scholarly journals Detection of simple sequence repeats in the chloroplast genome of Tetraphis pellucida Hedw.

2016 ◽  
Vol 3 (2) ◽  
pp. 207 ◽  
Author(s):  
Asheesh Shanker
Keyword(s):  
Chloroplast Genome ◽  
Simple Sequence Repeats ◽  
Average Length ◽  
Accession Number ◽  
Repeat Type ◽  
Perl Script ◽  
Repeat Units ◽  
Short Repeat ◽  
Diversity Studies ◽  
Simple Sequence

Simple sequence repeats (SSRs) consist of short repeat motifs of 1-6 nucleotides and are found in DNA sequences.The present study was conducted to detect SSRs in chloroplast genome of Tetraphis pellucida (Accession number: NC_024291), downloaded from the National Center for Biotechnology Information (NCBI). The sequence was mined with the help of MISA, a Perl script, to detect SSRs. The length of SSRs defined as ≥12 for mono, di, tri and tetranucleotide, ≥15 for pentanucleotide and ≥18 for hexanucleotide repeats. In total, 41 perfect microsatellites were identified in 127.489 kb sequence mined. An average length of 13.56 bp was calculated for mined SSRs with a density of 1 SSR/3.04 kb. Depending on the repeat units, the length of SSRs ranged from 12 to 20 nt. Dinucleotides (14, 34.15%) were the most frequent repeat type, followed by tetranucleotides (10, 24.39%), trinucleotides (7, 17.07%), mononucleotides (6, 14.63%) and pentanucleotide (4, 9.76%) repeats. Hexanucleotide repeats were completely absent in chloroplast genome of Tetraphis pellucida. The mined SSRs can be used to develop molecular markers and genetic diversity studies in Tetraphis species.

scholarly journals Computational Mining of Microsatellites in the Chloroplast Genome of Ptilidium pulcherrimum, a Liverwort

2014 ◽  
Vol 3 (3) ◽  
pp. 50-58
Author(s):  
Asheesh Shanker
Keyword(s):  
Chloroplast Genome ◽  
Dna Sequences ◽  
Pcr Primers ◽  
Repeat Type ◽  
Dinucleotide Repeats ◽  
Perl Script ◽  
Repeat Units ◽  
Chloroplast Genome Sequence ◽  
Nucleotide Repeats ◽  
Simple Sequence

Microsatellites also known as simple sequence repeats (SSRs) are found in DNA sequences. These repeats consist of short motifs of 1-6 bp and play important role in population genetics, phylogenetics and also in the development of molecular markers. In this study chloroplastic SSRs (cpSSRs) in the chloroplast genome of Ptilidium pulcherrimum, downloaded from the National Center for Biotechnology Information (NCBI), were detected. The chloroplast genome sequence of P. pulcherrimum was mined with the help of a Perl script named MISA. A total of 23 perfect cpSSRs were detected in 119.007 kb sequence mined showing density of 1 SSR/5.17 kb. Depending on the repeat units, the length of SSRs found to be 12 bp for mono and tri, 12 to “22 bp for di, 12 to 16 bp for tetra nucleotide repeats. Penta and hexanucleotide repeats were completely absent in chloroplast genome of P. pulcherrimum. Dinucleotide repeats were the most frequent repeat type (47.83%) followed by tri (21.74%) and tetranucleotide (21.74%) repeats. Out of 23 SSRs detected, PCR primers were successfully designed for 22 (95.65%) cpSSRs. DOI: http://dx.doi.org/10.3126/ije.v3i3.11063 International Journal of Environment Vol.3(3) 2014: 50-58

scholarly journals Transcriptome analysis of two contrasting genotypes of pearl millet to gain insight into heat stress responses

2020 ◽  
Author(s):  
Albert Maibam ◽  
Sunil Nigombam ◽  
Harinder Vishwakarma ◽  
Showkat Ahmad Lone ◽  
Kishor Gaikwad ◽  
...  
Keyword(s):  
Heat Stress ◽  
Pearl Millet ◽  
Stress Responses ◽  
Simple Sequence Repeats ◽  
Pennisetum Glaucum ◽  
Average Length ◽  
Gc Content ◽  
Functional Markers ◽  
Sequencing Data ◽  
Simple Sequence

