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
Spionid worms of Polydora ciliata inhabit the shells of many commercially important bivalves and cause disease in molluscan aquaculture. Their sperm structure is closely related to their fertilization method. To give ...Spionid worms of Polydora ciliata inhabit the shells of many commercially important bivalves and cause disease in molluscan aquaculture. Their sperm structure is closely related to their fertilization method. To give an insight into the sperm structure and spermatogenesis, ultrastructure details of the subcellular components of germ cells during spermiogenesis of Polydora ciliata are detected by transmission electron microscopy(TEM). In P. ciliata, during spermiogenesis, chromatin is regularly arranged as dense fibrils and becomes more condensed when the nucleus elongates. Microtubules do not surround the nucleus during its elongation. The Golgi phase is characterized by the formation of proacrosomal granules within the Golgi apparatus. The proacrosomal granules fuse to form a single, spherical acrosomal vesicle that migrates to the anterior pole of the cell. At the time of nuclear condensation, mitochondria become reduced in number but increased in size, causing deep indentation at the base of the nucleus. The mid-piece has a few mitochondria. The cap phase includes the spreading of the acrosomal granule over the surface of the nucleus of the differentiating spermatid. The acrosomal phase of spermiogenesis is typically associated with changes in the shape of the nucleus, acrosome and tail. The relationship of sperm ultrastructure to spermiogenesis in spionidae species was discussed.展开更多
The honesty of structural-based ornaments is controversial. Sexual selection theory predicts that the honesty of a sexual signal relies on its cost of production or maintenance. Therefore, environmental factors with n...The honesty of structural-based ornaments is controversial. Sexual selection theory predicts that the honesty of a sexual signal relies on its cost of production or maintenance. Therefore, environmental factors with negative impact on individuals could generate high costs and affect the expres- sion of these sexual signals. In this sense, parasites are a main cost for their hosts. To probe the effect of parasites on the structural-based coloration of a lacertid species Lacerta schreiberi, we have experimentally removed ticks from a group of male Iberian green lizards using an acaricide treatment （i.e., the broad-use insecticide fipronil）. All individuals were radio-tracked and recaptured after 15 days to study changes in coloration in both the ultraviolet （UV）-blue （structural-based） and UV-yellow （structural and pigment-based） ornamentations after manipulation, as well as changes in endoand ectoparasitic load and body condition. Additionally, after the experiment, we measured the skin inflammatory response to a mitogen. The fipronil treatment was effective in reducing ticks and it was associated with a significant reduction of hemoparasite load. Throughout the season, individuals treated with fipronil tended to maintain the brightness of the UV-blue throat coloration while control lizards tended to increase it. However, individuals treated with fipronil that were not infected with hemoparasites significantly reduced the brightness of the UV-blue throat color ation. Individuals with a higher initial tick load exhibited a lower UV saturation increment （UV-blue） and a higher brightness increment （UV-yellow） during the experiment. Overall these results experimentally support the idea that parasites adversely influence the expression of the structural-based coloration of male Iberian green lizards. This adds evidence to the hypothesis that sexual ornaments in lizards function as honest signals.展开更多
Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures ...Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures of some host-selective plant pathogen mycotoxins discovered in recent years and the correlation between biological activity and chemical structure of toxin.展开更多
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.
基金supported by the National Key Technology Support Program (2011BAD13B05)
文摘Spionid worms of Polydora ciliata inhabit the shells of many commercially important bivalves and cause disease in molluscan aquaculture. Their sperm structure is closely related to their fertilization method. To give an insight into the sperm structure and spermatogenesis, ultrastructure details of the subcellular components of germ cells during spermiogenesis of Polydora ciliata are detected by transmission electron microscopy(TEM). In P. ciliata, during spermiogenesis, chromatin is regularly arranged as dense fibrils and becomes more condensed when the nucleus elongates. Microtubules do not surround the nucleus during its elongation. The Golgi phase is characterized by the formation of proacrosomal granules within the Golgi apparatus. The proacrosomal granules fuse to form a single, spherical acrosomal vesicle that migrates to the anterior pole of the cell. At the time of nuclear condensation, mitochondria become reduced in number but increased in size, causing deep indentation at the base of the nucleus. The mid-piece has a few mitochondria. The cap phase includes the spreading of the acrosomal granule over the surface of the nucleus of the differentiating spermatid. The acrosomal phase of spermiogenesis is typically associated with changes in the shape of the nucleus, acrosome and tail. The relationship of sperm ultrastructure to spermiogenesis in spionidae species was discussed.
文摘The honesty of structural-based ornaments is controversial. Sexual selection theory predicts that the honesty of a sexual signal relies on its cost of production or maintenance. Therefore, environmental factors with negative impact on individuals could generate high costs and affect the expres- sion of these sexual signals. In this sense, parasites are a main cost for their hosts. To probe the effect of parasites on the structural-based coloration of a lacertid species Lacerta schreiberi, we have experimentally removed ticks from a group of male Iberian green lizards using an acaricide treatment （i.e., the broad-use insecticide fipronil）. All individuals were radio-tracked and recaptured after 15 days to study changes in coloration in both the ultraviolet （UV）-blue （structural-based） and UV-yellow （structural and pigment-based） ornamentations after manipulation, as well as changes in endoand ectoparasitic load and body condition. Additionally, after the experiment, we measured the skin inflammatory response to a mitogen. The fipronil treatment was effective in reducing ticks and it was associated with a significant reduction of hemoparasite load. Throughout the season, individuals treated with fipronil tended to maintain the brightness of the UV-blue throat coloration while control lizards tended to increase it. However, individuals treated with fipronil that were not infected with hemoparasites significantly reduced the brightness of the UV-blue throat color ation. Individuals with a higher initial tick load exhibited a lower UV saturation increment （UV-blue） and a higher brightness increment （UV-yellow） during the experiment. Overall these results experimentally support the idea that parasites adversely influence the expression of the structural-based coloration of male Iberian green lizards. This adds evidence to the hypothesis that sexual ornaments in lizards function as honest signals.
基金Supported by the National Science Foundation Program (30271084).
文摘Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures of some host-selective plant pathogen mycotoxins discovered in recent years and the correlation between biological activity and chemical structure of toxin.
