Scanning Electron Microscopy of Third- and Fourth-Stage Larvae and Adults of Brugia pahangi (Nematoda: Filarioidea)

Aoki, Yoshiki; Vincent, Albert L.; Ash, Lawrence R.; Katamine, Daisuke

doi:10.2307/3280747

Cited by 11 publications

(5 citation statements)

References 15 publications

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“…Schacher (1962) demonstrated that in the cat the 4th moult of B. pahangi is not as highly synchronized as the 3rd moult and that male larvae moulted at about day 23 whereas females moulted between days 27 and 33. Fourth-stage larvae were also observed in the jird as late as days 33-34 (Aoki et al 1980). The 5th-stage immature worms observed in the present study could therefore have been male worms and their surface area should be compared to that of adult males rather than females.…”

Section: Discussionmentioning

confidence: 60%

“…Growth during the instar is achieved by expansion of the cuticular folds or annuli but the capacity of the larvae to grow from approximately 2 mm at day 5 to > 10 mm at day 25 is achieved at the 3rd moult when the larvae increases its surface area by approximately 800 %. Aoki et al (1980) observed that the growth of the vertebrate stages of B. pahangi involves a broadening of the cuticular annulations. Johnson, Van Grundy & Thompson (1970), Lee (1970), Bonner, Menefee & Etges (1970), Kozek (1971) described similar processes in the growth of other nematode species.…”

Section: Resultsmentioning

confidence: 99%

“…These workers described 'finely spaced annulation grooves' on the surface of the worms, which occurred at 025-075 fim intervals and were uniformly distributed over the entire body surface. A further scanning electron microscopic study of the development of surface features of B. pahangi from the 3rd stage t o the adult worm (Aoki, Vincent, Ash & Katamine, 1980) confirmed that all stages have closely spaced cuticular annulations over the entire surface, except a t the extremities. That study also demonstrated that the cuticular annulations in recently moulted worms were narrower than those seen late in the preceding stage, but widened as the worm grew.…”

Section: Introductionmentioning

confidence: 81%

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The moulting process and the phenomenon of intermoult growth in the filarial nematode Brugia pahangi

Howells

Blainey

1983

Parasitology

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The larvae of Brugia pahangi recovered from the jird have been shown to grow continuously between moults, their length increasing at least 5-fold during the 4th instar. This intermoult growth is achieved without an increase in the surface area of larvae. The cuticle of very early 4th and 5th-stage worms is highly folded and intermoult growth is accommodated by an expansion of surface annular folds. The major increases in the surface area of larvae occur only through ecdysis, with an 8-fold increase in the surface area being achieved at the 3rd moult. The growth curve of these worms is therefore sigmoidal but the surface area curve is stepped. The relationship between the cuticles of nematodes and insects is discussed.

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Section: Discussionmentioning

confidence: 60%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 81%

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The moulting process and the phenomenon of intermoult growth in the filarial nematode Brugia pahangi

Howells

Blainey

1983

Parasitology

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“…Limited growth and morphological changes were associated with the development of both species, and in O. lienalis the caudal appendages served as a useful marker for rapid identification of L4 larvae. Changes in caudal papillae after moulting arise in other species, such as Brugia pahangi (AOKI et al, 1980), but these are not a universal feature of fourth stage larvae as illustrated by Wuchereria bancrofti (FRANZ & ZIELKE, 1980) and O. volvulus (STROTE, 1985). Significant growth of larvae occurred within 3 days of implantation in chambers, but over subsequent weeks while some growth continued this was highly attenuated compared with worms of systemic infections.…”

Section: Discussionmentioning

confidence: 99%

Fate of developing larvae of Onchocerca lienalis and O.volvulus in micropore chambers implanted into laboratory hosts

1989

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Infective larvae of Onchocerca lienalis and O.volvulus implanted subcutaneously within micropore chambers into laboratory hosts moulted to the fourth stage (L4) and underwent limited development and growth. Similar recoveries of O. lienalis L4 larvae in the range of 33–66% were obtained from chambers implanted into CBA and BALB/c strains of mice, jirds, and the natural bovine host. A relatively constant proportion of larvae survived up to 24 days post implantation and thereafter recoveries declined, although some worms were still alive after 96 days. Recoveries of O. volvulus L4 larvae from chambers given to normal or T-cell deprived mice were equivalent to one another and to those obtained with O. lienalis. Moulting of O. lienalis in chambers was observed on days 3 and 5, in close accordance with the timing of the third moult in cattle following systemic infection. Moulting of O. volvulus occurred between days 3–6. Morphological changes in developing larvae included a small but significant increase in length, a transient increase in width, and early development of the spicular primordia and genital tube. L4 larvae of O. lienalis, but not those of O. volvulus, exhibited 3 distinct caudal papillae not present on infective larvae.

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“…The anterior end of male Onchocerca volvulus demonstrates sensory equipment comparable to that of infective 3rd and 4th juvenile stages of this parasite (Strote & Bonow, 1991. The pattern of 2 circles of 4 head papillae and the paired amphids (Franz, 1980) corresponds to that of other filarial nematodes (Shoho & Uni, 1977;Aoki et al 1980;Franz & Lenze, 1982;Holdsworth, 1987;Gutierrez-Perm, 1989;Storey & Ogbogu, 1991) and probably reflects part of the sensory demands for nematodes in their vertebrate hosts.…”

Section: Discussionmentioning

confidence: 95%

The ultrastructure of the anterior end of maleOnchocerca volvulus: papillae, amphids, nerve ring and first indication of an excretory system in the adult filarial worm

Strote

Bonow

Attah³

1996

Parasitology

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A detailed morphological investigation of the anterior sensory organs, the nerve ring and a glomerulus-like structure in male Onchocerca volvulus was performed by means of electron microscopy. The 8 head papillae are arranged in the common 4 + 4 pattern of most filarial worms in circles around the mouth opening. The amphidial openings are found between the circles of inner and outer papillae on both sides of the mouth. Inside, several additional nerve axons are seen in the tissue of the anterior tip not related to one of the identified papillar structures. The inner and outer papillae exhibit a remarkably different fine structure, and are part of a complex system of at least 2 different receptor cell types at the anterior tip of the worm. The amphidial channel contains 8 modified cilia; accessory axons are associated with the cytoplasm of the sheath cell. The anterior nerve ring of male worms is located about 150 micrometers posterior from the outermost tip of the head region. It consists of several fibres coiled around the oesophagus. The comparison of the fine structure of the central nervous system did not show the expected morphological differences associated with the heterogeneous age distribution in the natural worm population. This was in contrast to previous findings with respect to tissues in different parts of the worm. The study also provides the first evidence that suggests the existence of an excretory organ in a filarial worm in the region of the anterior nerve ring. Paired glomerulus-like structures in the lateral chords and a canal formed by a projection of the basal zone of the cuticles were identified.

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Scanning Electron Microscopy of Third- and Fourth-Stage Larvae and Adults of Brugia pahangi (Nematoda: Filarioidea)

Cited by 11 publications

References 15 publications

The moulting process and the phenomenon of intermoult growth in the filarial nematode Brugia pahangi

The moulting process and the phenomenon of intermoult growth in the filarial nematode Brugia pahangi

Fate of developing larvae of Onchocerca lienalis and O.volvulus in micropore chambers implanted into laboratory hosts

The ultrastructure of the anterior end of maleOnchocerca volvulus: papillae, amphids, nerve ring and first indication of an excretory system in the adult filarial worm

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