Frequency of microsatellite sequences in rice (Oryza sativa L.)

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1170-1176 ◽  
Author(s):  
Olivier Panaud ◽  
Xiuli Chen ◽  
Susan R. McCouch
Keyword(s):  
Genomic Library ◽  
Oryza Sativa L ◽  
Rice Genome ◽  
Cdna Libraries ◽  
Sequence Length ◽  
Tetranucleotide Repeat ◽  
Hybridization Probes ◽  
Microsatellite Map ◽  
Dissociation Temperature ◽  
Simple Sequence

This study was undertaken to estimate the relative frequencies of 13 microsatellite motifs in the rice genome as a basis for efficient development of a microsatellite map. Two dinucleotide, seven trinucleotide, and four tetranucleotide repeat motifs were end labelled and used as hybridization probes to screen genomic and cDNA libraries of rice, cv. IR36. Optimal washing temperatures for identification of clones containing specific microsatellite motifs were estimated based on washing temperatures near Td (dissociation temperature; Td = Tm − 7.6 °C). Sequencing of 20 putatively positive clones corresponding to each of 4 microsatellite motifs suggested that while Td provides a useful predictor of washing stringency for most of the repeats studied, those with a very high GC or AT content were most prone to error. The results from screening the rice genomic library suggest that there are an estimated 1360 poly(GA)n and 1230 poly(GT)n microsatellites in the rice genome, and that the relative frequency of different repeats decreased with increasing size of the motif. The most frequently observed microsatellites in the cDNA library were the same as for the genomic library, but no poly(CGG)n, poly(ATC)n, or tetranucleotide motifs were observed among cDNAs in this study.Key words: microsatellite, simple sequence repeat, SSR, simple sequence length polymorphism, SSLP.

Exact word matches in rice pseudomolecules

Genome ◽  
2006 ◽  
Vol 49 (8) ◽  
pp. 1047-1051 ◽  
Author(s):  
Shaolin Liu ◽  
Nicholas A Tinker ◽  
Diane E Mather
Keyword(s):  
High Frequency ◽  
Genomic Sequence ◽  
Oryza Sativa L ◽  
Rice Genome ◽  
Low Frequency ◽  
Nucleotide Position ◽  
Genome Wide ◽  
Transposon Activity ◽  
Simple Sequence ◽  
Oligonucleotide Sequence

Using pseudomolecules of assembled genomic sequence, we computed the frequencies of 6 to 24 bp oligonucleotide (oligo) "words" across the genome of rice (Oryza sativa L. subsp. japonica). All oligos of 10 or fewer basepairs were repeated at least 12 times in the genome. The percentage of unique (non-repeated) oligos ranged from 0.1% for 12 bp oligos to 76.0% for 24 bp oligos. For three 200 kb regions, we annotated each nucleotide position with the genome-wide frequency of the 18 bp oligo starting at that position. These frequencies formed landscapes consisting of high- and low-frequency zones. Low-frequency zones contained occasional high-frequency spikes; these may represent footprints of RIM2 transposon activity. BLASTn searches of high-frequency non-SSR (simple sequence repeat) 18 bp oligos returned few sequences from species other than rice. These results demonstrate that, in rice, words are not randomly used between different regions within the same genome, and indicate that words that are frequently repeated within the rice genome tend to be unique to rice.Key words: oligonucleotide, sequence repetition, word match frequency, rice.

Comparative evaluation of within-cultivar variation of rice (Oryza sativa L.) using microsatellite and RFLP markers

Genome ◽  
1997 ◽  
Vol 40 (3) ◽  
pp. 370-378 ◽  
Author(s):  
Johnson O. Olufowote ◽  
Yunbi Xu ◽  
Xiuli Chen ◽  
Mak Goto ◽  
Susan R. McCouch ◽  
...  
Keyword(s):  
Microsatellite Markers ◽  
Length Polymorphism ◽  
Oryza Sativa L ◽  
Simple Sequence Length Polymorphism ◽  
Sequence Length ◽  
Rflp Markers ◽  
Rice Varieties ◽  
Germplasm Collections ◽  
Cultivar Variation ◽  
Simple Sequence

