Objective Io evaluate changes in morphology of the cesarean scar and uterus between one and two years after cesarean section using high-resolution,three dimensional T2-weighted sampling perfection with application opt...Objective Io evaluate changes in morphology of the cesarean scar and uterus between one and two years after cesarean section using high-resolution,three dimensional T2-weighted sampling perfection with application optimized contrast using diflerent flip angle evolutions Magnetic Resonance Imaging(3DT2w SPACE MRI).Methods This prospective study was performed to investigate morphological changes in the cesarean scars and uterus from one to two years after cesarean section using high-resolution,3D T2w SPACE MRI.The healthy volunteers having no childbearing history were recruited as the controls.All data were measured by two experienced radiologists.All data with normal distribution between the one-year and two-year groups were compared using a paired-sample t test or independent t test.Results Finally,46 women took a pelvic MR examination one year after cesarean section,and a subset of 15 completed the same examination again after two years of cesarean section.Both the uterine length and the anterior wall thickness after two years of cesarean section(5.75±0.46 and 1.45±0.35 cm)were significantly greater than those measured at one year(5.33±0.59 and 1.25±0.27 cm)(t=-2.363 and-2.175,P=0.033 and 0.048).No significant difference was shown in myometrial thickness two years after cesarean section(1.45±0.35 cm)with respect to the control group(1.58±0.21 cm,P=0.170).Nine women who underwent MRI twice were considered to have scar diverticula one year after cesarean section,and still had diverticula two years after cesarean section.The thickness,height,and width of the uterine scar showed no significant change from one to two years(all P>0.05).Conclusions 3D T2w SPACE MRI provides overall morphologic details and shows dynamic changes in the scar and the uterus between one and two years after cesarean section.Scar morphology after cesarean section reached relatively stable one year after cesarean section,and uterine morphology was closer to normal two years after cesarean section.展开更多
In Chlamydomonas reinhardtii, the major protease involved in the maintenance of photosynthetic machinery in thylakoid membranes, the FtsH protease, mostly forms large hetero-oligomers （-1 MDa） comprising FtsH1 and F...In Chlamydomonas reinhardtii, the major protease involved in the maintenance of photosynthetic machinery in thylakoid membranes, the FtsH protease, mostly forms large hetero-oligomers （-1 MDa） comprising FtsH1 and FtsH2 subunits, whatever the light intensity for growth. Upon high light exposure, the FtsH subunits display a shorter half-life, which is counterbalanced by an increase in FTSH1/2 mRNA levels, resulting in the modest upregulation of FtsH1/2 proteins. Furthermore, we found that high light increases the protease activity through a hitherto unnoticed redox-controlled reduction of intermolecular disulfide bridges. We iso- lated a Chlamydomonas FTSH1 promoter-deficient mutant, ftsh1-3, resulting from the insertion of a TOC1 transposon, in which the high light-induced upregulation of FTSH1 gene expression is largely lost. In ftsh1- 3, the abundance of FtsH1 and FtsH2 proteins are loosely coupled （decreased by 70% and 30%, respectively） with no formation of large and stable homo-oligomers. Using strains exhibiting different accumulation levels of the FtsH1 subunit after complementation of ftsh1-3, we demonstrate that high light tolerance is tightly correlated with the abundance of the FtsH protease. Thus, the response of Chlamydomonas to light stress involves higher levels of FtsH 1/2 subunits associated into large complexes with increased proteolytic activity.展开更多
Plant interphase cortical microtubules(cMTs)mediate anisotropic cell expansion in response to environmental and developmental cues.In Arabidopsis thaliana,KATANIN 1(KTN1),the p60 catalytic subunit of the conserved MT-...Plant interphase cortical microtubules(cMTs)mediate anisotropic cell expansion in response to environmental and developmental cues.In Arabidopsis thaliana,KATANIN 1(KTN1),the p60 catalytic subunit of the conserved MT-severing enzyme katanin,is essential for cMT ordering and anisotropic cell expansion.However,the regulation of KTN1-mediated cMT severing and ordering remains unclear.In this work,we report that the Arabidopsis IQ67 DOMAIN(IQD)family gene ABNORMAL SHOOT 6(ABS6)encodes a MT-associated protein.Overexpression of ABS6 leads to elongated cotyledons,directional pavement cell expansion,and highly ordered transverse cMT arrays.Genetic suppressor analysis revealed that ABS6-mediated cMT ordering is dependent on KTN1 and SHADE AVOIDANCE 4(SAV4).Live imaging of cMT dynamics showed that both ABS6 and SAV4 function as positive regulators of cMT severing.Furthermore,ABS6 directly interacts with KTN1 and SAV4 and promotes their recruitment to the cMTs.Finally,analysis of loss-of-function mutant combinations showed that ABS6,SAV4,and KTN1 work together to ensure the robust ethylene response in the apical hook of dark-grown seedlings.Together,our findings establish ABS6 and SAV4 as positive regulators of cMT severing and ordering,and highlight the role of cMT dynamics in fine-tuning differential growth in plants.展开更多
