Amplified fragment length polymorphisms (AFLP) technique was used to analyze the fingerprint- ing of four successive generations of Fenneropenaeus chinensis to reveal their disease-resistance traits. Some loci showed ...Amplified fragment length polymorphisms (AFLP) technique was used to analyze the fingerprint- ing of four successive generations of Fenneropenaeus chinensis to reveal their disease-resistance traits. Some loci showed quite different genetic frequencies due to artificial selection, which implied that these fragments were putative markers related to the disease-resistance trait. We developed a simple and effective method to fur- ther characterize these AFLP fragments. Specific AFLP bands were cut directly from polyacrylamide gels, re-amplified, cloned and sequenced. Eight putative genetic markers were sequenced and their sizes ranged from 63 to 209 bp. The sequences were submitted to dbGSS (database of Genome Sequence Survey); and the BLAST analysis showed low similarity to the function genes, indicating these markers were tightly linked to a dis- ease-resistance trait but were not functional genes.展开更多
The eukaryotic genome is packaged into a complex nucleoprotein structure named chromatin, balancing the compactness of genome and the accessibility of regulatory proteins and RNA polymerases to DNA. The mechanisms of ...The eukaryotic genome is packaged into a complex nucleoprotein structure named chromatin, balancing the compactness of genome and the accessibility of regulatory proteins and RNA polymerases to DNA. The mechanisms of the regulation of chromatin dynamics include the post-translational modification of histones, alteration of nucleosome positions by chromatin remodelers, replacement of canonical histones by histone variants with the aid of histone chaperones, and dynamic organization of the three-dimensional genome in the small nucleus. Histone variants are different from canonical histones by substitution of several amino acid residues or changes in amino acid sequence. Histone variants perform specialized functions such as altering nucleosome stability, dynamics, structure, as well as playing critical roles in a range of biological processes like transcriptional regulation, DNA repair and recombination, development and immune responses. Here we discuss how histone variants, their modification and specific loading to chromatin are involved in transcriptional regulation, DNA repair and plant development.展开更多
The clustered regularly interspaced short palindromic repeats(CRISPR)-associated endonuclease 9(CRISPR/Cas9) system has emerged as a promising technology for specific genome editing in many species. Here we constructe...The clustered regularly interspaced short palindromic repeats(CRISPR)-associated endonuclease 9(CRISPR/Cas9) system has emerged as a promising technology for specific genome editing in many species. Here we constructed one vector targeting eight agronomic genes in rice using the CRISPR/Cas9 multiplex genome editing system. By subsequent genetic transformation and DNA sequencing, we found that the eight target genes have high mutation efficiencies in the T_0 generation. Both heterozygous and homozygous mutations of all editing genes were obtained in T_0 plants. In addition, homozygous sextuple, septuple, and octuple mutants were identified. As the abundant genotypes in T_0 transgenic plants, various phenotypes related to the editing genes were observed. The findings demonstrate the potential of the CRISPR/Cas9 system for rapid introduction of genetic diversity during crop breeding.展开更多
基金This research was supported by special funds from the National KeyBasic Research Program (G1999012007) and the National High-TechResearch and Development Program of China (863 Program,2001AA620105)
文摘Amplified fragment length polymorphisms (AFLP) technique was used to analyze the fingerprint- ing of four successive generations of Fenneropenaeus chinensis to reveal their disease-resistance traits. Some loci showed quite different genetic frequencies due to artificial selection, which implied that these fragments were putative markers related to the disease-resistance trait. We developed a simple and effective method to fur- ther characterize these AFLP fragments. Specific AFLP bands were cut directly from polyacrylamide gels, re-amplified, cloned and sequenced. Eight putative genetic markers were sequenced and their sizes ranged from 63 to 209 bp. The sequences were submitted to dbGSS (database of Genome Sequence Survey); and the BLAST analysis showed low similarity to the function genes, indicating these markers were tightly linked to a dis- ease-resistance trait but were not functional genes.
基金supported by the National Natural Science Foundation of China(31171168 and 91319304)National Basic Research Program of China(2012CB910503)
文摘The eukaryotic genome is packaged into a complex nucleoprotein structure named chromatin, balancing the compactness of genome and the accessibility of regulatory proteins and RNA polymerases to DNA. The mechanisms of the regulation of chromatin dynamics include the post-translational modification of histones, alteration of nucleosome positions by chromatin remodelers, replacement of canonical histones by histone variants with the aid of histone chaperones, and dynamic organization of the three-dimensional genome in the small nucleus. Histone variants are different from canonical histones by substitution of several amino acid residues or changes in amino acid sequence. Histone variants perform specialized functions such as altering nucleosome stability, dynamics, structure, as well as playing critical roles in a range of biological processes like transcriptional regulation, DNA repair and recombination, development and immune responses. Here we discuss how histone variants, their modification and specific loading to chromatin are involved in transcriptional regulation, DNA repair and plant development.
基金supported by the National Natural Science Foundation of China (31271681, 3140101312)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural SciencesJiangsu Agriculture Science and Technology Innovation Fund (CX(13)5075)
文摘The clustered regularly interspaced short palindromic repeats(CRISPR)-associated endonuclease 9(CRISPR/Cas9) system has emerged as a promising technology for specific genome editing in many species. Here we constructed one vector targeting eight agronomic genes in rice using the CRISPR/Cas9 multiplex genome editing system. By subsequent genetic transformation and DNA sequencing, we found that the eight target genes have high mutation efficiencies in the T_0 generation. Both heterozygous and homozygous mutations of all editing genes were obtained in T_0 plants. In addition, homozygous sextuple, septuple, and octuple mutants were identified. As the abundant genotypes in T_0 transgenic plants, various phenotypes related to the editing genes were observed. The findings demonstrate the potential of the CRISPR/Cas9 system for rapid introduction of genetic diversity during crop breeding.