The objective of this study was to determine an efficient way of detecting within-cultivar variation in rice varieties obtained from national and international germplasm collections. Seventy-one rice cultivars were evaluated for within-cultivar variation using a combination of phenotypic, RFLP, and microsatellite or simple sequence length polymorphism (SSLP). Variation between individuals within an accession and between duplicate accessions within a cultivar was detected even in cultivars that had been purified by phenotypic evaluation. Landrace cultivars were more heterogeneous and displayed a larger number of both RFLP and SSLP alleles than did modern cultivars. Microsatellite markers detected a greater number of alleles and were able to discriminate between even closely related individuals more efficiently than RFLPs. Some microsatellite markers were more informative than others for assessing genetic diversity. Single markers revealed 5.6–61.1% of the total variation detected by the 10 SSLP markers. Some marker combinations were complementary, providing more information than others. Several combinations of 4 SSLP markers detected as much as 94% of the total within-cultivar variation detected by the 10 SSLP markers. These results suggest that the use of four well-chosen microsatellites would be an efficient method for evaluating the heterogeneity of rice accessions.Key words: genetic variation, RFLP, microsatellite markers, simple sequence length polymorphism, SSLP, rice.

scholarly journals New eSSR and gSSR markers added to Australian barley maps

2006 ◽  
Vol 57 (9) ◽  
pp. 953 ◽  
Author(s):  
Kerrie L. Willsmore ◽  
Paul Eckermann ◽  
Rajeev K. Varshney ◽  
Andreas Graner ◽  
Peter Langridge ◽  
...  
Keyword(s):  
Expressed Sequence Tag ◽  
Genomic Library ◽  
Rice Genome ◽  
Genetic Maps ◽  
Net Blotch ◽  
Genomic Ssr ◽  
On Line ◽  
Good Coverage ◽  
Expressed Sequence ◽  
Simple Sequence

To enhance genetic maps of barley previously developed in Australia for identifying markers useable in molecular breeding, a new set of simple sequence repeat (SSR) and indel markers was added to the maps. These markers were developed through (i) database mining of barley expressed sequence tag (EST) sequences, (ii) comparative barley-rice genome analysis, and (iii) screening of a genomic library with SSR probes. The primer set selected for this study comprised 216 EST-SSR (eSSR) and 25 genomic SSR (gSSR) markers, which were screened for polymorphism on 4 doubled haploid (DH) or recombinant inbred line (RIL) populations. In total, 81 new markers were added to the maps, with good coverage on all 7 chromosomes, except 6H, which only had 2 new markers added. The marker order of previously published maps was re-evaluated by comparing recombination fractions calculated by 2 methods to discover the best position for each marker. The new SSR markers were then added to the updated maps. Several of these new markers are linked to important barley disease resistance genes such as those for cereal cyst nematode, spot form of net blotch, and leaf scald resistance, and are readily useable for marker-assisted barley breeding. The new maps are available on-line at www.genica.net.au.

Murine Albino-Deletion Complex: High-Resolution Microsatellite Map and Genetically Anchored YAC Framework Map

Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 787-799
Author(s):  
Brad A Rikke ◽  
Dabney K Johnson ◽  
Thomas E Johnson
Keyword(s):  
Positional Cloning ◽  
Interspecific Backcross ◽  
Genetic Distances ◽  
Sequence Length ◽  
Recombination Rates ◽  
Oak Ridge ◽  
Artificial Chromosomes ◽  
Microsatellite Map ◽  
Specific Locus ◽  
Yeast Artificial Chromosomes

The murine albino-deletion complex developed as part of the Oak Ridge specific-locus test covers 6–11 cM of chromosome 7. This complex has proven to be a valuable resource for localizing traits to a small target region suitable for positional cloning. In this study, we mapped the endpoints of deletions in this complex using all of the available Mit simple-sequence length polymorphism (SSLP) markers. Concurrently, this mapping has determined the map order of nearly all of the SSLP markers, most of which were previously unresolved. The SSLP-based deletion map was confirmed and genetic distances were determined using the European Collaborative Interspecific Backcross panel of nearly a thousand mice. The average SSLP marker resolution is 0.3–0.4 cM, comparable to the cloning capacity of yeast artificial chromosomes (YACs). The SSLP markers were then used to construct a genetically anchored YAC framework map that further confirms the deletion map. We find that the largest deleted region distal to Tyr is about two to three times larger than the largest proximal deleted region, and the original C3H/101 regions flanking the deletions (moved to an St2A cch/cch background) are smaller than anticipated, which we suggest may result from increased recombination rates immediately flanking the deleted regions.

scholarly journals Cloning of long sterile lemma (lsl2), a single recessive gene that regulates spike germination in rice (Oryza sativa L.)

