The function and structure of the ovipositor in Hymenoptera have been studied intensively, although there is a lack of information on the external sheaths. We provide here a contribution on the structure of the external sheaths of the ovipositor of the parasitic wasp Aphidius ervi, in particular the secretory structure is described for the first time. These glands are made up of a large epithelial structure that consists a single layer of large secretory cells that occupy most of the lumen of the valve and belong to gland cell class 1. Based on the different features of the glands, a lubricating and/or host marking function is hypothesized and discussed., Sara Ruschioni, Paola Riolo, Roberto Romani, Donatella Battaglia, Nunzio Isidoro., and Obsahuje bibliografii
The fine structure of the ovary, ovicapt, oviduct, fertilisation canal, vitelline ducts, vitelline reservoir, ovovitelline duct, ootype and Mehlis' gland, and proximal, middle and distal parts of the uterus of the spathebothriidean cestode, Cyathocephalus truncatus (Pallas, 1781), from salmoniform fish, has been studied for the first time by transmission electron microscopy (TEM). Emphasis was given to characteristics which might shed light on the unclarified phylogenetic position of spathebothriideans, belonging among the most basal tapeworms (Eucestoda). New for cestodes is the finding of a multinucleate cell that plugs the ovicapt lumen. The morphology of the proximal part of the oviduct resembles that of the pseudophyllidean tapeworm Diphyllobothrium latum. After fertilisation in the fertilisation canal, vitellocytes of C. truncatus become associated with fertilized oocytes in the ovovitelline duct. Only one type of Mehlis' gland secretory cell is present. The eggs with electron-dense eggshells containing large pores first appear in the proximal part of the uterus. The middle portion of the uterus has well-developed uterine glands. The distal portion of the uterus has apical microtriches. Ultrastructural data on the female genital system of C. truncatus are compared and discussed with those for other cestodes. However, on the basis of available ultrastructural data it is not possible to conclude whether the Spathebothriidea are phylogenetically closer to the Caryophyllidea or to the Pseudophyllidea.
Fine structure of the vas efferens, vas deferens, ejaculatory duct with accessory glands and vagina with seminal receptacle is described in the spathebothriidean tapeworm, Cyathocephalus truncatus (Pallas, 1781) Kessler, 1868. The numerous well-developed prostate glands are characterised by having secretory granules with an electron-dense core surrounded by a matrix of lower electron density. Coalescence of the outer part of the granules with each other takes place in the terminal end of the secretory ducts. The position of prostate glands around the proximal part of the cirrus pouch and terminating in the ejaculatory duct is a characteristic feature of the Spathebothriidea. Up to 20 closely arranged muscle layers make up the muscular cirrus pouch wall with 4 well-developed muscular layers in the ejaculatory duct and cirrus. Both the cirrus and the vagina are covered with the same uniform cone-shaped microtriches. The vagina has an extensive seminal receptacle. All of these structures are well-adapted to insure successful sperm transfer involving ejaculation and storage, probably for both self- and cross-insemination. Cyathocephalus truncatus has a cirrus similar to that of the monozoic, progenetic caryophyllidean, Archigetes sieboldi and well-developed prostate glands like those of the polyzoic pseudophyllidean, Diphyllobothrium latum. The ultrastructural aspects of the male and female reproductive system of C. truncatus are compared with those of other tapeworms.
Studies involving comparisons of taxa that vary in their degree of relatedness may allow the distinction of functional and phylogenetic components in cercarial sensory systems. In this study, cercariae of allocreadiids Bunodera Railliet, 1896 and Crepidostomum Braun, 1900, lecithodendriid Allassogonoporus Olivier, 1938 and opecoelid Allopodocotyle Pritchard, 1966 were compared as regards ultrastructure and chaetotaxy of sensory receptors as well as neuromorphology. Cercariae were treated with acetylthiocholine iodide and silver nitrate and some were processed for scanning and transmission electron microscopy. The types of cercarial sensory receptors differed in the presence of a tegumentary sheath, a dome-like base and a tegumentary collar, number of cilia (0, 1, 2 or more), cilium length (short, moderately long or long) and tegumentary collar length (low to moderately low, high or very high). Chaetotaxic patterns were consistent at the family level in all taxa studied. Irregular cholinergic nerve networks were identified. The present study indicates that the major categories of cercarial sensory receptors are nonciliated (including sheathed and subtegumentary types) and ciliated (including uncollared and collared types) receptors. It also allows the distinction of functional and phylogenetic components in the sensory systems of the cercariae studied. Functional components were reflected in the numbers of sensory receptors associated with each nerve region and in the ultrastructure and site-specificity of receptor types. Phylogenetic components included taxon-specific chaetotaxic patterns and receptor types.
