Morphological and somatic clonal analyses of pattern triplications

The growth of pattern triplications induced by a 48-hr 29 degrees C treatment given to larvae homo- or hemizygous for a ts cell-lethal mutation was examined to determine which structures result from new, regulative growth and which are produced by the original imaginal disc cells. Pattern triplications contain one complete leg pattern (orthodrome) and two partial patterns (antidrome and paradrome). The results of two morphological analyses and one somatic clonal analysis suggest that in triplications in which the antidrome and paradrome become more complete distally (diverge) the paradrome is formed by a portion of the original leg pattern, and the antidrome and orthodrome are formed by extra, regulative growth. A different result is suggested for triplications in which the antidrome and paradrome become less complete distally (converge). In these, the orthodrome appears to be formed by the original leg pattern and the antidrome and paradrome by extra growth. These results agree with predictions based on the polar coordinate model of positional information.     

Morphological and biochemical analyses of the salivary glands of the malaria vector, Anopheles darlingi.

Adult Anopheles darlingi salivary glands are paired organs located on either side of the esophagus. The male glands consist of a single small lobe. The female gland is composed of two lateral lobes, with distinct proximal and distal portions, and a medial lobe. The lobes are acinar structures, organized as a unicellular epithelium that surrounds a salivary canal. The general cellular architecture is similar among the lobes, with secretory material appearing as large masses that push the cellular structures to the periphery of the organ. Cells of the proximal-lateral lobes show asynchronous cycles of secretory activity and contain secretory masses with finely filamentous aspect. In the distal-lateral lobes, cells display synchronous cycles of activity, and have a dense secretory product with mottled pattern. Cells of the medial lobe have secretory masses uniformly stained and highly electrondense. Biochemical analysis of the adult female salivary glands revealed apyrase, alpha-glucosidase and lysozyme activities. Alpha-glucosidase and lysozyme activities are detected mostly in the proximal lobes while apyrase is mainly accumulated in the distal lobes. This differential distribution of the analyzed enzymes reflects a specialization of different regions for sugar and blood feeding. Thus, the morphological differences observed in the lobes correlate with functional ones.     

Flow cytometric DNA analyses of epithelial dysplasia of the esophagus

OBJECTIVE: To investigate, with flow cytometry, DNA aneuploidy as a marker of early carcinogenesis in dysplastic esophageal lesions. STUDY DESIGN: DNA content of exfoliated cells from 789 cases of esophageal dysplasia (including mild dysplasia, 195 cases; moderate dysplasia, 383 cases; and severe dysplasia, 211 cases) was determined with a FACS 420 flow cytometer. RESULTS: Cellular DNA content was closely related to the severity of dysplasia. The carcinogenesis rate in patients with dysplasia showed that DNA aneuploidy was significantly higher than in patients showing DNA diploidy. CONCLUSION: DNA aneuploidy in dysplastic lesions is a very important early signal of carcinogenesis. Patients with dysplastic lesions showing DNA aneuploidy should be treated and closely followed.     

Multiplexed and microparticle-based analyses: quantitative tools for the large-scale analysis of biological systems.

While the term flow cytometry refers to the measurement of cells, the approach of making sensitive multiparameter optical measurements in a flowing sample stream is a very general analytical approach. The past few years have seen an explosion in the application of flow cytometry technology for molecular analysis and measurements using microparticles as solid supports. While microsphere-based molecular analyses using flow cytometry date back three decades, the need for highly parallel quantitative molecular measurements that has arisen from various genomic and proteomic advances has driven the development in particle encoding technology to enable highly multiplexed assays. Multiplexed particle-based immunoassays are now common place, and new assays to study genes, protein function, and molecular assembly. Numerous efforts are underway to extend the multiplexing capabilities of microparticle-based assays through new approaches to particle encoding and analyte reporting. The impact of these developments will be seen in the basic research and clinical laboratories, as well as in drug development.     

Morphological and immunocytochemical analyses on the effects of diet-induced hypocalcemia on enamel maturation in the rat incisor.

