The paper investigates the ability to retrieve the true soil moisture profile by assimilating near-surface soil moisture into a soil moisture model with an ensemble Kalman filter （EnKF） assimilation scheme, includin...The paper investigates the ability to retrieve the true soil moisture profile by assimilating near-surface soil moisture into a soil moisture model with an ensemble Kalman filter （EnKF） assimilation scheme, including the effect of ensemble size, update interval and nonlinearities in the profile retrieval, the required time for full retrieval of the soil moisture profiles, and the possible influence of the depth of the soil moisture observation. These questions are addressed by a desktop study using synthetic data. The ＂true＂ soil moisture profiles are generated from the soil moisture model under the boundary condition of 0.5 cm d^-1 evaporation. To test the assimilation schemes, the model is initialized with a poor initial guess of the soil moisture profile, and different ensemble sizes are tested showing that an ensemble of 40 members is enough to represent the covariance of the model forecasts. Also compared are the results with those from the direct insertion assimilation scheme, showing that the EnKF is superior to the direct insertion assimilation scheme, for hourly observations, with retrieval of the soil moisture profile being achieved in 16 h as compared to 12 days or more. For daily observations, the true soil moisture profile is achieved in about 15 days with the EnKF, but it is impossible to approximate the true moisture within 18 days by using direct insertion. It is also found that observation depth does not have a significant effect on profile retrieval time for the EnKF. The nonlinearities have some negative influence on the optimal estimates of soil moisture profile but not very seriously.展开更多
Computer-navigated pedicle screw insertion is applied to the thoracic and lumbar spine to attain high insertion accuracy and a low rate of screw-related complications.However,some in vivo and in vitro studies have sho...Computer-navigated pedicle screw insertion is applied to the thoracic and lumbar spine to attain high insertion accuracy and a low rate of screw-related complications.However,some in vivo and in vitro studies have shown that no advantages are gained with the use of navigation techniques compared to conventional techniques.Additionally,inconsistent conclusions have been drawn in various studies due to different population characteristics and methods used to assess the accuracy of screw placement.Moreover,it is not clear whether pedicle screw insertion with navigation techniques decreases the incidence of screw-related complications.Therefore,this study was sought to perform a meta-analysis of all available prospective evidence regarding pedicle screw insertion with or without navigation techniques in human thoracic and lumbar spine.We considered in vivo comparative studies that assessed the results of pedicle screw placement with or without navigation techniques.PubMed,Ovid MEDLINE and EMBASE databases were searched.Three published randomized controlled trials（RCTs） and nine retrospective comparative studies met the inclusion criteria.These studies included a total of 732 patients in whom 4,953 screws were inserted.In conclusion,accuracy of the position of grade I,II,III and IV screws and complication rate related to pedicle screw placement were significantly increased when navigation techniques were used in comparison to conventional techniques.Future research in this area should include RCTs with well-planned methodology to limit bias and report on validated,patient-based outcome measures.展开更多
核苷酸替代和indels(插入、缺失统称)发生是进化的重要动力。以茄科植物为研究对象,探讨茄属中番茄和马铃薯、烟草属中绒毛状烟草和普通烟草分化时叶绿体基因组indels和核苷酸替代的发生方式,以及这两种突变对基因组造成的影响。结果显...核苷酸替代和indels(插入、缺失统称)发生是进化的重要动力。以茄科植物为研究对象,探讨茄属中番茄和马铃薯、烟草属中绒毛状烟草和普通烟草分化时叶绿体基因组indels和核苷酸替代的发生方式,以及这两种突变对基因组造成的影响。结果显示:indels和核苷酸替代的发生都不是随意的。indels发生在A+T丰富的区域,1 bp indels占据总数的30%以上,大部分indels都为低于10bp的较短片段。核苷酸替代表现出Ts(转换)/Tv(颠换)偏差,但T→G,A→C颠换频率却明显增加。Ts/Tv比值出现种属特异性,番茄和马铃薯比较时替代的Ts/Tv比值低于绒毛状烟草和普通烟草比较时Ts/Tv比值。不同物种替代的(A+T)/(G+C)比值有一定差异,从而影响基因组的(G+C)%,此比值的差异与形成物种的生长习性有一定的关系。展开更多
AIM:To investigate and compare the decompression effect on small bowel obstruction of a long tube inserted using either endoscopic or fluoroscopic placement.METHODS:Seventy-eight patients with small bowel obstruction ...AIM:To investigate and compare the decompression effect on small bowel obstruction of a long tube inserted using either endoscopic or fluoroscopic placement.METHODS:Seventy-eight patients with small bowel obstruction requiring decompression were enrolled in the study and divided into two groups.Intubation of a long tube was guided by fluoroscopy in one group and by endoscopy in the other.The duration of the procedure and the success rate for each group were evaluated.RESULTS:A statistically significant difference in the mean duration of the procedure was found between the fluoroscopic group(32.6±14.6 min)and the endoscopic group(16.5±7.8 min)among the cases classified as successful(P<0.05).The success rate was significantly different between the groups:88.6%in the fluoroscopic group and 100%in the endoscopic group(P <0.05).CONCLUSION:For patients with adhesive small bowel obstruction,long-tube decompression is recommended and long-tube insertion by endoscopy was superior to fluoroscopic placement.展开更多
