首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
Colonial Morphology of Escherichia coli on Tergitol-7 Medium   总被引:4,自引:0,他引:4       下载免费PDF全文
Escherichia coli cultures grown on Tergitol-7 medium, with 2,3,5-triphenyltetrazolium chloride added, produced three main types of colonies: rough, intermediate, and mucoid. These colonies were yellow to amber in color and produced slight yellow zones in the medium. Rough colonies were flat, dry, and spreading, with a cut-glass appearance. Intermediate-type colonies varied considerably, but could be divided into two general subtypes. Intermediate-rough colonies had the cut-glass appearance characteristic of rough colonies, but were much more compact and raised, with irregular edges. Intermediate-smooth colonies had a slight cut-glass appearance, but were smooth and entire. Mucoid-type colonies also appeared in two subtypes. Mucoid A colonies were mucoid hemispheres. Mucoid B colonies, after incubation at 37 C for 24 hr, appeared as small, intermediate colonies. However, during a 24-hr holding period at room temperature, mucuslike material proliferated around the colonies. A fourth type of colony was red with blue surrounding medium. Only mucoid-type cultures could not be serologically O-grouped.  相似文献   

2.
The possible multipotential nature of the neural retina of early chick embryos was examined by the technique of clonal cell culture. Cultures were prepared from cells dissociated from freshly excised neural retinas of 3.5-day-old chick embryos or from cells harvested from primary highdensity cultures. The following four colony types were obtained: colonies differentiating into “lentoid bodies”; colonies with pigment cells; colonies with both “lentoid bodies” and pigment cells; and colonies comprised entirely of unidentifiable cells. Neuronal differentiation occurred frequently in the early stages of culture (up to about 10 days). In some of these neuronal colonies, “lentoid bodies” and, rarely, both “lentoid bodies” and pigment cells differentiated after a further culture period of up to 30 days. Secondary colonies established from primary colonies after 9–10 days demonstrated that these original colonies fell into four different categories: those giving rise to secondary colonies containing only “lentoid bodies,” those giving rise to pigmented colonies only, those developing both lentoid and pigmented colonies, and finally those which gave rise to secondary colonies of all three types, lentoid, pigmented, and mixed colonies. When primary pigmented colonies were recloned at about 30 days after inoculation, the differentiated pigment cells transdifferentiated into lens. Whether multispecific colonies were really of clonal origin or not is discussed. The possible presence of a multipotent progenitor cell able to give rise to multispecific clones in the neural retina of 3.5-day-old chick embryos is suggested. A sequence of differentiation starting from multipotent neural retinal cells to be terminated with lens through the differentiation of neuronal and pigment cells is hypothetically proposed.  相似文献   

3.
G Egert  L Kanz  G W L?hr  A A Fauser 《Blut》1990,60(5):282-286
Studies have shown that recombinant human alpha interferon (rIFN alpha) inhibits the growth of colonies of multipotential stem cells from human bone marrow. This report demonstrates that rIFN alpha inhibits the growth of such colonies from the bone marrow of patients with chronic myelogenous leukemia (CML) to a greater extent than from bone marrow of healthy individuals. It also shows that T lymphocyte colonies subcloned with interleukin 2 (IL-2) from CML mixed colonies were inhibited more by rIFN alpha than were similar colonies subcultured from normal mixed colonies. The report demonstrates that the Ph' chromosome is present in such T cell colonies subcultured from CML mixed colonies. When mixed colonies were grown from CML bone marrow in the presence of rIFN alpha, Ph' negative colonies were observed, whereas no such Ph' negative mixed colonies grew from a similar number of bone marrow cells incubated without rIFN alpha. These observations confirm that T lymphocytes derived from bone marrow stem cells are from the CML clone, and that the inhibition of growth of Ph' positive colonies, by rIFN alpha permits the growth of residual normal stem cells. The disappearance of the Ph-chromosome in subclones of T lymphocytes supports the notion of nonclonal hematopoiesis in patients with CML.  相似文献   

4.
Summary: The reproductive strategy between queen-right and orphaned colonies of Myrmica kotokui was compared. The ratio of orphaned colonies reached about 30 percent in the field. Although colony size was significantly smaller in orphaned colonies, the mean body size and mean ovariole length of the workers were significantly larger than those in queen-right colonies. The reproductive individuals in orphaned colonies were also significantly larger than those in queen-right colonies. Only 38.5 % of the orphaned colonies, however, contained eggs during the reproductive season, compared to 100 % of the queen-right colonies. This indicates that worker reproduction under natural conditions is relatively low, even in orphaned colonies.  相似文献   

