The emergence of antiretroviral resistance mutations represents a major threat to the achievement of national and global goals for the elimination of HIV-1 infection. The global strategy in 2019 in Cte d'Ivoire is...The emergence of antiretroviral resistance mutations represents a major threat to the achievement of national and global goals for the elimination of HIV-1 infection. The global strategy in 2019 in Cte d'Ivoire is a new national policy for the management of people living with HIV with the administration of dolutegravir (DTG)-based fixed-dose combination. The aim of our study was to evaluate HIV-1 resistance to antiretrovirals (ARVs) in infected adult subjects in Cte d’Ivoire in the context of a systematic switch to a DTG-based combination. Between February 2022 and October 2023, a cross-sectional survey with random sampling was conducted in 06 services caring for people living with HIV. A total of 139 participants were included in the study. Adults with a viral load ≥ 1000 copies/mL were tested for HIV-1 ARV resistance mutations. Molecular analyses were performed using protocol of ANRS-MIE (National Agency for Research on AIDS and emerging infectious diseases). The interpretation is performed by HIVGRAD (https://www.hiv-grade.de/cms/grade/). The frequencies of HIV-1 resistance to non-nucleotide reverse transcriptase inhibitors (NNRTIs), nucleotide reverse transcriptase inhibitors (NRTIs), integrase inhibitors (IINTs) and protease inhibitors (PIs) were 82%, 73%, 19% and 11% respectively. The main mutations observed in the different classes were K103N (45%), M184V (64%), E157Q (19%) and L10V/M46I/A71V/I54V (6%) respectively. This study reveals the emergence of resistance to DTG-based fixed-dose combinations, favored by high rates of resistance to NRTIs and NNRTIs. This finding underlines the need for enhanced viral load monitoring and HIV-1 genotyping tests to guide the choice of NRTIs for combination therapy. In addition, monitoring for mutations to second-generation NRTIs is essential, given the scale-up of DTG-based regimens currently underway in Cte d’Ivoire.展开更多
Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-st...Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species.展开更多
Chlorophyll (Chl) content,especially Chl b content,and stomatal conductance (G_s) are the key factors affecting the net photosynthetic rate (P_n).Setaria italica,a diploid C_4 panicoid species with a simple genome and...Chlorophyll (Chl) content,especially Chl b content,and stomatal conductance (G_s) are the key factors affecting the net photosynthetic rate (P_n).Setaria italica,a diploid C_4 panicoid species with a simple genome and high transformation efficiency,has been widely accepted as a model in photosynthesis and drought-tolerance research.The current study characterized Chl content,G_s,and P_n of 48 Setaria mutants induced by ethyl methanesulfonate.A total of 24,34,and 35 mutants had significant variations in Chl content,G_s,and P_n,respectively.Correlation analysis showed a positive correlation between increased G_s and increased P_n,and a weak correlation between decreased Chl b content and decreased P_n was also found.Remarkably,two mutants behaved with significantly decreased Chl b content but increased P_n compared to Yugu 1.Seven mutants behaved with significantly decreased G_s but did not decrease P_(n )compared to Yugu 1.The current study thus identified various genetic lines,further exploration of which would be beneficial to elucidate the relationship between Chl content,G_s,and P_n and the mechanism underlying why C_4 species are efficient at photosynthesis and water saving.展开更多