Rechargeable aqueous zinc-ion batteries are recently gaining incremental attention because of low cost and material abundance, but their development is plagued by limited choice of cathode materials with satisfactory ...Rechargeable aqueous zinc-ion batteries are recently gaining incremental attention because of low cost and material abundance, but their development is plagued by limited choice of cathode materials with satisfactory cycling performance. Here, we report a porous V2O5 nanofibers cathode with high Znstorage performance in an aqueous Zn(CF3SO3)2 electrolyte. We propose a reaction mechanism based on phase transition from orthorhombic V2O5 to zinc pyrovanadate on first discharging and reversible Zn^2+ (de)intercalation in the open-structured hosts during subsequent cycling. This open and stable architecture enables a high reversible capacity of 319 mAh g^-1 at 20 mAg^-1 and a capacity retention of 81% over 500 cycles. The remarkable electrochemical performance makes V2O5 a promising cathode for aqueous zinc-ion batteries.展开更多
BACKGROUND Obstructive colorectal cancer(OCC)is always accompanied by severe complications,and the optimal strategy for patients with OCC remains undetermined.Different from emergency surgery(ES),self-expandable metal...BACKGROUND Obstructive colorectal cancer(OCC)is always accompanied by severe complications,and the optimal strategy for patients with OCC remains undetermined.Different from emergency surgery(ES),self-expandable metal stents(SEMS)as a bridge to surgery(BTS),could increase the likelihood of primary anastomosis.However,the stent failure and related complications might give rise to a high recurrence rate.Few studies have focused on the indications for either method,and the relationship between preoperative inflammation indexes and the prognosis of OCC is still underestimated.AIM To explore the indications for ES and BTS in OCCs based on preoperative inflammation indexes.METHODS One hundred and twenty-eight patients who underwent ES or BTS from 2008 to 2015 were enrolled.Receiver operating characteristic(ROC)curve analysis was used to define the optimal preoperative inflammation index and its cutoff point.Kaplan–Meier analyses and Cox proportional hazards models were applied to assess the association between the preoperative inflammation indexes and the survival outcomes[overall survival(OS)and disease-free survival(DFS)].Stratification analysis was performed to identify the subgroups that would benefit from ES or BTS.RESULTS OS and DFS were comparable between the ES and BTS groups(P>0.05).ROC curve analysis showed derived neutrophil-to-lymphocyte ratio(dNLR)as the optimal biomarker for the prediction of DFS in ES(P<0.05).Lymphocyte-tomonocyte ratio(LMR)was recommended for BTS with regard to OS and DFS(P<0.05).dNLR was related to stoma construction(P=0.001),pneumonia(P=0.054),and DFS(P=0.009)in ES.LMR was closely related to lymph node invasion(LVI)(P=0.009),OS(P=0.020),and DFS(P=0.046)in the BTS group.dNLR was an independent risk factor for ES in both OS(P=0.032)and DFS(P=0.016).LMR affected OS(P=0.053)and DFS(P=0.052)in the BTS group.LMR could differentiate the OS between the ES and BTS groups(P<0.05).CONCLUSION Preoperative dNLR and LMR could predict OS and DFS in patients undergoing ES and BTS,respectively.For O展开更多
Inframe insertions of three or more base pairs in exon 20 of the epidermal growth factor receptor(EGFR)gene were among the first EGFR mutations to be identified as oncogenic drivers in non-small cell lung cancer(NSCLC...Inframe insertions of three or more base pairs in exon 20 of the epidermal growth factor receptor(EGFR)gene were among the first EGFR mutations to be identified as oncogenic drivers in non-small cell lung cancer(NSCLC).However,unlike the classical EGFR L858R point mutation or exon 19 deletions,which represent the majority of EGFR mutations in NSCLC,low frequency EGFR exon 20 insertion mutations are associated with de novo resistance to targeted EGFR inhibitors and correlate with a poor patient prognosis.Here,we review the developments over the last 5 years in which pre-clinical studies,including elucidation of the crystal structure of an EGFR exon 20 insertion mutant kinase,have revealed a unique mechanism of kinase activation and steric conformation that define the lack of response of these EGFR mutations to clinically approved EGFR inhibitors.The recent development of several novel small molecule compounds that selectively inhibit EGFR exon 20 insertions holds promise for future therapeutic options that will be effective for patients with this molecular subtype of NSCLC.展开更多
