Zebrafish embryos possess two major types of myofibers,the slow and fast fibers,with distinct patterns of cell fusion.The fast muscle cells can fuse,while the slow muscle cells cannot.Here,we show that myomaker is exp...Zebrafish embryos possess two major types of myofibers,the slow and fast fibers,with distinct patterns of cell fusion.The fast muscle cells can fuse,while the slow muscle cells cannot.Here,we show that myomaker is expressed in both slow and fast muscle precursors,whereas myomixer is exclusive to fast muscle cells.The loss of Prdm1a,a regulator of slow muscle differentiation,results in strong myomaker and myomixer expression and slow muscle cell fusion.This abnormal fusion is further confirmed by the direct ectopic expression of myomaker or myomixer in slow muscle cells of transgenic models.Using the transgenic models,we show that the heterologous fusion between slow and fast muscle cells can alter slow muscle cell migration and gene expression.Furthermore,the overexpression of myomaker and myomixer also disrupts membrane integrity,resulting in muscle cell death.Collectively,this study identifies that the fiber-type-specific expression of fusogenic proteins is critical for preventing inappropriate fusion between slow and fast fibers in fish embryos,highlighting the need for precise regulation of fusogenic gene expression to maintain muscle fiber integrity and specificity.展开更多
We studied the effect of growth on wood anatomical dimensions and specific gravity of seed-raised plantation wood of Dalbergia sissoo with twelve trees of different diameters and similar ages. Fiber length ranged from...We studied the effect of growth on wood anatomical dimensions and specific gravity of seed-raised plantation wood of Dalbergia sissoo with twelve trees of different diameters and similar ages. Fiber length ranged from 925 to1,287 lm, fiber-diameter was 19–23 lm, wall thickness was4.2–5.4 lm, vessel-element-length was 152–188 lm, vesselelement-diameter was 152–200 lm, and specific gravity was0.59–0.72. Growth parameters including tree height, diameter at breast height, net primary productivity and net ecosystem productivity were significantly and positively correlated.Growth parameters showed non-significant positive relationships with fiber-length, fiber diameter, wall thickness, vessel element length, and vessel element diameter. The trend of wood traits increased with growth. Specific gravity showed non-significant negative relationships with growth parameters. Although the growth rate had varied relationships with wood properties, as reported by various workers, the wood element dimensions showed no significant relationship with growth parameters and there was little effect of growth rate on wood traits in seed-raised plantation of D. sissoo.展开更多
Gut microbiota specific tryptophan metabolites—indole-3-aldehyde(IAId)and indole-3-lactic acid(ILA),are key substances in improving atopic dermatitis(AD).However,probiotics that can be directly supplemented currently...Gut microbiota specific tryptophan metabolites—indole-3-aldehyde(IAId)and indole-3-lactic acid(ILA),are key substances in improving atopic dermatitis(AD).However,probiotics that can be directly supplemented currently have a low capacity to produce indole derivatives;thus,targeting the modulation of the gut microbiota to increase the content of indole derivatives is a potential alleviation strategy.Here we initially identified four types of dietary fibers—fructooligosaccharides(FOS),galactooligosaccharides(GOS),konjac glucomannan(KGM),and chitosan(CH)—that significantly increased IAId and ILA levels through in vitro fecal fermentation experiments.Subsequently,these dietary fibers and their combination were applied to AD model mice.The results indicated that dietary fiber intervention could elevate IAId and ILA levels in both feces and serum of mice,alleviate skin pathological symptoms,and are accompanied by a reduction in the infiltration of effector cells related to allergic inflammation,a decrease in serum immunoglobulin E and leukocyte interleukins(IL)-4,IL-5,and IL-13,thymic stromal lymphopoietin levels,and an increase in interferon-γand IL-10 levels.Additionally,the dietary fiber combination increased the relative abundance of high-indole derivative-producing bacteria,such as Clostridium sensu stricto 1,Lachnospiraceae,and Akkermansia,restoring the gut microbiota disorder caused by AD.Collectively,the combination of FOS,GOS,KGM,and CH can regulate gut microbiota and increase the content of indole derivatives in the gut,thereby reducing Th2 immune responses and alleviating AD pathological symptoms,providing ample scientific evidence for the development of new strategies to improve AD.展开更多
