups. The genetic distance between animals in Nanxian and Huangcuo areas was 0.07 and classified into 1 group, while the population in Xiekou belonged to another group because its genetic distances in Nanxian and Huangcuo were 0.12 and 0.14, respectively. The result was in accordance with the morphological comparison among animals from those areas. For individually sampled population, Shannon's index of genetic diversity was used to partition the diversity of the animals among these 3 sea areas, and the results showed that the indices in populations of Xiekou, Nanxian and Huangcuo, were 0.583, 0.482 and 0.374, respectively. The linear regression equation analysis for amphioxus' genetic diversity versus the environment factors revealed that granularity/sorting coefficient and water depth were the most important factors that affect amphioxus genetic diversity. On the basis of the results, the suggestions for amphioxus resource conservation in Xiamen sea areas are put forward.
基金Supported by grants from NSFC (No.30570208)SRFDP of Ministry of Education, China (20070384041)The Education Department of Fujian Province, China (JB07063)
文摘Amphioxus has an important evolutionary position as a result of their phylogenetic position relative to vertebrates. Understanding their chromosomes would provide key points in the study of evolutionary biology and comparative genomics. The difficulty in preparing amphioxus chromosomes currently provides a significant hurdle in this research. In the current study, we describe an improved method for metaphase preparation from amphioxus embryos and methodology for preparing metaphase spreads from regenerative somatic cells. Chromosomes of two amphioxus species from Xiamen waters in China are also observed. The diploid chromosome number was found to be 40 in Branchiostoma belcheri, while B. japonicum has 36, confirming the two are distinct species from cytotaxonomic viewpoint.
文摘In this study, we isolated a polysaccharide from Branchiostoma belcheri （PBB） by enzymatic protein hydrolysis and alcohol precipitation. We investigated the effects of PBB supplementation on DNA oxidation and growth of the transplanted tumor cells Sarcoma （S180） in mice. Sixty healthy Kunming mice weighing between 18 and 25 g were randomly assigned to 6 groups, each consisting of 10 animals. All the mice, except for the blank control group, were inoculated with S180 sarcoma cells into the axilla of the left foreleg. PBB was given to mice by gavage at doses of 0 （model control）, 25, 50, or 100 mg/kg b.w. in 0.2 ml saline for 30 days. The fifth group of S180-mice was given cytoxan （50 mg/kg） by peritoneal injection as a positive control group. The animals had free access to food and water. The mice were sacrificed after the final treatment and blood was quickly collected. Spontaneous and oxidized DNA damage of peripheral lymphocytes induced by H2O2 were analyzed by SCGE. O6-methyl-guanine （O6-MeG） was measured by high-performance capillary zone electrophoresis. The average tumor weights （0.856-1.118 g） of the three PBB groups were significantly lower than that of the model control group （1.836 g） （p〈0.05）. The tumor inhibition ratios of the PBB groups were 39.1%-53.4% and similar to the cytoxan positive group （57.5%）. There were no significant differences in spontaneous DNA damage in peripheral lymphocytes among the groups. The oxidative DNA damage induced by 10 μmol/L H2O2 in the 50 and 100 mg/kg b.w. groups were 246.1 AU and 221.7 AU, respectively, both of which were significantly lower than that in the model group （289.0 AU; p〈0.05）. The plasma concentrations of O6-MeG in the 25, 50, and 100 mg/kg supplemented groups were 2.09 μmol/L, 1.86 μmol/L, and 1.63 lamol/L, respectively, all of which were significantly lower than that of the model group （2.67 μmol/L; p〈0.05）. These results indicated that PBB may have antioxidative activity and thus reduce oxidation-in
基金Supported by grants from the National Natural Science Foundation of China (30425011 30530380)~~
文摘GATA factors are evolutionarily conserved and play crucial roles during embryonic development in both vertebrates and invertebrates. Vertebrate GATAs can be divided into two subgroups, the GATAI/2/3 and the GATA4/5/6 classes. Through genomic analysis, we have identified three GATA factors, representing the GATA1/2/3 and GATA4/5/6 subfamilies respectively, and one GATA like protein in the genome of the basal chordate amphioxus （Branchiostoma floridae, cephalochordata）. Partial sequence of GATA123 in the amphioxus Branchiostoma belcheri （BbGATA123） was cloned and its expression pattern during early embryonic development was studied. Expression of BbGATA123 is first detected in the mesendoderm during gastrulation. Interestingly, in the late neurula and early larva stages, it is expressed strongly in the cerebral vesicle and the mid gut region. Its expression is compared to Otx, a gene known crucial for the development of anterior structures. Our observations suggest that GATA123, together with Otx, might play an important role in the development of amphioxus cerebral vesicle, the counterpart of the vertebrate brain.
