It has been generally held in botany that Oryza sativa L. is a monocotyledon. Based on studies of rice embryo development we confirmed that rice embryo has two dimorphic cotyledons rather than just one cotyledo...It has been generally held in botany that Oryza sativa L. is a monocotyledon. Based on studies of rice embryo development we confirmed that rice embryo has two dimorphic cotyledons rather than just one cotyledon. In the present study we attempt to know if the morphology of embryos in other species of Oryza differs from O. sativa and if these embryos have dimorphic cotyledon. Two types of embryo structures were observed in 22 species and/or subspecies of genus Oryza under the scanning electron microscope. Type 1, the O.sativa type, which is characterized by ventral scale and lateral scales, was found in 16 species. Type 2, the O. meyeriana (Zoll. et Mor. ex Steud.) Baill. ssp. tuberculata W. C. Wu et Y. G. Lu, G. C. Wang type, with no ventral scale and lateral scales, was found in 6 species and subspecies. The embryogenic process of O.sativa and O.meyeriana sub. tuberculata showed that the scutellum primordium, coleorhiza primordium, coleoptile primordium and shoot apical meristem directly differentiate from proembryo. The former two later develop into the embryo envelope, which is the outside cotyledon; the coleoptile primordium develops into the coleoptile with the shape of inverted empty cone surrounding and covering the growth cone, which is the apical cotyledon. Both types of rice embryos have dimorphic cotyledons. The structural difference between them is that the scutellum primordium of the young embryo in type 2 does not differentiate ventral scale and lateral scales while the embryo of type 1 does. The dimorphic cotyledons of embryo of Oryza plants originate from the dorsiventrality of proembryo.展开更多
The ovipositor of parasitic insect is a highly specialized organ and crucial for parasitising. Morphology and structure of the ovipositor in female Macrocentrus cingulum, a polyembryonic parasitoid, are observed in SE...The ovipositor of parasitic insect is a highly specialized organ and crucial for parasitising. Morphology and structure of the ovipositor in female Macrocentrus cingulum, a polyembryonic parasitoid, are observed in SEM studies. The ovipositor of M. cingulum consists of the valvulae 1, 2 and 3. The valvulae 1 and 2 of ovipositor house in the valvulae 3 at rest and the valvulae 1 and 2 part from the valvulae 3 at probing and ovipositing. The cross-section of valvulae 3 shows that the valvulae 3 is hollow which may reduce the weight of ovipositor and make the ovipositor more flexible. The distal end of stylus （valvulae l, 2） becomes extremely sharp and the piercing tip of valvulae 1 and 2 form the arrangement of tongue-and-groove. This arrangement may support valvulae 2 slide longitudinally along the valvulae 1. Numbers of pores are distributed on the cuticle of the valvulae l and 2. The piecing tip of valvulae 1 and 2 have more pores than proximal and intermediate region. The out side of valvulae 3 is completely covered with chactica sensilla and the distal end of valvulae 3 has more sensilla than proximal and intermediate region. The function and structure of ovipositor of M. cingulum was discussed and compared with other species.展开更多
The purpose of this study was to analyze spatio-temporal dynamics of localization of protease-sensitive sites Arg-X in non-histone and histone blocks of heteropolymer suprastructures （nucleoplasm, chromatin, nuclear ...The purpose of this study was to analyze spatio-temporal dynamics of localization of protease-sensitive sites Arg-X in non-histone and histone blocks of heteropolymer suprastructures （nucleoplasm, chromatin, nuclear matrix） as possible zones affecting the conformational rearrangements of the total interphase chromatin at the induction of increasing morphogenesis of mature embryos-germs of spring and transformed from its winter wheat. Germinated embryos-germs were detached from endosperm after 24 hours from the start of soaking. Cell nuclei have been allocated from embryos-germs and cleared, and then from their heteropolymer suprastructures （nucleoplasm, chromatin loosely bound with nuclear matrix and chromatin tightly bound with nuclear matrix, and nuclear matrix） were extracted by increasing ionic strength of solution. From isolated nuclear suprastructures, non-histone proteins were separated from histones using ion exchange chromatography. Trypsin-like complexes from non-histone proteins and histone blocks were isolated using the affinity chromatography. The Arg-X （tryptase） activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine. Hypersensitivity to the Arg-X proteolysis in trypsin-like complexes detected at the level suprastructures of chromatin tightly bound with the nuclear matrix was shown. The most active changes of the nuclear proteome have occurred at the level of the non-histone proteins and the core histones （H2A ＋ H2B） （H3 ＋ H4） of induced to growth embryos-seedlings of winter wheat （compared to the initial spring form of wheat）. Perhaps hypersensitivity to the Arg-X activity of the trypsin-like complexes in the non-histone proteins and the core blocks of chromatin tightly bound with nuclear matrix have been entrenched during the transforming of the winter wheat from the initial spring wheat.展开更多
We give a necessary and sufficient condition for the fundamental group homomorphism of a map between CW-complexes(manifolds) to induce partial homology equivalences. As applications, we obtain characterizations of fun...We give a necessary and sufficient condition for the fundamental group homomorphism of a map between CW-complexes(manifolds) to induce partial homology equivalences. As applications, we obtain characterizations of fundamental groups of homology spheres and Moore manifolds. Moreover, a classification of one-sided h-cobordism of manifolds up to diffeomorphisms is obtained, based on Quillen's plus construction with Whitehead torsions.展开更多