Needle insertion is a common surgical procedure used in diagnosis and treatment.The needle steering technologies make continuous developments in theoretical and practical aspects along with the in-depth research on ne...Needle insertion is a common surgical procedure used in diagnosis and treatment.The needle steering technologies make continuous developments in theoretical and practical aspects along with the in-depth research on needle insertion.It is necessary to summarize and analyze the existing results to promote the future development of theories and applications of needle insertion.Thus,a survey of the state of the art of research is presented on algorithms of needle steering techniques,the surgical robots and devices.Based on the analysis of the needle insertion procedure,the concept of needle steering is defined as a kinematics problem,which is to place the needle at the target and avoid the obstacles.The needle steering techniques,including the artificial potential field method and the nonholonomic model,are introduced to control the needles for improving the accuracy.Based on the quasi-static thinking,the virtual spring model and the cantilever-beam model are developed to calculate the amount of needle deflection and generate the needle path.The phantoms instead of the real tissue are used to verify the models mentioned in most of the experimentations.For the desired needle trajectories,the image-guided robotic devices and some novel needles are presented to achieve the needle steering.Finally,the challenges are provided involving the controllability of the long flexible needle and the properties of soft tissue.The results and investigations can be used for further study on the precision and accuracy of needle insertion.展开更多
This paper presents an approach for mitigating the cross-eye jamming using a dual-polarization array. By transmitting a sum beam and a difference beam in two orthogonal polarimetric channels, a synthesized transmitted...This paper presents an approach for mitigating the cross-eye jamming using a dual-polarization array. By transmitting a sum beam and a difference beam in two orthogonal polarimetric channels, a synthesized transmitted beam with spatially varying polarization is produced, such that the polarization of the transmitted radar wave varies in azimuth or elevation. Thus, the phases of the signals received on the two antennas of a cross-eye jammer become unequal, and an additional phase difference is introduced to disrupt the 180？ phase shifting in the retrodirective loop of the jammer. By means of beam scanning in a small angular range,the optimal beam steering configuration can be found to maximize the phase error for the mitigation of cross-eye jamming. As a result, the jamming performance of the cross-eye jammer degrades largely. Theoretical analysis and simulation results indicate that the proposed method is valid and feasible.展开更多
To improve several agronomic traits in crisphead lettuce(Lactuca sativa L.)under high-temperature growth conditions,we investigated the correlation among those traits in multiple cultivars and performed genetic mappin...To improve several agronomic traits in crisphead lettuce(Lactuca sativa L.)under high-temperature growth conditions,we investigated the correlation among those traits in multiple cultivars and performed genetic mapping of their causal genes.In a field cultivation test of Empire type(serrated leaf)and Salinas type(wavy leaf)cultivars,Empire type cultivars showed increased tipburn susceptibility and late bolting compared with Salinas type cultivars.We attempted genetic mapping of leaf shape and bolting time by ddRAD-seq using the F2 population derived from a cross between‘VI185’(Empire type)and‘ShinanoGreen’(Salinas type).These analyses suggested that both traits are controlled by a single locus in LG5.Genotyping of 51 commercial lettuce cultivars with a tightly linked marker(LG5_v8_252.743Mbp)at this locus showed an association between its genotype and the serrated leaf phenotype.By further fine mapping and transcriptome analysis,a gene encoding putative CIN-like TCP transcription factor was determined to be a candidate gene at this locus and was designated as LsTCP4.An insertion of retrotransposable element was found in the allele of‘VI185’,and its transcript level in the leaves was lower than that in‘ShinanoGreen’.Because shapes of leaf epidermal cells in‘VI185’were similar to those in the TCP family mutant of Arabidopsis thaliana,the leaf shape phenotype was likely caused by reduced expression of LsTCP4.Furthermore,because it is known that the TCP family protein also controls flowering time via interaction with FT in A.thaliana,it was highly possible that LsTCP4 gave pleiotropic effects on both leaf shape and bolting time in lettuce.展开更多
基金the National Natural Science Foundation of China(Grant Nos.40475012,90202014, 2001CB309404).
