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1.
The early stages and capsulogenetic stages of sporogenesis of Myxobolus kwangsiensis were studied indetail by electron microscopy. M. kwangsiensis is an intrasellular myxsporen infecting the epithelial cellsof kidney tubules of young dace Labeo rohita. The M. kwangsiensis sporogenesis presents the typical featuresof myxosporea. The initial stages are multinuceate primary cells, with one primary cell typicallyenclosing one secondary cell. The secondary cells are formed directly by cytokinesis inside the primary cells. Theprimary cell participates in the formation of the secondary cell nucleus. The nuclear division of primarycell is asynchronous by amitosis. The parasitic organisms may degenerate inside the epithelial cells at anystage. The modes of sporoblast formation , the typical features of myxosporea and the cause of its degradationare discussed. 相似文献
2.
Eucheuma gelatinae (Esper) J. Agardh has vegetative and reproductive features distinguishing it from other species ofEucheuma. The occurrence of reproductive nemathecia containing carpogonial branches, auxiliary cells and post-fertilization stages
including gonimoblast and pericarp initiation, fusion cell formation stages and carposporophyte development are described
and ilustrated for the first time for this species.
Contribution No. 2380 of the Institute of Oceanology, Chinese Academy of Sciences. 相似文献
3.
Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis in C. farreri has different developmental stages: spermatogonia, primary spermatocyte, second spermatocyte, spermatid and spermatozoon. A large number of same developmental stage spermatic cells converge at a definite area of the testis. Premeiotic, previtellogenic and vitellogenic oocytes can be found during oogenesis in C. farreri, where oocyte distribution is obviously irregular. The A. irradians gonad consists of two different parts in one individual: one part functions as testis, the other as ovary. Between these two parts is a special appearance area, where a large number of spermatic cells are bound with two layers of acellular substance with many oocytes in it. 相似文献
4.
Observation of female gamete (Carpogonia) germination of Porphyra yezoensis and P. oligospermatangia
Several papers have reported that part or whole leafy thallus seemingly consisting of zygotospores can give rise to both blades
and conchocelis in the same culture ofPorphyra. Study on samples of wild and cultivatedPorphyra yezoensis andP. oligospermatangia were conducted to clarify the origination of the young blades in the culture. It is confirmed that single cells on the blade
of both species, which normally intermixed with zygotospores, germinated into young blades. TEM and SEM observation has shown
that the single cells ofPorphyra yezoensis had typical features of female gamete (carpogonia) but archeospore. Therefore, the female gametes are responsible in developing
leafy thalli.
This project was sponsored by the NSFC (No. C-0205-05-39770593) 相似文献
5.
Two new species of the genusTinocladia Kylin (1940)T. eudesmoides Ding et Lu sp. nov. andTinocladia zhangii Ding et Lu sp. nov., are described.T. eudesmoides is mainly characterized by its longitudinally and transversely produced sub-cortical filaments from the medulla, its short
uniseriate assimilating filaments, usually composed of 6–10 cells with slightly swollen and narrow ultimate cells, and its
unilocular sporangia (60–115)×55–70μm, variable in size.T. zhangii is mainly characterized by its very solid frond, not rip apart by hands, its evident longer primary branches, its short and
slender secondary branches, with very evident sub-cortical layer, and filaments divided repeatedly, and its large and small
unilocular sporangia, with the latter borne on an evidently swollen pedicel.
Project B80981816 supported by the NSFC.
Contribution No. 4443 from the Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. 相似文献
6.
Amphioxus, a cephalochordate, is an important model fish for studies in evolution and comparative biology. A successful cell
culture from amphioxus tissues in vitro would help understanding some basic issues. To determine the optimal culture conditions for proliferation of amphioxus cells,
primary cultures were initiated from buccal cirri, tail, gill, gut and metapleural fold of amphioxus Branchiostoma belcheri tsingtauense. The media tested were L-15, F-12, M 199, MEM, DMEM, PRMI 1640 and LDF, each was supplemented with 20% fetal bovine serum.
