scholarly journals Characteristics of achenes in Potentilla collina group (Rosaceae)

2011 ◽  
Vol 76 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Jeremi Kołodziejek ◽  
Barbara Gabara
Keyword(s):  
Epidermal Cells ◽  
Type I ◽  
Type Ii ◽  
Separate Species ◽  
Surface Sculpture ◽  
Dorsal Ridge ◽  
Fruit Wall ◽  
Scanning Electron ◽  
Shape And Size ◽  
Sem Analyses

Achenes morphology in taxa from <em>Potentilla collina</em> s.l. i.e., <em>P. collina</em> Wibel s.s., <em>P. leucopolitana</em> P.J. Müller, <em>P. thyrsiflora</em> Hülsen ex Zimmet., <em>P. thyrsiflora</em> var. <em>isosepala</em> Th. W., <em>P. silesiaca</em> Uechtr. And <em>P. wimanniana</em> Günther and Schummel was examined with stereoscope and scanning electron microscopy. Achenes of these taxa varied slightly in shape, size and colour, while marked differences among them appeared in the surface sculpture and in the dimensions of aril, dorsal ridge and ribs. SEM analyses allowed to distinguish two distinct morphological types of achenes. Type I - with ruminate sculpture and aggregates of some material, various in shape and size, at the surface of partly destroyed epidermal cells covering fruit wall in <em>P. leucopolitana</em>, <em>P. wimanniana</em> and <em>P. thyrsiflora</em>. Type II - with ruminate-reticulate sculpture due to well preserved epidermal cells in <em>P. silesiaca</em> and <em>P. thyrsiflora</em> var. <em>isosepala</em>. The obtained results have supported Błocki’s suggestion to treat <em>P. thyrsiflora</em> var. <em>isosepala</em> as a separate species named <em>P. isosepala</em>. However, similarities in the surface sculpture of achenes in some taxa of <em>P. collina</em> group did not facilitate their classification, therefore this feature may be a valuable taxonomical criterium only in combination with others.

scholarly journals OBSERVATIONS ON ETCHED ENAMEL IN NON-ERUPTED DECIDUOUS MOLARS: A SCANNING ELECTRON MICROSCOPIC STUDY

1997 ◽  
Vol 11 (3) ◽  
pp. 157-160 ◽  
Author(s):  
Marcelo FAVA ◽  
Ii-Sei WATANABE ◽  
Flávio FAVA DE MORAES ◽  
Luciane RIBEIRO DE REZENDE SUCASAS DA COSTA
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Phosphoric Acid ◽  
Acid Etching ◽  
Etching Time ◽  
Type I ◽  
Type Ii ◽  
Electron Microscopic ◽  
Deciduous Molars ◽  
Scanning Electron

Under the scanning electron microscope, the characteristics of the buccal surface enamel of human non-erupted deciduous molars were evaluated after using 15, 30, and 45 seconds of phosphoric acid etching time. The teeth were extracted, kept in a 70% alcohol solution and later dehydrated and metallized for analysis with the scanning electron microscope JEOL, JSM-6.100. The in vitro experiment with 35% phosphoric acid revealed that there is a tendency of predominance of interprismatic enamel dissolution or type II pattern with 15 and 45 seconds etching time. The dissolution of the interprismatic enamel was more pronounced when an acid etching time of 45 seconds was used. The enamel surface demonstrated type I and type II patterns when acid etching time was 30 seconds

Sequence and expression of a type II keratin, K5, in human epidermal cells

1988 ◽  
Vol 8 (1) ◽  
pp. 486-493
Author(s):  
R Lersch ◽  
E Fuchs
Keyword(s):  
Human Gene ◽  
Basal Layer ◽  
Epidermal Cells ◽  
Amino Acid Sequences ◽  
Type I ◽  
Type Ii ◽  
Gene Encoding ◽  
Human Epidermal Cells ◽  
Rna Blot Analysis

We report here the cDNA and amino acid sequences of a human 58-kilodalton type II keratin, K5, which is coexpressed with a 50-kilodalton type I keratin partner, K14, in stratified squamous epithelia. Using a probe specific for the 3'-noncoding portion of this K5 cDNA, we demonstrated the existence of a single human gene encoding this sequence. Using Northern (RNA) blot analysis and in situ hybridization with cRNA probes for both K5 and K14, we examined the expression of these mRNAs in the epidermis and in cultured epidermal cells. Our results indicate that the mRNAs for K5 and K14 are coordinately expressed and abundant in the basal layer of the epidermis. As cells undergo a commitment to terminally differentiate, the expression of both mRNAs seems to be downregulated.