文摘The paper investigates the ability to retrieve the true soil moisture profile by assimilating near-surface soil moisture into a soil moisture model with an ensemble Kalman filter （EnKF） assimilation scheme, including the effect of ensemble size, update interval and nonlinearities in the profile retrieval, the required time for full retrieval of the soil moisture profiles, and the possible influence of the depth of the soil moisture observation. These questions are addressed by a desktop study using synthetic data. The ＂true＂ soil moisture profiles are generated from the soil moisture model under the boundary condition of 0.5 cm d^-1 evaporation. To test the assimilation schemes, the model is initialized with a poor initial guess of the soil moisture profile, and different ensemble sizes are tested showing that an ensemble of 40 members is enough to represent the covariance of the model forecasts. Also compared are the results with those from the direct insertion assimilation scheme, showing that the EnKF is superior to the direct insertion assimilation scheme, for hourly observations, with retrieval of the soil moisture profile being achieved in 16 h as compared to 12 days or more. For daily observations, the true soil moisture profile is achieved in about 15 days with the EnKF, but it is impossible to approximate the true moisture within 18 days by using direct insertion. It is also found that observation depth does not have a significant effect on profile retrieval time for the EnKF. The nonlinearities have some negative influence on the optimal estimates of soil moisture profile but not very seriously.
文摘Computer-navigated pedicle screw insertion is applied to the thoracic and lumbar spine to attain high insertion accuracy and a low rate of screw-related complications.However,some in vivo and in vitro studies have shown that no advantages are gained with the use of navigation techniques compared to conventional techniques.Additionally,inconsistent conclusions have been drawn in various studies due to different population characteristics and methods used to assess the accuracy of screw placement.Moreover,it is not clear whether pedicle screw insertion with navigation techniques decreases the incidence of screw-related complications.Therefore,this study was sought to perform a meta-analysis of all available prospective evidence regarding pedicle screw insertion with or without navigation techniques in human thoracic and lumbar spine.We considered in vivo comparative studies that assessed the results of pedicle screw placement with or without navigation techniques.PubMed,Ovid MEDLINE and EMBASE databases were searched.Three published randomized controlled trials（RCTs） and nine retrospective comparative studies met the inclusion criteria.These studies included a total of 732 patients in whom 4,953 screws were inserted.In conclusion,accuracy of the position of grade I,II,III and IV screws and complication rate related to pedicle screw placement were significantly increased when navigation techniques were used in comparison to conventional techniques.Future research in this area should include RCTs with well-planned methodology to limit bias and report on validated,patient-based outcome measures.
文摘核苷酸替代和indels(插入、缺失统称)发生是进化的重要动力。以茄科植物为研究对象,探讨茄属中番茄和马铃薯、烟草属中绒毛状烟草和普通烟草分化时叶绿体基因组indels和核苷酸替代的发生方式,以及这两种突变对基因组造成的影响。结果显示:indels和核苷酸替代的发生都不是随意的。indels发生在A+T丰富的区域,1 bp indels占据总数的30%以上,大部分indels都为低于10bp的较短片段。核苷酸替代表现出Ts(转换)/Tv(颠换)偏差,但T→G,A→C颠换频率却明显增加。Ts/Tv比值出现种属特异性,番茄和马铃薯比较时替代的Ts/Tv比值低于绒毛状烟草和普通烟草比较时Ts/Tv比值。不同物种替代的(A+T)/(G+C)比值有一定差异,从而影响基因组的(G+C)%,此比值的差异与形成物种的生长习性有一定的关系。
文摘AIM:To investigate and compare the decompression effect on small bowel obstruction of a long tube inserted using either endoscopic or fluoroscopic placement.METHODS:Seventy-eight patients with small bowel obstruction requiring decompression were enrolled in the study and divided into two groups.Intubation of a long tube was guided by fluoroscopy in one group and by endoscopy in the other.The duration of the procedure and the success rate for each group were evaluated.RESULTS:A statistically significant difference in the mean duration of the procedure was found between the fluoroscopic group(32.6±14.6 min)and the endoscopic group(16.5±7.8 min)among the cases classified as successful(P<0.05).The success rate was significantly different between the groups:88.6%in the fluoroscopic group and 100%in the endoscopic group(P <0.05).CONCLUSION:For patients with adhesive small bowel obstruction,long-tube decompression is recommended and long-tube insertion by endoscopy was superior to fluoroscopic placement.