Abstract Background Pennisetum glaucum (L.) R. Br. is mainly grown in arid and semi-arid regions. Being naturally tolerant to various adverse condtitions, it is a good biological resource for deciphering the molecular basis of abiotic stresses such as heat stress in plants but limited studies have been carried out till date to this effect. Here, we performed RNA-sequencing from the leaf of two contrasting genotypes of pearl millet (841-B and PPMI-69) subjected to heat stress (42 °C for 6 h). Results Over 274 million high quality reads with an average length of 150 nt were generated. Assembly was carried out using trinity, obtaining 47,310 unigenes having an average length of 1254 nucleotides, N50 length of 1853 nucleotides and GC content of 53.11%. Blastx resulted in annotation of 35,628 unigenes and functional classification showed 15,950 unigenes designated to 51 Gene Ontology terms, 13,786 unigenes allocated to 23 Clusters of Orthologous Groups and 4,255 unigenes distributed into 132 functional KEGG pathways. 12,976 simple sequence repeats were identified from 10,294 unigenes for the development of functional markers. A total of 3,05,759 SNPs were observed in the transcriptome data. Out of 2,301 differentially expressed genes, 10 potential candidates genes were selected based on log2 fold change and adjusted p-value parameters for their differential gene expression by qRT-PCR. Conclusions The dynamic expression changes in two genotypes of P. glaucum reflect transcriptome regulation of signaling pathways in heat stress response. In order to develop genetic markers, 12,976 simple sequence repeats (SSRs) were identified. The sequencing data generated in this study shall serve as an important resource for further research in the area of crop biotechnology.

Microsatellite repeats are not randomly distributed within Norway spruce (Picea abies K.) expressed sequences

Genome ◽  
2000 ◽  
Vol 43 (1) ◽  
pp. 41-46 ◽  
Author(s):  
I Scotti ◽  
F Magni ◽  
R Fink ◽  
W Powell ◽  
G Binelli ◽  
...  
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Natural Variation ◽  
Average Length ◽  
Coding Region ◽  
Microsatellite Repeats ◽  
Repeat Units ◽  
Potential Applications ◽  
Vegetative Bud ◽  
Simple Sequence

A Norway spruce (Picea abies K.) cDNA library obtained from vegetative bud tissue was screened for the presence of (AG)n and (AC)n microsatellite repeats. Ten (AG)n and six (AC)n microsatellites were found, with an average length of 25.5 repeat units. Most of the microsatellites are simple perfect repeats. The microsatellite distribution within the clones is clearly non-random, with different classes of repeats lying in different positions relative to the coding region and in a highly conserved orientation. An estimate of the frequency of dinucleotide microsatellites in expressed regions was obtained, showing that SSRs (simple sequence repeats) are found in genes about 20 times less frequently than in random genomic clones, with (AG)n repeats more frequent than (AC)n repeats. Potential applications of these sequences as expressed region-based molecular markers are shown by developing six SSR markers for the detection of natural variation in Norway spruce populations and testing two of them for the identification of illegitimate progenies from a mapping population. Key words: Picea abies, microsatellites, SSRs, ESTs, population genetics, trees.

scholarly journals Genome-Wide Characterization and Comparative Analyses of Simple Sequence Repeats among Four Miniature Pig Breeds

Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1792
Author(s):  
Hongyang Wang ◽  
Yang Fu ◽  
Peng Gu ◽  
Yingying Zhang ◽  
Weilong Tu ◽  
...  
Keyword(s):  
Simple Sequence Repeats ◽  
Growth And Development ◽  
Miniature Pig ◽  
Sequencing Data ◽  
Pig Breeds ◽  
Polymorphic Ssrs ◽  
Repeat Units ◽  
Genome Wide ◽  
Polymerase Chain ◽  
Simple Sequence

Simple sequence repeats (SSRs) are commonly used as molecular markers in research on genetic diversity and discrimination among taxa or breeds because polymorphisms in these regions contribute to gene function and phenotypically important traits. In this study, we investigated genome-wide characteristics, repeat units, and polymorphisms of SSRs using sequencing data from SSR-enriched libraries created from Wuzhishan (WZS), Bama (BM), inbred Luchuan (LC) and Zangxiang (ZX) miniature pig breeds. The numbers and types of SSRs, distributions of repeat units and polymorphic SSRs varied among the four breeds. Compared to the Duroc pig reference genome, 2518 polymorphic SSRs were unique and common to all four breeds and functional annotation revealed that they may affect the coding and regulatory regions of genes. Several examples, such as FGF23, MYF6, IGF1R, and LEPROT, are associated with growth and development in pigs. Three of the polymorphic SSRs were selected to confirm the polymorphism and the corresponding alleles through fluorescence polymerase chain reaction (PCR) and capillary electrophoresis. Together, this study provides useful insights into the discovery, characteristics and distribution of SSRs in four pig breeds. The polymorphic SSRs, especially those common and unique to all four pig breeds, might affect associated genes and play important roles in growth and development.

