China is a hotspot of relict plant species that were once widespread throughout the Northern Hemisphere.Recent research has demonstrated that the occurrence of long-term stable refugia in the mountainous regions of ce...China is a hotspot of relict plant species that were once widespread throughout the Northern Hemisphere.Recent research has demonstrated that the occurrence of long-term stable refugia in the mountainous regions of central and south-western China allowed their persistence through the late Neogene climate fluctuations.One of these relict lineages is Dipteronia,an oligotypic tree genus with a fossil record extending to the Paleocene.Here,we investigated the genetic variability,demographic dynamics and diversification patterns of the two currently recognized Dipteronia species(Dipteronia sinensis and D.dyeriana).Molecular data were obtained from 45 populations of Dipteronia by genotyping three cpDNA regions,two single copy nuclear genes and 15 simple sequence repeat loci.The genetic study was combined with niche comparison analyses on the environmental space,ecological niche modeling,and landscape connectivity analysis.We found that the two Dipteronia species have highly diverged both in genetic and ecological terms.Despite the incipient speciation processes that can be observed in D.sinensis,the occurrence of long-term stable refugia and,particularly,a dispersal corridor along Daba Shan-west Qinling,likely ensured its genetic and ecological integrity to date.Our study will not only help us to understand how populations of Dipteronia species responded to the tectonic and climatic changes of the Cenozoic,but also provide insight into how Arcto-Tertiary relict plants in East Asia survived,evolved,and diversified.展开更多
Laser speckle contrast imaging(LSCI)is an optical imaging method,which can monitor microvascularflow variation directly without addition of any ectogenous dye.All the existing laser speckle contrast analysis(LASCA)met...Laser speckle contrast imaging(LSCI)is an optical imaging method,which can monitor microvascularflow variation directly without addition of any ectogenous dye.All the existing laser speckle contrast analysis(LASCA)methods are a combination of spatial and temporal statistics.In this study,we have proposed a new method,Gaussian kernel laser speckle contrast analysis(gLASCA),which processes the raw images primarily with the Gaussian kernel operator along the spatial direction of bloodflow.We explored the properties of gLASCA in the simulation and animal cerebral ischemia perfusion model.Compared with the other existing speckle processing methods based on spatial,temporal,spatial-temporal or anisotropic linear structure;the present gLASCA method has a high spatial-temporal resolution to respond the change of velocity especially in microvasculature.Besides,the gLASCA method obtains approximately 10.2%and 7.1%higher contrast-to-noise ratio(CNR)over the anisotropic linear method(aLASCA)in the simulation and experiment models.For these advantages,gLASCA could be a better method for local microvascular laser speckle imaging in terms of cerebral ischemia reperfusion,spreading depression and brain injury diseases.展开更多
Gynostemma pentaphyllum(Thunb.)Makino is a perennial creeping herbaceous plant in the family Cucurbitaceae,which has great medicinal value and commercial potential,but urgent conservation efforts are needed due to the...Gynostemma pentaphyllum(Thunb.)Makino is a perennial creeping herbaceous plant in the family Cucurbitaceae,which has great medicinal value and commercial potential,but urgent conservation efforts are needed due to the gradual decreases and fragmented distribution of its wild populations.Here,we report the high-quality diploid chromosome-level genome of G.pentaphyllum obtained using a combination of next-generation sequencing short reads,Nanopore long reads,and Hi-C sequencing technologies.The genome is anchored to 11 pseudo-chromosomes with a total size of 608.95 Mb and 26588 predicted genes.Comparative genomic analyses indicate that G.pentaphyllum is estimated to have diverged from Momordica charantia 60.7 million years ago,with no recent whole-genome duplication event.Genomic population analyses based on genotyping-by-sequencing and ecological niche analyses indicated low genetic diversity but a strong population structure within the species,which could classify 32 G.pentaphyllum populations into three geographical groups shaped jointly by geographic and climate factors.Furthermore,comparative transcriptome analyses showed that the genes encoding enzyme involved in gypenoside biosynthesis had higher expression levels in the leaves and tendrils.Overall,the findings obtained in this study provide an effective molecular basis for further studies of demographic genetics,ecological adaption,and systematic evolution in Cucurbitaceae species,as well as contributing to molecular breeding,and the biosynthesis and biotransformation of gypenoside.展开更多
基金co-supported by the National Natural Science Foundation of China(Grant No.31470311)the Ph.D.Programs Foundation of the Ministry of Education of China(Grant No.20136101130001).