基金financially supported by Tianjin Natural Science Foundation (No. 18JCZDJC31100)MOST(2017YFA0206700 and 2016YFA0202503)+1 种基金MOE(B12015)the Fundamental Research Funds for the Central Universities
文摘Rechargeable aqueous zinc-ion batteries are recently gaining incremental attention because of low cost and material abundance, but their development is plagued by limited choice of cathode materials with satisfactory cycling performance. Here, we report a porous V2O5 nanofibers cathode with high Znstorage performance in an aqueous Zn(CF3SO3)2 electrolyte. We propose a reaction mechanism based on phase transition from orthorhombic V2O5 to zinc pyrovanadate on first discharging and reversible Zn^2+ (de)intercalation in the open-structured hosts during subsequent cycling. This open and stable architecture enables a high reversible capacity of 319 mAh g^-1 at 20 mAg^-1 and a capacity retention of 81% over 500 cycles. The remarkable electrochemical performance makes V2O5 a promising cathode for aqueous zinc-ion batteries.
基金Supported by Qihang Project of Fujian Medical University,No.2017XQ1050
文摘BACKGROUND Obstructive colorectal cancer(OCC)is always accompanied by severe complications,and the optimal strategy for patients with OCC remains undetermined.Different from emergency surgery(ES),self-expandable metal stents(SEMS)as a bridge to surgery(BTS),could increase the likelihood of primary anastomosis.However,the stent failure and related complications might give rise to a high recurrence rate.Few studies have focused on the indications for either method,and the relationship between preoperative inflammation indexes and the prognosis of OCC is still underestimated.AIM To explore the indications for ES and BTS in OCCs based on preoperative inflammation indexes.METHODS One hundred and twenty-eight patients who underwent ES or BTS from 2008 to 2015 were enrolled.Receiver operating characteristic(ROC)curve analysis was used to define the optimal preoperative inflammation index and its cutoff point.Kaplan–Meier analyses and Cox proportional hazards models were applied to assess the association between the preoperative inflammation indexes and the survival outcomes[overall survival(OS)and disease-free survival(DFS)].Stratification analysis was performed to identify the subgroups that would benefit from ES or BTS.RESULTS OS and DFS were comparable between the ES and BTS groups(P>0.05).ROC curve analysis showed derived neutrophil-to-lymphocyte ratio(dNLR)as the optimal biomarker for the prediction of DFS in ES(P<0.05).Lymphocyte-tomonocyte ratio(LMR)was recommended for BTS with regard to OS and DFS(P<0.05).dNLR was related to stoma construction(P=0.001),pneumonia(P=0.054),and DFS(P=0.009)in ES.LMR was closely related to lymph node invasion(LVI)(P=0.009),OS(P=0.020),and DFS(P=0.046)in the BTS group.dNLR was an independent risk factor for ES in both OS(P=0.032)and DFS(P=0.016).LMR affected OS(P=0.053)and DFS(P=0.052)in the BTS group.LMR could differentiate the OS between the ES and BTS groups(P<0.05).CONCLUSION Preoperative dNLR and LMR could predict OS and DFS in patients undergoing ES and BTS,respectively.For O
文摘Inframe insertions of three or more base pairs in exon 20 of the epidermal growth factor receptor(EGFR)gene were among the first EGFR mutations to be identified as oncogenic drivers in non-small cell lung cancer(NSCLC).However,unlike the classical EGFR L858R point mutation or exon 19 deletions,which represent the majority of EGFR mutations in NSCLC,low frequency EGFR exon 20 insertion mutations are associated with de novo resistance to targeted EGFR inhibitors and correlate with a poor patient prognosis.Here,we review the developments over the last 5 years in which pre-clinical studies,including elucidation of the crystal structure of an EGFR exon 20 insertion mutant kinase,have revealed a unique mechanism of kinase activation and steric conformation that define the lack of response of these EGFR mutations to clinically approved EGFR inhibitors.The recent development of several novel small molecule compounds that selectively inhibit EGFR exon 20 insertions holds promise for future therapeutic options that will be effective for patients with this molecular subtype of NSCLC.