During the maturation stage of amelogenesis, the loss of matrix proteins combined with an accentuated but regulated influx of calcium and phosphate ions into the enamel layer results in the "hardest" tissue of the body. The aim of the present investigation was to examine the effects of chronic hypocalcemia on the maturation of enamel. Twenty-one-day old male Wistar rats were given a calcium-free diet and deionized water for 28 days, while control animals received a normal chow. The rats were perfused with aldehyde and the mandibular incisors were processed for histochemical and ultrastructural analyses and for postembedding colloidal gold immunolabeling with antibodies to amelogenin, ameloblastin, and albumin. The maturation stage enamel organ in hypocalcemic rats exhibited areas with an apparent increase in cell number and the presence of cyst-like structures. In both cases the cells expressed signals for ameloblastin and amelogenin. The content of the cysts was periodic acid-Schiff- and periodic acid-silver nitrate-methanamine-positive and immunolabeled for amelogenin, ameloblastin, and albumin. Masses of a similar material were also found at the enamel surface in depressions of the ameloblast layer. In addition, there were accumulations of glycoproteinaceous matrix at the interface between ameloblasts and enamel. In decalcified specimens, the superficial portion of the enamel matrix sometimes exhibited the presence of tubular crystal "ghosts." The basal lamina, normally separating ameloblasts and enamel during the maturation stage, was missing in some areas. Enamel crystals extended within membrane invaginations at the apical surface of ameloblasts in these areas. Immunolabeling for amelogenin, ameloblastin, and albumin over enamel was variable and showed a heterogeneous distribution. In contrast, enamel in control rats exhibited a homogeneous labeling for amelogenin, a concentration of ameloblastin at the surface, and weak reactivity for albumin. These results suggest that diet-induced chronic hypocalcemia interferes with both cellular and extracellular events during enamel maturation.     

Morphological analyses of spring wheat (CIMMYT cv. PCYT-10) somaclones

The objectives of this study were to induce callus from single immature wheat embryos, produce multiple seedlings from the induced callus, and analyse the somaclonal regenerants for potential grain production in a space garden. Immature wheat, Triticum aestivum L. (cv. PCYT-10), embryos were excised 10 to 12 days post-anthesis and cultured on modified Murashige & Skoog's inorganic salts. Embryos cultured on medium containing kinetin (6-furfurylaminopurine) at 0.5 mgl^–1 plus 2 or 3 mgl^–1 dicamba (1-methoxy-3,6-dichlorobenzoic acid) or 0.2 mgl^–1 2,4-dichlorophenoxyacetic acid produced calli from which 24, 35 and 39% of the explant tissue exhibited regenerants, respectively. The size of flag leaves, plant heights, tillers per plant, spike lengths, awn lengths, and seeds per spike were significantly different in regenerants of two-selfed recurrent generations (SC₁, SC₂) than in parental controls. However, there were no significant differences in spikelets per spike between the SC₂ and parental controls. Desirable characteristics that were obtained included longer spikes, more seeds per spike, supernumerary spikelets, and larger flag leaves, variants that should be useful in wheat improvement programs.Contribution from the Plant Science Dept., Utah State University, Logan, UT 84322-4820. Utah Agricultural Experiment Station Journal Paper No. 3611     

Morphological and molecular analyses support the existence of host-specific Peronospora species infecting Chenopodium

About 20 species of Peronospora have been reported to cause downy mildew on Chenopodium, but, particularly in plant pathology literature, only one species, P. farinosa, is considered to be involved. We performed sequence analysis of the ITS rDNA to reveal the phylogenetic relationships of Peronospora specimens from five species of Chenopodium, viz. C. album, C. ambrosioides, C. bonus-henricus, C. hybridum, and C. polyspermum. The five clades corresponded to particular Chenopodium species, and showed a high level of sequence divergence. Differences in the morphology of the conidia and ultimate branchlets also supported the separation of the five groups at the host species level. These results suggest that the names P. variabilis, P. boni-henrici, P. chenopodii, and P. chenopodii-polyspermi should be used for the four downy mildew pathogens specific to C. album, C. bonus-henricus, C. hybridum, and C. polyspermum, respectively. The Peronospora on C. ambrosioides was found to be an independent species.     

Morphological basis of arm-swinging: multivariate analyses of the forelimbs of Hylobates and Ateles

Field and laboratory studies of arm-swinging in gibbons reveal its singularity even compared to spider monkeys. On the basis of principal components and discriminant analyses of size-corrected forelimb variables, this study confirms their morphological uniqueness and the more generalized nature of the spider monkey forelimb. Long forearms, well-developed scapular spines, and sagittally thicker radial shafts are features associated strictly with gibbon arm-swinging. On the other hand, large humeral heads, projecting medial epicondyles, and axially elongated scapulae, traditionally regarded as arm-swinging traits, are probably more important for climbing.     