Peanut(Arachis hypogaea L.)is an oil and economic crop of vital importance,and peanut pod is the key organ influencing the yield and processing quality.Hence,the Pod-related traits(PRTs)are considered as important agr...Peanut(Arachis hypogaea L.)is an oil and economic crop of vital importance,and peanut pod is the key organ influencing the yield and processing quality.Hence,the Pod-related traits(PRTs)are considered as important agronomic traits in peanut breeding.To broaden the variability of PRTs in current peanut germplasms,three elite peanut cultivars were used to construct Ethyl methane sulfonate(EMS)-induced mutant libraries in this study.The optimal EMS treatment conditions for the three peanut varieties were determined.It was found that the median lethal dose(LD50)of EMS treatment varied greatly among different genotypes.Finally,the EMS-induced peanut mutant libraries were constructed and a total of 124 mutant lines for PRTs were identified and evaluated.Furthermore,“M-8070”,one of the mutant lines for pod constriction,was re-sequenced via high-throughput sequencing technology.The genome-wide variations between“M-8070”and its wild parent“Fuhua 8”(FH 8)were detected.2994 EMS-induced single nucleotide polymorphisms(SNPs)and 1188 insertion-deletions(InDels)between“M-8070”and its wild parent were identified.The predominant SNP mutation type was C/G to T/A transitions,while the predominant InDel mutation type was“1-bp”.We analyzed the distribution of identified mutations and annotated their functions.Most of the mutations(91.68%of the SNPs and 77.69%of the InDels)were located in the intergenic region.72 SNPs were identified in the exonic region,leading to 27 synonymous,43 nonsynonymous and 2 stop-gain variation for gene structure.13 Indels were identified in the exonic region,leading to 4 frame-shift,8 non-frame-shift and 1 stop-gain variations of genes.These mutations may lead to the phenotypic variation of“M-8070”.Our study provided valuable resources for peanut improvement and functional genomic research.展开更多
The phenotype of a common bean plant is often closely related to its yield,and the yield of plants with reduced height or poor stem development during growth is low.Mutants serve as an essential gene resource for comm...The phenotype of a common bean plant is often closely related to its yield,and the yield of plants with reduced height or poor stem development during growth is low.Mutants serve as an essential gene resource for common bean breeding genetic research.Although model plants and crops are studied to comprehend the molecular mechanisms and genetic basis of plant phenotypes,the molecular mechanism of phenotypic variation in common beans remains underexplored.We here used the mutant‘nts’as material for transcriptome sequencing analysis.This mutant was obtained through 60Co-γirradiation from the common bean variety‘A18’.Differentially expressed genes were mainly enriched in GO functional entries such as cell wall organization,auxin response and transcription factor activity.Metabolic pathways significantly enriched in KEGG analysis included plant hormone signal transduction pathways,phenylpropanoid biosynthesis pathways,and fructose and mannose metabolic pathways.AUX1(Phvul.001G241500),the gene responsible for auxin transport,may be the key gene for auxin content inhibition.In the plant hormone signal transduction pathway,AUX1 expression was downregulated and auxin transport across the membrane was blocked,resulting in stunted growth of the mutant‘nts’.The results provide important clues for revealing the molecular mechanism of‘nts’phenotype regulation in bean mutants and offer basic materials for breeding beneficial phenotypes of bean varieties.展开更多
