? and ? spectrin distribution during the differentiation of pyriform cells in follicles of lizardPodarcis sicula

2003 ◽  
Vol 67 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Loredana Ricchiari ◽  
Vaccaro Maria Carmela ◽  
Prisco Marina ◽  
Carotenuto Rosa ◽  
Liguoro Annamaria ◽  
...  
Keyword(s):  
1978 ◽  
Vol 33 (1) ◽  
pp. 341-350
Author(s):  
P. Andreuccetti ◽  
C. Taddei ◽  
S. Filosa

Intercellular bridges first appear during lizard oogenesis when follicles are rather small (150 microgram in diameter); at this stage they form connecting links between the oocyte and follicle cells, which have not yet differentiated into pyriform cells. Later on, when the follicles have become larger (1 mm) and the follicular epithelium appears constituted by 3 types of cells (small, intermediate and pyriform cells) they form connecting links between the oocyte and both intermediate and pyriform cells. The establishment of intercellular bridges between pyriform cells and the oocyte precedes the complete differentiation of the former, which excludes the possibility that the fusion between pyriform cells and oocyte occurs only after these cells are completely differentiated. In still larger follicles (up to 2 mm in diameter), during the degeneration of the pyriform cells, the occurrence, inside the bridges, of mitochondria and other cytoplasmic material suggests that these cells at the end of their function transfer their contents into the oocyte.


1982 ◽  
Vol 60 (10) ◽  
pp. 2434-2441 ◽  
Author(s):  
Barbara M. MacKinnon

Catatropis verrucosa (Froelich 1789) Odhner 1905 and Paramonostomum alveatum (Mehlis in Creplin, 1846) Lühe 1909 were examined using light and scanning and transmission electron microscopy. The ventral ridge, papillae, and body margins of C. verrucosa contained numerous pyriform cells packed with mitochondria. Paramonostomum alveatum has no ventral projections and no pyriform cells full of mitochondria were seen within the worms. Both species contained numerous large electron-dense inclusions in various tissues throughout the body. Histochemistry indicated that these inclusions were lipid or lipoprotein, but their function is unknown. Protein, including haemoglobin, and lipid were identified within the pyriform cells of C. alveatum. Paramonostomum is the only genus within the Notocotylinae examined to date that has no ventral projections nor any internal aggregation of cells packed with mitochondria.


Phytotaxa ◽  
2019 ◽  
Vol 411 (2) ◽  
pp. 93-104
Author(s):  
ROU XUE ◽  
LU-LING WU ◽  
SHUAI JIANG ◽  
YAN-JIA HAO ◽  
HUI CHAI ◽  
...  

Two new species of Leccinellum, viz. L. alborufescens and L. fujianense are described based on morphological and molecular evidence. Both species have a rugulose or pitted brown pileus, a red color change of hymenophore and context, and a pileipellis and stipitipellis composed of chains of subglobose to pyriform cells. The differences between them are the width of the hyphae in the pileipellis and the range of distribution as well as the molecular data. Leccinellum alborufescens has hyphae in the pileipellis up to 13 μm in width, and a distribution in tropical China, whereas L. fujianense has pileipellis hyphae up to 20 μm in width, and a distribution in subtropical China. Detailed descriptions, color photos of fresh basidiomata and line drawings of the microstructures of the two new species are presented.


Parasitology ◽  
1982 ◽  
Vol 84 (2) ◽  
pp. 313-332 ◽  
Author(s):  
Barbara M. MacKinnon

SUMMARYNotocotylus triserialis bears three rows of eversible papillae on its ventral surface. These papillae, which in living worms are firmly applied to the host mucosa, contain numerous pyriform cells. Histochemical tests indicate the presence, within the papillar cells, of protein, lipid, haemoglobin and esterase, and the absence of carbohydrate, acid mucopolysaccharide, RNA, haemosiderin and acid and alkaline phosphatase. Transmission electron microscopy shows the tegument of the papillae to be similar to the non-papillar ventral tegument. The pyriform cells contain many mitochondria with numerous cristae. A mechanism is proposed whereby the musculature of the worm effects the retraction and eversion of the ventral papillae.