The optimal conditions include tail tissue cultured in L-15 or F-12 with supplement of 20% FBS and 1.5% NaCl at about 25°C.
Supported by Doctoral Initial Fund of Ludong University (No.43304) 相似文献
7.
Adult pharyngeal teeth inMylopharyngodon piceus are molariform. Based on SEM observations of the developing teeth, this paper describes the morphological diversification
of pharyngeal teeth inM. piceus. The larval and juvenile teeth are changed from conical to adult molariform teeth through seven stages. Comparisons are made
between each stage and corresponding types in some species of different subfamilies in Cyprinidae. It is considered that the
ontogenetic resemblances of the pharyngeal teeth bear relationship to the phylogeny of cyprinids.
This project was funded by the International Cooperation of Japan—China and the National Natural Science Foundation of China 相似文献
8.
通过组织切片对虎纹蛙性腺发育过程进行研究，根据其细胞学特征，雌性虎纹蛙的性腺发育过程分为卵原细胞期、初级卵泡期、生长卵泡期和成熟卵泡期；在第一个性周期内，从卵原细胞到成熟卵泡整个发育阶段需要2a。雄性虎纹蛙的生殖细胞成簇排列，性腺发育分为精原细胞、初级精母细胞、次级精母细胞、精子细胞以及精子形成5个阶段；性成熟期为1a。并报道了虎纹蛙的镶嵌型性腺。 相似文献
9.
There are many reports that cells (protoplasts) separated from the thallus ofPorphyra by enzyme can develop to normal leafy thalli in the same way as monospores. But there are few investigations on the subcellular
structure of the isolated vegetative cell for comparison with the subcellular structure of monospores. To clarify whether
the separated and cultured cells undergo the same or similar ultrastructure changes during culture and germination as monospores
undergo in their formation and germination, we observed their ultrastructure, compared them with those of the monospore and
found that the ultrastructure of separated and cultured cells did not have the characteristic feature as that of monospore
formation, such as production of small and large fibrous vesicles, but was accompanied by vacuolation and starch mobilization
like that in monospore germination. The paper also discusses the relations between monospores and separated and cultured cells.
Contribution No. 3875 from the Institute of Oceanology, Chinese Academy of Sciences.
Project 39770593 supported by NSFC; Project 96-C01-05-01 of the 9th Five-Year Plan supported by Science and Technology Commision
of China. 相似文献
10.
Defensin is one of preserved ancient host defensive materials formed in biological evolution. As a regulator and effector molecule, it is very important in animals＇ acquired immune system. This paper reports the defensin gene from the mixed liver and kidney cDNA library of abalone Haliotis discus hannai Ino. Sequence analysis shows that the gene sequence of full-length cDNA encodes 42 mature peptides （including six Cys）, molecular weight of 4 323 Da, and pI of 8.02. Amino acid sequence homology analysis shows that the peptides are highly similar （70% in common） to other insects defensin. Because of a typical insect-defensin structural character of mature peptide in the secondary structure, the polypeptide named Haliotis discus defensin （hd-def）, a novel of antimicrobial peptides, belongs to insects defensin subfamily. The RT-PCR result of Haliotis discus defensin shows that the gene can be expressed only in the hepatopancreas by Gram-negative and positive bacteria stimulation, which is ascribed to inducible expression. Therefore, it is revealed that the Haliotis discus defensin gene expression was related to the antibacterial infection of Haliotis discus hannai Ino. 相似文献
11.