文摘脊椎动物活化的(蛋白)激酶C受体1(receptor for activated C-kinase1,RACK1)在胚胎发育过程中起着至关重要的作用.克隆了RACK1基因在青岛文昌鱼(Branchiostoma belcheri)中的同源基因AmphiRACK1,对其进行了系统的进化学分析,并研究了该基因在正常胚胎发育过程中和经LiCl处理胚胎发育中的时空表达图式.系统进化学分析结果表明,文昌鱼RACK1位于脊椎动物进化枝的基部.在正常胚胎发育中,AmphiRACK1基因在脑泡、神经管和体节中都有明显的表达.在经LiCl处理的胚胎中,该基因在体节中的分节型表达变模糊,表达下调;在脑泡和神经管中的表达下调甚至消失.此外,在成体文昌鱼的轮器、鳃血管、肝盲囊和肠上皮以及精巢中都检测到AmphiRACK1基因不同程度的表达.
基金partially funded by Research Assistantships 2012,Mahidol University
文摘Objective: To determine the ability of oysters to trap and maintain viable Cryptosporidium oocysts, and the feasibility of Cryptosporidium multiplication in oysters’ organs. Methods: Seventy oysters were raised in experimentally seeded natural seawater for up to 3 months, with weekly oocysts inoculations. Cryptosporidium oocysts, viable and non-viable, as well as other stages were detected using two immunofluorescence vital staining techniques(SporoGlo and Merifluor~) with confocal microscopy. Viability rate at various times after inoculations were calculated. Results: Cryptosporidium oocysts were found most concentrated in oysters’ digestive organs than in gill and water inside the oysters. Oocysts numbers were 857.33 at 24 h after inoculation and strikingly decreased to 243.00 and 126.67 oocysts at 72 h and 7 days, respectively. The oocysts in oyster were also less viable over time; 70%, 60% and 30% viable at 24 hrs, 72 hrs and 7days after inoculation, respectively. At 77 days, the number of oocysts was very low and none was found at 84 days onwards. Although some oocysts were ruptured with released sporozoites, there was no evidence throughout the study of sporozoites multiplication to indicate that oyster is a biological host. Despite the significant reduction in oocysts number after 7 days of inoculation, the remained viable oocysts can still cause cryptosporidiosis. Conclusion: The findings confirm that Cryptosporidium parvum does not multiply in oyster, and is therefore not a biological host. Nevertheless, the results suggest that oyster can be an effective transmission vehicle for Cryptosporidium oocysts, especially within 24-72 h of contamination, with viable oocysts present at up to 7 days post infection. Unless consuming well-cooked oyster dishes, eating raw oyster remains a public health concern and at least 3 days of depuration in clean sea water prior to consumption is recommended.
基金supported by the National Natural Science Foundation of China (Nos.31071110,30830023 and 31101631)the Scientific and Technical Innovation Committee of Shenzhen,China (No.CXZZ20120614164555920)
文摘Amphioxus, also called lancelet or cephalochordate, is a promising model organism owning to its particularly evolu- tionary position, simple genome content and comparable body plan to that of vertebrates （Holland et aL, 2004; Bertrand and Escriva, 2011）. However, use of amphioxus as a model or- ganism has been limited for many years because of lack of an efficient genomic modification method. Recently, several revolutionary gene targeting methods that could induce directed mutations, insertions and deletions at intended target sites, have been developed （Gaj et al., 2013）.
基金Supported by the Pilot Projects of Knowledge Innovation Project of Chinese Academy of Sciences (No. KZCX2-YW-211-03 and MGE2008KG06)
文摘A full length amphioxus cDNA, encoding a novel phosducin-like protein （Amphi-PhLP）, was identified for the first time from the gut cDNA library of Branchiostoma belcheri. It is comprised of 1 550 bp and an open reading frame （ORF） of 241 amino acids, with a predicted molecular mass of approximately 28 kDa. In situ hybridization histochemistry revealed a tissue-specific expression pattern of Amphi-PhLP with the high levels in the ovary, and at a lower level in the hind grit and testis, hepatic caecum, gill, endostyle, and epipbaryngeal groove, while it was absent in the muscle, neural tube and notochord. In the Chinese Hamster Ovary （CHO） cells transfected with the expression plasmid pEGFP-NI/Amphi-PhLP, the fusion protein was targeted in the cytoplasm of CHO cells, suggesting that Amphi-PhLP is a cytosolic protein. This work may provide a framework for further understanding of the physiological function of Amphi-PhLP in B. belcheri.