scholarly journals Systematic significance of cypsela morphology in Lessingianthus (Vernonieae, Asteraceae)

2015 ◽  
Vol 28 (3) ◽  
pp. 173 ◽  
Author(s):  
María B. Angulo ◽  
María M. Sosa ◽  
Massimiliano Dematteis
Keyword(s):  
Electron Microscopy ◽  
South American ◽  
Taxonomic Significance ◽  
South American Species ◽  
Generic Level ◽  
Fruit Wall ◽  
Taxonomic Markers ◽  
First Time ◽  
Scanning Electron ◽  
Shape And Size

The taxonomic significance of cypsela features of South American species of Lessingianthus (Vernonieae, Asteraceae) is analysed for the first time and discussed in relation to other genera of the tribe Vernonieae. The morphology of the cypselae of 112 species of the genus were analysed using stereo-, light and scanning electron microscopy (SEM) to evaluate the infrageneric relationships and their reliability as taxonomic markers at a generic level. Characters such as cypsela pubescence, carpopodium structure, crystals and idioblasts on the fruit wall were examined. We established three types of cypsela on the basis of the presence or absence, and type of trichomes. Carpopodium is present in all species of the genus. Crystals are very variable in shape and size, with prismatic (rectangular and hexagonal) and styloid shapes. Idioblasts are present in all of the species, except for two. Cypsela features of Lessingianthus are often widespread in other related genera of Vernonieae. Therefore, these characters are not good taxonomic markers at the genus level, but they are valuable within genera to differentiate related species from one another.

scholarly journals Sequence and expression of a type II keratin, K5, in human epidermal cells.

1988 ◽  
Vol 8 (1) ◽  
pp. 486-493 ◽  
Author(s):  
R Lersch ◽  
E Fuchs
Keyword(s):  
Human Gene ◽  
Basal Layer ◽  
Epidermal Cells ◽  
Amino Acid Sequences ◽  
Type I ◽  
Type Ii ◽  
Gene Encoding ◽  
Human Epidermal Cells ◽  
Rna Blot Analysis

We report here the cDNA and amino acid sequences of a human 58-kilodalton type II keratin, K5, which is coexpressed with a 50-kilodalton type I keratin partner, K14, in stratified squamous epithelia. Using a probe specific for the 3'-noncoding portion of this K5 cDNA, we demonstrated the existence of a single human gene encoding this sequence. Using Northern (RNA) blot analysis and in situ hybridization with cRNA probes for both K5 and K14, we examined the expression of these mRNAs in the epidermis and in cultured epidermal cells. Our results indicate that the mRNAs for K5 and K14 are coordinately expressed and abundant in the basal layer of the epidermis. As cells undergo a commitment to terminally differentiate, the expression of both mRNAs seems to be downregulated.

scholarly journals Pollen morphology of Amygdalus L. (Rosaceae) in Iran

2011 ◽  
Vol 79 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Mahnaz Vafadar ◽  
Farideh Attar ◽  
Hosein Maroofi ◽  
Mansur Mirtadzadini
Keyword(s):  
Electron Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Polar View ◽  
Pollen Grain ◽  
Type I ◽  
Type Ii ◽  
Type V ◽  
Scanning Electron ◽  
Section Level

Pollen grain of 16 species and three hybrids of the genus <em>Amygdalus</em> L., representing two subgenera and two sections distributed in Iran were examined by light and scanning electron microscopy. All pollen grains are tricolporate. The shape of grains varies from subprolate through prolate. Regarding outline, in polar view, pollen grains are triangular-circular and in equatorial view, elliptic. Regarding sculpturing of exine, the frequent type like many members of family <em>Rosaceae</em> is striate with or without perforations that can be subdivided into three subtypes: type I (A-B), type II (A-B) and type V. In three species, <em>A. trichamygdalus</em>, <em>A. spinosissima</em> and <em>A. orientalis</em>, exine sculpture type is completely different. In the first species is rugulate, in the second species is reticulate and in <em>A. orientalis</em>, it is gemmate-perforate. Ornamentation of ridges (muri) in the striate sculpture is parallel to ectocolpus. Number of perforations in tectum, diameter of them, striae intervals and the thickness of ridges varies among studied taxa. The striae have different depth and slope. Results showed that among pollen grain characters, shape is useful character solely for separating of taxonomic ranks in Iranian Amygdalus specially in subgeneric or section level.

scholarly journals Retinoids as important regulators of terminal differentiation: examining keratin expression in individual epidermal cells at various stages of keratinization.

