국내의 주요 산느타리 품종인 호산47(일핵, 산타리 배우자), GB19(일핵, 산타리 배우자), 호산, 여름느타리1호, 삼복, 강산, 약산, 자산, 향산, 여름느타리2호의 유전체를 Hiseq을 이용하여 해독하였고 이 서열 정보에서 SSR을 분리하여 특성구명을 하였다. 일핵균사인 호산 47, GB19 의 유전체의 크기는 각각 37.3와 37.2 Mbp이고, 이핵균사인 나머지 산느타리 품종의 유전체 크기는 47.1~61.1 Mbp인 것으로 밝혀졌다. 품종별 총 SSR의 수는 HS47이 711개로 가장 적고, 강산이(GS)이 1.5배 많은 1,106개로 최다를 기록하였다. SSR의 repeat motif 중에서 hexanucleotide 와 octanucleotide가 가장 많은 빈도로 관찰되었고, 가장 많이 관찰되는 반복서열은 CGA/TCG, A/T, CTC/GAG이었다. SSR의 길이는 모든 품종에서 변이가 많아 유용성이 높은 20~30 nt가 가장 높은 비중인 70%를 차지하였다.
Simple sequence repeats (SSR), also referred to “microsatellites” consist of tandemly repeated short DNA sequence motifs and have been applied in various marker-based studies. SSRs were isolated and characterized from ‘Heuktari’ and ‘Miso’, which are major oyster mushroom cultivars in Korea, by genome sequencing and bioinformatic analysis. The genome sizes of ‘Heuktari’ and ‘Miso’ were estimated to be 40.8 and 40.3 Mb, respectively, which are larger than those of other P. ostreatus species (PC9 and PC10) and smaller than those of P. eryngii (KNR2312P5). In total, 949 and 968 SSRs were found in the ‘Heuktari’ and ‘Miso’ genomes, respectively. Comparative analysis of five mushrooms including P. ostreatus var. florida (PC9 and PC15) and P. eryngii revealed that the number of SSRs in ‘Heuktari’ and ‘Miso’ were the highest among them. All mushrooms studied showed similar SSR distribution patterns. Tri-, hexa-, and octanucleotide motifs accounted for the top three fractions of all SSRs.
Differentiation of Pleurotus eryngii is laborious and time-consuming tasks especially in mycelial status. For development of a method for differentiation of P. eryngii cultivars, simple sequence repeats (SSR) from whole genomic DNA sequence analysis was used for genotyping and two multiplex-SSR primer sets were developed. These SSR primer sets were employed to distinguish 12 cultivars and strains. Five polymorphic markers were selected based on the genotypes. PCR with the each primer produced one to four distinct bands ranging in size from 200 to 300 bp. Polymorphism information content (PIC) values of the five markers were in range of 0.6627 to 0.6848 with an average of 0.6775. Unweighted pair-group method with arithmetic mean clustering analysis based on genetic distances using five SSR markers classified 12 cultivars into 2 clusters. Cluster I and II comprised of 4 and 8 cultivars, respectively. Two multiplex sets, Multi-1 (SSR312 and SSR366) and Multi-2 (SSR178 and SSR277) completely discriminated 12 cultivar and strains with 21 allele with a PIC value of 0.9090. These results might be useful to provide an efficient method for the identification of P. eryngii cultivars with separate PCR reactions. (This work was supported by a grant from the Golded Seed Project (213003-04-3-SBY20), MIFAFF, Republic of Korea.]
Pleurotus eryngii, an edible white-rot fungus, is widespread in Eurasia and northern Africa. It has become a major cultivated mushroom in Asia, with a current global production rate of approximately 3 × 10 5 metrictons/yr. To improve the quality or productivity through breeding, a genetic linkage map is an important component. In this study, genetic linkage map of the P. eryngii was constructed using 98 monokaryotic progeny derived from dikaryon of parental KNR2312 strain derived from haploid meiotic spores. The whole genome sequence of P5 monokaryon from P. eryngii KNR2312 strain by Next Generation Sequencing (NGS) strategy was used to design the SSR markers. 484 primers pairs were identified by SSR Locator I and tested polymorphism via PCR. A total of 241 loci were mapped using Joinmap 4.0, comprising 222 SSR markers, 2 mating type factors, and the 13 INDEL markers. The map consisted of 14 linkage groups spanning 1003 cM at an average marker interval of 4.2 cM. The mating loci, A and B were mapped on linkage groups 4 and 11, respectively. The established linkage map and the genetic information based on NGS could be used for QTL mapping of agronomic traits, marker-assisted breeding that may ultimately lead to outstanding phenotypic characteristics. [Supported by a grant from the IPET (213003-04-3-SBY20), MIFAFF, Republic of Korea.]