Fusilade (fluazifop-p-butyl) is one of the herbicides that inhibit acetyl-CoA carboxylase. The exogenous effect of 30, 60, and 90 ppm fusilade on peanut (Arachis hypogaea L. cv. Giza 5) leaves was studied. With increasing fusilade concentration, the peanut leaf chlorosis appeared after 7-10 d. Declined leaf pigment contents confirmed the leaf chlorosis. Electron microscopic observation of the fusilade-treated (FT) leaves revealed disorganization in the ultrastructure of mesophyll cell chloroplasts. An increase of plastoglobuli occurrence within chloroplasts and degenerated grana thylakoids were observed in FT leaves. Fusilade treatments induced mainly the enhancement of malondialdehyde content and the activities of peroxidases (guaiacol and ascorbate). On contrary, a decrease in H2O2 content, catalase and superoxide dismutase activities was recorded. Enhancements of the guaiacol and ascorbate peroxidase activities were associated with the decreasing H2O2 content in the FT leaves. Hydrogen peroxide seems not to be involved in the oxidative stress of FT leaves. In the FT leaves, the oxidative stress confirmed by chlorophyll degradation and lipid peroxidation might be caused by the other reactive oxygen species probably due to the decrease of superoxide dismutase activity., K. A. Fayez, D. E. M. Radwan, A. K. Mohamed, A. M. Abdelrahman., and Obsahuje bibliografii
Myxobolus filamentum sp. n. was found infecting gill filaments of three of 39 Brycon orthotaenia Günther specimens examined (8%), which were taken from the river São Francisco in Minas Gerais state, Brazil. Plasmodia of the parasite were white and long, measuring 5 mm in lenght. Mature spores of M. filamentum sp. n. were oval from the frontal view and biconvex from the lateral view, measuring 7.5-9.7 µm (9.0 ± 0.3 µm) in length and 5.2-7.3 µm (6.2 ± 0.4 µm) in width. The polar capsules were elongated and equal in size, measuring 3.8-5.5 µm (4.7 ± 0.3 µm) in length and 1.3-2.2 µm (1.7 ± 0.1 µm) in width. The development of the parasite led to compression of the adjacent tissues and inflammatory infiltrate with granulocytic cells. Ultrastructural observation revealed that the plasmodia were delimited by two membranes, which had numerous and extensive pinocytotic channels extending into the wide ectoplasm zone. The plasmodial wall exhibited abundant villi-like projections and a thin layer of granular material prevented direct contact between the plasmodial wall and the host tissue. Phylogenetic analysis, based on 18S rDNA, showed M. filamentum sp. n. as a sister species of Myxobolus oliveirai Milanin, Eiras, Arana, Maia, Alves, Silva, Carriero, Ceccarelli et Adriano, 2010, a parasite of other fish species of the genus Brycon Müller et Troschel from South America., Juliana Naldoni, Suellen A. Zatti, Kassia R.H. Capodifoglio, Tiago Milanin, Antônio A.M. Maia, Marcia R.M. Silva, Edson A. Adriano., and Obsahuje bibliografii
Angiogenesis is known to be triggered by various stimuli including hypertension. It was previously found that NO-deficient hypertension is accompanied by structural remodeling of the cardiac muscle and large coronary arteries. This study was aimed to examine the qualitative subcellular alterations of capillaries in the heart of the rats treated with L-NAME (40 mg/kg/day for 4 weeks). The results showed that long-lasting inhibition of NO production induced an apparent activation of fibroblast function. This was associated with enhancement of fibrozation as well as with the induction of angiogenesis. Accordingly, fibroblasts were frequently located in the vicinity of capillary pericytes, which was followed by their detachment and migration. Moreover, besides inactive or even injured capillaries, the other ones exhibited extensive proteosynthetic activity linked to capillary growth, proliferation and migration of endothelial cells. The results strongly indicate enhanced triggering of the angiogenesis in L-NAME-induced NO-deficient hypertension., Ľ. Okruhlicová, N. Tribulová, I. Bernátová, O. Pecháňová., and Obsahuje bibliografii
Isospora carliae sp. n. is described from the blue-throated rainbow skink Carlia rhomboidalis (Peters), from Daintree Forest, North Queensland, Australia. Oocysts are ellipsoidal, 16.8-21.0 × 12.6-15.4 µm in size, with their two sporocysts, 9.0-14.0 × 7.0-9.24 µm in size, positioned along the wide axis. Sporozoites contain a distinct refractile body and are accompanied by a residuum. All endogenous development occurs within the host-cell nucleus. Nuclei are sometimes invaded by several merozoites, but only infections by a single parasite persist. Nuclei lodging meronts, mature microgamonts and premature macrogamonts have an elongate shape. Some meronts exhibit a membrane-bound cytoplasmic inclusion that contains many micronemes.
