scholarly journals Reniform Nematode, Rotylenchulus reniformis Linford & Oliveira (Nematoda: Tylenchida: Tylenchoidea: Hoplolaimidae: Rotylenchulinae)

EDIS ◽  
1969 ◽  
Vol 2004 (9) ◽  
Author(s):  
Koon-Hui Wang

Reniform nematodes in the genus Rotylenchulus are semiendoparasitic (partially inside roots) species in which the females penetrate the root cortex, establish a permanent-feeding site in the stele region of the root and become sedentary or immobile. The anterior portion (head region) of the body remains embedded in the root whereas the posterior portion (tail region) protrudes from the root surface and swells during maturation. The term 'reniform' refers to the kidney-shaped body of the mature female. There are ten species in the genus Rotylenchulus. Rotylenchulus reniformis is the most economically important species (Robinson 1997 ) and is called the reniform nematode. This document is EENY-210, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: May 2001.  EENY-210/IN367: Reniform Nematode, Rotylenchulus reniformis Linford and Oliveira (Nematoda: Tylenchida: Tylenchoidea: Hoplolaimidae: Rotylenchulinae) (ufl.edu)

1990 ◽  
Vol 96 (3) ◽  
pp. 477-484
Author(s):  
T. Fujimoto ◽  
K. Ogawa

Fodrin, a membrane skeletal protein, was found to accumulate in the posterior portion of human neutrophils polarized morphologically after stimulation by the chemotactic peptide, N-formylmethionyl-leucylphenylalanine (FMLP). In most (greater than 90%) unstimulated neutrophils, the distribution of fodrin was found to be uniform by immunofluorescence microscopy. When FMLP (10(−8)M) was applied at 25 degrees C, fodrin became polarized in about 40% of cells by 1 min, about 70% by 2 min, and about 80% by 10 min. The cells with polarized distribution decreased thereafter to about 60% of the cells at 20 min and about 20% at 60 min. Using the under-agarose system, it was confirmed that the concentration of fodrin occurred in the region opposite to the direction of chemoattraction in moving cells. By immunoelectron microscopy, most of the labeling for fodrin was observed in the filamentous cell cortex and not associated with the plasma membrane itself. In cells polarized morphologically by FMLP, the fodrin labeling became concentrated in the posterior portion of the cell; the labeling was found most densely in the granule-rich cytoplasm, while the filamentous tail region was not labeled intensely. The lamellipodium in the head region was also labeled only sparsely. The results indicate that in human neutrophils fodrin exists as a cytoskeletal protein rather than as a membrane protein and that the protein accumulates in the endoplasm of the posterior portion in migrating cells. The rearrangement is likely to modulate the organization of the actin-rich cell cortex for cell locomotion.


1937 ◽  
Vol s2-79 (316) ◽  
pp. 507-557
Author(s):  
DATUS M. HAMMOND

1. The neuromotor system of Euplotes patella Ehrenberg was studied in different stages of the life-cycle, including the adult, and asexual and sexual reproduction. 2. In the adult the basal granules of all the cirri are arranged in straight primary and secondary rows. The fibrils from the bases of the cirri are in general parallel with either the primary or secondary rows of basal granules of the cirri to which they are attached. This is interpreted as an indication of the evolution of the organism from an ancestor with a simple neuromotor system in which the cilia were uniformly distributed over the surface of the body in longitudinal, slightly spiral rows. 3. The basal apparatus of a bristle consists of a basal granule at the bottom of a depression in the ectoplasm which is surrounded by a group of rodlets and ends at the surface in a ring connected with the polygonal system. The polygonal or silverline system is pellicular in position. 4. During asexual reproduction the entire set of cirri is resorbed and replaced by two new sets of cirri, one for each daughter. One frontal cirrus for the anterior daughter develops in the old peristomial field of the parent, while the corresponding cirrus for the posterior daughter develops in the new peristome. The right marginal cirri arise on the dorsal surface along the rows of bristles and later move to the ventral surface. The fibrils develop outward from the bases of the cirri. 5. During binary fission a new peristome arises in a depression in the ectoplasm independently of the old peristome. The old peristome remains in the anterior daughter without at the time undergoing any visible change in structure. 6. The multiplication of the bristles is limited to a zone on either side of the future plane of constriction. Multiplication occurs by a series of fissions of the basal granules in this area. Dedifferentiation of bristles was not seen. 7. The polygonal system is replaced over the entire surface of the body with the exception of the old peristomial field. The new system originates in many separate loci in connexion with the bristles on the dorsal surface, and with the rudiments (Anlagen) of the cirri and peristome on the ventral surface. 8. During conjugation there are two successive reorganizations of the neuromotor system, that of the ‘gamete’ (conjugant) and that of the zygote. 9. The first reorganization, that of the gamete, begins during the maturation divisions preparatory to fertilization. During this reorganization the posterior portion of the peristome is resorbed and the remaining anterior portion is later replaced. The eighteen cirri are replaced by a set containing only seventeen cirri. 10. The second reorganization, that of the zygote, occurs during the differentiation of the nuclei in the exconjugants. It involves the completion of the peristome by differentiation of the missing posterior portion, and the replacement of the set of seventeen cirri by a complete set of eighteen cirri. 11. These protoplasmic reorganizations, invariably associated with both asexual and sexual reproduction, involve a structural and presumably a physiological rejuvenation resulting in the possibility of an indefinitely continued existence of the individual in the Protozoa. It may be that sexual reproduction is not necessary to bring about this result, but further work on the relationship of endomixis to the problem is needed.