5.
The population recovery of Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) colonies were monitored after an areawide elimination of all detectable colonies from September 2003 to August 2005 in Louis Armstrong Park, New Orleans, LA. Six colonies reinvaded the vacant niche created by the full elimination. These colonies expanded their territories throughout the study period. This represented 43% of the original number of colonies present in the park before the elimination. To determine the mode of the reinvasion, nuptial pair establishment was monitored during the C. formosanus dispersal flight seasons. Nuptial pairs were discovered up to 1 yr after the elimination. Morphological and genetic data were collected from field colonies before the full elimination in 2002 and again in 2005 after the reinvasion of these territories by new colonies. These data were used to estimate the relative age of reinvading colonies as compared with their predecessors. It is proposed that the first three reinvading colonies detected were smaller colonies that were undetectable before the full elimination, or were older, established colonies present outside of the park, that expanded their foraging territories into the park in the absence of competition from the eliminated populations. The subsequent three colonies to reinvade seemed to be small colonies founded during or just before the study period by an imago pair after a dispersal flight into the park from outlying areas. The implications of this study on subterranean termite areawide integrated pest management strategies are discussed.  相似文献   

6.
Histological analysis was carried out on the hemopoietic spleen colonies within 7 and 11 days after transplantation of the embryonic liver cells. Large superficial colonies were always present and were, predominantly, erythroid and mixed. Small superficial colonies consisted of undifferentiated cells and, unlike large colonies, appeared on the 11th day only. In the spleen thickness erythroid colonies predominated. The possibility of formation of small superficial 11 day colonies at the expense of pre-CFU-S is discussed.  相似文献   

7.
Bone marrow samples, from newly diagnosed patients with chronic myeloid leukemia (CML) and normal individuals, were grown in methylcellulose and serially recultured under identical conditions. Specimens derived from normal individuals gave rise to multilineage and megakaryocyte colonies for one to two sequential cultures. Erythroid bursts and granulocyte-macrophage colonies were observed for three to five sequential cultures. Cultures initiated from samples of patients with CML showed a rapid decline of all types of colonies. Colonies were rarely seen for more than two sequential cultures. When pooled colonies and background cells were recloned separately, secondary colonies were mainly seen in cultures of background cells. This observation is consistent with the view that secondary colonies are more likely to arise from dormant clonogenic progenitors, rather than through cells that have formed primary colonies through a self-renewal process.  相似文献   

8.
刘明花  张小晶  薛薇  陈娇玲  刘鹤  吴佳  苏晓红 《昆虫学报》2014,57(11):1328-1334
摘要: 【目的】为了探讨圆唇散白蚁Reticulitermes labralis补充生殖蚁对巢群稳定和发展的作用。【方法】对野外巢群进行调查研究, 及对婚飞成虫通过雌雄配对与补充生殖蚁隔离巢群进行人工饲养的对比研究。【结果】在野外巢群只发现1对原始蚁王蚁后, 而补充生殖蚁的数量最多可达到689头/巢。圆唇散白蚁有3种类型的补充生殖蚁, 即由工蚁转化来的无翅型补充生殖蚁、若蚁转化来的翅芽型补充生殖蚁和末龄若蚁羽化来的拟成虫型补充生殖蚁。实验室条件下婚飞配对群体和隔离群体建群1个月后的存活率分别为64%和96%。建巢初期婚飞配对群体的子代数目增长缓慢, 2个月时的群体数量为6.3±1.54, 10个月时的群体数量也仅为8.4±1.47; 而隔离建群补充生殖蚁2个月时的群体数量为52.4±6.44, 10个月时的群体数量为164.3±20.85, 都高于婚飞配对群体。 此外, 野外巢群的补充蚁后跟原始蚁后一样都具有发达的卵巢。【结论】在圆唇散白蚁中补充生殖蚁是白蚁巢群主要的繁殖力量, 也是建立新巢群的重要繁殖品级。  相似文献   

9.
The cellular composition of individual hemopoietic spleen colonies has been studied using techniques which tested primarily for cell function rather than cell morphology. Erythroblastic cells were recognized by their capacity to incorporate radioiron, granulocytic cells by their content of peroxidase-positive material, and hemopoietic stem cells by their ability to form spleen colonies in irradiated hosts. It was found that, 14 days after the initiation of spleen colonies, the distribution of these cell types among individual colonies was very heterogeneous, but that most colonies contained detectable numbers of erythroblasts, granulocytes and colony-forming cells. An appreciable proportion of the cells in the colonies could not be identified as any of these three cell types. No strong correlations between numbers of erythroblasts, granulocytes and colony-forming cells in individual colonies were observed, though there was a tendency for colonies containing a high proportion of erythroblasts to contain a low proportion of granulocytes, and for colonies containing a high proportion of granulocytes to contain a higher proportion of colony-forming cells. An analysis of colonies which contained cells bearing radiation-induced chromosomal markers indicated that 83–98% of the dividing cells within 14-day spleen colonies were derived from single precursors.  相似文献   