An EMS(ethy methanesulfonate)-induced lethal etiolated(le)mutant obtained from the rice variety Zhongjian 100 was characterized by lethal etiolated phenotypes,with significantly reduced levels of chlorophyll a,chlorop...An EMS(ethy methanesulfonate)-induced lethal etiolated(le)mutant obtained from the rice variety Zhongjian 100 was characterized by lethal etiolated phenotypes,with significantly reduced levels of chlorophyll a,chlorophyll b,total chlorophyll,and carotenoids.Additionally,the mutant displayed a significantly decreased number of chloroplast grana,along with irregular and less-stacked grana lamellae.The le mutant showed markedly diminished root length,root surface area,and root volume compared with the wild type.It also exhibited significantly lower catalase activity and total protein content,while peroxidase activity was significantly higher.Using the map-based cloning method,we successfully mapped the LE gene to a 48-kb interval between markers RM16107 and RM16110 on rice chromosome 3.A mutation(from T to C)was identified at nucleotide position 692 bp of LOC_Os03g59640(ChlD),resulting in a change from leucine to proline.By crossing HM133(a pale green mutant with a single-base substitution of A for G in exon 10 of ChlD subunit)with a heterozygous line of le(LEle),we obtained two plant lines heterozygous at both the LE and HM133 loci.Among 15 transgenic plants,3 complementation lines displayed normal leaf color with significantly higher total chlorophyll,chlorophyll a,and chlorophyll b contents.The mutation in le led to a lethal etiolated phenotype,which has not been observed in other ChlD mutants.The mutation in the AAA+domain of ChlD disrupted the interaction of ChlDle with ChlI as demonstrated by a yeast two-hybrid assay,leading to the loss of ChlD function and hindering chlorophyll synthesis and chloroplast development.Consequently,this disruption is responsible for the lethal etiolated phenotype in the mutant.展开更多
柱头外露作为提高作物异交率、制种纯度和降低制种成本的优良性状,在杂交制种中得到了广泛的利用。绿豆是一种闭花授粉的作物,被报道的柱头外露突变体很少。通过对冀绿7号的化学诱变,发现了1个柱头外露突变体se2,为明确该突变体柱头外...柱头外露作为提高作物异交率、制种纯度和降低制种成本的优良性状,在杂交制种中得到了广泛的利用。绿豆是一种闭花授粉的作物,被报道的柱头外露突变体很少。通过对冀绿7号的化学诱变,发现了1个柱头外露突变体se2,为明确该突变体柱头外露的分子机制,对该突变体及其野生型冀绿7号即将开放的花蕾进行了转录组测序(RNA-seq)分析。根据差异倍数|log2(Fold Change)|≥1,P≤0.05的标准筛选,在se2中共得到572个差异表达基因(differentially expressed genes,DEGs),其中262个DEGs上调,310个DEGs下调。在基因本体(gene ontology,GO)数据库中,差异表达基因显著富集到代谢和生物合成等生物过程,定位在质外体和细胞壁、细胞膜等区域,与结合、氧化还原等分子功能有关。在京都基因与基因组百科全书(kyoto encyclopedia of genes and genome,KEGG)数据库中,差异表达基因显著富集在植物激素信号传导、次生代谢物生物合成等通路。功能注释发现许多有关细胞壁合成和代谢、细胞分裂和细胞扩张、植物激素相关的基因,因此推测se2突变体中龙骨瓣的细胞分裂、细胞扩张以及植物激素信号传导过程受到影响,从而导致了柱头外露。本研究为今后探究绿豆柱头外露的分子机制以及该性状在绿豆杂种优势中的利用奠定了基础。展开更多
为探讨水稻叶绿体发育的分子机制,通过对粳稻日本晴进行甲基磺酸乙酯(EMS)诱变,获得一个稳定遗传的叶色白化突变体wrg20(white turn green 20),并对其进行表型鉴定、基因定位和功能分析。与野生型(WT)相比,该突变体于30℃培养时在三叶...为探讨水稻叶绿体发育的分子机制,通过对粳稻日本晴进行甲基磺酸乙酯(EMS)诱变,获得一个稳定遗传的叶色白化突变体wrg20(white turn green 20),并对其进行表型鉴定、基因定位和功能分析。与野生型(WT)相比,该突变体于30℃培养时在三叶期之前完全白化,26℃时突变体白化叶片部分返绿。遗传分析结果表明,该突变性状受单隐性核基因控制。将该突变体与籼稻93-11杂交,构建F2分离群体并进行基因定位,将该基因定位于2号染色体198 kb区间内,通过测序发现LOC_Os02g33610存在由G至A单碱基替换,导致编码的天冬氨酸转化为天冬酰胺,表明该基因可能为OsWRG20的候选基因,与先前所报道的调控叶绿体发育的基因GRY79为等位基因。对该基因进行结构和功能分析,表明OsWRG20可能是调控水稻苗期幼叶生长发育的重要基因。与野生型相比,突变体的叶绿体基因内含子剪接效率降低,由此推断OsWRG20可能通过调控叶绿体RNA的剪接,参与调控水稻苗期叶绿体的发育。本研究结果为苗期水稻叶绿体发育研究提供了新的理论基础。展开更多