文摘Objective Io evaluate changes in morphology of the cesarean scar and uterus between one and two years after cesarean section using high-resolution,three dimensional T2-weighted sampling perfection with application optimized contrast using diflerent flip angle evolutions Magnetic Resonance Imaging(3DT2w SPACE MRI).Methods This prospective study was performed to investigate morphological changes in the cesarean scars and uterus from one to two years after cesarean section using high-resolution,3D T2w SPACE MRI.The healthy volunteers having no childbearing history were recruited as the controls.All data were measured by two experienced radiologists.All data with normal distribution between the one-year and two-year groups were compared using a paired-sample t test or independent t test.Results Finally,46 women took a pelvic MR examination one year after cesarean section,and a subset of 15 completed the same examination again after two years of cesarean section.Both the uterine length and the anterior wall thickness after two years of cesarean section(5.75±0.46 and 1.45±0.35 cm)were significantly greater than those measured at one year(5.33±0.59 and 1.25±0.27 cm)(t=-2.363 and-2.175,P=0.033 and 0.048).No significant difference was shown in myometrial thickness two years after cesarean section(1.45±0.35 cm)with respect to the control group(1.58±0.21 cm,P=0.170).Nine women who underwent MRI twice were considered to have scar diverticula one year after cesarean section,and still had diverticula two years after cesarean section.The thickness,height,and width of the uterine scar showed no significant change from one to two years(all P>0.05).Conclusions 3D T2w SPACE MRI provides overall morphologic details and shows dynamic changes in the scar and the uterus between one and two years after cesarean section.Scar morphology after cesarean section reached relatively stable one year after cesarean section,and uterine morphology was closer to normal two years after cesarean section.
文摘In Chlamydomonas reinhardtii, the major protease involved in the maintenance of photosynthetic machinery in thylakoid membranes, the FtsH protease, mostly forms large hetero-oligomers （-1 MDa） comprising FtsH1 and FtsH2 subunits, whatever the light intensity for growth. Upon high light exposure, the FtsH subunits display a shorter half-life, which is counterbalanced by an increase in FTSH1/2 mRNA levels, resulting in the modest upregulation of FtsH1/2 proteins. Furthermore, we found that high light increases the protease activity through a hitherto unnoticed redox-controlled reduction of intermolecular disulfide bridges. We iso- lated a Chlamydomonas FTSH1 promoter-deficient mutant, ftsh1-3, resulting from the insertion of a TOC1 transposon, in which the high light-induced upregulation of FTSH1 gene expression is largely lost. In ftsh1- 3, the abundance of FtsH1 and FtsH2 proteins are loosely coupled （decreased by 70% and 30%, respectively） with no formation of large and stable homo-oligomers. Using strains exhibiting different accumulation levels of the FtsH1 subunit after complementation of ftsh1-3, we demonstrate that high light tolerance is tightly correlated with the abundance of the FtsH protease. Thus, the response of Chlamydomonas to light stress involves higher levels of FtsH 1/2 subunits associated into large complexes with increased proteolytic activity.
基金the Teaching and Research Core Facility at the College of Life Sciences,NWAFU for support in this worksupported by grants from the National Natural Science Foundation of China(31770205 and 31970186 to X.L.,31870268 to F.Y.)。
文摘Plant interphase cortical microtubules(cMTs)mediate anisotropic cell expansion in response to environmental and developmental cues.In Arabidopsis thaliana,KATANIN 1(KTN1),the p60 catalytic subunit of the conserved MT-severing enzyme katanin,is essential for cMT ordering and anisotropic cell expansion.However,the regulation of KTN1-mediated cMT severing and ordering remains unclear.In this work,we report that the Arabidopsis IQ67 DOMAIN(IQD)family gene ABNORMAL SHOOT 6(ABS6)encodes a MT-associated protein.Overexpression of ABS6 leads to elongated cotyledons,directional pavement cell expansion,and highly ordered transverse cMT arrays.Genetic suppressor analysis revealed that ABS6-mediated cMT ordering is dependent on KTN1 and SHADE AVOIDANCE 4(SAV4).Live imaging of cMT dynamics showed that both ABS6 and SAV4 function as positive regulators of cMT severing.Furthermore,ABS6 directly interacts with KTN1 and SAV4 and promotes their recruitment to the cMTs.Finally,analysis of loss-of-function mutant combinations showed that ABS6,SAV4,and KTN1 work together to ensure the robust ethylene response in the apical hook of dark-grown seedlings.Together,our findings establish ABS6 and SAV4 as positive regulators of cMT severing and ordering,and highlight the role of cMT dynamics in fine-tuning differential growth in plants.
