The next - generation sequencing platform has revealed the genomic sequences of numer-ous plant species that are ideal resources for simple sequence repeat （SSR） locus screening. In this stud-y, we performed a ...The next - generation sequencing platform has revealed the genomic sequences of numer-ous plant species that are ideal resources for simple sequence repeat （SSR） locus screening. In this stud-y, we performed a comparative genomic SSR analysis on 9 sequenced plants. This showed that the total numbers of mono-, di-, tri-, tetra-, penta-, and hexa-nucleotide repeat SSRs and compound SSRs ranged from 45,552 to 326,319, and the frequencies varied from 177.9 to 573.7 with an average of 401. 3 per Mb. The SSR numbers decreased as the size of the repeat unit increased. The mono-and di-nucleotide SSRs and compound SSRs accounted for more than 78% of the total SSRs in these plants. A/T-rich re-peat motifs were generally dominant in most plants. The sizes of different SSRs varied from 10 to 7288 bp, but at least 85% of them were less than 45 bp. The polymorphism rates of different SSR types ranged from 1.5% to 14.4% in Sesamum indicum, and the mono- and di-nucleotide SSRs displayed the highest polymorphism, followed by the compound SSRs （11.2% ） . These results provide comprehensive insight into the SSR loci of plants and serve as an experimental reference for improvement of SSR marker devel-opment based on plant genomic sequences.展开更多
The kuruma prawn, Marsupenaeus japonicus, is one of the most cultivated and consumed species of shrimp. However, very few molecular genetic/genomic resources are publically available for it. Thus, the characterization...The kuruma prawn, Marsupenaeus japonicus, is one of the most cultivated and consumed species of shrimp. However, very few molecular genetic/genomic resources are publically available for it. Thus, the characterization and distribution of simple sequence repeats(SSRs) remains ambiguous and the use of SSR markers in genomic studies and marker-assisted selection is limited. The goal of this study is to characterize and develop genome-wide SSR markers in M. japonicus by genome survey sequencing for application in comparative genomics and breeding. A total of 326 945 perfect SSRs were identified, among which dinucleotide repeats were the most frequent class(44.08%), followed by mononucleotides(29.67%), trinucleotides(18.96%), tetranucleotides(5.66%), hexanucleotides(1.07%), and pentanucleotides(0.56%). In total, 151 541 SSR loci primers were successfully designed. A subset of 30 SSR primer pairs were synthesized and tested in 42 individuals from a wild population, of which 27 loci(90.0%) were successfully amplified with specific products and 24(80.0%) were polymorphic. For the amplified polymorphic loci, the alleles ranged from 5 to 17(with an average of 9.63), and the average PIC value was 0.796. A total of 58 256 SSR-containing sequences had significant Gene Ontology annotation; these are good functional molecular marker candidates for association studies and comparative genomic analysis. The newly identified SSRs significantly contribute to the M. japonicus genomic resources and will facilitate a number of genetic and genomic studies, including high density linkage mapping, genome-wide association analysis, marker-aided selection, comparative genomics analysis, population genetics, and evolution.展开更多
The pen shell(Atrina pectinata) is a large wedge-shaped bivalve, which belongs to family Pinnidae. Due to its large and nutritious adductor muscle, it is the popular seafood with high commercial value in Asia-Pacific ...The pen shell(Atrina pectinata) is a large wedge-shaped bivalve, which belongs to family Pinnidae. Due to its large and nutritious adductor muscle, it is the popular seafood with high commercial value in Asia-Pacific countries. However, limiting genomic and transcriptomic data have hampered its genetic investigations. In this study, the transcriptome of A. pectinata was deeply sequenced using Illumina pair-end sequencing technology. After assembling, a total of 127263 unigenes were obtained. Functional annotation indicated that the highest percentage of unigenes(18.60%) was annotated on GO database, followed by 18.44% on PFAM database and 17.04% on NR database. There were 270 biological pathways matched with those in KEGG database. Furthermore, a total of 23452 potential simple sequence repeats(SSRs) were identified, of them the most abundant type was mono-nucleotide repeats(12902, 55.01%), which was followed by di-nucleotide(8132, 34.68%), tri-nucleotide(2010, 8.57%), tetra-nucleotide(401, 1.71%), and penta-nucleotide(7, 0.03%) repeats. Sixty SSRs were selected for validating and developing genic SSR markers, of them 23 showed polymorphism in a cultured population with the average observed and expected heterozygosities of 0.412 and 0.579, respectively. In this study, we established the first comprehensive transcript dataset of A. pectinata genes. Our results demonstrated that RNA-Seq is a fast and cost-effective method for genic SSR development in non-model species.展开更多
