Data Mining for Simple Sequence Repeats in Expressed Sequence Tags from Japanese Flounder (Paralichthys olivaceus)

2013 ◽  
Vol 765-767 ◽  
pp. 274-277
Author(s):  
Song Bo Chen ◽  
Xin Lu Xie ◽  
Gong Li ◽  
Hai Jin Liu

Based on ESTs of Japanese flounder (Paralichthys olivaceus) in the public database, EST-SSR makers were developed after mining and evaluating SSRs in them by bioinformatics methods. 5 927 non-redundant ESTs of Japanese flounder were screened and 390 SSRs were mined out. The frequency of these EST-SSRs was 7.95% and the average distance of distribution was 7.9 kb in non-redundant ESTs. The dinucleotide repest motif was dominant type (59.02%) with repeat motif AC being the most common (16.91%). The distribution of trinucleotide, tetranucleotide and hexanucleotide repeats were dispersive. 30 primer pairs for EST-SSRs were designed, 27 primer pairs showed the amplification, and 17 primer pairs showed polymorphisms, the rates of polymorphic EST-SSRs were 62.96% with the alleles per locus ranging from 2 to 6 (mean 3.5). The observed (HO) and expected (HE) heterozygosities of these EST-SSRs were 0.280.92 and 0.31550.8033, respectively. Two EST-SSR loci significantly deviated from the HardyWeinberg equilibrium (HWE) expectation, and theremaining 15 loci were in HWE. These new EST-SSR markers would provide sufficient polymorphism for population genetic studies and genome mapping of Japanese flounder.

2002 ◽  
Vol 68 (sup2) ◽  
pp. 1233-1234 ◽  
Author(s):  
NUR R. ARMA ◽  
IKUO HIRONO ◽  
MIDORI YAMAMOTO ◽  
TAKASHI AOKI

2018 ◽  
Vol 16 (4) ◽  
pp. 306-314
Author(s):  
Chan Liu ◽  
Qing Tang ◽  
Chaohua Cheng ◽  
Ying Xu ◽  
Zemao Yang ◽  
...  

AbstractChinese jiaotou is an economically important crop that is widely cultivated in East Asia. The lack of simple sequence repeat (SSR) markers has been a major obstacle for genetic studies of this crop. In the present study, SSR markers were developed for Chinese jiaotou on a large scale, based on the crop's transcriptome assembledde novoby a previous study. A search for SSR loci in the transcriptome's expressed sequence tags (ESTs) revealed 2157 SSRs, of which primer pairs could be developed for 1494. Among these resulting SSRs, trinucleotide repeat motifs were the most abundant type, with GAA/TTC motifs occurring most frequently. Analysing the annotated function of SSR-containing ESTs revealed that they enriched into the GO categories involved in transcription regulation, oxidation–reduction, transport, etc. The quality and transferability of these markers were also assessed using 100 randomly selected EST–SSRs, and the result showed that these markers were of good quality and possessed high cross-species transferability. In addition, the developed SSR markers were used to analyse the genetic diversity of 19 cultivated and four wild accessions, resulting in three distinct groups, cluster I, II and III. Interestingly, all four wild accessions were assigned to cluster III, and two local varieties from northern Hunan, China, were closely related to the wild genotypes. These results provide new insights into the origin of Chinese jiaotou. The EST–SSRs developed herein represent the first large-scale development of SSR markers in Chinese jiaotou, and they can be widely used for genetic studies of the crop.


Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 644 ◽  
Author(s):  
Li Dong ◽  
Yuhan Sun ◽  
Keqi Zhao ◽  
Jing Zhang ◽  
Yuwei Zhang ◽  
...  

Black locust (Robinia pseudoacacia L.) is an economically and ecologically important tree species which is used for pillar construction, honey production and soil improvement. More EST-SSR (Expressed sequence tag simple sequence repeat) markers of black locust can be used as a complement and improvement of Genomic-SSR markers for the identification of the function of gene and the construction of genetic map. Additionally, currently there is no simple method for identifying black locust cultivars. In this study, we obtained 2702 unigenes from 3095 expressed sequence tags (ESTs) from the National Center of Biotechnology Information (NCBI) database to identify simple sequence repeats (SSRs) in R. pseudoacacia samples. A total of 170 SSR loci were found to be distributed in 162 non-redundant sequences with a frequency of 6.29%. Dinucleotide repeats were the most predominant types among microsatellites (62.35%), followed by tri-nucleotide repeats (25.88%); the remaining SSRs accounted for less than 12%. The repeat motifs AG/TC (29.25%) and CT/GA (29.25%) were the most abundant among dinucleotides, and AAT/TTA (15.91%) was the most common among tri-nucleotides. A total of 62 primer pairs were designed to screen polymorphic and stable SSR loci. The resulting 25 EST-SSR markers capable of amplifying polymorphic, stable, and repeatable products. Eight newly developed EST-SSR markers and four published SSR markers were selected for DNA fingerprinting and genetic diversity analysis of the 123 main R. pseudoacacia cultivars in China. The 12 SSR loci amplified 102 alleles, with an average number of alleles per locus of 8.5 (range 4–15). The average polymorphism information content at the 12 SSR loci for the 123 cultivars was 0.670 (range 0.427–0.881). The 123 cultivars clustered into six main groups based on similarity coefficients, with most cultivars in one subgroup. Fingerprinting was performed using eight SSR markers; 110 black locust cultivars were distinguished. The results of this study increase the availability of EST-SSR markers in black locust and make it a simple method for checking the collection, the certification, and the correct attribution of clones and cultivars.