10.
Mast cells have been proposed to originate from diverse sources, including connective tissues, macrophages, T lymphocytes, and hemopoietic cells. Evidence for a hemopoietic origin of mast cells includes the presence of mast cell precursors in spleen colonies and the presence of mast cells in hemopoietic colonies in culture. Here we report a detailed analysis of mouse spleen mixed hemopoietic colonies containing mast cells. All of the colonies in cultures plated at low cell densities were individually removed for analysis by May-Grunwald-Giemsa staining on day 15 of culture. Examination of five dishes which contained a total of 82 colonies showed 16 pure mast cell colonies and 36 mixed mast cell colonies. Sixteen different combinations of cell types were seen and were not distinguishable from each other in situ. The most diverse type of mixed colony contained macrophages (m), neutrophils (n), eosinophils (e), mast cells (Mast), megakaryocytes (M), erythroid cells (E), and blast cells. The clonal origin of mixed mast cell colonies was established by the replating of single cells obtained from blast cell colonies. Individual cells were removed with a micromanipulator, replated, and allowed to grow for 15 days. Cytospin preparations of 10 such colonies showed diverse combinations of cell lineages which were seen in the different types of mixed mast cell colonies described above. Replating studies of mixed mast cell colonies were carried out and a high incidence of replating was seen. Approximately one half of these colonies formed only mast cell colonies upon replating. Further studies showed that pure mast cell colonies could be serially replated four to five times. The replating efficiency of cells in the primary mast cell colonies varied over a wide range (2.5–44%) with an average replating efficiency of 13%. The data also revealed that cells containing metachromatic granules possess significant proliferative capacity. From these studies of pure and mixed mast cell colonies, we concluded (1) that mast cells are in wide variety of types of mixed colonies and that the in situ identification of mixed colonies is unreliable, (2) that mast cells are derived from pluripotent hemopoietic stem cells, and (3) that mast cells with metachromatic granules can have a high proliferating ability.  相似文献   

11.
The biological characteristics of individual colonies of Pseudomonas aeruginosa from 138 specimens were investigated. Of these isolates, 90 (65.2%) formed colonies of similar appearance and morphology, and 48 (34.8%) formed colonies which differed either in appearance or morphology. The individual colonies of 138 isolates were tested for serotype. The former 90 isolates formed only the colonies with one kind of serotype, whereas 17 of the latter 48 isolates formed the colonies with more than one kind of serotype. All the 9 isolates tested also differed in other biochemical characteristics: acid productions from xylose, mannitol and maltose, urease production and gelatin liquefaction. beta-Lactamase activity was investigated in 7 isolates forming colonies with more than one serotype. There were no marked differences in beta-lactamase activity among the different colonies in 5 isolates but marked differences among those in the other 2 isolates.  相似文献   

12.
We evaluated a year-long treatment regime testing synthetic, 10-component, honey bee, Apis mellifera L. (Hymenoptera: Apidae), brood pheromone (SuperBoost; Contech Enterprises Inc., Delta, BC, Canada) on the productivity and vigor of package bee colonies in the lower Fraser Valley of British Columbia, Canada. Fifty-eight newlyestablished 1.3-kg (3-lb) colonies treated three times with SuperBoost at 5-wk intervals starting 30 April 2009 were compared with 52 untreated control colonies. Treated colonies produced 84.3% more honey than untreated control colonies. By 8 September 2009, SuperBoost-treated colonies had 35.4% more adults than untreated colonies. By 28 September, net survival of treated and control colonies was 72.4 and 67.3%, respectively. On 5 October, treated and control colonies were divided into two additional groups, making up four cohorts: SuperBoost-treated colonies treated again during fall and spring build-up feeding with pollen substitute diet (BeePro, Mann Lake Ltd., Hackensack, MN; TIT); controls that remained untreated throughout the year (CCC); colonies treated with SuperBoost in spring-summer 2009 but not treated thereafter (TCC); and original control colonies treated with SuperBoost during the fall and spring build-up feeding periods (CTT). There was no difference among cohorts in consumption of BeePro during fall feeding, but TTT colonies (including daughter colonies split off from parent colonies) consumed 50.8% more diet than CCC colonies during spring build-up feeding. By 21 April, the normalized percentages of the original number of colonies remaining (dead colonies partially offset by splits) were as follows: CCC, 31.4%; CTT, 43.8%; TCC, 53.59%; and TTT, 80.0%. The net benefit of placing 100 newly established package bee colonies on a year-long six-treatment regime with SuperBoost would be US$6,202 (US$62.02 per colony). We conclude that treatment with SuperBoost enhanced the productivity and survival of package bee colonies and hypothesize that similar results could be achieved with established colonies.  相似文献   

