Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,a...Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,and selfing the pentaploid hybrids to the F7 generation yielded mostly euploid tetraploids and a few hexaploids.Two special derivatives of tetraploid were isolated,including a 4D(4B)substitution line with large panicles and high resistance to stripe rust and a 2DS.2AL translocation line with non-waxy epidermis.The discovery of small D-genome introgressions in the A and B genomes suggested that pentaploidization can be used to induce homoeologous recombination.The introgression of D genome from Aegilops tauschii to the AB genomes might promote the development of super tetraploid wheat with hexaploid biological characteristics(especially stress resistance)and quality functions and the functional study of the introduced chromosomes or fragments.展开更多
The allotetraploid wild grass Aegilops ventricosa(2n=4x=28,genome D^(v)D^(v)N^(v)N^(v))has been recognized as an important germplasm resource for wheat improvement owing to its ability to tolerate biotic stresses.In p...The allotetraploid wild grass Aegilops ventricosa(2n=4x=28,genome D^(v)D^(v)N^(v)N^(v))has been recognized as an important germplasm resource for wheat improvement owing to its ability to tolerate biotic stresses.In particular,the 2N^(v)S segment from Ae.ventricosa,as a stable and effective resistance source,has contributed greatly to wheat improvement.The 2N^(v)S/2AS translocation is a prevalent chromosomal translocation between common wheat and wild relatives,ranking just behind the 1B/1R translocation in importance for modern wheat breeding.Here,we assembled a high-quality chromosome-level reference genome of Ae.ventricosa RM271 with a total length of 8.67 Gb.Phylogenomic analyses revealed that the progenitor of the D^(v) subgenome of Ae.ventricosa is Ae.tauschii ssp.tauschii(genome DD);by contrast,the progenitor of the D subgenome of bread wheat(Triticumaestivum L.)is Ae.tauschii ssp.strangulata(genome DD).The oldest polyploidization time of Ae.ventricosa occurred0.7 mya.The D^(v) subgenome of Ae.ventricosa is less conserved than the D subgenome of bread wheat.Construction of a graph-based pangenome of 2AS/6N^(v)L(originally known as 2N^(v)S)segments from Ae.ventricosa and other genomes in the Triticeae enabled us to identify candidate resistance genes sourced from Ae.ventricosa.We identified 12 nonredundant introgressed segments from the D^(v) and N^(v) subgenomes using a large winter wheat collection representing the full diversity of the European wheat genetic pool,and 29.40%of European wheat varieties inherit at least one of these segments.The high-quality RM271 reference genome will provide a basis for cloning key genes,including the Yr17-Lr37-Sr38-Cre5 resistance gene cluster in Ae.ventricosa,and facilitate the full use of elite wild genetic resources to accelerate wheat improvement.展开更多
Background:Colorectal cancer(CRC)is one of the most common cancers in China.However,detailed clinical characteristics and survival information are limited.This study aimed to investigate the potential epidemiological ...Background:Colorectal cancer(CRC)is one of the most common cancers in China.However,detailed clinical characteristics and survival information are limited.This study aimed to investigate the potential epidemiological and clinical risk factors affecting the survival of CRC patients in southern China.Methods:Patients with primary CRC between 1994 and 2019 at the First and the Sixth Affiliated Hospitals of Sun Yat-sen University(Guangzhou,China)were included.Clinical characteristics and survival outcomes were collected from medical records.The Kaplan–Meier method was used to estimate overall survival(OS)and progression-free survival(PFS),and Cox’s proportional-hazards regression model was used to estimate hazard ratios and 95%confidence intervals.Results:Of all 13,328 patients,60.1%were men;the mean age was 61.3 years;53.5%had colon cancer.Among all patients,1,864(14.0%)were diagnosed with stage IV disease.The 3-and 5-year OS rates were 79.90%and 71.50%,respectively,whereas the 3-and 5-year PFS rates were 70.30%and 63.90%,respectively.The median OS and PFS times were 189 and 149 months,respectively.Among 13,328 patients,428(14.0%)patients with poor/undifferentiated cancer suffered recurrence.In patients with stageⅢand stageⅣdiseases,the median PFS times of the patients who received chemotherapy were significantly longer than those in patients who had not received chemotherapy(stageⅢ:147 vs 62 months,P<0.001;stageⅣ:14 vs 9.5 months,P<0.001).Conclusions:This retrospective cohort study illustrates the current status of the clinical characteristics of patients with CRC in southern China.Sex,age,family history,location of cancer occurrence,differentiation status,T status,N status,M status,clinical stage,operation,and surgical margin are independent factors associated with the OS of CRC patients.展开更多
基金funded by the Natural Science Foundation of Sichuan Province for Young Scholars(2024NSFSC1218)the HighLevel Talent Introduction Project of Sichuan Academy of Agricultural Sciences(NKYRCZX2024022)+1 种基金the Accurate Identification Project of Crop Germplasm from Sichuan Provincial Finance Department(1+3 ZYGG001)the Strategic Scientist Studio of Sichuan Academy of Agricultural Sciences.