Differentiation of Pleurotus eryngii is laborious and time-consuming tasks especially in mycelial status. For development of a method for differentiation of P. eryngii cultivars, simple sequence repeats (SSR) from whole genomic DNA sequence analysis was used for genotyping and two multiplex-SSR primer sets were developed. These SSR primer sets were employed to distinguish 12 cultivars and strains. Five polymorphic markers were selected based on the genotypes. PCR with the each primer produced one to four distinct bands ranging in size from 200 to 300 bp. Polymorphism information content (PIC) values of the five markers were in range of 0.6627 to 0.6848 with an average of 0.6775. Unweighted pair-group method with arithmetic mean clustering analysis based on genetic distances using five SSR markers classified 12 cultivars into 2 clusters. Cluster I and II comprised of 4 and 8 cultivars, respectively. Two multiplex sets, Multi-1 (SSR312 and SSR366) and Multi-2 (SSR178 and SSR277) completely discriminated 12 cultivar and strains with 21 allele with a PIC value of 0.9090. These results might be useful to provide an efficient method for the identification of P. eryngii cultivars with separate PCR reactions. (This work was supported by a grant from the Gold Seed Project [Supported by a grant from the IPET (213003-04-3-WTI11), MIFAFF, Republic of Korea.]
This paper extends research on interactional forms of teacher repeats and their management in third turn by analyzing teacher student interaction in Korean EFL classrooms. Research has shown that classroom interaction is characterized by an overwhelming number of teacher repetition in feedback moves fo llowing the Initiation-Response-Feedback seq uence (S inclair & Coulthard 1975); whereby the teacher controls the interaction through evaluation of the student answer. In the tightly contro lled contexts of Korean EFL classrooms, the teacher appears to be constantly placed in a position of conflict. She has to fo llow a tightly sched ul ed lesson plan, which allocates a rather strict time frame and organization, at the same time attend to indi vidual student learning. The foca l practice is understood as these teachers' attempt at resolving the obstacle through interactive practices of repeating the student response. The focal practice promotes the possib ili ty of producing a soc ially harmonious, accepting response (i.e., intersubjectiv ity) without compromising lesson progressivity, desp ite the fact that the responses or part of the response produced by the student is not fu lly accurate. Fi nally, the in teractive consequences of the focal practice are compared with other eva luative tokens that may also occur in the third turn.
Osmolarity of culture media is one of the most important factors affecting in vitro development. This study was conducted to investigate the DNA methylation status of Pre-1 and satellite sequence in pig nuclear transfer (pNT) embryos produced under different osmolarity culture conditions. Control group of pNT embryos was cultured in PZM-3 for six days. Other two treatment groups of pNT embryos were cultured in modified PZM-3 with 138 mM NaCl or 0.05M sucrose (mPZM-3, 320 mOsmol) for two days, and then cultured in PZM-3 (270 mOsmol) for four days. Previous our studies have reported that pNT embryos cultured in both hypertonic media showed significantly higher blastocyst formation rate than that of control. The DNA methylation status of the satellite sequences in blastocyst was characterized using bisulfite-sequencing technology. The satellite region had a similar methylation pattern of in vivo blastocyst among two culture groups excepting the control group. Each level of methylation is that the satellite DNA moderately methylated (43.10% of PZM-3; 56.12% of NaCl; 55.06% of sucrose; 60.00% of in vivo embryos). As a result of the sequence of PRE-1, CpG methylation pattern was similar to three groups, including in vivo group. In case of the satellite DNA region, the osmolarity conditions were affected CpG DNA methylation status while PRE-1 sequence was not affected CpG DNA methylation in pNT blastocyst stage. These results indicate that the modification of osmolarity in a culture media may influence to spatially change of DNA methylation of repetitive sequence for pNT embryo development.