文摘The next - generation sequencing platform has revealed the genomic sequences of numer-ous plant species that are ideal resources for simple sequence repeat （SSR） locus screening. In this stud-y, we performed a comparative genomic SSR analysis on 9 sequenced plants. This showed that the total numbers of mono-, di-, tri-, tetra-, penta-, and hexa-nucleotide repeat SSRs and compound SSRs ranged from 45,552 to 326,319, and the frequencies varied from 177.9 to 573.7 with an average of 401. 3 per Mb. The SSR numbers decreased as the size of the repeat unit increased. The mono-and di-nucleotide SSRs and compound SSRs accounted for more than 78% of the total SSRs in these plants. A/T-rich re-peat motifs were generally dominant in most plants. The sizes of different SSRs varied from 10 to 7288 bp, but at least 85% of them were less than 45 bp. The polymorphism rates of different SSR types ranged from 1.5% to 14.4% in Sesamum indicum, and the mono- and di-nucleotide SSRs displayed the highest polymorphism, followed by the compound SSRs （11.2% ） . These results provide comprehensive insight into the SSR loci of plants and serve as an experimental reference for improvement of SSR marker devel-opment based on plant genomic sequences.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A409)
文摘The kuruma prawn, Marsupenaeus japonicus, is one of the most cultivated and consumed species of shrimp. However, very few molecular genetic/genomic resources are publically available for it. Thus, the characterization and distribution of simple sequence repeats(SSRs) remains ambiguous and the use of SSR markers in genomic studies and marker-assisted selection is limited. The goal of this study is to characterize and develop genome-wide SSR markers in M. japonicus by genome survey sequencing for application in comparative genomics and breeding. A total of 326 945 perfect SSRs were identified, among which dinucleotide repeats were the most frequent class(44.08%), followed by mononucleotides(29.67%), trinucleotides(18.96%), tetranucleotides(5.66%), hexanucleotides(1.07%), and pentanucleotides(0.56%). In total, 151 541 SSR loci primers were successfully designed. A subset of 30 SSR primer pairs were synthesized and tested in 42 individuals from a wild population, of which 27 loci(90.0%) were successfully amplified with specific products and 24(80.0%) were polymorphic. For the amplified polymorphic loci, the alleles ranged from 5 to 17(with an average of 9.63), and the average PIC value was 0.796. A total of 58 256 SSR-containing sequences had significant Gene Ontology annotation; these are good functional molecular marker candidates for association studies and comparative genomic analysis. The newly identified SSRs significantly contribute to the M. japonicus genomic resources and will facilitate a number of genetic and genomic studies, including high density linkage mapping, genome-wide association analysis, marker-aided selection, comparative genomics analysis, population genetics, and evolution.
基金the grants from Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, P. R. China (No. 2016LMFS-B02)the Key Research and Development Program of Shandong Province (No. 2016GSF115012)+1 种基金Basic Scientific Research Fund of YSFRI (No. 2060302201516054)Natural Science Foundation of Shandong Province (No. ZR2016 CQ32)
文摘The pen shell(Atrina pectinata) is a large wedge-shaped bivalve, which belongs to family Pinnidae. Due to its large and nutritious adductor muscle, it is the popular seafood with high commercial value in Asia-Pacific countries. However, limiting genomic and transcriptomic data have hampered its genetic investigations. In this study, the transcriptome of A. pectinata was deeply sequenced using Illumina pair-end sequencing technology. After assembling, a total of 127263 unigenes were obtained. Functional annotation indicated that the highest percentage of unigenes(18.60%) was annotated on GO database, followed by 18.44% on PFAM database and 17.04% on NR database. There were 270 biological pathways matched with those in KEGG database. Furthermore, a total of 23452 potential simple sequence repeats(SSRs) were identified, of them the most abundant type was mono-nucleotide repeats(12902, 55.01%), which was followed by di-nucleotide(8132, 34.68%), tri-nucleotide(2010, 8.57%), tetra-nucleotide(401, 1.71%), and penta-nucleotide(7, 0.03%) repeats. Sixty SSRs were selected for validating and developing genic SSR markers, of them 23 showed polymorphism in a cultured population with the average observed and expected heterozygosities of 0.412 and 0.579, respectively. In this study, we established the first comprehensive transcript dataset of A. pectinata genes. Our results demonstrated that RNA-Seq is a fast and cost-effective method for genic SSR development in non-model species.
