Fourteen species of nonmarine gastropod opercula are found to be in high abundance in the Oligocene upper member of the Yehucheng Formation,Lanzhou Basin,northwest China.They are attributed to two families,namely Bith...Fourteen species of nonmarine gastropod opercula are found to be in high abundance in the Oligocene upper member of the Yehucheng Formation,Lanzhou Basin,northwest China.They are attributed to two families,namely Bithyniidae and Assimineidae,and four genera,namely Pseudemmericia,Bithynia,Mirolaminatus and Assiminea.Among them,three species are new,and they are Bithynia paramonolithic sp.nov.,B.obliquus sp.nov.,and B.disregularis sp.nov.Some of these species were first discovered in Paleogene strata of the vast Northwest China and can be compared with the opercula recovered from the Paleogene deposits in East and South China.It is inferred from the paleontology and sediment associations that the climate was slightly humid and the fauna probably inhabited the fresh or brackish water of a shallow lake in the Lanzhou Basin during the late early Oligocene period.展开更多
Sp7/Osterix as a zinc finger transcription factor is expressed specifically in osteoblasts.Embryonic lethality of Sp7 knockout mice,however,has prevented from examining the functions of Sp7 in osteoblast and bone form...Sp7/Osterix as a zinc finger transcription factor is expressed specifically in osteoblasts.Embryonic lethality of Sp7 knockout mice,however,has prevented from examining the functions of Sp7 in osteoblast and bone formation in live animals.Here we used TALEN,a versatile genome-editing tool,to generate one zebrafish sp7 mutant line.Homozygous sp7-/- mutant zebrafish are able to survive to adulthood.Alizarin Red staining and Micro-CT analysis showed that sp7-/- larvae and adult fish fail to develop normal opercula,and display curved tail fins and severe craniofacial malformation,while Alcian Blue staining showed no obvious cartilage defects in sp7-/- fish.Quantitative RT-PCR showed that a number of osteoblast markers including spp1,phex,col1 ala,and col1a1 b are significantly down-regulated in sp7-/- fish.Furthermore,col10a1 a,whose ortholog is the cartilage marker in mice,was shown to be a novel downstream gene of Sp7 as an osteoblast marker in zebrafish.Together,these results suggest that Sp7 is required for zebrafish bone development and zebrafish sp7 mutants provide animal models for investigating novel aspects of bone development.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42172010)。
文摘Fourteen species of nonmarine gastropod opercula are found to be in high abundance in the Oligocene upper member of the Yehucheng Formation,Lanzhou Basin,northwest China.They are attributed to two families,namely Bithyniidae and Assimineidae,and four genera,namely Pseudemmericia,Bithynia,Mirolaminatus and Assiminea.Among them,three species are new,and they are Bithynia paramonolithic sp.nov.,B.obliquus sp.nov.,and B.disregularis sp.nov.Some of these species were first discovered in Paleogene strata of the vast Northwest China and can be compared with the opercula recovered from the Paleogene deposits in East and South China.It is inferred from the paleontology and sediment associations that the climate was slightly humid and the fauna probably inhabited the fresh or brackish water of a shallow lake in the Lanzhou Basin during the late early Oligocene period.
基金supported by the grants from National High Technology Research and Development Program of China (2011AA100402-2)the National Natural Science Foundation of China (NSFC) (31271356, 31030062, 81070455)+5 种基金National Basic Research Program of China (2012CB947600)the Jiangsu Distinguished Professorship Program (SR13400111)the Natural Science Foundation of Jiangsu Province (BK2012052)the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions (YX13400214)the High-Level Innovative Team of Jiangsu Provincethe ‘‘333” project of Jiangsu Province (BRA2015328)
文摘Sp7/Osterix as a zinc finger transcription factor is expressed specifically in osteoblasts.Embryonic lethality of Sp7 knockout mice,however,has prevented from examining the functions of Sp7 in osteoblast and bone formation in live animals.Here we used TALEN,a versatile genome-editing tool,to generate one zebrafish sp7 mutant line.Homozygous sp7-/- mutant zebrafish are able to survive to adulthood.Alizarin Red staining and Micro-CT analysis showed that sp7-/- larvae and adult fish fail to develop normal opercula,and display curved tail fins and severe craniofacial malformation,while Alcian Blue staining showed no obvious cartilage defects in sp7-/- fish.Quantitative RT-PCR showed that a number of osteoblast markers including spp1,phex,col1 ala,and col1a1 b are significantly down-regulated in sp7-/- fish.Furthermore,col10a1 a,whose ortholog is the cartilage marker in mice,was shown to be a novel downstream gene of Sp7 as an osteoblast marker in zebrafish.Together,these results suggest that Sp7 is required for zebrafish bone development and zebrafish sp7 mutants provide animal models for investigating novel aspects of bone development.