2020 ◽  
Vol 110 (9) ◽  
pp. 1511-1521
Author(s):  
Juliet Wilkes ◽  
Christopher Saski ◽  
Mariola Klepadlo ◽  
Benjamin Fallen ◽  
Paula Agudelo

Reniform nematode (Rotylenchulus reniformis) is a yield-limiting pathogen of soybean (Glycine max) in the southeastern region of the United States. A population of 250 recombinant inbred lines (RIL) (F2:8) developed from a cross between reniform nematode resistant soybean cultivar Forrest and susceptible cultivar Williams 82 was utilized to identify regions associated with host suitability. A genetic linkage map was constructed using single-nucleotide polymorphism markers generated by genotyping-by-sequencing. The phenotype was measured in the RIL population and resistance was characterized using normalized and transformed nematode reproduction indices in an optimal univariate cluster analysis. Quantitative trait loci (QTL) analysis using normalized phenotype scores identified two QTLs on each arm of chromosome 18 (rrn-1 and rrn-2). The same QTL analysis performed with log10(x) transformed phenotype data also identified two QTLs: one on chromosome 18 overlapping the same region in the other analysis (rrn-1), and one on chromosome 11 (rrn-3). While rrn-1 and rrn-3 have been reported associated with reduced reproduction of reniform nematode, this is the first report of the rrn-2 region associated with host suitability to reniform nematode. The resistant parent allele at rrn-2 showed an inverse relationship with the resistance phenotype, correlating with an increase in nematode reproduction or host suitability. Several candidate genes within these regions corresponded with host plant defense systems. Interestingly, a characteristic pathogen resistance gene with a leucine-rich repeat was discovered within rrn-2. These genetic markers can be used by soybean breeders in marker-assisted selection to develop lines with resistance to reniform nematode.


1950 ◽  
Vol 27 (1) ◽  
pp. 110-122 ◽  
Author(s):  
G. E. NEWELL

1. A short review is given of the coelom and of its morphological relations in the earthworm. 2. The arrangement of the intrinsic muscles in a typical septum is described. Four main sets of muscles are recognized: viz. radial muscles, circular muscles, oblique muscles, and the sphincter around the ventral foramen. 3. It is suggested that the function of the radial, circular and possibly of the oblique muscles is to control bulging of the septa, and so serve to localize differences in pressure in the coelomic fluid. Normally, in active worms, the sphincter of the ventral foramen is contracted and forms an effective barrier to the passage of fluid from one coelomic compartment to the next. This was verified experimentally and by X-ray photography. 4. A series of measurements of the pressure in the coelomic fluid in different regions of active worms was recorded by means of a capillary manometer and by the use of a spoon-gauge apparatus. Manometric measurements showed the average pressure in the anterior third of the body to be 16.0 cm. water and in the tail region to be 8.0 cm. water. The corresponding figures obtained with a spoon gauge were 13.5 and 8.5 cm. water. The pressure in narcotized worms is zero. 5. These results are discussed, and it is pointed out that the manometer readings suffer from the disadvantage of failing to show the rapid fluctuations in pressure which occur during wriggling movements of the worms. 6. It is calculated from these pressure readings that a worm can exert a forward thrust equivalent to forces of between 1.5 and 8.0 g. These figures agree well with those obtained by Gray & Lissman by the use of a special torsion balance. 7. The burrowing movements of earthworms are briefly described. 8. It is shown that the sphincters of the dorsal pores and of the nephridiopores do not normally allow of the escape of coelomic fluid, and will withstand a pressure well outside the normal range.


1963 ◽  
Vol 40 (1) ◽  
pp. 23-56 ◽  
Author(s):  
RICHARD BAINBRIDGE

1. Observations made on bream, goldfish and dace swimming in the ‘Fish Wheel’ apparatus are described. These include: 2. An account of the complex changes in curvature of the caudal fin during different phases of the normal locomotory cycle. Measurements of this curvature and of the angles of attack associated with it are given. 3. An account of changes in area of the caudal fin during the cycle of lateral oscillation. Detailed measurements of these changes, which may involve a 30 % increase in height or a 20 % increase in area, are given. 4. An account of the varying speed of transverse movement of the caudal fin under various conditions and the relationship of this to the changes in area and amount of bending. Details of the way this transverse speed may be asymmetrically distributed relative to the axis of progression of the fish are given. 5. An account of the extent of the lateral propulsive movements in other parts of the body. These are markedly different in the different species studied. Measurements of the wave length of this movement and of the rate of progression of the wave down the body are given. 6. It is concluded that the fish has active control over the speed, the amount of bending and the area of the caudal fin during transverse movement. 7. The bending of the fin and its changes in area are considered to be directed to the end of smoothing out and making more uniform what would otherwise be an intermittent thrust from the oscillating tail region. 8. Some assessment is made of the proportion of the total thrust contributed by the caudal fin. This is found to vary considerably, according to the form of the lateral propulsive movements of the whole body, from a value of 45% for the bream to 84% for the dace.