Techniques for quantitative analyses of calcareous marine phytoplankton

This paper discusses the techniques used to sample and analyse living marine calcareous phytoplankton. The various methods are described and tested within several research projects aimed at the determination of coccolithophore cell densities in seawater. In addition, the potential advantages and drawbacks associated with the application of light and scanning electron microscopic techniques to the quantitative analysis of coccolithophores are discussed. Several tests have been carried out in order to quantify potential errors related to: (1) homogeneity of material distribution on filter membranes; (2) use of different microscopes (scanning electron microscope versus light microscope); (3) use of different filter membranes (cellulose mixed-ester membranes versus polycarbonate membranes); and (4) Utermöhl settling versus filtration method. These tests revealed that major errors in cell density calculations could result from the uneven distribution of coccolithophore specimens on a filter membrane. The error resulting from the use of a light microscope arises from its low resolution, which restricts the identification of species, especially of small coccospheres. The use of different filter membranes does not show a statistically significant difference in cell density calculations, although polycarbonate membranes can be examined much more efficiently with the scanning electron microscopy than cellulose mixed-ester membranes. The Utermöhl method, however, gives lower cell densities consistently (several times) than the filtration method.     

Qualitative and quantitative analyses of flower scent in Silene latifolia

The quantitative and qualitative variability in floral scent of 98 specimens of the dioecious species Silene latifolia belonging to 15 European and 19 North American populations was determined. Floral scent was collected from single flowers using dynamic headspace methods, and analysed by Micro-SPE and GC-MS methods. The flowers showed a nocturnal rhythm, and scent was emitted only at night. The amount of emitted volatiles varied greatly during the season, from 400 ng/flower/2 min in June to 50 ng/flower/2 min in August and September. The qualitative variability in the floral scent was high and different chemotypes, characterised by specific scent compounds, were found. Female and male flowers emitted the same type and amount of volatiles. The differences in floral scent composition between European and North American populations were small. Typical compounds were isoprenoids like lilac aldehyde isomers, or trans-beta-ocimene, and benzenoids like benzaldehyde, phenyl acetaldehyde, or veratrole. Some of these compounds are known to attract nocturnal Lepidoptera species. The high qualitative variability is discussed in relation to the pollination biology of S. latifolia, and the results are compared with other studies investigating intraspecific variability of flower scent.     

芫花的花粉形态观察及生活力和萌发率分析

Pollen morphology of Daphne genkwa Sieb.et Zucc.was observed by scanning electron microscope(SEM),and its viability and germination rate were measured by TTC and sucrose in vitro culture methods.The results show that pollen is stenopalynous type with a diameter of 15.6-21.6 μm.Per pollen has 10-16 apertures which is irregular circular with a diameter of 1.4-2.0 μm.Surface ornamentation of pollen is rough reticulate pattern which is circular polygon(tetragon-heptagon,mostly pentagon-hexagon).Pollen viability is 51% by TTC.Sucrose of different concentrations has a significant effect on pollen germination rate during pollen culture.And pollen germination rate is the highest with a percentage of 27.0% in medium containing 50 g·L-1 sucrose,while pollen could not germinate in medium containing sucrose over 250 g·L-1.Otherwise,there is the phenomenon of "multi-aperture germination" during pollen germinating.     

Morphological and anatomical analyses of rheophytic Rhododendron ripense Makino (Ericaceae)

The comparative morphology and anatomy of the leaves of the rheophytic Rhododendron ripense and the closely related inland species Rhododendron macrosepalum were examined. The leaf of R. ripense is thinner than that of R. macrosepalum, with leaf length to width ratios (leaf index) of 2.92 and 1.91, respectively. Moreover, the leaf of R. ripense consists of fewer cells than the leaf of R. macrosepalum, suggesting stenophyllization of R. ripense caused by the decreased number of cells. In addition, leaf thickness and the number of stomata per leaf of R. ripense were significantly greater than those of R. macrosepalum, but the density of the short glandular pilose hairs on the leaf of R. ripense was lower. The observed morphological differences between the two species may be explained by certain aspects of the riparian environment, such as high irradiation and frequent flooding after heavy rainfall, to which R. ripense is exposed.     

