Chinese shrimp(Fenneropenaeus chinensis)is an economically important aquaculture species in China.However,cytogenetic and genomic data is limited in the organism partly because the chromosomes are difficult to isolate...Chinese shrimp(Fenneropenaeus chinensis)is an economically important aquaculture species in China.However,cytogenetic and genomic data is limited in the organism partly because the chromosomes are difficult to isolate and analyze.In this study,fluorescence in-situ hybridization(FISH) was used to identify the chromosomes of F.chinensis.The 5S ribosomal RNA gene(rDNA)of F. chinensis was isolated,cloned and then used as a hybridization probe.The results show that the 5S rDNA was located on one pair of homologous chromosomes in F.chinensis.In addition,triploid shrimp were used to evaluate the feasibility of chromosome identification using FISH and to validate the method.It was confirmed that 5S rDNA can be used as a chromosome-specific probe for chromosome identification in F.chinensis.The successful application of FISH in F.chinensis shows that chromosome-specific probes can be developed and this finding will facilitate further research on the chromosomes of penaeid shrimps.展开更多
W952684 杂种小麦:现代杂种的表现和生产[会,英]/Wilson,P.//Wheat Breeding-into the secondcentury.Proceedings of The Seventh AssemblyWheat Breeding Society of Australia,The Universityof Adelaide,25～30 Sep.1994/Paull,J.…...W952684 杂种小麦:现代杂种的表现和生产[会,英]/Wilson,P.//Wheat Breeding-into the secondcentury.Proceedings of The Seventh AssemblyWheat Breeding Society of Australia,The Universityof Adelaide,25～30 Sep.1994/Paull,J.….-Ade-laide,Australia:Wheat Breeding Society of Australi-a,1994.展开更多
Meiotic recombination is a deeply conserved process within eukaryotes that has a profound effect on patterns of natural genetic variation. During meiosis homologous chromosomes pair and undergo DNA double strand break...Meiotic recombination is a deeply conserved process within eukaryotes that has a profound effect on patterns of natural genetic variation. During meiosis homologous chromosomes pair and undergo DNA double strand breaks generated by the Spo11 endonuclease. These breaks can be repaired as crossovers that result in reciprocal exchange between chromosomes. The frequency of recombination along chromosomes is highly variable, for example, crossovers are rarely observed in heterochromatin and the centromeric regions. Recent work in plants has shown that crossover hotspots occur in gene promoters and are associated with specific chromatin modifications, including H2 A.Z. Meiotic chromosomes are also organized in loop-base arrays connected to an underlying chromosome axis, which likely interacts with chromatin to organize patterns of recombination.Therefore, epigenetic information exerts a major influence on patterns of meiotic recombination along chromosomes, genetic variation within populations and evolution of plant genomes.展开更多
基金Supported by the Key Program of the National Natural ScienceFoundation of China(No.30730071)the National High-Tech Researchand Development Program of China(863 program)(No.2007AA09Z430)the General Program of National Natural Science Foundation of China(Nos.30471347&40706048)
文摘Chinese shrimp(Fenneropenaeus chinensis)is an economically important aquaculture species in China.However,cytogenetic and genomic data is limited in the organism partly because the chromosomes are difficult to isolate and analyze.In this study,fluorescence in-situ hybridization(FISH) was used to identify the chromosomes of F.chinensis.The 5S ribosomal RNA gene(rDNA)of F. chinensis was isolated,cloned and then used as a hybridization probe.The results show that the 5S rDNA was located on one pair of homologous chromosomes in F.chinensis.In addition,triploid shrimp were used to evaluate the feasibility of chromosome identification using FISH and to validate the method.It was confirmed that 5S rDNA can be used as a chromosome-specific probe for chromosome identification in F.chinensis.The successful application of FISH in F.chinensis shows that chromosome-specific probes can be developed and this finding will facilitate further research on the chromosomes of penaeid shrimps.
文摘W952684 杂种小麦:现代杂种的表现和生产[会,英]/Wilson,P.//Wheat Breeding-into the secondcentury.Proceedings of The Seventh AssemblyWheat Breeding Society of Australia,The Universityof Adelaide,25～30 Sep.1994/Paull,J.….-Ade-laide,Australia:Wheat Breeding Society of Australi-a,1994.
文摘Meiotic recombination is a deeply conserved process within eukaryotes that has a profound effect on patterns of natural genetic variation. During meiosis homologous chromosomes pair and undergo DNA double strand breaks generated by the Spo11 endonuclease. These breaks can be repaired as crossovers that result in reciprocal exchange between chromosomes. The frequency of recombination along chromosomes is highly variable, for example, crossovers are rarely observed in heterochromatin and the centromeric regions. Recent work in plants has shown that crossover hotspots occur in gene promoters and are associated with specific chromatin modifications, including H2 A.Z. Meiotic chromosomes are also organized in loop-base arrays connected to an underlying chromosome axis, which likely interacts with chromatin to organize patterns of recombination.Therefore, epigenetic information exerts a major influence on patterns of meiotic recombination along chromosomes, genetic variation within populations and evolution of plant genomes.