Zootaxa ◽  
2018 ◽  
Vol 4461 (3) ◽  
pp. 438
Author(s):  
CARLOS AUGUSTO FIGUEIREDO ◽  
CRISTIANO R. MOREIRA

A new species, Poecilia (Pamphorichthys) akroa, is described from the Rio Tocantins drainage, Brazil. The new species differs from the remaining species of the genus by the possession of 10 or 11 pectoral-fin rays, entire preopercular ramus and posterior portion of the supraorbital ramus of the cephalic sensory system enclosed in canals, a faint longitudinal band along the body, a single gonapophysis, a homogeneous reticulate color pattern on sides of body, urogenital region of females heavily pigmented, distalmost segments of the anterior branch (4a) of the fourth gonopodial ray fused into an elongated segment turned anteriorly, subdistal segments of anterior branch (5a) of fifth gonopodial ray simple, without anterior (ventral) projections, dorsal fin with pigmentation at its distal portion and with a basal black blotch, and chromatophores more concentrated on the posterior margin of the mid-ventral scale series of the caudal peduncle and ventrolateral margin of the adjacent scales forming a series of rhombi posterior to anal fin. 


2002 ◽  
Vol 16 (5) ◽  
pp. 265-268 ◽  
Author(s):  
Seung-Kyu Chung ◽  
Do Yeon Cho ◽  
Hun Jong Dhong

Background The phenomenon of recirculation involves the circulation of mucous secretion between the natural ostium and other openings and is observed mainly after surgery when the surgical opening is not connected. Methods Seven patients with a mucous stream transporting into an accessory ostium, as found during endoscopic examination, were entered into study. The coronal computed tomogram findings of the mucous recirculation were analyzed at three levels: anterior, middle, and posterior portion of it. Results The anterior portion was visualized at the level of the natural ostium in five patients. The middle portion inside the maxillary sinus was visible in six cases. The posterior portion was visualized at the level of the accessory ostium in five patients. Among the axial scans, mucous rings were visible in two patients. Conclusions The primary mucous recirculation between the natural and accessory openings is shown as a ring structure in coronal computed tomogram scans.


Zootaxa ◽  
2018 ◽  
Vol 4526 (4) ◽  
pp. 447
Author(s):  
REZA GHADERI ◽  
AKBAR KAREGAR ◽  
ESMAEIL MIRAEIZ

Trichotylenchus gorganiensis n. sp. is described and illustrated based on morphological and morphometric data. The new species is characterized by its 760–1073 µm long body, conoid-rounded lip region continuous with the body contour and bearing 5–7 fine striae, 22.0–24.5 µm long stylet, basal pharyngeal bulb offset or slightly overlapping intestine, post-anal sac extending 50–73 % of the tail region, and cylindrical or subclavate tail with a striated terminus. Differences of the new species from the closely related species T. astriatus, T. astriatoides, T. changlingensis and T. papyrus are discussed. Photomicrographs and several taxonomic notes on 13 other species of Telotylenchinae, collected from Iran, are provided. 


2022 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Vena Chupia ◽  
Jirapat Ninsuwon ◽  
Kakanang Piyarungsri ◽  
Chollada Sodarat ◽  
Worapat Prachasilchai ◽  
...  

Dermatophytosis is a disease caused by dermatophytes, a group of fungi that can cause disease both in humans and animals. The important genera that are pathogenic in animals include Trichophyton and Microsporum. Microsporum canis is an important species because it can cause zoonosis and is commonly found in domestic animals. Cats, which live very close to humans, may expose humans to this pathogen. This research focused on the epidemiology of M. canis found in cats. Hair samples were collected via the Mackenzie technique from cats with and without skin lesions, preliminarily examined with 10% KOH preparation, and cultured for fungal identification. Samples were confirmed with molecular techniques including polymerase chain reaction, gel electrophoresis, and sequencing. Samples were collected from 138 cats located in 93 households, 43 from cats with skin lesions (31.16%) and 95 from cats without skin lesions (68.84%). Eighteen cats with lesions (13.04%) and ten cats without lesions (7.2%) were found to carry M. canis. In eleven of the eighteen cats both with skin lesions and positive for M. canis (61.11%), the pathogen was found both at the site of the lesion and at other sites in the body. Because the pathogen can be found in the hair of cats with and without skin lesions, owners, keepers, veterinarians, and others who come into contact with these animals are at risk of infection if they are not aware or do not take precautions after contact with them.


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