1995 ◽  
Vol 273 (3) ◽  
pp. 247-256 ◽  
Author(s):  
C. M. Motta ◽  
M. Castriota Scanderbeg ◽  
S. Filosa ◽  
P. Andreuccetti
Keyword(s):  

2018 ◽  
Vol 50 (3) ◽  
pp. 357-369 ◽  
Author(s):  
Pavel ŠKALOUD ◽  
Patricia MOYA ◽  
Arántzazu MOLINS ◽  
Ondřej PEKSA ◽  
Arnoldo SANTOS-GUERRA ◽  
...  

AbstractIntrathalline phycobiont diversity was investigated in a rosette-forming lichen, Parmotrema pseudotinctorum, using a combination of Sanger sequencing, 454-pyrosequencing, conventional light and confocal microscopy, and transmission electron microscopy. A total of 39 thalli sampled in five Canary Island populations were investigated. Three novel lineages of lichen phycobionts were detected, all being inferred within the Trebouxia clade G. The most abundant phycobiont lineage, occurring in all lichen populations investigated, is described here as Trebouxia crespoana sp. nov. This species produces spherical to pyriform cells possessing a crenulate chloroplast with lobes elongated at their ends, and one corticola-type pyrenoid with very thin, unbranched tubules of curved profile. Trebouxia crespoana is clearly distinguished from all other Trebouxia species by a characteristic cap-like cell wall thickening produced on one side of vegetative cells, and the larger size of vegetative cells that reach 21(–26) µm in diameter.


Author(s):  
J. A. C. Nicol

The piddock, Pholas dactylus L., gives off a luminous secretion when irritated. The luminous glands which produce the secretion are two longitudinal stripes in the exhalant siphon, a pair of triangular organs in the mantle cavity near the base of the siphon, and a stripe around the ventral rim of the mantle (Panceri, 1872).The histology of the light-organs has been described several times. A light-organ is covered by a simple columnar ciliated epithelium, below which are many glandular cells, which discharge through the surface epithelium. The outer part of the glandular layer consists of a mass of large mucus cells. Deeper lies a second glandular region containing large cells with long necks that extend to the external epithelial surface. Dubois (1892, 1914, 1928) believed that the photogenic tissue was made up of two kinds of secretory cells; these were the superficial ciliated cells, which possessed glandular bases (fixed secretory cells); and deeper lying glandular cells derived from clasmatocytes (migratory secretory cells). Rawitz (1891) clearly distinguished a mucous from an underlying photogenic layer. The latter, according to Förster (1914), contains pyriform cells with long necks. He believed that he could distinguish a secretory cycle in the photogenic cells. Exhausted cells at the beginning of the cycle possessed an alveolar cytoplasm; granules began to appear in the cytoplasm; the granules increased in number and stained intensely with iron haematoxylin. Those photogenic cells which were filled with granules were in the active secretory state. Transitional stages between the inactive (or depleted) cells and the active (granular) cells were rare.


1982 ◽  
Vol 60 (6) ◽  
pp. 1308-1313 ◽  
Author(s):  
Barbara M. MacKinnon

Ventral papillae of Notocotylus triserialis contain pyriform cells filled with mitochondria. To investigate the possible respiratory function of the papillae, N. triserialis was examined histochemically for numerous respiratory enzymes. α-Glycerophosphate, succinate, glutamate, lactate, and glucose-6-phosphate dehydrogenases and cytochrome oxidase were identified within the pyriform cells of the ventral papillae and lateral margins of the worm.Living N. triserialis are red, particularly the ventral papillae and lateral margins of the worms. Using spectroscopy, this pigment was identified as a true oxyhaemoglobin, with the α and β peaks at 570–580 and 530–540 nm, respectively, corresponding closely with those of its experimentally infected chicken host haemoglobin. Polyacrylamide gel electrophoresis showed three, possibly four, haemoglobins in N. triserialis, distinct from the two chicken haemoglobins. During in vitro experiments the bright red colour of the worms turned to a dull grey–blue when worms were deprived of oxygen and the red colour returned upon addition of oxygen to the culture medium. This suggested that the haemoglobins of N. triserialis had the ability to deoxygenate and reoxygenate in vitro.


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