文摘The emergence of antiretroviral resistance mutations represents a major threat to the achievement of national and global goals for the elimination of HIV-1 infection. The global strategy in 2019 in Cte d'Ivoire is a new national policy for the management of people living with HIV with the administration of dolutegravir (DTG)-based fixed-dose combination. The aim of our study was to evaluate HIV-1 resistance to antiretrovirals (ARVs) in infected adult subjects in Cte d’Ivoire in the context of a systematic switch to a DTG-based combination. Between February 2022 and October 2023, a cross-sectional survey with random sampling was conducted in 06 services caring for people living with HIV. A total of 139 participants were included in the study. Adults with a viral load ≥ 1000 copies/mL were tested for HIV-1 ARV resistance mutations. Molecular analyses were performed using protocol of ANRS-MIE (National Agency for Research on AIDS and emerging infectious diseases). The interpretation is performed by HIVGRAD (https://www.hiv-grade.de/cms/grade/). The frequencies of HIV-1 resistance to non-nucleotide reverse transcriptase inhibitors (NNRTIs), nucleotide reverse transcriptase inhibitors (NRTIs), integrase inhibitors (IINTs) and protease inhibitors (PIs) were 82%, 73%, 19% and 11% respectively. The main mutations observed in the different classes were K103N (45%), M184V (64%), E157Q (19%) and L10V/M46I/A71V/I54V (6%) respectively. This study reveals the emergence of resistance to DTG-based fixed-dose combinations, favored by high rates of resistance to NRTIs and NNRTIs. This finding underlines the need for enhanced viral load monitoring and HIV-1 genotyping tests to guide the choice of NRTIs for combination therapy. In addition, monitoring for mutations to second-generation NRTIs is essential, given the scale-up of DTG-based regimens currently underway in Cte d’Ivoire.
基金the National Key R&D Program of China(Nos.2018YFD0901506,2018YFD0900305)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018 SDKJ0406-3)。
文摘Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species.
基金supported by the National Natural Science Foundation of China (32241042 and 31771807)the National Key R&D Program of China (2021YFF1000103)+1 种基金the China Agricultural Research System (CARS-06-04)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences。
文摘Chlorophyll (Chl) content,especially Chl b content,and stomatal conductance (G_s) are the key factors affecting the net photosynthetic rate (P_n).Setaria italica,a diploid C_4 panicoid species with a simple genome and high transformation efficiency,has been widely accepted as a model in photosynthesis and drought-tolerance research.The current study characterized Chl content,G_s,and P_n of 48 Setaria mutants induced by ethyl methanesulfonate.A total of 24,34,and 35 mutants had significant variations in Chl content,G_s,and P_n,respectively.Correlation analysis showed a positive correlation between increased G_s and increased P_n,and a weak correlation between decreased Chl b content and decreased P_n was also found.Remarkably,two mutants behaved with significantly decreased Chl b content but increased P_n compared to Yugu 1.Seven mutants behaved with significantly decreased G_s but did not decrease P_(n )compared to Yugu 1.The current study thus identified various genetic lines,further exploration of which would be beneficial to elucidate the relationship between Chl content,G_s,and P_n and the mechanism underlying why C_4 species are efficient at photosynthesis and water saving.
基金funded by the Basic Scientific Research Special Project for Fujian Provincial Public Research Institutes(2020R10310011,2019R1031-12)the National Natural Science Foundation of China(32001577)+4 种基金the Foreign Cooperation Projects for FAAS(DWHZ2021-20)the Opening Foundation of Fujian Key Laboratory for Vegetable Breeding(FJVRC2020-02)the Free Explore Program for FAAS(ZYTS2019007)the Guangxi Natural Science Foundation Program(2018GXNSFDA281027)the Science and Technology Innovative Team in Fujian Academy of Agricultural Sciences(CXTD2021008-3).
