Gossypium hirsutum L. and G. barbadense L. are the two cultivated tetraploid species of cotton. The first is characterized by a high yield and wide adaptation, and the second by its super fiber property. Substit...Gossypium hirsutum L. and G. barbadense L. are the two cultivated tetraploid species of cotton. The first is characterized by a high yield and wide adaptation, and the second by its super fiber property. Substitution line in which a pair of intact chromosomes of TM_1 ( G. hirsutum ) were replaced by a pair of homozygous chromosomes of 3_79 ( G. barbadense ) is an excellent material for genetic research and molecular tagging. In this study, substitution line 16 (Sub 16) was used to evaluate the performance of the 16th chromosome in G. barbadense in TM_1 background. The genetic analysis using the major gene plus polygene mixed inheritance model in F 2∶3 family revealed that there might exist 2 QTLs respectively for boll size, lint percentage, lint index, fiber length and the first fruit branch node, 1 QTL for fiber elongation and flowering date, and no QTL for seed index, fiber strength and Micronaire in chromosome 16. However, 9 QTLs (LOD (logarithm of odds)≥3.0) controlling 6 quantitative traits were significantly identified in linkage group of chromosome 16 constructed in (TM_1×3_79) F 2by interval mapping. Among them, 1 QTL for boll size, fiber length, flowering date and fiber elongation could explain 15.2%, 19.7%, 12.1%, and 11.7% phenotypic variance respectively, 2 QTLs for lint index could explain 11.6% and 41.9%, and 3 QTLs for lint percentage could explain 8.7%, 9.6% and 29.2% phenotypic variance respectively. One unlinked SSR marker was associated with one QTL respectively for boll size and flowering date and they could explain 1.60% and 4.63% phenotypic variance. The traits associated significantly with chromosome 16 from Sub 16 were boll weight, lint percentage, lint index, fiber length, fiber elongation and flowering days.展开更多
Objective： The aim of this study was to study the clinicopathological and immunohistochemical features of pilo- myxoid astrocytoma （PMA）. Methods： The clinical and pathologic features in six cases of PMA were anal...Objective： The aim of this study was to study the clinicopathological and immunohistochemical features of pilo- myxoid astrocytoma （PMA）. Methods： The clinical and pathologic features in six cases of PMA were analyzed. Immunohisto- chemical staining for glial fibrillary acidic protein （GFAP）, synaptophysin （Syn）, Chromogranin A （CgA）, cytokeratin （AEI/AE3）, epithelial membrane antigen （EMA） and Ki67 was performed on paraffin-embedded sections. Results： Among the six cases, five occurred in female patients, one was male, the age at diagnosis ranged from 2 to 15 years. Four cases were located in the hypothalamic area and optic pathway, one case in the third ventricle, and one case in left parietal lobe. On imaging, PMAs often appears as well-circumscribed mass. Microscopically, the tumor was composed of monomorphous bipolar （piloid） cells setting in a prominent myxoid background with an angiocentric radiating growth pattern in some areas. PMA lacked biphasic pattern, Rosenthal fibers and eosinophilic granular bodies which were usually typical in a classic pilocytic astrocytoma （PA）. Immunohistochemcal study showed that the tumor cells were diffusely positive for GFAP. Syn positive staining was observed in one case. The Ki67 labeling index measured less than 5%. Conclusion： PMA is a distinct aggressive variant of pilocytic astrocytoma with special histological and immunohistochemical features. It is typically a rare tumor of early childhood. Im- munohistochemical staining for GFAP and Syn is helpful in differential diagnosis.展开更多
Spatial expression patterns of homeobox （HOX） genes delineate positional identity of primary fibroblasts from different topo- graphic sites. The molecular mechanism underlying the establishing or maintaining of HOX ...Spatial expression patterns of homeobox （HOX） genes delineate positional identity of primary fibroblasts from different topo- graphic sites. The molecular mechanism underlying the establishing or maintaining of HOX gene expression pattern remains an attractive developmental issue to be addressed. Our previous work suggested a critical role of CTCF/cobesin-mediated high- er-order chromatin structure in RA-induced HOXA activation in human teratocarcinoma NT2/D1 cells. This study investigated the recruitment of CTCF and cohesin, and the higher-order chromatin structure of the HOXA locus in fetal lung and adult foreskin fibroblasts, which display complementary HOXA gene expression patterns. Chromatin contacts between the CTCF-binding sites were observed with lower frequency in human foreskin fibroblasts. This observation is consistent with the lower level of cohesin recruitment and 5＇ HOXA gene expression in the same cells. We also showed that CTCF-binding site A56 （CBSA56） related chromatin structures exhibit the most notable changes in between the two types of cell, and hence may stand for one of the key CTCF-binding sites for cell-type specific chromatin structure organization. Together, these results im- ply that CTCF/cohesin coordinates HOXA cluster higher-order chromatin structure and expression during development, and provide insight into the relationship between cell-type specific chromatin organization and the spatial collinearity.展开更多