文摘It has been generally held in botany that Oryza sativa L. is a monocotyledon. Based on studies of rice embryo development we confirmed that rice embryo has two dimorphic cotyledons rather than just one cotyledon. In the present study we attempt to know if the morphology of embryos in other species of Oryza differs from O. sativa and if these embryos have dimorphic cotyledon. Two types of embryo structures were observed in 22 species and/or subspecies of genus Oryza under the scanning electron microscope. Type 1, the O.sativa type, which is characterized by ventral scale and lateral scales, was found in 16 species. Type 2, the O. meyeriana (Zoll. et Mor. ex Steud.) Baill. ssp. tuberculata W. C. Wu et Y. G. Lu, G. C. Wang type, with no ventral scale and lateral scales, was found in 6 species and subspecies. The embryogenic process of O.sativa and O.meyeriana sub. tuberculata showed that the scutellum primordium, coleorhiza primordium, coleoptile primordium and shoot apical meristem directly differentiate from proembryo. The former two later develop into the embryo envelope, which is the outside cotyledon; the coleoptile primordium develops into the coleoptile with the shape of inverted empty cone surrounding and covering the growth cone, which is the apical cotyledon. Both types of rice embryos have dimorphic cotyledons. The structural difference between them is that the scutellum primordium of the young embryo in type 2 does not differentiate ventral scale and lateral scales while the embryo of type 1 does. The dimorphic cotyledons of embryo of Oryza plants originate from the dorsiventrality of proembryo.
基金Acknowledgements： This study was supported by the National Natural Science Foundation of China （No. 30370195）. We thank Mr QIU, H. G and QIU, Z. L for culture of insects.
文摘The ovipositor of parasitic insect is a highly specialized organ and crucial for parasitising. Morphology and structure of the ovipositor in female Macrocentrus cingulum, a polyembryonic parasitoid, are observed in SEM studies. The ovipositor of M. cingulum consists of the valvulae 1, 2 and 3. The valvulae 1 and 2 of ovipositor house in the valvulae 3 at rest and the valvulae 1 and 2 part from the valvulae 3 at probing and ovipositing. The cross-section of valvulae 3 shows that the valvulae 3 is hollow which may reduce the weight of ovipositor and make the ovipositor more flexible. The distal end of stylus （valvulae l, 2） becomes extremely sharp and the piercing tip of valvulae 1 and 2 form the arrangement of tongue-and-groove. This arrangement may support valvulae 2 slide longitudinally along the valvulae 1. Numbers of pores are distributed on the cuticle of the valvulae l and 2. The piecing tip of valvulae 1 and 2 have more pores than proximal and intermediate region. The out side of valvulae 3 is completely covered with chactica sensilla and the distal end of valvulae 3 has more sensilla than proximal and intermediate region. The function and structure of ovipositor of M. cingulum was discussed and compared with other species.
文摘The purpose of this study was to analyze spatio-temporal dynamics of localization of protease-sensitive sites Arg-X in non-histone and histone blocks of heteropolymer suprastructures （nucleoplasm, chromatin, nuclear matrix） as possible zones affecting the conformational rearrangements of the total interphase chromatin at the induction of increasing morphogenesis of mature embryos-germs of spring and transformed from its winter wheat. Germinated embryos-germs were detached from endosperm after 24 hours from the start of soaking. Cell nuclei have been allocated from embryos-germs and cleared, and then from their heteropolymer suprastructures （nucleoplasm, chromatin loosely bound with nuclear matrix and chromatin tightly bound with nuclear matrix, and nuclear matrix） were extracted by increasing ionic strength of solution. From isolated nuclear suprastructures, non-histone proteins were separated from histones using ion exchange chromatography. Trypsin-like complexes from non-histone proteins and histone blocks were isolated using the affinity chromatography. The Arg-X （tryptase） activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine. Hypersensitivity to the Arg-X proteolysis in trypsin-like complexes detected at the level suprastructures of chromatin tightly bound with the nuclear matrix was shown. The most active changes of the nuclear proteome have occurred at the level of the non-histone proteins and the core histones （H2A ＋ H2B） （H3 ＋ H4） of induced to growth embryos-seedlings of winter wheat （compared to the initial spring form of wheat）. Perhaps hypersensitivity to the Arg-X activity of the trypsin-like complexes in the non-histone proteins and the core blocks of chromatin tightly bound with nuclear matrix have been entrenched during the transforming of the winter wheat from the initial spring wheat.
基金supported by National Natural Science Foundation of China(Grand No.10901151)RDF-13-02-08 of Xi’an Jiaotong-Liverpool University
文摘We give a necessary and sufficient condition for the fundamental group homomorphism of a map between CW-complexes(manifolds) to induce partial homology equivalences. As applications, we obtain characterizations of fundamental groups of homology spheres and Moore manifolds. Moreover, a classification of one-sided h-cobordism of manifolds up to diffeomorphisms is obtained, based on Quillen's plus construction with Whitehead torsions.
