Effects of cyclohexamide and hydroxyurea on mating behavior and its development in the free-living nematode Panagrellus silusiae (de Man 1913) Goodey, 1945

1972 ◽  
Vol 50 (3) ◽  
pp. 333-336 ◽  
Author(s):  
Ronald Cheng ◽  
M. R. Samoiloff
Keyword(s):  
Reproductive System ◽  
Sexual Attraction ◽  
Copulatory Behavior ◽  
Postembryonic Development ◽  
Free Living ◽  
Complete Development ◽  
Adult Females ◽  
Free Living Nematode ◽  
Attraction System ◽  
De Man

Females of the free-living dioecious nematode Panagrellus silusiae that have undergone postembryonic development in hydroxyurea do not attract males, and treated males do not respond to normal females. Nematodes placed in hydroxyurea as adults have normal gonads and retain the sexual attraction system. Hydroxyurea has no effect upon copulatory behavior of adult animals. Treatment of adult females with actidione stops production of attractant, although production resumes within 24 h after removal of the females from actidione. Actidione treatment of males has no effect upon the response to attractant by males or on copulation. It is proposed that sexual attraction depends on complete development of the reproductive system, but that copulation does not.

Nematode morphogenesis: fine structure of the cuticle of each stage of the nematode, Panagrellus silusiae (de Man 1913) Goodey 1945

1968 ◽  
Vol 46 (5) ◽  
pp. 1019-1022 ◽  
Author(s):  
M. R. Samoiloff ◽  
J. Pasternak
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Outer Region ◽  
Free Living ◽  
Larval Stages ◽  
Transparent Layer ◽  
Layer 2 ◽  
Free Living Nematode ◽  
Inner Region ◽  
De Man

The fine structure of the cuticle of each of the five stages of the free-living nematode Panagrellus silusiae (de Man 1913) Goodey 1945 has been examined. The cuticle plan is made up of a few regions: (1) an outer region (~350 Å) which consists of three layers: a thin outer layer, an electron transparent layer, and a thin but diffuse inner layer; (2) an inner region which has virtually no resolvable substructure other than a striated layer. This layer is not usually seen in the early stages of development but is readily apparent in the L4 and adult stages. The pattern of the cuticle is the same for each stage.The lateral fields—alae—reveal a definite differentiation during the life cycle; in the larval stages they are mere bulges but in the adults they take on a distinct four-lobed shape. The cuticle lining the pharynx consists of two regions, and there is never a striated band present nor does the cuticle increase in width during nematode growth.The interchordal hypodermis is devoid of endoplasmic reticulum, Golgi material, and mitochondria, but in some regions glycogen is found.

Nematode morphogenesis: fine structure of the molting cycles in Panagrellus silusiae (de Man 1913) Goodey 1945

1969 ◽  
Vol 47 (4) ◽  
pp. 639-643 ◽  
Author(s):  
M. R. Samoiloff ◽  
J. Pasternak
Keyword(s):  
Protein Synthesis ◽  
Fine Structure ◽  
Adult Female ◽  
Adult Male ◽  
Early Stage ◽  
Free Living ◽  
Microscopic Evidence ◽  
Molting Process ◽  
Free Living Nematode ◽  
De Man

The mode of formation of a new cuticle in the free-living nematode Panagrellus silusiae is similar at each of the three postpartum molts. Molting begins with the appearance of filaments adjacent to the hypodermis. The new cuticle accumulates material and lacks organization during the early stage of the molt. The edge of the new cuticle adjacent to the old cuticle is composed of an amorphous row of particles and a filamentous region abuts the hypodermis. Eventually, a complete cuticle is produced beneath the preexisting one.The shedding of the old cuticle varies in different molts. In the larval molts (L2 to L3 and L3 to L4) and the molt to the adult female the cuticle is discarded piecemeal. During the molt to the adult male the old cuticle splits and is shed as a single piece.Before completion of ecdysis in the final female molt, the new cuticle folds extensively. This folding does not occur during any other molt.Resorption of the old cuticle is never observed. There is no microscopic evidence of protein synthesis in the interchordal hypodermis during the molting process.

Sexual attraction in the free-living nematode Panagrellus silusiae (Cephalobidae)

1971 ◽  
Vol 49 (11) ◽  
pp. 1443-1448 ◽  
Author(s):  
Ronald Cheng ◽  
M. R. Samoiloff
Keyword(s):  
Sexual Attraction ◽  
Juvenile Stage ◽  
Free Living ◽  
Free Living Nematode ◽  
Water Borne

Female Panagrellus silusiae produce a substance that attracts males. Males do not produce attractant, nor is there homosexual attraction. The attractant is water borne and forms a gradient in agar. The attractant is first produced by females during the fourth juvenile stage and males first respond to the attractant during the fourth juvenile stage. Female Cephalobus persegnis also produce an attractant, but the attractants of each species only attract males of that species.

REDESCRIPTION OF HYPOASPISELLA SPICULIFER (BERLESE, 1918) COMB. N. (ACARI: MESOSTIGMATA: LAELAPIDAE) FROM SOUTH AFRICA

Acarina ◽  
2020 ◽  
Vol 28 (1) ◽  
pp. 55-64
Author(s):  
Omid Joharchi ◽  
Elizabeth Hugo-Coetzee ◽  
Sergey G. Ermilov ◽  
Alexander A. Khaustov
Keyword(s):  
South Africa ◽  
Soil Invertebrates ◽  
Current Concept ◽  
Free Living ◽  
Adult Females

Hypoaspisella spiculifer comb. n. is redescribed on the basis of adult females, collected from soil in South Africa. Hypoaspisella spiculifer fits well with the current concept of the genus Hypoaspisella Bernhard. The chelicerae of this species are similar to those of free-living mites, suggesting that it may be a predator of small soil invertebrates.

STUDIES ON STRONGYLOIDES OF PRIMATES: IV. EFFECT OF TEMPERATURE ON THE MORPHOLOGY OF THE FREE-LIVING STAGES OF STRONGYLOIDES FULLEBORNI

1958 ◽  
Vol 36 (4) ◽  
pp. 623-628 ◽  
Author(s):  
Premvati
Keyword(s):  
Morphological Changes ◽  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Free Living ◽  
Infective Larvae ◽  
Complete Development

The optimum temperature for the complete development of the free-living and the infective larvae of Strongyloides fülleborni is 25 °C. Morphological changes are seen at higher or lower temperatures.

scholarly journals Nematode Hsp90: highly conserved but functionally diverse

Parasitology ◽  
2014 ◽  
Vol 141 (9) ◽  
pp. 1203-1215 ◽  
Author(s):  
VICTORIA GILLAN ◽  
EILEEN DEVANEY
Keyword(s):  
Life Cycle ◽  
Heat Shock Protein 90 ◽  
Ecological Niches ◽  
Actual Number ◽  
Host Organism ◽  
Free Living ◽  
Parasitic Species ◽  
Free Living Nematode ◽  
Functionally Diverse

SUMMARYNematodes are amongst the most successful and abundant organisms on the planet with approximately 30 000 species described, although the actual number of species is estimated to be one million or more. Despite sharing a relatively simple and invariant body plan, there is considerable diversity within the phylum. Nematodes have evolved to colonize most ecological niches, and can be free-living or can parasitize plants or animals to the detriment of the host organism. In this review we consider the role of heat shock protein 90 (Hsp90) in the nematode life cycle. We describe studies on Hsp90 in the free-living nematode Caenorhabditis elegans and comparative work on the parasitic species Brugia pahangi, and consider whether a dependence upon Hsp90 can be exploited for the control of parasitic species.

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