A Low Mutation Rate For Chloroplast Microsatellites

Genetics ◽  
1999 ◽  
Vol 153 (2) ◽  
pp. 943-947
Author(s):  
Jim Provan ◽  
Nicole Soranzo ◽  
Neil J Wilson ◽  
David B Goldstein ◽  
Wayne Powell
Keyword(s):  
Chloroplast Genome ◽  
Mutation Rate ◽  
Simple Sequence Repeats ◽  
Mutation Rates ◽  
Chloroplast Microsatellites ◽  
Ssr Loci ◽  
Nuclear Ssr ◽  
Monomorphic Population ◽  
Simple Sequence ◽  
Pinus Torreyana

Abstract We used chloroplast simple sequence repeats (cpSSRs) to examine whether there is any variation present in the chloroplast genome of Pinus torreyana (Parry ex Carrière) that may previously not have been detected using RFLPs. Analysis of 17 cpSSR loci showed no variation, which is consistent with previous cpRFLP work and confirms that the species is descended from an original, highly monomorphic population following a bottleneck. This lack of biological variation in the chloroplast genome of P. torreyana allowed us to estimate the mutation rates at cpSSR loci as between 3.2 × 10-5 and 7.9 × 10-5. This estimate is lower than published mutation rates at nuclear SSR loci but higher than substitution rates elsewhere in the chloroplast genome.

Simple sequence repeats in watermelon (Citrullus lanatus (Thunb.) Matsum. &Nakai)

Genome ◽  
1997 ◽  
Vol 40 (4) ◽  
pp. 433-441 ◽  
Author(s):  
R. L. Jarret ◽  
L. C. Merrick ◽  
T. Holms ◽  
J. Evans ◽  
M. K. Aradhya
Keyword(s):  
Genetic Diversity ◽  
Simple Sequence Repeats ◽  
Genetic Relatedness ◽  
Genomic Library ◽  
Citrullus Lanatus ◽  
Dinucleotide Repeats ◽  
Length Polymorphisms ◽  
Ssr Loci ◽  
Diversity Studies ◽  
Simple Sequence

Simple sequence repeat length polymorphisms were utilized to examine genetic relatedness among accessions of watermelon (Citrullus lanatus (Thunb.) Matsum. &Nakai). A size-fractionated TaqI genomic library was screened for the occurrence of dimer and trimer simple sequence repeats (SSRs). A total of 96 (0.53%) SSR-bearing clones were identified and the inserts from 50 of these were sequenced. The dinucleotide repeats (CT)n and (GA)n accounted for 82% of the SSRs sequenced. PCR primer pairs flanking seven SSR loci were used to amplify SSRs from 32 morphologically variable watermelon genotypes from Africa, Europe, Asia, and Mexico and a single accession of Citrullus colocynthis from Chad. Cluster analysis of SSR length polymorphisms delineated 4 groups at the 25% level of genetic similarity. The largest group contained C. lanatus var. lanatus accessions. The second largest group contained only wild and cultivated "citron"-type or C. lanatus var. citroides accessions. The third group contained an accession tentatively identified as C. lanatus var. lanatus but which perhaps is a hybrid between C. lanatus var. lanatus and C. lanatus var. citroides. The fourth group consisted of a single accession identified as C. colocynthis. "Egusi"-type watermelons from Nigeria grouped with C. lanatus var. lanatus. The use of SSRs for watermelon germplasm characterization and genetic diversity studies is discussed.Key words: Citrullus, watermelon, simple sequence repeats, genetic diversity.

scholarly journals The Complete Chloroplast Genome Sequence of Four Plant Species, Their SSR Identification and Phylogenetic Analysis

2021 ◽  
Author(s):  
Yueyi Zhu ◽  
Xianwen Zhang ◽  
Guopeng Li ◽  
Jiqian Xiang ◽  
Jinghua Su ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Molecular Markers ◽  
Chloroplast Genome ◽  
Simple Sequence Repeats ◽  
Genetic Information ◽  
Phylogenetic Trees ◽  
Complete Chloroplast Genome ◽  
Chloroplast Genomes ◽  
Chloroplast Genome Sequence ◽  
Simple Sequence

The chloroplast genome is conservative and stable, which can be employed to resolve genotypes. Currently, published nuclear sequences and molecular markers failed to differentiate the species from taxa robustly, including Machilus leptophylla, Hanceola exserta, Rubus bambusarum, and Rubus henryi. In this study, the four chloroplast genomes were characterized, and then their simple sequence repeats (SSRs) and phylogenetic positions were analyzed. The results demonstrated the four chloroplast genomes consisted of 152.624 kb, 153.296kb, 156.309 kb, and 158.953 kb in length, involving 124, 130, 129, and 131 genes, respectively. Moreover, the chloroplast genomes contained typical four regions. Six classes of SSR were identified from the four chloroplast genomes, in which mononucleotide was the class with the most members. The types of the repeats were various within individual classes of SSR. Phylogenetic trees indicated that M. leptophylla was clustered with M. yunnanensis, and H. exserta was confirmed under family Ocimeae. Additionally, R. bambusarum and R. henryi were clustered together, whereas they did not belong to the same species due to the differing SSR features. This research would provide evidence for resolving the species and contributed new genetic information for further study.

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