文摘Peanut(Arachis hypogaea L.)is an oil and economic crop of vital importance,and peanut pod is the key organ influencing the yield and processing quality.Hence,the Pod-related traits(PRTs)are considered as important agronomic traits in peanut breeding.To broaden the variability of PRTs in current peanut germplasms,three elite peanut cultivars were used to construct Ethyl methane sulfonate(EMS)-induced mutant libraries in this study.The optimal EMS treatment conditions for the three peanut varieties were determined.It was found that the median lethal dose(LD50)of EMS treatment varied greatly among different genotypes.Finally,the EMS-induced peanut mutant libraries were constructed and a total of 124 mutant lines for PRTs were identified and evaluated.Furthermore,“M-8070”,one of the mutant lines for pod constriction,was re-sequenced via high-throughput sequencing technology.The genome-wide variations between“M-8070”and its wild parent“Fuhua 8”(FH 8)were detected.2994 EMS-induced single nucleotide polymorphisms(SNPs)and 1188 insertion-deletions(InDels)between“M-8070”and its wild parent were identified.The predominant SNP mutation type was C/G to T/A transitions,while the predominant InDel mutation type was“1-bp”.We analyzed the distribution of identified mutations and annotated their functions.Most of the mutations(91.68%of the SNPs and 77.69%of the InDels)were located in the intergenic region.72 SNPs were identified in the exonic region,leading to 27 synonymous,43 nonsynonymous and 2 stop-gain variation for gene structure.13 Indels were identified in the exonic region,leading to 4 frame-shift,8 non-frame-shift and 1 stop-gain variations of genes.These mutations may lead to the phenotypic variation of“M-8070”.Our study provided valuable resources for peanut improvement and functional genomic research.
基金supported by grants from the National Natural Science Foundation of China,Youth Science Foundation Project(Grant Number 32002031)the Basic Scientific Research Operating Expenses of Provincial College in Heilongjiang Province,China(Grant Numbers 2020-KYYWF-1026,2020-KYYWF-1027)the Heilongjiang Provincial Natural Science Foundation of China(Grant Number LH2020C090).
文摘The phenotype of a common bean plant is often closely related to its yield,and the yield of plants with reduced height or poor stem development during growth is low.Mutants serve as an essential gene resource for common bean breeding genetic research.Although model plants and crops are studied to comprehend the molecular mechanisms and genetic basis of plant phenotypes,the molecular mechanism of phenotypic variation in common beans remains underexplored.We here used the mutant‘nts’as material for transcriptome sequencing analysis.This mutant was obtained through 60Co-γirradiation from the common bean variety‘A18’.Differentially expressed genes were mainly enriched in GO functional entries such as cell wall organization,auxin response and transcription factor activity.Metabolic pathways significantly enriched in KEGG analysis included plant hormone signal transduction pathways,phenylpropanoid biosynthesis pathways,and fructose and mannose metabolic pathways.AUX1(Phvul.001G241500),the gene responsible for auxin transport,may be the key gene for auxin content inhibition.In the plant hormone signal transduction pathway,AUX1 expression was downregulated and auxin transport across the membrane was blocked,resulting in stunted growth of the mutant‘nts’.The results provide important clues for revealing the molecular mechanism of‘nts’phenotype regulation in bean mutants and offer basic materials for breeding beneficial phenotypes of bean varieties.
基金supported by the National Natural Science Foundation of China(Grant No.32072049)Open Foundation of State Key Laboratory of Rice Biology,China(Grant No.20210208).