基金supported by funding from the U.S.National Institute of Health(NIH)National Institute of Arthritis and Musculoskeletal and Skin Diseases(R01AR072703 to S.D.)。
文摘Zebrafish embryos possess two major types of myofibers,the slow and fast fibers,with distinct patterns of cell fusion.The fast muscle cells can fuse,while the slow muscle cells cannot.Here,we show that myomaker is expressed in both slow and fast muscle precursors,whereas myomixer is exclusive to fast muscle cells.The loss of Prdm1a,a regulator of slow muscle differentiation,results in strong myomaker and myomixer expression and slow muscle cell fusion.This abnormal fusion is further confirmed by the direct ectopic expression of myomaker or myomixer in slow muscle cells of transgenic models.Using the transgenic models,we show that the heterologous fusion between slow and fast muscle cells can alter slow muscle cell migration and gene expression.Furthermore,the overexpression of myomaker and myomixer also disrupts membrane integrity,resulting in muscle cell death.Collectively,this study identifies that the fiber-type-specific expression of fusogenic proteins is critical for preventing inappropriate fusion between slow and fast fibers in fish embryos,highlighting the need for precise regulation of fusogenic gene expression to maintain muscle fiber integrity and specificity.
文摘We studied the effect of growth on wood anatomical dimensions and specific gravity of seed-raised plantation wood of Dalbergia sissoo with twelve trees of different diameters and similar ages. Fiber length ranged from 925 to1,287 lm, fiber-diameter was 19–23 lm, wall thickness was4.2–5.4 lm, vessel-element-length was 152–188 lm, vesselelement-diameter was 152–200 lm, and specific gravity was0.59–0.72. Growth parameters including tree height, diameter at breast height, net primary productivity and net ecosystem productivity were significantly and positively correlated.Growth parameters showed non-significant positive relationships with fiber-length, fiber diameter, wall thickness, vessel element length, and vessel element diameter. The trend of wood traits increased with growth. Specific gravity showed non-significant negative relationships with growth parameters. Although the growth rate had varied relationships with wood properties, as reported by various workers, the wood element dimensions showed no significant relationship with growth parameters and there was little effect of growth rate on wood traits in seed-raised plantation of D. sissoo.
基金supported by the Natural Science Foundation of Jiangsu(Grant No.BK20221078)the National Key Research and Development Program of China(No.2022YFF1100203)the collaborative innovation center of food safety and quality control in Jiangsu Province.
文摘Gut microbiota specific tryptophan metabolites—indole-3-aldehyde(IAId)and indole-3-lactic acid(ILA),are key substances in improving atopic dermatitis(AD).However,probiotics that can be directly supplemented currently have a low capacity to produce indole derivatives;thus,targeting the modulation of the gut microbiota to increase the content of indole derivatives is a potential alleviation strategy.Here we initially identified four types of dietary fibers—fructooligosaccharides(FOS),galactooligosaccharides(GOS),konjac glucomannan(KGM),and chitosan(CH)—that significantly increased IAId and ILA levels through in vitro fecal fermentation experiments.Subsequently,these dietary fibers and their combination were applied to AD model mice.The results indicated that dietary fiber intervention could elevate IAId and ILA levels in both feces and serum of mice,alleviate skin pathological symptoms,and are accompanied by a reduction in the infiltration of effector cells related to allergic inflammation,a decrease in serum immunoglobulin E and leukocyte interleukins(IL)-4,IL-5,and IL-13,thymic stromal lymphopoietin levels,and an increase in interferon-γand IL-10 levels.Additionally,the dietary fiber combination increased the relative abundance of high-indole derivative-producing bacteria,such as Clostridium sensu stricto 1,Lachnospiraceae,and Akkermansia,restoring the gut microbiota disorder caused by AD.Collectively,the combination of FOS,GOS,KGM,and CH can regulate gut microbiota and increase the content of indole derivatives in the gut,thereby reducing Th2 immune responses and alleviating AD pathological symptoms,providing ample scientific evidence for the development of new strategies to improve AD.