文摘China is a hotspot of relict plant species that were once widespread throughout the Northern Hemisphere.Recent research has demonstrated that the occurrence of long-term stable refugia in the mountainous regions of central and south-western China allowed their persistence through the late Neogene climate fluctuations.One of these relict lineages is Dipteronia,an oligotypic tree genus with a fossil record extending to the Paleocene.Here,we investigated the genetic variability,demographic dynamics and diversification patterns of the two currently recognized Dipteronia species(Dipteronia sinensis and D.dyeriana).Molecular data were obtained from 45 populations of Dipteronia by genotyping three cpDNA regions,two single copy nuclear genes and 15 simple sequence repeat loci.The genetic study was combined with niche comparison analyses on the environmental space,ecological niche modeling,and landscape connectivity analysis.We found that the two Dipteronia species have highly diverged both in genetic and ecological terms.Despite the incipient speciation processes that can be observed in D.sinensis,the occurrence of long-term stable refugia and,particularly,a dispersal corridor along Daba Shan-west Qinling,likely ensured its genetic and ecological integrity to date.Our study will not only help us to understand how populations of Dipteronia species responded to the tectonic and climatic changes of the Cenozoic,but also provide insight into how Arcto-Tertiary relict plants in East Asia survived,evolved,and diversified.
基金This study was supported by National Major Scientific Instruments and Equipments Development Project Funded by National Natural Science Foundation of China(81827803,81727804)National Natural Science Foundation of China(61875085,81601532)+2 种基金Natural Science Foundation of Jiangsu Province(BK20160814)Jiangsu Science and Technology Support Plan(Social Development)(BE2016759)Jiangsu Innovation Program for Graduate Education(KYLX16339).
文摘Laser speckle contrast imaging(LSCI)is an optical imaging method,which can monitor microvascularflow variation directly without addition of any ectogenous dye.All the existing laser speckle contrast analysis(LASCA)methods are a combination of spatial and temporal statistics.In this study,we have proposed a new method,Gaussian kernel laser speckle contrast analysis(gLASCA),which processes the raw images primarily with the Gaussian kernel operator along the spatial direction of bloodflow.We explored the properties of gLASCA in the simulation and animal cerebral ischemia perfusion model.Compared with the other existing speckle processing methods based on spatial,temporal,spatial-temporal or anisotropic linear structure;the present gLASCA method has a high spatial-temporal resolution to respond the change of velocity especially in microvasculature.Besides,the gLASCA method obtains approximately 10.2%and 7.1%higher contrast-to-noise ratio(CNR)over the anisotropic linear method(aLASCA)in the simulation and experiment models.For these advantages,gLASCA could be a better method for local microvascular laser speckle imaging in terms of cerebral ischemia reperfusion,spreading depression and brain injury diseases.
基金This study was supported by the National Natural Science Foundation of China(Nos.32000256,31900273,31770229,and 31270364)a Project funded by the China Postdoctoral Science Foundation(No.2020M673627XB)the Key Pro-gram of Research and Development of Shaanxi Province(No.2022ZDLSF06-02).
文摘Gynostemma pentaphyllum(Thunb.)Makino is a perennial creeping herbaceous plant in the family Cucurbitaceae,which has great medicinal value and commercial potential,but urgent conservation efforts are needed due to the gradual decreases and fragmented distribution of its wild populations.Here,we report the high-quality diploid chromosome-level genome of G.pentaphyllum obtained using a combination of next-generation sequencing short reads,Nanopore long reads,and Hi-C sequencing technologies.The genome is anchored to 11 pseudo-chromosomes with a total size of 608.95 Mb and 26588 predicted genes.Comparative genomic analyses indicate that G.pentaphyllum is estimated to have diverged from Momordica charantia 60.7 million years ago,with no recent whole-genome duplication event.Genomic population analyses based on genotyping-by-sequencing and ecological niche analyses indicated low genetic diversity but a strong population structure within the species,which could classify 32 G.pentaphyllum populations into three geographical groups shaped jointly by geographic and climate factors.Furthermore,comparative transcriptome analyses showed that the genes encoding enzyme involved in gypenoside biosynthesis had higher expression levels in the leaves and tendrils.Overall,the findings obtained in this study provide an effective molecular basis for further studies of demographic genetics,ecological adaption,and systematic evolution in Cucurbitaceae species,as well as contributing to molecular breeding,and the biosynthesis and biotransformation of gypenoside.