13.
We selected honey bee colonies (Apis mellifera L.) with a high tendency to collect sunflower pollen and estimated the heritability of this trait. The percentage of sunflower pollen collected by 74 colonies was evaluated. Five colonies that collected the highest percentages of sunflower pollen were selected. Nineteen colonies headed by daughters of these selected queens were evaluated for this characteristic in comparison with 20 control (unselected) colonies. The variation for the proportion of sunflower pollen was greater among colonies of the control group than among these selected daughter colonies. The estimated heritability was 0.26 +/- 0.23, demonstrating that selection to increase sunflower pollen collection is feasible. Such selected colonies could be used to improve sunflower pollination in commercial fields.  相似文献   

14.
The evolution of borings has shown that the morphology of borings is a function of both the borer and its substrate. This study investigated the effect of bryozoan internal skeletal morphology on the dimensions and distribution of borings. One hundred and forty-three trepostome colonies from the Middle and Upper Ordovician strata of northern Estonia were examined. Of these, 80% were matrix entombed, longitudinally sectioned ramose and hemispherical colonies, and 20% were matrix-free hemispherical colonies that allowed examination of the colony surfaces. Seventy-one percent of the ramose colonies were bored, whereas 88% of the hemispherical colonies were bored. On average, only 8% of colony surface areas were bored out. Borings were more randomly oriented in the hemispherical colonies. In contrast in the ramose colonies, the borings tended to more restricted to the thin-walled endozone and thus parallel to the branch axis. This is interpreted to be a function of the thick-walled exozones controlling to some extent where the borer could bore. Based on morphology, the borings in the hemispherical colonies are referred to Trypanites and those in the ramose colonies to Sanctum . Sanctum is revised to include two possible openings and to recognize that boring shapes were inherently constrained by the thick-walled exozones of the host bryozoan colonies. Both trace fossils were probably produced by a boring polychaete that used the tubes as domiciles.  相似文献   

15.
Scanning Electron Microscopy of Intact Colonies of Microorganisms   总被引:7,自引:3,他引:4       下载免费PDF全文
Colonies of S. mutans OMZ61, Streptococcus sp. D182, Staphylococcus aureus Oxford NCTC 6571, and Candida albicans type A, MRL 3153 were grown on various media. Cubes of agar bearing two to three colonies were excised and processed for scanning electron microscopy. The characteristic shape of the colonies was seen when examined at low magnifications. At a magnification of 2,000 diameters, the arrangement of individual organisms within the colonies was observed. Plano-convex colonies consisted of uniformly distributed organisms, whereas S. mutans colonies presented a more complex arrangement possibly associated with the production of extracellular polysaccharides. Certain colonies were totally or partially covered by an adherent film through which the outline of the organisms could be distinguished.  相似文献   

16.
A fibrin clot culture system with high plating efficiency is described for the growth of erythroid cells from chick bone marrow. Erythroid colonies grown in the absence of adult chicken plasma (spontaneous colonies) were either benzidine-negative or weakly benzidine-positive. Colonies grown in the presence of chicken plasma were 90% strongly benzidine-positive and 40% more abundant than spontaneous colonies. Plasma from anemic chickens was more effective than control plasma in inducing heme accumulation (heme-stimulating activity) and in increasing the number of erythroid colonies (colony-stimulating activity). Spontaneous colonies from 48-h cultures were transformed into benzidine-positive colonies by exposing them for 6-10 h to chicken plasma.  相似文献   

