• Journal of Plant Biotechnology
• /
• 제37권2호
• /
• pp.212-219
• /
• 2010

Selectable marker gene systems are vital for the development of transgenic plants, but the presence of selectable marker genes encoding antibiotic or herbicide resistance in genetically modified plants poses a number of problems. A lot of research results and various techniques have been developed to produce marker-free GM plants. The aim of this review is to describe the principal methods used for eliminating selectable marker genes to generate marker-free GM plants, concentrating on the three significant methods(co-transformation, site-specific recombinase-mediated excision, non-selected transformation) in several marker-free techniques.

• The Plant Pathology Journal
• /
• 제39권5호
• /
• pp.494-503
• /
• 2023

Xanthomonas campestris pv. campestris (Xcc) is a plant pathogen of Brassica crops that causes black rot disease throughout the world. At present, 11 physiological races of Xcc (races 1-11) have been reported. The conventional method of using differential cultivars for Xcc race detection is not accurate and it is laborious and time-consuming. Therefore, the development of specific molecular markers has been used as a substitute tool because it offers an accurate and reliable result, particularly a quick diagnosis of Xcc races. Previously, our laboratory has successfully developed race-specific molecular markers for Xcc races 1-6. In this study, specific molecular markers to identify Xcc race 7 have been developed. In the course of study, whole genome sequences of several Xcc races, X. campestris pv. incanae, X. campestris pv. raphani, and X. campestris pv. vesicatoria were aligned to identify variable regions like sequence-characterized amplified regions and insertions and deletions specific to race 7. Primer pairs were designed targeting these regions and validated against 22 samples. The polymerase chain reaction analysis revealed that three primer pairs specifically amplified the DNA fragment corresponding to race 7. The obtained finding clearly demonstrates the efficiency of the newly developed markers in accurately detecting Xcc race 7 among the other races. These results indicated that the newly developed marker can successfully and rapidly detect Xcc race 7 from other races. This study represents the first report on the successful development of specific molecular markers for Xcc race 7.

• Journal of Plant Biotechnology
• /
• 제50권
• /
• pp.190-199
• /
• 2023

Date palm (Phoenix dactylifera L.: Arecaceae) is a dioecious species where only female trees bear fruits. In their natural state, date palms produce dates once a year. However, in Thailand, some trees were observed to produce dates during the off-season, despite no variations in morphology. The availability of such off-season fruits can significantly increase their market value. Interestingly, most female off-season date palms investigated in this study were obtained through micropropagation. Hence, there is an urgent need for genetic markers to distinguish female offseason flowering plantlets within tissue culture systems. In this study, we aimed to develop random amplification of polymorphic DNA-sequence characterized amplified region (RAPD-SCAR) markers for the identification of female off-season flowering date palms cultivated in Thailand. A total of 160 random decamer primers were employed to screen for specific RAPD markers in off-season flowering male and female populations. Out of these, only one primer, OPN-02, generated distinct genomic DNA patterns in female off-season flowering (FOFdp) individuals compared to female seasonal flowering genotypes. Based on the RAPD-specific sequence, specific SCAR primers denoted as FOFdpF and FOFdpR were developed. These SCAR primers amplified a single 517-bp DNA fragment, predominantly found in off-season flowering populations, with an accuracy rate of 60%. These findings underscore the potential of SCAR marker technology for tracking offseason flowering in date palms. Notably, a BLAST analysis revealed a substantial similarity between the SCAR marker sequence and the transcript variant mRNA from Phoenix dactylifera encoding the SET DOMAIN GROUP 40 protein. In Arabidopsis, this protein is involved in the epigenetic regulation of flowering time. The genetic potential of the off-season flowering traits warrants further elucidation.

• 한국육종학회지
• /
• 제42권2호
• /
• pp.139-143
• /
• 2010

Late blight caused by Phytophthora infestans is historically a serious epidemic disease in potato and tomato cultivations. Accession L3708 (Solanum pimpinellifolium), a new source for late blight resistance was identified in AVRDC, and carries the resistance gene, Ph-3, incompatible to P. infestans race 3. The AFLP markers linked to Ph-3 were previously developed from the L3708 accession (Chunwongse et al. 2002). To facilitate tomato breeding with the Ph-3 gene, an attempt was made to convert AFLP markers to sequence-characterized amplified region (SCAR) markers. Among 6 AFLP markers, only one AFLP marker, L87, was successfully converted to SCAR marker. The resistance-specific 230 bp AFLP fragment was cloned and sequenced, and the PCR primer amplifying a 123 bp fragment was designed. This SCAR marker could discriminate resistant and susceptible individuals with high stringency. The developed SCAR marker could be used for the marker assisted-selection in tomato breeding programs.

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 2001년도 한국생물과학협회 학술발표대회
• /
• pp.120.2-120
• /
• 2001

• Journal of Microbiology and Biotechnology
• /
• 제28권5호
• /
• pp.826-830
• /
• 2018

A Cre/loxP-${\delta}$-integration system was developed to allow sequential and simultaneous integration of a multiple gene expression cassette in Saccharomyces cerevisiae. To allow repeated integrations, the reusable Candida glabrata MARKER (CgMARKER) carrying loxP sequences was used, and the integrated CgMARKER was efficiently removed by inducing Cre recombinase. The XYLP and XYLB genes encoding endoxylanase and ${\beta}$-xylosidase, respectively, were used as model genes for xylan metabolism in this system, and the copy number of these genes was increased to 15.8 and 16.9 copies/cell, respectively, by repeated integration. This integration system is a promising approach for the easy construction of yeast strains with enhanced metabolic pathways through multicopy gene expression.

