Background:NANOG is a core transcription factor(TF)in embryonic stem cells(ESCs)and primordial germ cells(PGCs).Regulation of the NANOG gene by TFs,epigenetic factors,and autoregulatory factors is well characterized i...Background:NANOG is a core transcription factor(TF)in embryonic stem cells(ESCs)and primordial germ cells(PGCs).Regulation of the NANOG gene by TFs,epigenetic factors,and autoregulatory factors is well characterized in ESCs,and transcriptional regulation of NANOG is well established in these cells.Although NANOG plays a key role in germ cells,the molecular mechanism underlying its transcriptional regulation in PGCs has not been studied.Therefore,we investigated the mechanism that regulates transcription of the chicken NANOG(cNANOG)gene in PGCs and ESCs.Results:We first identified the transcription start site of cNANOG by 5′-rapid amplification of cDNA ends PCR analysis.Then,we measured the promoter activity of various 5′flanking regions of cNANOG in chicken PGCs and ESCs using the luciferase reporter assay.cNANOG expression required transcriptional regulatory elements,which were positively regulated by POU5F3(OCT4)and SOX2 and negatively regulated by TP53 in PGCs.The proximal region of the cNANOG promoter contains a positive transcriptional regulatory element(CCAAT/enhancer-binding protein(CEBP)-binding site)in ESCs.Furthermore,small interfering RNA-mediated knockdown demonstrated that POU5F3,SOX2,and CEBP played a role in cell type-specific transcription of cNANOG.Conclusions:We show for the first time that different trans-regulatory elements control transcription of cNANOG in a cell type-specific manner.This finding might help to elucidate the mechanism that regulates cNANOG expression in PGCs and ESCs.展开更多
Purpose: This study was conducted to develop a guideline for HIV testing in South Korea where the HIV prevalence is very low. It is necessary to make the recommendations presented here based on the epidemiology of opp...Purpose: This study was conducted to develop a guideline for HIV testing in South Korea where the HIV prevalence is very low. It is necessary to make the recommendations presented here based on the epidemiology of opportunistic infection and cancer in the community. Methods: The development of a guideline for HIV testing was conducted using literature reviews and the agreement of Korean experts for HIV patients using a two-round Delphi consensus technique. Each expert was asked to independently answer to each item related to HIV risk. Ten experts participated in the two-round survey. Results: The individual items were determined based on the following categories: high risk behavior, symptom and diseases, colo-rectal diseases, uro-genital diseases and gynecology, skin and oral diseases. The final guideline consisted of 4-scale agreement rating (strongly recommended, recommended, not routinely recommended, no recommendation for routine provision). Discussion: We have developed the guideline for HIV testing in a country where the HIV prevalence is low based on a systematic investigation and expert consensus.展开更多
Dear Editor, The merits of using quaff as an avian experimental model include high egg production, low maintenance cost, small body size, and short generation period （approximately 6-8 weeks）. Indeed, these charact...Dear Editor, The merits of using quaff as an avian experimental model include high egg production, low maintenance cost, small body size, and short generation period （approximately 6-8 weeks）. Indeed, these characteristics make quail an ideal species for many biological areas including transgenic research. Methods of primordial germ cell （PGC）-mediated germline chimera production are considered very reliable and have been used in avian transgenesis.展开更多
基金This work was supported by a National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)[2015R1A3A2033826]and[2018R1D1A1B07049376].
文摘Background:NANOG is a core transcription factor(TF)in embryonic stem cells(ESCs)and primordial germ cells(PGCs).Regulation of the NANOG gene by TFs,epigenetic factors,and autoregulatory factors is well characterized in ESCs,and transcriptional regulation of NANOG is well established in these cells.Although NANOG plays a key role in germ cells,the molecular mechanism underlying its transcriptional regulation in PGCs has not been studied.Therefore,we investigated the mechanism that regulates transcription of the chicken NANOG(cNANOG)gene in PGCs and ESCs.Results:We first identified the transcription start site of cNANOG by 5′-rapid amplification of cDNA ends PCR analysis.Then,we measured the promoter activity of various 5′flanking regions of cNANOG in chicken PGCs and ESCs using the luciferase reporter assay.cNANOG expression required transcriptional regulatory elements,which were positively regulated by POU5F3(OCT4)and SOX2 and negatively regulated by TP53 in PGCs.The proximal region of the cNANOG promoter contains a positive transcriptional regulatory element(CCAAT/enhancer-binding protein(CEBP)-binding site)in ESCs.Furthermore,small interfering RNA-mediated knockdown demonstrated that POU5F3,SOX2,and CEBP played a role in cell type-specific transcription of cNANOG.Conclusions:We show for the first time that different trans-regulatory elements control transcription of cNANOG in a cell type-specific manner.This finding might help to elucidate the mechanism that regulates cNANOG expression in PGCs and ESCs.
文摘Purpose: This study was conducted to develop a guideline for HIV testing in South Korea where the HIV prevalence is very low. It is necessary to make the recommendations presented here based on the epidemiology of opportunistic infection and cancer in the community. Methods: The development of a guideline for HIV testing was conducted using literature reviews and the agreement of Korean experts for HIV patients using a two-round Delphi consensus technique. Each expert was asked to independently answer to each item related to HIV risk. Ten experts participated in the two-round survey. Results: The individual items were determined based on the following categories: high risk behavior, symptom and diseases, colo-rectal diseases, uro-genital diseases and gynecology, skin and oral diseases. The final guideline consisted of 4-scale agreement rating (strongly recommended, recommended, not routinely recommended, no recommendation for routine provision). Discussion: We have developed the guideline for HIV testing in a country where the HIV prevalence is low based on a systematic investigation and expert consensus.
文摘Dear Editor, The merits of using quaff as an avian experimental model include high egg production, low maintenance cost, small body size, and short generation period （approximately 6-8 weeks）. Indeed, these characteristics make quail an ideal species for many biological areas including transgenic research. Methods of primordial germ cell （PGC）-mediated germline chimera production are considered very reliable and have been used in avian transgenesis.