17.
Mutagenesis assays at the thymidine kinase (TK) locus in L5178Y mouse lymphoma cells frequently yield mutant colonies with a bimodal size distribution. The objectives of this study were to determine whether a relationship exists between mutant colony size and chromosomal aberrations and whether the colony-size distributions obtained from this assay can indicate the clastogenic activity of a test chemical. Cells from 8 different types of L5178Y mouse lymphoma cell colonies were examined for chromosomal abnormalities within 10 cell generations after colony isolation. The colonies included small (sigma) and large (lambda) unselected cell (UC) and trifluorothymidine-resistant (TFTr) colonies derived from TK +/- cell cultures treated with the solvent dimethyl sulfoxide (DMSO) or hycanthone methanesulfonate (HYC). Chromosome abnormalities were present in cells from 12% (7/60) of the UC colonies, but there was no apparent relationship between colony diameter and the presence of chromosomal abnormalities. Abnormalities affecting chromosome 11, which is believed to be the site of the TK gene, were not observed in cells from UC colonies. Abnormalities affecting chromosome 11 were observed only in cells from sigma-TFTr colonies irrespective of whether they were spontaneous (5/15 colonies) or induced by HYC (4/15 colonies). Overall, 30% (9/30) of sigma-TFTr colonies had cells with an abnormal chromosome 11 and 10% (3/30) had abnormalities affecting other chromosomes. Abnormalities affecting chromosome 11 were not observed in cells from lambda-TFTr colonies (0/30 colonies). The observation of only 30% of sigma-TFTr colonies with chromosome damage affecting chromosome 11 indicates that other mechanisms, in addition to chromosome damage at the level of resolution used in this study (i.e., 200-300 chromosome bands). contribute to small TFTr colony size.  相似文献   

18.
The effects of changes in spring pollen diet on the development of honey bee, Apis mellifera L. (Hymenoptera: Apidae), colonies were examined in a 3-yr study (2002-2004). Pollen-supplemented and pollen-limited conditions were created in colonies every spring, and brood rearing and honey yields were subsequently monitored throughout the summer. In all 3 yr, colonies that were supplemented with pollen or a pollen substitute in the spring started rearing brood earlier than colonies in other treatment groups and produced the most workers by late April or early May. In 2002, these initial differences were reflected by a two-fold increase in annual honey yields by September for colonies that were pollen-supplemented during the spring compared with pollen-limited colonies. In 2003 and 2004, differences between treatment groups in the cumulative number of workers produced by colonies disappeared by midsummer, and all colonies had similar annual honey yields (exception: in one year, productivity was low for colonies supplemented with pollen before wintering). Discrepancies between years coincided with differences in spring weather conditions. Colonies supplemented with pollen or a substitute during the spring performed similarly in all respects. These results indicate that an investment in supplementing the pollen diet of colonies would be returned for situations in which large spring populations are important, but long-term improvement in honey yields may only result when spring foraging is severely reduced by inclement weather. Beekeepers should weigh this information against the nutritional deficiencies that are frequently generated in colonies by the stresses of commercial management.  相似文献   

19.
The guts of 195 adult worker honeybees, Apis mellifera, from free-flying control colonies fed sucrose, from caged control colonies fed sucrose, from free-flying colonies fed 2,4,5-T, and from caged colonies fed 2,4,5-T were examined for yeasts and molds. Only 25% of the bee guts contained fungi. Torulopsis magnoliae, T. glabrata, Hansenula anomala, Penicillium cyclopium, and P. cyclopium var. echinulatum were the most frequent isolates. Molds were most prevalent in bees from free-flying control colonies fed sucrose, and yeasts were found most often in bees from caged colonies fed 2,4,5-T.  相似文献   

20.
Growth of Pseudomonas aeruginosa in 2 atmospheres absolute of 100% oxygen at 37 degrees C produced two types of abnormal colonies--stunted, rough colonies, termed dwarfs, and large, domed, mucoid colonies, termed giants. The occurrence of these variants depended upon the partial pressure of oxygen and the inoculum size. Subculture of dwarf or giant colonies produced a mixture of both colony types after incubation in hyperbaric oxygen, and colonies of normal appearance after incubation in air. Electron micrographs of ultrathin sections showed that cells from dwarf colonies had a more clearly defined envelope region than cells from normal colonies. Giant colony and normal colony-derived cells were of similar appearance. Whole cells from giant colonies contained more carbohydrate, readily extractable lipid, neutral lipid and free fatty acid than cells from normal colonies; the two cell types showed similar contents of 2-keto,3-deoxyoctonic acid and total phospholipid, but different proportions of individual phospholipids. Cells from dwarf, giant and normal (air-grown) colonies were incubated in air on nutrient agar containing either polymyxin, tetracycline or phenoxyethanol. Relative to cells from normal colonies, cells from dwarf colonies showed enhanced resistance to all three agents and cells from giant colonies showed enhanced resistance to polymyxin and tetracycline only. The resistance of cells from variant colonies was lost following a single subculture in air in the absence of antibacterial agents. It was concluded that the envelopes of cells from dwarf and giant colonies differed both from each other and from those of normal cells. These differences, and the formation of variant colonies, appeared to result from bacterial adaptation to hyperbaric oxygen rather than from mutation.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号