文摘Gossypium hirsutum L. and G. barbadense L. are the two cultivated tetraploid species of cotton. The first is characterized by a high yield and wide adaptation, and the second by its super fiber property. Substitution line in which a pair of intact chromosomes of TM_1 ( G. hirsutum ) were replaced by a pair of homozygous chromosomes of 3_79 ( G. barbadense ) is an excellent material for genetic research and molecular tagging. In this study, substitution line 16 (Sub 16) was used to evaluate the performance of the 16th chromosome in G. barbadense in TM_1 background. The genetic analysis using the major gene plus polygene mixed inheritance model in F 2∶3 family revealed that there might exist 2 QTLs respectively for boll size, lint percentage, lint index, fiber length and the first fruit branch node, 1 QTL for fiber elongation and flowering date, and no QTL for seed index, fiber strength and Micronaire in chromosome 16. However, 9 QTLs (LOD (logarithm of odds)≥3.0) controlling 6 quantitative traits were significantly identified in linkage group of chromosome 16 constructed in (TM_1×3_79) F 2by interval mapping. Among them, 1 QTL for boll size, fiber length, flowering date and fiber elongation could explain 15.2%, 19.7%, 12.1%, and 11.7% phenotypic variance respectively, 2 QTLs for lint index could explain 11.6% and 41.9%, and 3 QTLs for lint percentage could explain 8.7%, 9.6% and 29.2% phenotypic variance respectively. One unlinked SSR marker was associated with one QTL respectively for boll size and flowering date and they could explain 1.60% and 4.63% phenotypic variance. The traits associated significantly with chromosome 16 from Sub 16 were boll weight, lint percentage, lint index, fiber length, fiber elongation and flowering days.
文摘Objective： The aim of this study was to study the clinicopathological and immunohistochemical features of pilo- myxoid astrocytoma （PMA）. Methods： The clinical and pathologic features in six cases of PMA were analyzed. Immunohisto- chemical staining for glial fibrillary acidic protein （GFAP）, synaptophysin （Syn）, Chromogranin A （CgA）, cytokeratin （AEI/AE3）, epithelial membrane antigen （EMA） and Ki67 was performed on paraffin-embedded sections. Results： Among the six cases, five occurred in female patients, one was male, the age at diagnosis ranged from 2 to 15 years. Four cases were located in the hypothalamic area and optic pathway, one case in the third ventricle, and one case in left parietal lobe. On imaging, PMAs often appears as well-circumscribed mass. Microscopically, the tumor was composed of monomorphous bipolar （piloid） cells setting in a prominent myxoid background with an angiocentric radiating growth pattern in some areas. PMA lacked biphasic pattern, Rosenthal fibers and eosinophilic granular bodies which were usually typical in a classic pilocytic astrocytoma （PA）. Immunohistochemcal study showed that the tumor cells were diffusely positive for GFAP. Syn positive staining was observed in one case. The Ki67 labeling index measured less than 5%. Conclusion： PMA is a distinct aggressive variant of pilocytic astrocytoma with special histological and immunohistochemical features. It is typically a rare tumor of early childhood. Im- munohistochemical staining for GFAP and Syn is helpful in differential diagnosis.
基金supported by the National Natural Science Foundation of China(31030026)the National Basic Research Program(2011CB-965203)the PUMC Youth funds(3332013138)
文摘Spatial expression patterns of homeobox （HOX） genes delineate positional identity of primary fibroblasts from different topo- graphic sites. The molecular mechanism underlying the establishing or maintaining of HOX gene expression pattern remains an attractive developmental issue to be addressed. Our previous work suggested a critical role of CTCF/cobesin-mediated high- er-order chromatin structure in RA-induced HOXA activation in human teratocarcinoma NT2/D1 cells. This study investigated the recruitment of CTCF and cohesin, and the higher-order chromatin structure of the HOXA locus in fetal lung and adult foreskin fibroblasts, which display complementary HOXA gene expression patterns. Chromatin contacts between the CTCF-binding sites were observed with lower frequency in human foreskin fibroblasts. This observation is consistent with the lower level of cohesin recruitment and 5＇ HOXA gene expression in the same cells. We also showed that CTCF-binding site A56 （CBSA56） related chromatin structures exhibit the most notable changes in between the two types of cell, and hence may stand for one of the key CTCF-binding sites for cell-type specific chromatin structure organization. Together, these results im- ply that CTCF/cohesin coordinates HOXA cluster higher-order chromatin structure and expression during development, and provide insight into the relationship between cell-type specific chromatin organization and the spatial collinearity.