文摘An EMS(ethy methanesulfonate)-induced lethal etiolated(le)mutant obtained from the rice variety Zhongjian 100 was characterized by lethal etiolated phenotypes,with significantly reduced levels of chlorophyll a,chlorophyll b,total chlorophyll,and carotenoids.Additionally,the mutant displayed a significantly decreased number of chloroplast grana,along with irregular and less-stacked grana lamellae.The le mutant showed markedly diminished root length,root surface area,and root volume compared with the wild type.It also exhibited significantly lower catalase activity and total protein content,while peroxidase activity was significantly higher.Using the map-based cloning method,we successfully mapped the LE gene to a 48-kb interval between markers RM16107 and RM16110 on rice chromosome 3.A mutation(from T to C)was identified at nucleotide position 692 bp of LOC_Os03g59640(ChlD),resulting in a change from leucine to proline.By crossing HM133(a pale green mutant with a single-base substitution of A for G in exon 10 of ChlD subunit)with a heterozygous line of le(LEle),we obtained two plant lines heterozygous at both the LE and HM133 loci.Among 15 transgenic plants,3 complementation lines displayed normal leaf color with significantly higher total chlorophyll,chlorophyll a,and chlorophyll b contents.The mutation in le led to a lethal etiolated phenotype,which has not been observed in other ChlD mutants.The mutation in the AAA+domain of ChlD disrupted the interaction of ChlDle with ChlI as demonstrated by a yeast two-hybrid assay,leading to the loss of ChlD function and hindering chlorophyll synthesis and chloroplast development.Consequently,this disruption is responsible for the lethal etiolated phenotype in the mutant.
文摘柱头外露作为提高作物异交率、制种纯度和降低制种成本的优良性状,在杂交制种中得到了广泛的利用。绿豆是一种闭花授粉的作物,被报道的柱头外露突变体很少。通过对冀绿7号的化学诱变,发现了1个柱头外露突变体se2,为明确该突变体柱头外露的分子机制,对该突变体及其野生型冀绿7号即将开放的花蕾进行了转录组测序(RNA-seq)分析。根据差异倍数|log2(Fold Change)|≥1,P≤0.05的标准筛选,在se2中共得到572个差异表达基因(differentially expressed genes,DEGs),其中262个DEGs上调,310个DEGs下调。在基因本体(gene ontology,GO)数据库中,差异表达基因显著富集到代谢和生物合成等生物过程,定位在质外体和细胞壁、细胞膜等区域,与结合、氧化还原等分子功能有关。在京都基因与基因组百科全书(kyoto encyclopedia of genes and genome,KEGG)数据库中,差异表达基因显著富集在植物激素信号传导、次生代谢物生物合成等通路。功能注释发现许多有关细胞壁合成和代谢、细胞分裂和细胞扩张、植物激素相关的基因,因此推测se2突变体中龙骨瓣的细胞分裂、细胞扩张以及植物激素信号传导过程受到影响,从而导致了柱头外露。本研究为今后探究绿豆柱头外露的分子机制以及该性状在绿豆杂种优势中的利用奠定了基础。
文摘为探讨水稻叶绿体发育的分子机制,通过对粳稻日本晴进行甲基磺酸乙酯(EMS)诱变,获得一个稳定遗传的叶色白化突变体wrg20(white turn green 20),并对其进行表型鉴定、基因定位和功能分析。与野生型(WT)相比,该突变体于30℃培养时在三叶期之前完全白化,26℃时突变体白化叶片部分返绿。遗传分析结果表明,该突变性状受单隐性核基因控制。将该突变体与籼稻93-11杂交,构建F2分离群体并进行基因定位,将该基因定位于2号染色体198 kb区间内,通过测序发现LOC_Os02g33610存在由G至A单碱基替换,导致编码的天冬氨酸转化为天冬酰胺,表明该基因可能为OsWRG20的候选基因,与先前所报道的调控叶绿体发育的基因GRY79为等位基因。对该基因进行结构和功能分析,表明OsWRG20可能是调控水稻苗期幼叶生长发育的重要基因。与野生型相比,突变体的叶绿体基因内含子剪接效率降低,由此推断OsWRG20可能通过调控叶绿体RNA的剪接,参与调控水稻苗期叶绿体的发育。本研究结果为苗期水稻叶绿体发育研究提供了新的理论基础。