The histology, evolution of the structure, composition and morphology of oogonia and primary oocytes in different phases during the ovary development of snakehead, Channa scopoli, were studied. The traditional method ...The histology, evolution of the structure, composition and morphology of oogonia and primary oocytes in different phases during the ovary development of snakehead, Channa scopoli, were studied. The traditional method of wax section was employed to perform the hematoxylineosin staining. The ovary of snakehead is overlaid by the 2layer membrane featured with abundant veins. The primordial germ cell of ovary extends into the ovary together with the inner connective tissue membrane to develop into many ovarial lamellae that arrange radiately around the ovarium cavity. With regard to the developing snakehead, the pattern and structure of its oogonia and early primary oocyte are of fundamental homology with most of the osteichthyes, while the nutrimental composition, accumulation, distribution and the composition of ova membrane for the primary oocyte in phase Ⅲ and Ⅳ are of preferable difference with them. The nutriment of its oocyte is primarily composed of glucoprotein which is included in the vesicle. But the amount of yolk which is primarily composed of protein is comparatively small, even the same for the oocyte developing into the phase Ⅳ which is featured with the deviation of nucleus. So the amount of nucleoli in the primary oocyte of the snakehead is significantly limited than most of the osteichthyes. The primary oocyte in phase Ⅲ and Ⅳ of the snakehead only have 1 layer of ova plasmalemma which is covered by another 2 layers follicular membrane developed from the follicle cell, but there is not any radiated belt of jelly membrane between the membrane and the follicular membrane which is developed from the primary ova membrane and the secondary one in most of the osteichthyes cases.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
文摘The histology, evolution of the structure, composition and morphology of oogonia and primary oocytes in different phases during the ovary development of snakehead, Channa scopoli, were studied. The traditional method of wax section was employed to perform the hematoxylineosin staining. The ovary of snakehead is overlaid by the 2layer membrane featured with abundant veins. The primordial germ cell of ovary extends into the ovary together with the inner connective tissue membrane to develop into many ovarial lamellae that arrange radiately around the ovarium cavity. With regard to the developing snakehead, the pattern and structure of its oogonia and early primary oocyte are of fundamental homology with most of the osteichthyes, while the nutrimental composition, accumulation, distribution and the composition of ova membrane for the primary oocyte in phase Ⅲ and Ⅳ are of preferable difference with them. The nutriment of its oocyte is primarily composed of glucoprotein which is included in the vesicle. But the amount of yolk which is primarily composed of protein is comparatively small, even the same for the oocyte developing into the phase Ⅳ which is featured with the deviation of nucleus. So the amount of nucleoli in the primary oocyte of the snakehead is significantly limited than most of the osteichthyes. The primary oocyte in phase Ⅲ and Ⅳ of the snakehead only have 1 layer of ova plasmalemma which is covered by another 2 layers follicular membrane developed from the follicle cell, but there is not any radiated belt of jelly membrane between the membrane and the follicular membrane which is developed from the primary ova membrane and the secondary one in most of the osteichthyes cases.
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.