한국꿩 (Korean ring-necked Pheasant, Phasianus colchicus karpowi)과 외국 아종의 유전적 유연관계를 파악하기 위해 야생 한국꿩, 사육 한국꿩, 사육 한국꿩과 외국꿩간의 잡종꿩, 외국꿩 4아종(중국 링넥, 흑 뮤탄트, 백 뮤탄트, 녹치)을 대상으로 ISSR 표지자 분석과 AMOVA 분석을 수행하였다. 야생 한국꿩의 전체 유전 다양성중 94.08%가 서식지 내 개체간 유전적 차이에 기인하고, 5.9% (Φ
There is a growing number of plant genomes that are being sequenced, but most of these available assemblies do not cover the entire genome mainly due to the highly repetitive sequences found in most plant genomes. Nevertheless, these repeats, although a challenge in assembly algorithms, provide relevant information about a genome’s history that could help explain its structure and complexity. Here, we cytogenetically mapped previously and presently characterized major repeats of Panax ginseng genome, including several LTR retrotransposons (PgDel2, PgDel3, PgTat1, PgTat2, PgTork) and one tandem repeat, PgTR Fluorescence in situ hybridization (FISH) results showed differential accumulation of Ty3/gypsy LTR retrotransposons into different chromosomal regions or subgenomes, suggesting a non-random preferential amplification of retrotransposons in these regions and an allopolyploid origin of P. ginseng. In silico analysis based on 1x whole genome sequence reads suggests that PgTR is the most abundant tandem repeat in ginseng, which was further corroborated by FISH analysis. More importantly, its unique distribution pattern among the 24 ginseng chromosomes, coupled with the non-random distribution of LTR retrotransposons and rDNA arrays, allowed us to discriminate and characterize each individual ginseng chromosome. These different newly characterized cytogenetic markers allowed reorganization of previously reported ginseng karyotype with better resolution, demonstrating the irutility in ginseng chromosome identification. These information give us insight about the genomic structure of P. ginseng, and should be useful for future comparative cytogenetics studies among closely related species to unravel its genomic history. This work was supported by the Next-Generation BioGreen21 Program (No. PJ008202), Rural Development Administration, Republic of Korea.
This study was performed to analyze genetic relationship of the four major Cucurbitaceae crop. We used 120 Expressed Sequence Tag(EST)-Simple Sequence Repeat(SSR) primer sets of developed from watermelon and published in International Cucurbit Genomics Initiative (ICuGI) database. Among 120 EST-SSR primer, 51(49.17%) EST-SSR primer set successfully amplified and 49(40.8%) EST-SSR primer set showed polymorphisms among eight cultivars of Cucurbitaceae. In the first instance, amplified PCR products analysis was conducted by the agarose-gel electrophoresis then further analyzed by using Fragment Analyzer. A total 382 PCR band were producted by 49 EST-SSR primers in 24 plant panels, used the analysis of pairwise similarity and dendrogram construction. Assessment of the genetic relationships resulted in similarity index with range of 0.0103 to 0.8452. In dendrogram, 24 plant panels were formed three major groups (A, B, C) and 7 subgroups (A-1, A-2, B-1, B-2, B-3, C-1, C-2). Major group A was comprised of 2 subgroups, subgroup A-1 (6 watermelon cultivars, Citrullus lanatus var. vulgaris Schrad.) and subgroup A-2 (3 wild type watermelon, Citrullus lanatus var. citroides Mats. & Nakai). Major group B was comprised of 3 subgroups, subgroup B-1 (4 melon cultivars, Cucumis melo var. cantalupensis Naudin.), subgroup B-2 (2 oriental melon cultivars, Cucumis melo var. conomon Makino.) and subgroup B-3 (5 cucumber cultivars, Cucumis sativus L.). Major group C was comprised of 2 subgroups, subgroup C-1 [2 squash/ pumpkin cultivars, Cucurbita moschata (Duch. ex Lam.)/Duch. & Poir. and Cucurbita maxima Duch.] and subgroup C-2(2 squash/pumpkin cultivars, Cucurbita pepo L./Cucurbita ficifolia Bouche.)
Gastrodia elata, an achlorophyllous orchid plant, is rare medicinal plant. We investigated the genetic diversity in G. elata from 4 locations by using Inter-Simple Sequence Repeats (ISSR) markers. Shannon's information Index (S.I.) indicating genetic diversity ranged from 0.255 (Pocheon) to 0.322 (Muju) with the mean of 0.29. The level of genetic diversity was lower than other plant and most genetic diversity was allocated among individuals within populations (26.81%). The UPGMA dendrogram based on genetic distance failed in showing decisive geographic relationship. In the case of gastrodin (GA), the major components in G. elata, Sangju was highest. The ergothionine (ERG) was detected a lot of contents in Muju and Pocheon. In conclusion, our results is very important information for explaining relationship of genetic variation and functional substances without the effects of environment factors and developing genetic marker by ISSR in G. elata, which may be responsible for the development of breeds with a lot of functional substance in G. elata.