This Mar. 1993 to Aug. 1994 study on suspended conchocelis ofPorphyra haitanensis showed that there were three patterns for development of vegetative filaments: filaments to filaments by “budding”; filaments
to sporangial branchlets by “budding”, or cell swelling. There were also three patterms for sporangial branchlet development:
vegetatively propagating, changing into conchospores, or dying. Each developmental stage had one or more different developmental
directions between vegetative filaments and sporangial branchlets. Developments from conchosporangial branchlets to conchospores
were sequential and irreversible. Although sporangial branchlets formed at 29°C could give rise to filaments, they could not
propagate as healthily under the same conditions as those formed at 25°C did. Probably the crucial period of plant cell differentiation
is in the late stage of sporangial branchlets. In line with the developmental directions of different stages, the authors
regulated the development of conchocelis to get ideal different developmental stages materials to obtain very developmentally
homogeneous stages, including filaments and sporangial branchlets.
Contribution No 3283 from the Institute of Oceanology, Chinese Academy of Sciences.
Study supported by the Climbing Project B PD-B6-4-2 of the State Science and Technology Commission of China. 相似文献
12.
The gastric shield and underlying stomach epithelium of Chlymas ffarreri were examined at the light and ultrastructural levels.The results showed that the gastric shield consisted of two different size lobes joined together by a narrow middle piece,the thicker lobe was shaped like a funnel,but unclosed at the lateral side;the other lobe was irregularly triangular-shaped.The transverse section of the thicker lobe was obviously laminated and gradually decreased in thickness from the peak to the margins of the shield.The underlying epithelium bore numerous about 3μm diameter spherical processes formed by the apical plasmalemma of the epithelial cells becoming blunt pseudopodia.Microvilli and some interspersed cilia were present in the areas among the spherical processes regions where only microvilli existed.Rough endoplasmic reticulum,Golgi apparatus,different-sized electron-dense secretory granules and electron-lucent vacuoles as well las abundant mitochondria were present in the underlying epithelial cells.Fused droplets of the secretion from the underlying epithelial cells formed the gastric shield. 相似文献
13.
Wei Yin-xin 《中国海洋湖沼学报》1994,12(2):180-184
The morphology and reproduction cycles of a new species,Zygnemopsis hubeiensis Wei are described and illustrated for a culture homothallic strain collected from Wuhan, Hubei, China. The asexual reproduction
is by parthenospores, aplanospores and akinetes. The major events of the sexual cycle, including the genuflection of reproductive
cells, gametangial development, gamete formation, gamete fusion, zygote formation, zygospore development, and zygospore germination
are observed. 相似文献
14.
Fe^2＋ acted as an accessorial factor for many cellular enzymatic reactions is very important for seaweed growth and development, but the Fe^2＋ requirement in nori had not been seen. Porphyra yezoensis cells were separated enzymatically and cultured in a series of sterilized seawater media containing various concentrations of Fe^2＋. The growth development and cell were investigated in this work. Through this experiment, two biologically-meant concentration scales were found, one is low concentrations, 12.1-102.1μg/L, 10-100 times than that in seawater, favoring the development of isolated cells of Porphyra and the other was high concentrations, more than 10mg/L inhibiting the cell growth, leading to the deformity and shrinkage of the cells. At the concentration of 50 mg/L, the cells stopped growing and died eventually. 相似文献
15.
Alan Warren 《中国海洋大学学报(英文版)》2009,8(4):317-321
The morphology and infraciliature of a new marine colepid ciliate, Apocoleps magnus gen. nov., spec. nov., are described based on living observations and silver impregnations. The new genus Apocoleps is characterized by having 8 (vs. 6 in most other related genera) armour tiers, spines at both ends of the cell, 3 adoral organelles and plates with 4 reniform uni-windows. Apocoleps magnus spec. nov. is defined by the following features: body elongated and slightly curved, about 100–120μm× 35–45 μm in vivo; an... 相似文献
16.
In aquatic ecosystems, macrophytes and phytoplankton are main primary producers, in which macrophyte plays an important role
in maintaining clear water state, while phytoplankton often dominates in turbid waterbodies. In the present study, the growth
and photosynthetic activity of the submerged aquatic plant Ceratophyllum oryzetorum Kom. in different cell densities of cyanobacterial bloom are studied. The results show that the plant length and fresh mass
of C. oryzetorum are promoted by low cyanobacterial cell densities. Medium and high cyanobacterial cell densities, on the contrary, act as
inhibitory. Furthermore, the photosynthetic activity of C. oryzetorum is strongly inhibited by high cyanobacterial cell densities. To a certain extent, the growth of cyanobacteria is inhibited
by C. oryzetorum, but no significant effect is found in this study.
