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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Analysis of Sex Determination in Some Cycads Using Methylation- Sensitive Amplification Polymorphism (MSAP)) ผู้เขียน: ฐิติ กาญจนเกตุ,  ดร.วิภา หงษ์ตระกูล, รองศาสตราจารย์ , ดร.นิตย์ศรี แสงเดือน, ศาสตราจารย์เกียรติคุณ สื่อสิ่งพิมพ์:pdf AbstractThis is the first report on the analysis of sex determination in cycads using MSAP technique. Prior works using cytogenetic techniques, molecular markers such as random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) did not clearly identify sex in cycads. This modified AFLP technique using isochizomer enzyme (MspI and HpaII) called methylationsensitive amplification polymorphism (MSAP) was carried out to assess the pattern of cytosine methylation in both sexes of Cycas and Zamia. Using seven pairs of primers, 364 bands some of which showing sex-specific were produced and classified into three groups. The first group was non-polymorphic markers, whereas the second group was chosen from the results of differentation ability of MspI and HpaII to cut the methylated sequences, but sex-different markers were not obtained. Markers in the third group were methylation-sensitive and they also showed some polymorphic patterns between the two sexes. We suggested that sex in cycads may be associated with DNA methylation, but further study is required to reach a conclusive result. |
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ที่มา:มหาวิทยาลัยเกษตรศาสตร์หัวเรื่อง:การวิเคราะห์รูปแบบการเติมหมู่เมธิลให้กับดีเอ็นเอต่อลักษณะเพศของปรงสกุล Cycas ในประเทศไทยโดยเทคนิค Methylation-Sensitive Amplification Polymorphism (MSAP) เพื่อนำไปสู่การพัฒนาเครื่องหมายโมเลกุลจำเพาะกั |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Treatment of 5-Azacytidine as DNA Demethylating Agent in Jatropha curcas L.) ผู้เขียน:ฐิติ กาญจนเกตุ, ดร.วิภา หงษ์ตระกูล, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThe role of DNA methylation (the most well-known epigenetic regulation mechanism found in many plant species) was investigated in the development of Jatropha curcas L. using the DNA demethylating agent, 5-azacytidine (AzaC). The treatments were performed in the greenhouse and as a separate embryo culture experiment. The results showed that plants responded to AzaC by both accelerating and inhibiting growth and development. Some plants exhibited observable morphological abnormalities, such as stem bending, reduced plant height and increased stem branching. The most severe effect in the treated plants was the significant failure of root development, which was lethal. The efficiency of AzaC was confirmed by methylation sensitive amplification polymorphism (MSAP) analysis of the treated plants. The MSAP fingerprints showed changes in DNA methylation at the nucleotide level. The cDNA-amplified fragment length polymorphism (cDNA-AFLP) analysis revealed differential gene expression in the treated plants compared to the untreated control plants in both the greenhouse and embryo culture experiments. The differential sequences matched with some known genes. However, the majority of differential sequences were found to be retroelement derivatives. Reverse transcription polymerase chain reaction (RT-PCR) analysis of four major DNA methyltransferase genes indicated that only the DRM and Dnmt2 genes were up-regulated in AzaC-treated J. curcas plants. This study demonstrated the important role of DNA methylation in the normal development of J. curcas. The cDNA-AFLP and RT-PCR results led to the hypothesis that AzaC inhibits DNA methylation in particular regions during the first stage of plant development and is involved in the movement of the transposable element in the genome which in turn causes phenotypic abnormalities and activates RNA-dependent DNA methylation pathways. However, this hypothesis requires further intensive study. |
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