文摘Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,and selfing the pentaploid hybrids to the F7 generation yielded mostly euploid tetraploids and a few hexaploids.Two special derivatives of tetraploid were isolated,including a 4D(4B)substitution line with large panicles and high resistance to stripe rust and a 2DS.2AL translocation line with non-waxy epidermis.The discovery of small D-genome introgressions in the A and B genomes suggested that pentaploidization can be used to induce homoeologous recombination.The introgression of D genome from Aegilops tauschii to the AB genomes might promote the development of super tetraploid wheat with hexaploid biological characteristics(especially stress resistance)and quality functions and the functional study of the introduced chromosomes or fragments.
基金supported by the Sichuan Provincial Finance Department Project of China(1+3 ZYGG001)the Sichuan Province Science and Technology Department Project of China(2021YFYZ0020,2022NSFSC0161,2023NSFSC1925)the Program of Strategic Scientist Studio of Sichuan Academy of Agricultural Sciences,and the Program of Chinese Agriculture Research System(CARS-03).
文摘The allotetraploid wild grass Aegilops ventricosa(2n=4x=28,genome D^(v)D^(v)N^(v)N^(v))has been recognized as an important germplasm resource for wheat improvement owing to its ability to tolerate biotic stresses.In particular,the 2N^(v)S segment from Ae.ventricosa,as a stable and effective resistance source,has contributed greatly to wheat improvement.The 2N^(v)S/2AS translocation is a prevalent chromosomal translocation between common wheat and wild relatives,ranking just behind the 1B/1R translocation in importance for modern wheat breeding.Here,we assembled a high-quality chromosome-level reference genome of Ae.ventricosa RM271 with a total length of 8.67 Gb.Phylogenomic analyses revealed that the progenitor of the D^(v) subgenome of Ae.ventricosa is Ae.tauschii ssp.tauschii(genome DD);by contrast,the progenitor of the D subgenome of bread wheat(Triticumaestivum L.)is Ae.tauschii ssp.strangulata(genome DD).The oldest polyploidization time of Ae.ventricosa occurred0.7 mya.The D^(v) subgenome of Ae.ventricosa is less conserved than the D subgenome of bread wheat.Construction of a graph-based pangenome of 2AS/6N^(v)L(originally known as 2N^(v)S)segments from Ae.ventricosa and other genomes in the Triticeae enabled us to identify candidate resistance genes sourced from Ae.ventricosa.We identified 12 nonredundant introgressed segments from the D^(v) and N^(v) subgenomes using a large winter wheat collection representing the full diversity of the European wheat genetic pool,and 29.40%of European wheat varieties inherit at least one of these segments.The high-quality RM271 reference genome will provide a basis for cloning key genes,including the Yr17-Lr37-Sr38-Cre5 resistance gene cluster in Ae.ventricosa,and facilitate the full use of elite wild genetic resources to accelerate wheat improvement.
基金supported by the National Natural Science Foundation of China[81773098,82111530099]Guangdong Special Young Talent Plan of Scientific and Technological Innovation[2019TQ05Y510]+2 种基金the Guangdong International Joint Research Program[2020A0505100027]Nature Science Foundation of Guangzhou[202102080387]Guangdong Public Health Project[2021-58]and National Key Clinical Discipline.
文摘Background:Colorectal cancer(CRC)is one of the most common cancers in China.However,detailed clinical characteristics and survival information are limited.This study aimed to investigate the potential epidemiological and clinical risk factors affecting the survival of CRC patients in southern China.Methods:Patients with primary CRC between 1994 and 2019 at the First and the Sixth Affiliated Hospitals of Sun Yat-sen University(Guangzhou,China)were included.Clinical characteristics and survival outcomes were collected from medical records.The Kaplan–Meier method was used to estimate overall survival(OS)and progression-free survival(PFS),and Cox’s proportional-hazards regression model was used to estimate hazard ratios and 95%confidence intervals.Results:Of all 13,328 patients,60.1%were men;the mean age was 61.3 years;53.5%had colon cancer.Among all patients,1,864(14.0%)were diagnosed with stage IV disease.The 3-and 5-year OS rates were 79.90%and 71.50%,respectively,whereas the 3-and 5-year PFS rates were 70.30%and 63.90%,respectively.The median OS and PFS times were 189 and 149 months,respectively.Among 13,328 patients,428(14.0%)patients with poor/undifferentiated cancer suffered recurrence.In patients with stageⅢand stageⅣdiseases,the median PFS times of the patients who received chemotherapy were significantly longer than those in patients who had not received chemotherapy(stageⅢ:147 vs 62 months,P<0.001;stageⅣ:14 vs 9.5 months,P<0.001).Conclusions:This retrospective cohort study illustrates the current status of the clinical characteristics of patients with CRC in southern China.Sex,age,family history,location of cancer occurrence,differentiation status,T status,N status,M status,clinical stage,operation,and surgical margin are independent factors associated with the OS of CRC patients.
