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Journal of Parasitic Diseases: June 2006, Vol. 30, No. 1, 68–75J P DUltrastructure, differential density and distributionpattern of polymorphic microtriches in tegument ofStilesia globipunctata infecting Ovis aries (sheep)C. Venkatesh, K. Ramalingam and V. VijayalakshmiP.G. and Research Department of Zoology, Govt. Arts College, Chennai.ABSTRACT. Scanning electron and transmission electron microscopic study of tegument ofStilesia globipunctata revealed a complex pattern of microtrichial brush border. They show a widerange of morphological variations. S. globipunctata shows species specific pattern of papilliform,filiform, spiniform and blade-like microtriches. The scolex shows the presence of papilla-like,spine-like and blade-like microtriches. The immature proglottid region is densely covered byposteriorly directed filiform, spiniform and papilliform microtriches. In mature proglottid region,papilla-like and filament-like microtriches are predominantly seen. The microtriches appear to benon-uniform in density and size. In gravid segments, there is obviously an increasing degree ofdisorder in the arrangement of microtriches. It increases the absorptive surface. It helps to resistthe peristaltic movement of intestine and maintains the parasite in position. Its absence in thegravid region is due to the morphological changes in the tegument and the interaction of luminalenvironment.Keywords: density, distribution, microtriches, polymorphism, Stilesia globipunctataINTRODUCTIONThe external surface organization of the cestodeparasite not only confers protection to the parasite, butalso functions as a metabolically active tissue takingup nutrients from the luminal environment and as anoutlet for elimination of its extracellular secretionsand the excretion phenomenon. It has been noticedthat in cestodes, the basic structure may be comparedwith a gut turned inside out, with the external bodycovering serving the absorptive functions normallyassociated with the intestinal mucosa (Smyth andMcManus, 1989).Corresponding author: Dr. V. Vijaylakshmi, P. G. and ResearchDepartment of Zoology, Govt. Arts college, Men (Autonomous),Nandanam, Chennai - 600 035, Tamil Nadu, India.Ultrastructural studies have shown that the externalbody covering of the adult tapeworm consists of anaked cytoplasmic layer. There is no resistant cuticle.This outer layer is a syncytium with no partitions ofcell walls. It is referred to as a tegument distinguishingit from non-living cuticles of the type that occur innematode species. Before discussing the functionalmorphology of the tegument, it is essential to havesome understanding of the structural properties ofabsorptive surfaces in general. The structure,physiology and biochemistry of the tegument are,therefore, of fundamental importance inunderstanding cestode physiology as a whole.In cestodes, the tegument grows, not by cell division,but by recruitment. Cells form the parenchyma comeup and attach to the tegument and vesicles pass up intothe tegument. However, the amplification of the
Ultrastructure of microtriches in Stilesia globipunctata69surface is achieved by the presence of delicate a. Immature proglottides containing scolex andcytoplasmic extensions called microtriches, anterior region.reminiscent of mucosal cell microvilli. Themicrotriches on the tapeworm surface increase theb. Mature proglottides with functionalsurface area of the parasite by about 20-times. Thereproductive organs.most dominant feature of the cestode tegument is thecovering by microtriches, which are thought to bec. Gravid proglottides containing eggs.responsible for nutrition and protection and possibly Scanning electron microscopic study : The scanningalso the mechanical functions of anchoring and electron microscopic (SEM) studies of the soclex,traction. They show a wide renge of morphlogical immature, mature and gravid proglottides of S.variations.globipunctata were undertaken to understand itsultrastructure. For this purpose, the specimens wereMicrotriches are unique in the cestodes and are dissected in chilled glutaraldehyde (2.5%) and fixedevident on the tegument and other epithelia that open for 16 h at 4° C. The tissues were subsequently washedinto the tegument. Microtriches have been widely thrice at an interval of 15 min each in phosphate bufferrepeated among all major orders of Eucestoda. These at pH 7.0 and then dehydrated by passing through anare present on the scolices and strobila of ascending series of alcohol from 30 to 100% an h inrepresentatives of most groups that have been each concentration. They were ultimately kept inexamined with SEM. Papilliform, spiniform and 100% alcohol overnight. Following dehydration, thefiliform structures have been variously reported tissues were air-dried in a desiccator for 7 to 10 days.among the Pseudophyllidea (Anderson, 1975, The dried samples were mounted on an aluminiumGranath et al., 1983) Cyclophyllidea (Berger and stub and gold sputtered in vacuum for 10 min, using anMettrick, 1971; Ubelaker et al., 1973; Sampathkumar, Eiko IB-2 ion coater. The samples were observed2001; Vijayalakshmi, 2001; Radha, 2003). eventually on a Hitachi, S-415A scanning electronIn the present study the characterization ofmicroscope, scanned at 25 KV and micrographed atmicrotrichial structure, density, distribution and theirdifferent magnifications (Hayat, 1977).functional significance in S. globipunctata has been Transmission electron microscopic study: Theattempted as the species of cestode has so far not been scolex, mature and gravid proglottid regions of S.exclusively studied due to its inconspicuousness in the globipunctata for transmission electron microscopygut of sheep.