Morphological and phylogenetic analyses of Pythium species in South Africa

The genus Pythium is important in agriculture, since it contains many plant pathogenic species, as well as species that can promote plant growth and some that have biocontrol potential. In South Africa, very little is known about the diversity of Pythium species within agricultural soil, irrigation and hydroponic systems. Therefore, the aim of the study was to characterise a selection of 85 Pythium isolates collected in South Africa from 1991 through to 2007. The isolates were characterised morphologically as well as through sequence and phylogenetic analyses of the internal transcribed spacer regions (ITS) and the 5.8S gene of the nuclear ribosomal DNA. Phylogenetic analyses showed that the isolates represented ten of the 11 published Pythium clades [Lévesque & De Cock, 2004. Molecular phylogeny and taxonomy of the genus Pythium. Mycological Research 108: 1363–1383]. Characterisation of isolates in clade D and J suggested that the phylogenetic concept of Pythium acanthicum and Pythium perplexum respectively, needs further investigation in order to enable reliable species identification within these clades. Our phylogenetic analyses of Pythium species in clade B also showed that species with globose sporangia group basal within this clade, and are not dispersed within the clade as previously reported. The 85 South African isolates represented 34 known species, of which 20 species have not been reported previously in South Africa. Additionally, three isolates (PPRI 8428, 8300 and 8418) were identified that may each represent putative new species, Pythium sp. WJB-1 to WJB-3.     

Morphological and histological study of castration-induced degeneration and androgen-induced regeneration in the mouse prostate

Degenerative and regenerative changes in the ductal architecture of the ventral and dorsolateral prostates (VP and DLP) of the adult mouse were investigated in microdissected specimens over a time-course of 14 days following castration and subsequently during 14 days of administration of testosterone propionate. After castration, about 35% of the ductal tips and branch-points were lost in distal regions (usually near the capsule) in both prostatic lobes. By contrast, in more proximal regions of the prostate (closer to the urethra), the ducts survived in an atrophic condition. The ductal morphology that had been lost in the distal regions completely regenerated after testosterone propionate was administered to the castrated males. In the VP, androgen replacement simply returned the gland to its former size with moderate ductal distension; in the DLP, excessive epithelial infoldings and ductal distension were elicited in the distal regions of the ducts after 14 days of treatment with testosterone propionate. These results suggest that androgenic responsiveness and dependency are different in distal versus proximal ducts. Distal ducts are exquisitely androgen-dependent and androgen-sensitive; in proximal regions, androgen-dependency is not as strict.     

Tissue microdissection techniques in quantitative genome and gene expression analyses

Current advances in quantitative genome and gene expression analyses allow precise molecular genetic fingerprinting of tumor tissues. A crucial factor for the reliability of the data obtained with these refined techniques is the use of morphologically well-defined cell populations. Microdissection technology has been developed to procure pure cell populations from specific areas of tissue sections under microscopic control. This review covers techniques of tissue microdissection in the context of commonly used methods of quantitative genome and gene expression analysis. The first part of the review will summarize the technical aspects of various methods developed for tissue microdissection. In the latter part, current applications of quantitative genome and gene expression analysis techniques employed in microdissected tissue samples will be described.     

Stability analyses for estimating relative durability of quantitative resistance

Summary Experiments in which a series of host cultivars are inoculated in all combinations with a series of pathogen isolates have been used to detect specificity in the host resistance. A theoretical model of polygenic resistance involving both general and specific interactions with pathogen virulence was developed to test the abilities of statistical analyses to discriminate between host genotypes with different levels of general and specific resistance. Estimates of levels of specific resistance could be obtained in regressions of disease severity scores for each host cultivar X pathogen isolate combination vs. the virulence index of each isolate. If the virulence index was based on the mean disease severity induced by the isolate over all host cultivars, the slopes of the regression lines were correlated with the levels of specific resistance in host cultivars. If the virulence index was based on the disease severity induced by the isolate on a host cultivar with a minimum of specific resistance, the mean squares for deviations from the regression were correlated with the levels of specific resistance in host cultivars. A method was developed to consistently choose host cultivars with minimum specific resistance. The two regression analyses gave estimates of specificity in randomly generated, model genotypes of approximately equal accuracy, although the second method appeared to be more accurate when the numbers of loci controlling resistance and virulence were small. The best estimates of numbers of genes for specific resistance were obtained by calculating a rating based on mean disease severity, the mean square for deviation from the regression on the virulence index based on disease severity on the cultivar with minimum specific resistance and the slope of the regression on the virulence index based on the mean disease severity. The best estimates of proportions of resistance genes that were specific were obtained by calculating a rating based on the above deviation mean square and slope alone.Cooperative investigation of the U.S. Department of Agriculture, Agricultural Research Service and the North Carolina Agricultural Research Service. Journal Series Paper No. 8326 of the North Carolina Agricultural Research Service