The genetic diversity and the genetic relationship among 30 genetic resources of T. officinale and T. coreanum collected from 20 regions in Korea were evaluated by using ISSR markers. Out of 127 loci detected overall, 122 were identified to be polymorphic with a rate of 96.0% at the 30 individuals. The intraspecific polymorphism between T. officinale and T. coreanum was 92.6% and 88.2%, respectively. The genetic similarity matrix (GSM) revealed a wide range of variablility among the 30 accessions, spanning from 0.179 to 922. According to the clustering analysis, different species T. officinale and T. coreanum, were divided into independent groups and all of the accessions could be classified into 7 categories. Especially, all of the mountain collected accessions belonged to independent groups. The study findings indicate that T. officinale and T. coreanum accessions have a high genetic diversity and accordingly carry a germ-plasm qualifying as good genetic resources for breeding.
The polymorphism and the genetic relationships among 32 genetic resources of genus Nelumbo from Korea, Japan, China, USA, India, Thailand and Gabong were thoroughly investigated and extensively examined using ISSR markers. Out of 103 loci detected overall, 94 were identified to be polymorphic with a rate of 91.2%. The genetic similarity matrix revealed a wide range of variability among the 32 accessions, spanning from 0.227 to 0.833. The study findings indicate that the Nelumbo accessions have a high genetic diversity, and accordingly carry a germplasm qualifying as good genetic resources for cross breeding. According to the clustering analysis, different subspecies, N. nucifera and N. lutea, were divided into independent groups and all of the N. nucifera accessions could be classified into five categories. Compared to RAPD analysis, ISSR method showed a clearer picture of polymorphism among the accessions and exhibited a definite distinction even among the subspecies. In this respect, ISSR analysis is considered to be more effective in differentiating the accessions and subspecies of the genus Nelumbo than RAPD test.
Cowpea might have been introduced from China to Korea and cultivated for several hundred years but it has never been a staple food crop in Korea. In this study, genetic diversity of 492 Korean cowpea landrace accessions that have passport information was estimated using six SSR markers. The mean of Weir's gene diversity was 0.665 from all accessions investigated in the study. Cowpea gene diversity of six local provinces in Korea was ranged from 0.370 in accessions of Gangwon to 0.680 in Jeonra provinces. Low gene diversity of the cowpea genepool of Gangwon province was probably derived from relatively few introductions. Especially SSR markers VM36 and VM39 seem to be good markers to distinguish the Gangwon accessions from others by occurring at a specific locus with higher than 78% of allele frequency. Except for the Gangwon province with the low genetic diversity, gene diversity of cowpea accessions from other provinces was ranged from 0.600 to 0.680 indicating no big differences among provinces. Distribution pattern of the allele frequencies was similar among the other provinces. This may reveal that Korean farmers might exchange cowpea seeds easily with even their neighbors with geographical barriers. A core collection, 100 landraces, ca. 20% of base collection, was developed at the 70% of a similarity coefficient level using random sampling approaches after stratification of the entire landrace collection based on the phenetic dendrogram. The variability of SSR in the base and core collections of Korean cowpea landrace was compared by calculating Weir's gene diversity. The mean of Weir's gene diversity of the core was 0.707 while that of the base collection was 0.665. The higher diversity index in the core collection indicates that it maintains the initial variability and well represents the base collection. The core collection included one of determinate accession (IT 216155) and two of no branching type accessions (IT 103959 and IT 161024). The core collection could be used to guide more efficient management and utilization of the entire collection. This core collection should be revised periodically as additional accessions are collected and further characterization is conducted.
In Korea, chilli pepper (Capsicum annum L.) is a major vegetable crop. The pepper seed market is about $35 million and the whole sale market including processed products is equivalent to $2 billion, representing the second highest market value among crops, next to rice in Korea. Since the development of elite pepper variety is so competitive, vegetable seed companies usually run two important programs to keep the credibility of seed quality. One program is to deliver F1 hybrid seeds with a high purity test to farmers. The purity control of parents and F1 hybrid to avoid any contamination is conducted by DNA markers because pepper seeds are obtained using MS line. The other program is to identify the F1 variety from other varieties by analyzing the polymorphism so that the company and/or breeder protects the intellectual property from copying by others or from non-intentional contamination.
We have developed about 900 EST-SSR sets from pepper and used to both programs. A total of 66 markers were selected to identify 32 F1 varieties and their own parents. Using these markers, the purity control of F1 hybrid rose up to the highest degree. We also found several SSR markers to distinguish F1 variety from other varieties and these markers could be useful to find the uniqueness of F1 cultivar.