1987 ◽  
Vol 105 (1) ◽  
pp. 427-440 ◽  
Author(s):  
R Kopan ◽  
G Traska ◽  
E Fuchs
Keyword(s):  
Retinoic Acid ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Terminal Differentiation ◽  
Epidermal Cells ◽  
Type I ◽  
Type Ii ◽  
Submerged Cultures ◽  
Normal Medium ◽  
Large Type

When human epidermal cells were seeded on floating rafts of collagen and fibroblasts, they stratified at the air-liquid interface. The suprabasal cells synthesized the large type II (K1) and type I (K10/K11) keratins characteristic of terminal differentiation in skin. At earlier times in culture, expression of the large type II keratins appeared to precede the expression of their type I partners. At later times, all suprabasal cells expressed both types, suggesting that the accumulation of a critical level of K1 keratin may be a necessary stimulus for K10 and K11 expression. Expression of the terminal differentiation-specific keratins was completely suppressed by adding retinoic acid to the culture medium, or by submerging the cultures in normal medium. In submerged cultures, removal of vitamin A by delipidization of the serum restored the keratinization process. In contrast, calcium and transforming growth factor-beta did not influence the expression of the large keratins in keratinocytes grown in the presence of retinoids, even though they are known to induce certain morphological features of terminal differentiation. Retinoic acid in the raft medium not only suppressed the expression of the large keratins, but, in addition, induced the synthesis of two new keratins not normally expressed in epidermis in vivo. Immunofluorescence localized one of these keratins, K19, to a few isolated cells of the stratifying culture. In contrast, the other keratin, K13, appeared uniformly in a few outer layers of the culture. Interestingly, K13 expression correlated well with the gradient of retinoid-mediated disruptions of intercellular interactions in the culture. These data suggest that K13 induction may in some way relate to the reduction in either the number or the strength of desmosomal contacts between suprabasal cells of stratified squamous epithelial tissues.

scholarly journals Three-Dimensional Reconstructions of Mouse Circumvallate Taste Buds Using Serial Blockface Scanning Electron Microscopy: I. Cell Types and the Apical Region of the Taste Bud

2019 ◽  
Author(s):  
Ruibiao Yang ◽  
Yannick K. Dzowo ◽  
Courtney E. Wilson ◽  
Rae L. Russell ◽  
Grahame J. Kidd ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Nerve Fibers ◽  
Taste Bud ◽  
Type I ◽  
Type Ii ◽  
Basal Cells ◽  
Type Iii ◽  
Type Iv ◽  
I Cells ◽  
Scanning Electron

ABSTRACTTaste buds comprise four types of taste cells: 3 mature, elongate types: Type I, Type II, Type III; and basally-situated, immature post-mitotic Type IV cells. We employed serial blockface scanning electron microscopy to delineate the characteristics and interrelationships of the taste cells in the circumvallate papillae of adult mice. Type I cells have an indented, elongate nucleus with invaginations, folded plasma membrane, and multiple apical microvilli in the taste pore. Type I microvilli may be either restricted to the bottom of the pore or extend outward reaching midway up into the taste pore. Type II cells (aka receptor cells) are characterized by a large round or oval nucleus, a single apical microvillus extending through the taste pore, and specialized “atypical” mitochondria at functional points of contact with nerve fibers. Type III cells (aka “synaptic cells”) are elongate with an indented nucleus, possess a single, apical microvillus extending through the taste pore and are characterized by a small accumulation of synaptic vesicles at points of contact with nerve fibers. About one-quarter of Type III cells also exhibit an atypical mitochondrion amidst the presynaptic vesicle clusters at the synapse. Type IV cells (non-proliferative “basal cells”) have a nucleus in the lower quarter of the taste bud but have a foot process extending to the basement membrane often contacting nerve processes along the way. Type I cells represent just over 50% of the population, whereas Type II, Type III, and Type IV (basal cells) represent 19%, 15%, and 14% respectively.

scholarly journals Leaf epidermal micromorphology defining the clades in Cinnamomum (Lauraceae)