2020 ◽  
Author(s):  
dewei yang ◽  
Niqing He ◽  
Xianghua Zheng ◽  
Yanmei Zhen ◽  
Zhenxin Xie ◽  
...  
Keyword(s):  
Seed Germination ◽  
Agronomic Traits ◽  
Oryza Sativa L ◽  
Gene Prediction ◽  
Germination Rate ◽  
Rice Genome ◽  
Recessive Gene ◽  
Floral Organ ◽  
Monocotyledonous Plant ◽  
Sterile Lemma

Abstract Background: Rice is a typical monocotyledonous plant and an important cereal crop. The structural units of rice flowers are spikelets and florets, and floral organ development and spike germination affect rice reproduction and yield.Results: In this study, we identified a novel long sterile lemma (lsl2) mutant from an EMS population. First, we mapped the lsl2 gene between the markers Indel7-22 and Indel7-27, which encompasses a 25-kb region. The rice genome annotation indicated the presence of four candidate genes in this region. Through gene prediction and cDNA sequencing, we confirmed that the target gene in the lsl2 mutant is allelic to LONG STERILE LEMMA1 (G1)/ELONGATED EMPTY GLUME (ELE), hereafter referred to as lsl2. Further analysis of the lsl2 and LSL2 proteins showed a one-amino-acid change, namely, the mutation of serine (Ser) 79 to proline (Pro) in lsl2 compared with LSL2, and this mutation might change the function of the protein. Knockout experiments showed that the lsl2 gene is responsible for the long sterile lemma phenotype. The lsl2 gene might reduce the damage induced by spike germination by decreasing the seed germination rate, but other agronomic traits of rice were not changed in the lsl2 mutant. Taken together, our results demonstrate that the lsl2 gene will have specific application prospects in future rice breeding.Conclusions: The lsl2 gene is responsible for the long sterile lemma phenotype and might reduce the damage induced by spike germination by decreasing the seed germination rate.

scholarly journals Developing Microsatellite DNA Markers in Pecan

2003 ◽  
Vol 128 (3) ◽  
pp. 374-380 ◽  
Author(s):  
L.J. Grauke ◽  
Muhammad J. Iqbal ◽  
Avutu S. Reddy ◽  
Tommy E. Thompson
Keyword(s):  
Dna Markers ◽  
Microsatellite Dna ◽  
Southern Hybridization ◽  
Genomic Library ◽  
Carya Illinoinensis ◽  
Enriched Library ◽  
Microsatellite Dna Markers ◽  
Ssr Primers ◽  
Nucleotide Repeats ◽  
Simple Sequence

A microsatellite-enriched library was developed from `Halbert', a native pecan [Carya illinoinensis (Wangenh.) K. Koch] selection from Coleman County, Texas. A genomic library enriched for simple sequence repeats (SSR) containing 6144 clones was archived in 384 well plates for screening. In total, 439 clones were identified after Southern hybridization using di- and tri-nucleotide repeats as probes. In total, 125 positive clones were sequenced and primers were designed for 24 repeats. The SSR markers chosen for analysis include di-(CT and GA) and tri-nucleotide repeats (CTT, GAA and GAT). Of the 24 primer pairs tested, 19 successfully amplified microsatellites from `Halbert'. DNA was isolated from 48 pecan and hickory accessions selected to strategically represent the genetic diversity of the National Clonal Germplasm Repository (NCGR) Carya collections. The 19 SSR primers that produced good amplification products in `Halbert' were used to evaluate the collection, with 11 revealing polymorphism. The number of fragments amplified with different primer combinations ranged from 4 to 32 in the 48 genotypes tested. Evaluation of the data confirms the utility of the microsatellites in delimiting known relationships.

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