During a survey the occurrence of Kudoa quraishii Mansour, Harrath, Abd-Elkader, Alwasel, Abdel-Baki et Al Omar, 2014, recently identified in the muscles of the Indian mackerel, Rastrelliger kanagurta (Cuvier), a species of Kudoa Meglitsch, 1947 infecting oocytes of mature females of the same host fish was found. The new species, for which the name Kudoa saudiensis sp. n. is proposed, infects oocytes that are enlarged with a whitish colour. The parasite develops in vesicular polysporous plasmodia within the oocyte. Infection occurs with a mean prevalence of 20% (7/35) of examined females. Mature spores are quadratic in shape in apical view, having four equal valves and four symmetrical polar capsules. Fresh spores are 2.4-3.6 µm long (mean ± SD 3.1 ± 0.3 µm), 4.3-5.4 µm (4.7 ± 0.3 µm) wide and 3.4-4.3 µm (3.8 ± 0.3 µm) in thickness and long. The smaller size of the new Kudoa species was the distinctive feature that separates it from all previously described species. Molecular analysis based on the SSU rDNA sequences shows that the highest percentage of similarity of 98.5% was observed with K. ovivora Swearer et Robertson, 1999, reported from oocytes of labroid fish from the Caribbean coasts of Panama. The percentage of similarity was 98% with K. azevedoi Mansour, Thabet, Chourabi, Harrath, Gtari, Al Omar et Ben Hassine, 2013 and 89% with K. quraishii. Phylogenetic analysis of the SSU and LSU rDNA data revealed a consistent of the new species with K. azevedoi and K. ovivora. Our findings support the creation of Kudoa saudiensis sp. n. that infects oocytes of the Indian mackerel Rastrelliger kanagurta., Lamjed Mansour, Abdel Halim Harrath, Abdel-Azeem S. Abdel-Baki, Saleh Alwasel, Saleh Al-Quraishy, Suliman Y. Al Omar., and Obsahuje bibliografii
Leaf chloroplast ultrastructure and photosynthetic properties of a natural, yellow-green leaf mutant (ygl1) of rice were characterized. Our results showed that chloroplast development was significantly delayed in the mutant leaves compared with the wild-type rice (WT). As leaves matured, more grana stacks formed concurrently with increasing leaf chlorophyll (Chl) content. Except for the lower intercellular CO2 concentration, the ygl1 plants had a higher leaf net photosynthetic rate, stomatal conductance, and transpiration rate than those of the WT plants. Under equal amounts of Chl, the excitation energy of PSI and PSII was much stronger in the mutant than that in the WT. The ygl1 plants showed higher nonphotochemical quenching and lower photochemical quenching. They also exhibited higher actual photochemical efficiency of PSII with a higher electron transport rate. Under the light of 200 μmol(photon) m-2 s-1, the ygl1 mutant showed lesser deepoxidation of violaxanthin in the xanthophyll cycle than WT, but it increased substantially under strong light conditions. In conclusion, the photosynthetic machinery of the ygl1 remained stable during leaf development. The plants were less sensitive to photoinhibition compared with WT due to the active xanthophyll cycle. The ygl1 plants were efficient in both light harvesting and conversion of solar energy., Z. M. Wu, X. Zhang, J. L. Wang, J. M. Wan., and Obsahuje bibliografii