• Plant Resources
• /
• 제7권2호
• /
• pp.136-140
• /
• 2004

Co-segregation of male fertility with DNA markers selected by RAPD analysis as being potentially linked to the restorer gene (Rf) for Cytoplasmic male sterility (CMS) was analyzed using segregating F2 population. One RAPD marker directly linked to the Rf locus was identified. Amplification of OPT-02/570 using the STS primers generated a monomorphic band of each fertile plants randomly selected F2 progenies. From these results, this specific marker would be strongly linked to be restoring gene. The use of STS marker is effective in overcoming the reliability of the RAPD phenotype and improving their utility for MAS, co-dominant STS markers are especially very useful.

• 한국버섯학회지
• /
• 제11권3호
• /
• pp.171-176
• /
• 2013

큰느타리버섯의 저온성적응성 형질에 관련된 SCAR marker를 개발하기 위하여 저온성 계통의 8균주와 대조구 8균주의 genomic DNA를 30 ug/ml의 농도로 bulking한 것을 주형 DNA로 사용하고 operon 사의 OPA(20개), OPB(20개), OPL(20개), OPP(20개), OPR(20개), OPS(20개) 등 총 120개 primer를 random primer(10 mer)로 사용하여 RAPD를 수행하였으며 이중에서 OP-S3 primer를 사용한 PCR 산물들이 대조구와 가장 뚜렷한 차이를 나타내었다. OP-S3 primer를 이용한 RAPD 결과, 약 480 bp 부근에서 저온성 계통에 특이적인 DNA band가 관찰되었으며 이 DNA band의 염기서열을 근거로 SCAR marker로 사용할 specific primer인 OP-S3-1-F와 OP-S3-1-R를 디자인하였다. SCAR marker OP-S3-1 primer를 이용하여 PCR을 수행한 결과에서는 저온성 계통에서만 480 bp 부근에서 대조구와 구별되는 DNA band를 확인할 수 있었으며 random primer인 OP-S3 primer를 이용하여 PCR을 수행했을 때보다 재현성이 높고 진한 DNA band를 확인할 수 있었다.

• 한국환경과학회지
• /
• 제20권10호
• /
• pp.1221-1232
• /
• 2011

We investigated the toxic effects of difenoconazole on the development in the African clawed frog, Xenopus laevis. To test the toxic effects, frog embryo teratogenesis assays using Xenopus were performed. Embryos were exposed to various concentrations of difenoconazole (0-30 ${\mu}M$). $LC_{100}$ for difenoconazole was 30 ${\mu}M$, and the $LC_{50}$ determined by probit analysis was 27.19 ${\mu}M$. Exposure to difenoconazole concentrations ${\geq}$5 ${\mu}M$ resulted in 10 different types of severe external malformation. Histological examinations revealed dysplasia of the eye, heart, liver, somatic muscle, and swelling of the pronephric ducts. The tissue-specific toxic effects were investigated with an animal cap assay. Blood cells were normally induced at a high frequency by mSCF and activin A. However, the induction of blood cells was strongly inhibited by the addition of difenoconazole. Electron micrographs of tested embryos showed the degeneration of somatic muscle and the shrinkage of microvilli on pronephric duct. The gene expression of cultivated animal cap explants was investigated by reverse transcriptase-polymerase chain reaction (RT-PCR). It revealed that the expression of the blood-specific marker(${\beta}$-globin II) and muscle-specific marker (XMA) were more strongly inhibited than the neural-specific marker(XEn2) by the addition of difenoconazole.

• 한국환경과학회지
• /
• 제19권8호
• /
• pp.1001-1012
• /
• 2010

We investigated the toxic effects of tebuconazole on development in the African clawed frog, Xenopus laevis. To test the toxic effects, frog embryo teratogenesis assays using Xenopus were performed. Embryos were exposed to various concentrations of tebuconazole($0-100\;{\mu}M$). $LC_{100}$ for tebuconazole was $100\;{\mu}M$, and the $LC_{50}$ determined by probit analysis was $82.35\;{\mu}M$. The exposure to tebuconazole concentrations ${\geq}40\;{\mu}M$ resulted in 11 different types of severe external malformations including gut dysplasia. Histological examinations revealed various dysplasia in the eye, heart, liver, intestine, somatic muscle, and in the pronephric ducts. The tissue-specific toxic effects were investigated with an animal cap assay. Blood cells are generally induced at a high frequency by the combination of mSCF and activin A, however, the induction of blood cells was strongly inhibited by the addition of tebuconazole. Electron micrographs of tested embryos showed many of multivesicular bodies and dysplasia of photo-receptive cell, however, the somatic muscle degeneration was not severe. The gene expression of cultivated animal cap explants was investigated by reverse transcriptase-polymerase chain reaction and revealed that expression of the blood-specific marker, $\beta$ globin II and muscle-specific marker, muscle actin were more strongly inhibited than the neural-specific marker, XEn2.