(TEM) were immersed in 2.5% glutaraldehyde inMATERIALS AND METHODSMillong's phosphate buffer (pH 7.3, 380 mOsm/L),where they were diced into small pieces. After 3-4hCollection of tapeworms: The tapeworm S. fixation at room temperature, the tissue was rinsed inglobipunctata (Rivolta, 1874) were collected from the Millong's buffer. The tissue was then post-fixed in 1%intestine of naturally infacted sheep autopsied in the osmium tetroxide in Millong's buffer for 1.5 h, rinsedslaughterhouse at Perambur, Chennai. The sheep quickly in distilled weter, dehydrated in an ethanolintestines were transported to the laboratory within series, infiltrated with propylene oxide, embedded inhalf an hour of collection. In the laboratory, each Spurr's low-viscosity epoxy resin and polymerized atintestine was carefully dissected and the tapeworms 60° C. Thin sections were cut at 70-90 nm with awere collected. Then the worms were washed in diamond knife, mounted on uncoated copper grids,distilled water to render them free from intestinal stained with uranyl acetate/ethanol and aqueous leadcontents and rinsed quickly 3-4 times in normal saline. citrate, and examined under a Philips 204 TEM at anThe tapeworms were then observed through aaccelerating voltage of 40 or 60 kV (Conn, 1993).compound microscope to confirm their taxonomic RESULTScharacters. The entire worm was spread out on a boardand the length was measured.The immature, matureSEM observations: Specimens of S. globipunctataand gravid proglottid region of the worm was locatedwere found to have species-specific patterns ofand separated as follows and dried on moist blottingpapilliform, filiform, spiniform and blade-likepaper and used for scanning and transmission electronmicrotriches that are restricted to particular regions ofmicroscopic studies.scolex and strobila. The central to peripheral regionsof the scolex are covered with papilliform and filiform
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TISSN: 0971-7196Journal ofVolume 30
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Editor's Note3this policy may not b
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Haemonchus histochemistry, biochemi
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Haemonchus histochemistry, biochemi
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12 Soodconcentration (Kocher et al.
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14 SoodKapur J and Sood ML. 1984b.
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Journal of Parasitic Diseases: June
Page 24 and 25: 18 Banyal and Elangbamin vitro. The
Page 26 and 27: 20 Banyal and Elangbamparasite in t
Page 28 and 29: 22 Banyal and Elangbamand presence
Page 30 and 31: 24 Banyal and ElangbamTable I: Mala
Page 32 and 33: 26 Banyal and Elangbamantibodies in
Page 34 and 35: 28 Banyal and ElangbamSchneider J,
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Page 38 and 39: 32 Lahiri and Bhattacharyasurfaces
Page 40 and 41: 34 Lahiri and Bhattacharya9+2 micro
Page 42 and 43: 36 Lahiri and BhattacharyaKillick-K
Page 44 and 45: 38Edward and Bernardtopographical f
Page 46 and 47: 40Edward and Bernardfour villages b
Page 48 and 49: 42Sangwan and Sangwanvaccinated aga
Page 50 and 51: 44Sangwan and Sangwanpathogenic mec
Page 52 and 53: 46Ravindran and WilliamsMATERIALS A
Page 54 and 55: 48Ravindran and WilliamsTable I. Mo
Page 56 and 57: 50Ravindran and WilliamsTable IV. D
Page 58 and 59: 52Ravindran and WilliamsACKNOWLEDGE
Page 60 and 61: 54 Jamali et al.(vaginal discharge,
Page 62 and 63: 56Jamali et al.1 2 3 4 5 6 7 8 9 10
Page 66 and 67: 60 Gupta et al.therefore, the prese
Page 68 and 69: 62 Gupta et al.Table II: Dimorphic
Page 72 and 73: 66 Jayraw and RaoteTable I. Effect
Page 76 and 77: 70 Venkatesh, Ramalingam and Vijayl
Page 84 and 85: 78 Ghosh and GayenDescription of th
Page 86 and 87: 80 Ghosh and Gayen30 µm30 µmCBCBC
Page 88 and 89: 82Manjula and Janardananmicrometres
Page 90 and 91: 84Manjula and JanardananMiracidiumF
Page 92 and 93: 86 Hirani et al.haemoglobin concent
Page 94 and 95: 88Hirani et al.ACKNOWLEDGEMENTSJosh
Page 96 and 97: 90 Gupta and SinghOvary rounded, en
Page 102 and 103: 96 Rajendran and DubeOptiMAL and IC
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