基金supported by National Natural Science Foundation of China (Grant Nos. 51165040,50775119)Visiting Scholar Foundation of Key Lab in University of China (Grant No. GZKF-201020)
文摘Needle insertion is a common surgical procedure used in diagnosis and treatment.The needle steering technologies make continuous developments in theoretical and practical aspects along with the in-depth research on needle insertion.It is necessary to summarize and analyze the existing results to promote the future development of theories and applications of needle insertion.Thus,a survey of the state of the art of research is presented on algorithms of needle steering techniques,the surgical robots and devices.Based on the analysis of the needle insertion procedure,the concept of needle steering is defined as a kinematics problem,which is to place the needle at the target and avoid the obstacles.The needle steering techniques,including the artificial potential field method and the nonholonomic model,are introduced to control the needles for improving the accuracy.Based on the quasi-static thinking,the virtual spring model and the cantilever-beam model are developed to calculate the amount of needle deflection and generate the needle path.The phantoms instead of the real tissue are used to verify the models mentioned in most of the experimentations.For the desired needle trajectories,the image-guided robotic devices and some novel needles are presented to achieve the needle steering.Finally,the challenges are provided involving the controllability of the long flexible needle and the properties of soft tissue.The results and investigations can be used for further study on the precision and accuracy of needle insertion.
基金supported by the National Natural Science Foundation of China(6149069261401488)
文摘This paper presents an approach for mitigating the cross-eye jamming using a dual-polarization array. By transmitting a sum beam and a difference beam in two orthogonal polarimetric channels, a synthesized transmitted beam with spatially varying polarization is produced, such that the polarization of the transmitted radar wave varies in azimuth or elevation. Thus, the phases of the signals received on the two antennas of a cross-eye jammer become unequal, and an additional phase difference is introduced to disrupt the 180？ phase shifting in the retrodirective loop of the jammer. By means of beam scanning in a small angular range,the optimal beam steering configuration can be found to maximize the phase error for the mitigation of cross-eye jamming. As a result, the jamming performance of the cross-eye jammer degrades largely. Theoretical analysis and simulation results indicate that the proposed method is valid and feasible.
基金supported by grants from the Ministry of Agriculture,Forestry and Fisheries of Japan(Project for Climate Change,Vegetable-4103)for K.S.,Cooperative Research Grant of the Genome Research for BioResource,NODAI Genome Research Center,Tokyo University of Agriculture for K.S.and K.K.,Grant-in-Aid for Scientific Research for K.K.,MEXT-Supported Program for the Strategic Research Foundation at Private Universities,2013-2017(S1311017)for K.K.We thank Rumi Ohtake of NODAI Genome Research Center,Tokyo University of Agriculture,and Masaki Kawakami of the Nagano Vegetable Ornamental Crops Experiment Station for helpful discussion and advice.We also thank Chizuru Kagami,Yoko Takahashi,Yoshie Nakayama,and especially Atsushi Tsukada and Hideaki Okazawa for technical assistance in the field experiment.We also thank Akane Igarashi,Reina Ohwaki,and Hiroto Kayama for technical assistance in the RNA-seq analysis and genome sequencing,Naho Takahashi for technical assistance in the extraction of genomic DNA.Moreover,we also thank‘Bas Breau’at hakuba for helpful assistance.
文摘To improve several agronomic traits in crisphead lettuce(Lactuca sativa L.)under high-temperature growth conditions,we investigated the correlation among those traits in multiple cultivars and performed genetic mapping of their causal genes.In a field cultivation test of Empire type(serrated leaf)and Salinas type(wavy leaf)cultivars,Empire type cultivars showed increased tipburn susceptibility and late bolting compared with Salinas type cultivars.We attempted genetic mapping of leaf shape and bolting time by ddRAD-seq using the F2 population derived from a cross between‘VI185’(Empire type)and‘ShinanoGreen’(Salinas type).These analyses suggested that both traits are controlled by a single locus in LG5.Genotyping of 51 commercial lettuce cultivars with a tightly linked marker(LG5_v8_252.743Mbp)at this locus showed an association between its genotype and the serrated leaf phenotype.By further fine mapping and transcriptome analysis,a gene encoding putative CIN-like TCP transcription factor was determined to be a candidate gene at this locus and was designated as LsTCP4.An insertion of retrotransposable element was found in the allele of‘VI185’,and its transcript level in the leaves was lower than that in‘ShinanoGreen’.Because shapes of leaf epidermal cells in‘VI185’were similar to those in the TCP family mutant of Arabidopsis thaliana,the leaf shape phenotype was likely caused by reduced expression of LsTCP4.Furthermore,because it is known that the TCP family protein also controls flowering time via interaction with FT in A.thaliana,it was highly possible that LsTCP4 gave pleiotropic effects on both leaf shape and bolting time in lettuce.