PhytoKeys ◽  
2021 ◽  
Vol 182 ◽  
pp. 125-148
Author(s):  
Zeng Gang ◽  
Bing Liu ◽  
Jens G. Rohwer ◽  
David Kay Ferguson ◽  
Yong Yang
Keyword(s):  
Type I ◽  
Type Ii ◽  
Phylogenetic Studies ◽  
The Family ◽  
Traditional Classification ◽  
Different Types ◽  
Species Groups ◽  
Periclinal Walls ◽  
Micromorphological Characters ◽  
Scanning Electron

In this study, we sampled 48 species of Asian Cinnamomum covering the species groups that were identified in recent phylogenetic studies and conducted leaf micromorphological observations using both light microscopy (LM) and scanning electron microscopy (SEM). Synapomorphies were determined by means of mapping micromorphological characters on a phylogenetic tree. The results indicate that Cinnamomum exhibits two different types of leaf upper epidermis: Type I has smooth/non-reticulate periclinal walls whereas Type II has reticulate periclinal walls and is unusual in the family Lauraceae. We found that the two types of micromorphological characters are clade-specific, sect. Camphora s.s. possesses Type I leaf upper epidermis, and sect. Cinnamomum s.l. has Type II leaf upper epidermis. Our study also reveals that C. saxatile, a member of sect. Camphora s.l. in the traditional classification, actually has Type II leaf upper epidermis, thus reinforcing the result of a recent molecular phylogeny that has this species in a clade consisting mainly of species of sect. Cinnamomum.

scholarly journals Expression of unusually large keratins during terminal differentiation: balance of type I and type II keratins is not disrupted.

1984 ◽  
Vol 99 (5) ◽  
pp. 1872-1877 ◽  
Author(s):  
K H Kim ◽  
D Marchuk ◽  
E Fuchs
Keyword(s):  
Transcriptional Regulation ◽  
Epidermal Cell ◽  
Intermediate Filaments ◽  
Terminal Differentiation ◽  
Epidermal Cells ◽  
Type I ◽  
Type Ii ◽  
Post Transcriptional Regulation

When a basal epidermal cell undergoes a commitment to terminally differentiate, it ceases to divide and begins to migrate outward towards the surface of the skin. Dramatic changes in its cytoskeletal architecture take place, accompanied by numerous changes in the expression of keratins, a family of related polypeptides that form 8-nm filaments in these cells. We show here that a shift to the synthesis of unusually large keratins occurs that does not seem to disrupt the ratio of two distinct subfamilies of keratins. Preliminary studies indicate that this differentiation-specific shift may be at the level of transcriptional rather than post-transcriptional regulation. The striking similarities between these large keratins and the type I and type II keratins of basal epidermal cells suggests the important role that both classes of large keratin sequences must play in the assembly of the intermediate filaments within the differentiating keratinocyte.

Adaptive Modifications in Four Fish Species of the GenusGarra(Teleostei; Cyprinidae) in Basistha River, Assam, India

2018 ◽  
Vol 24 (3) ◽  
pp. 310-317
Author(s):  
Jafrin F. Hussain ◽  
Sabitry Bordoloi
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Morphology ◽  
Fish Species ◽  
Taste Buds ◽  
Stream Fish ◽  
Type I ◽  
Type Ii ◽  
Guwahati City ◽  
Scanning Electron

AbstractThis paper deals with the study of the surface morphology of barbels, upper lips, and adhesive discs in four hill stream fish species collected from Basistha River, a torrential river in Guwahati city, Assam, India. The four species belonging to the genusGarranamely,Garra gotyla(Gray, 1830),Garra gravelyi(Annandale, 1919),Garra stenorhynchus(Jerdon, 1849), andGarra nasuta(McClelland, 1838) were collected from the same torrential habitat. These fish revealed anatomical peculiarities in their barbels, lips, and adhesive discs which are believed to help them in adapting to such habitats. Organs exhibiting adaptive modifications (barbels, lips, and adhesive discs) were studied with the scanning electron microscope. The study primarily revealed the presence of type I and type II taste buds in the barbels, lips, and adhesive discs, and numerous unculi surrounded by microridges in the upper lips and adhesive discs. A cumulative, intercalated action of these organs enables these fish to adhere and adapt to rocky, torrential streams. Special ability to adapt to these habitats was reflected from the two types of taste buds (I and II) present in the barbels, and the clustering of excrescencies bearing unculi in the lips and adhesive discs of the fish.

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