Supported by the Innovation Project of CAS (No.KZCX2-YW-426), a Provincial Project of Hubei (No. 2006AA305A0402) and the National
Basic Research Program of China (973 Program, No. 2002CB 412306) 相似文献
17.
The living morphology and infraciliature of two rare marine ciliates, Placus salinus Dietz, 1964 and Strombidium apolatum Wilbert and Song, 2005, collected from the coastal waters near Qingdao, China, were investigated by in vivo observation and protargol impregnation technique. The improved diagnosis for Placus salinus is as follows: medium-sized marine Placus, in vivo (50–60)μm×(30–40)μm; cell elliptical to barrel-shaped; 28–31 somatic kineties; single macronucleus usually ellipsoid and
one micronucleus located in the indention of the macronucleus; one contractile vacuole posteriorly positioned. Strombidium apolatum is characterized by: marine strombidium (40–60)μm×(30–45)μmm in vivo, cordiform in shape with somewhat pointed posterior end and conspicuous apical protrusion; extrusomes prominent, about 15μm
in length and evenly arranged along the circle kinety; about 16 collar and 5–6 buccal membranelles; one elongate macronucleus
and one micronucleus; circle and ventral kineties consisting of about 53 and 45 dikinetids respectively. 相似文献
18.
Eucheuma gelatinae (esper)J.Agardh has vegetative and reproductive features distinguishing it fromother species of Eucheuma.The occurrence of reproductive nemathecia containing carpogonial branches,auxiliary cells and post-fertilization stages including gonimoblast and pericarp initiation,fusion cell foram-tion stages and carposporophyte development are described and ilustrated for the first time for this species. 相似文献
19.
ZHUJie ZHANGXiumei GAOTianxiang 《中国海洋大学学报(英文版)》2005,4(2):145-151
Histological development of Japanese flounder Paralichthys olivaceus larval skin and ultrastructural difference of skin between reared normal and malpigmented Japanese flounder were studied with light microscopy (LM) and transmission electron microscopy (TEM). The results show that the skin develops slowly before the metamorphosis, while at the onset of metamorphosis, the skin develops quickly and becomes complete in structure till about 50d after being hatched. Ultrastructural observation on the normal and malpigmented skins shows that the iridophore and melanophore are adjacent to each other. Profile and structure of the two kinds of pigmcnt cells are more complete in the skin of normal ocular side than in the skin of pigmented blind side. The ultrastructure of typical chloride cell was observed in the skin of Japanese flounder larvae for the first time. 相似文献
20.
The ultrastructure of hemocytes ofPenaeus vannamei was examined by transmission electron microscope. Three types of hemocytes were identified: hyaline cell, small-granule cell
and large-granule cell. Hyaline cells are the smallest of the hemocytes, lack electron-dense granules, have average size of
11.11 μm (SE±0.50,n=10)×6.96μm (SE±0.55,n=10), comprise 25.8% (SE±2.87,n=4×10) of the hemocytes; small granule cells are the most abundant type of hemocytes, comprise 58.1% (SE±3.40,n=4×10) of the hemocytes, contain small electron—dense granules, have average size of 10.78 μm (SE±0.60,n=10)×8.63 μm (SE±0.44,n=10); and large-granule cells comprise 16.1% (SE±2.55,n=4×10) of the hemocytes, are filled with large electron dense granules, have average size of 12.51 μm (SE±0.63,n=10)×8.99μm (SE±0.71,n=10).
This research was supported by the National Climbing Project B, PDB6-6-3.
Contribution No. 3448 from the Institute of Oceanology, Chinese Academy of Sciences. 相似文献