2007 ◽  
Vol 42 (3) ◽  
pp. 377-384 ◽  
Author(s):  
Fernanda de Oliveira Pinto ◽  
Mirian Perez Maluf ◽  
Oliveiro Guerreiro-Filho

The objective of this work was to identify expressed simple sequence repeats (SSR) markers associated to leaf miner resistance in coffee progenies. Identification of SSR markers was accomplished by directed searches on the Brazilian Coffee Expressed Sequence Tags (EST) database. Sequence analysis of 32 selected SSR loci showed that 65% repeats are of tetra-, 21% of tri- and 14% of dinucleotides. Also, expressed SSR are localized frequently in the 5'-UTR of gene transcript. Moreover, most of the genes containing SSR are associated with defense mechanisms. Polymorphisms were analyzed in progenies segregating for resistance to the leaf miner and corresponding to advanced generations of a Coffea arabica x Coffea racemosa hybrid. Frequency of SSR alleles was 2.1 per locus. However, no polymorphism associated with leaf miner resistance was identified. These results suggest that marker-assisted selection in coffee breeding should be performed on the initial cross, in which genetic variability is still significant.


Agronomy ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 260 ◽  
Author(s):  
Ali Ahmad ◽  
Jin-Da Wang ◽  
Yong-Bao Pan ◽  
Rahat Sharif ◽  
San-Ji Gao

Recently-developed molecular markers are becoming powerful tools, with applications in crop genetics and improvement. Microsatellites, or simple sequence repeats (SSRs), are widely used in genetic fingerprinting, kinship analysis, and population genetics, because of the advantages of high variability from co-dominant and multi-allelic polymorphisms, and accurate and rapid detection. However, more recent evidence suggests they may play an important role in genome evolution and provide hotspots of recombination. This review describes the development of SSR markers through different techniques, and the detection of SSR markers and applications for sugarcane genetic research and breeding, such as cultivar identification, genetic diversity, genome mapping, quantitative trait loci (QTL) analysis, paternity analysis, cross-species transferability, segregation analysis, phylogenetic relationships, and identification of wild cross hybrids. We also discuss the advantages and disadvantages of SSR markers and highlight some future perspectives.


Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 61 ◽  
Author(s):  
Chengcai Zhang ◽  
Xiaohua Yao ◽  
Huadong Ren ◽  
Jun Chang ◽  
Jun Wu ◽  
...  

Research Highlights: The distribution of simple sequence repeat (SSR) motifs in two draft genomes of pecan was evaluated. Sixty-six SSR loci were validated by PCR amplification in pecan. Twenty-two new development markers can be used for genetic study in genus Carya. Background and Objectives: Pecan has good nutritional and health benefits and is an important crop worldwide. However, the genetic research in this species is insufficient. One of the main reasons for this is the lack of enough accurate, convenient, and economical molecular markers. Among different marker types, SSR loci are enormously useful in genetic studies. However, the number of SSRs in C. illinoinensis (Wangenh.) K. Koch is limited. Materials and Methods: The distribution of SSR motifs in the pecan genome was analyzed. Then, the primers for each SSR were designed. To evaluate their availability, 74 SSR loci were randomly selected and amplified in pecan. Finally, 22 new SSRs and eight former ones were picked to evaluate the genetic diversity in 60 pecan genotypes and to determine their transferability in other Carya species. Results: 145,714 and 143,041 SSR motifs were obtained from two draft genomes of ‘87MX3-2’ and ‘Pawnee’, respectively. In total, 9145 candidate primers were obtained. Sixty-six (89.19%) primers amplified the target products. Among the 30 SSRs, 29 loci showed polymorphism in 60 pecan genotypes. The polymorphic information content (PIC) values ranged from 0.012 to 0.906. In total, 26, 25, and 22 SSRs can be used in C. cathayensis Sarg., C. dabieshanensis W. C. Cheng & R. H. Chang, and C. hunanensis W.C. Liu, respectively. Finally, the dendrogram of all individuals was constructed. The results agree with the geographic origin of the four species and the pedigree relationships between different pecan cultivars. Conclusions: The characterization of SSRs in the pecan genome and the new SSRs will promote the progress of genetic study and breeding in pecan, as well as other species of genus Carya.


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