1
|
Ultrastructural evidence for the participation of muscle cells in the formation of extracellular matrices in aporocotylid blood flukes (Digenea). ZOOL ANZ 2021. [DOI: 10.1016/j.jcz.2021.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
2
|
Ultrastructure and Cytochemistry of the Mature Spermatozoon of Khawia Armeniaca (Cholodkovsky, 1915) (Caryophyllidea: Lytocestidae), a Parasite of Capoeta Capoeta Sevangi (De Filippi, 1865) (Teleostei, Cyprinidae). Helminthologia 2020; 57:353-360. [PMID: 33364904 PMCID: PMC7734663 DOI: 10.2478/helm-2020-0040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 07/09/2020] [Indexed: 11/20/2022] Open
Abstract
The mature spermatozoon of Khawia armeniaca, a monozoic caryophyllidean parasite of templar fish Capoeta capoeta sevangi (De Filippi, 1865) from the Lake Sevan, Armenia, has been studied using transmission electron microscopy and cytochemical technique of Thiéry (1967) for the first time. The mature spermatozoon of K. armeniaca consists of a single axoneme with the 9+'1' trepaxonematan structure, cortical microtubules and nucleus which are situated parallel to the longitudinal axis of the spermatozoon, and a moderately electrondense cytoplasm with glycogen particles. The cortical microtubules are arranged in one continuous semicircle beneath the plasma membrane in Region II and anterior part of Region III of the mature spermatozoon. The two opposite rows of cortical microtubules are observed in the remaining nuclear and at the beginning of the postnuclear part (Regions III, IV) of the male gamete The number of cortical microtubules is remarkably variable in the spermatozoa of various Khawia species. K. armeniaca exhibits the highest number of cortical microtubules in comparison with K. sinensis and K. rossittensis. Glycogen was detected in the cytoplasm of prenuclear (II), nuclear (III) and postnuclear (IV) regions with different ultrastructural organization of the mature spermatozoon of K. armeniaca. Variations of sperm ultrastructural characters within caryophyllideans and other cestodes are discussed.
Collapse
|
3
|
Spermiogenesis produces the spermatozoa with 9 + '1' and 9 + 0 axonemal pattern in progenetic cestode Diplocotyle olrikii Krabbe, 1874 (Spathebothriidea: Acrobothriidae). Parasitol Res 2020; 119:4103-4111. [PMID: 32869167 DOI: 10.1007/s00436-020-06862-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/23/2020] [Indexed: 11/30/2022]
Abstract
Spermiogenesis in the progenetic spathebothriidean cestode Diplocotyle olrikii has been examined using transmission electron microscopy (TEM) for the first time. Along with the typical features of spermatozoon cytodifferentiation (e.g., the electron-dense material in the apical region of the differentiation zone in the early stage of spermiogenesis, the intercentriolar body which is composed of three electron-dense plates and two electron-lucent zones, the orthogonal development of the two flagella, a flagellar rotation, proximo-distal fusion, the presence of two pairs of electron-dense attachment zones), new for the Eucestoda is detection of the formation of two types of free flagella during spermiogenesis in progenetic D. olrikii, exhibiting either standard 9 + '1' trepaxonematan pattern, or atypical 9 + 0 structure. Various combinations of these two types of flagella resulted in the production of three types of male gametes during spermiogenesis in this spathebothriidean cestode. The first type is represented with the two axonemes of the 9 + '1' structure; the second type exhibits two different axonemes, i.e., one with 9 + '1' and the other of 9 + 0 pattern; and the third type has two axonemes with atypical 9 + 0 structure. The occurrence of three sperm types in progenetic D. olrikii is associated with typical spermiogenesis and has never been described previously in the Platyhelminthes. We suppose that heteromorphism of male gametes in D. olrikii might be linked to progenesis, i.e., the programmed sexual maturation detected during the larval/developmental stage of an organism.
Collapse
|
4
|
Heteromorphism of sperm axonemes in a parasitic flatworm, progenetic Diplocotyle olrikii Krabbe, 1874 (Cestoda, Spathebothriidea). Parasitol Res 2019; 119:177-187. [DOI: 10.1007/s00436-019-06524-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/23/2019] [Indexed: 11/24/2022]
|
5
|
Are glial cells of the Digenea (Platyhelminthes) muscle cells? Parasitol Res 2019; 119:317-319. [PMID: 31782012 DOI: 10.1007/s00436-019-06490-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 09/25/2019] [Indexed: 10/25/2022]
Abstract
Muscle cells of a digenean fish blood fluke, Aporocotyle simplex, aggregate along the periphery of the cerebral ganglia. Solitary myocytons and sarcoplasmic processes with muscle fibres give rise to long, narrow lamellate projections, which are visible along the periphery and within ganglia. These ultrastructural observations suggest a switching of glial functions to muscle cells and represent additional evidence of the phylogenetic lability of glial cells in bilaterians.
Collapse
|
6
|
Ultrastructural characteristics of the male ducts and terminal genitalia of an endoparasitic monogenean, Calicotyle affinis Scott, 1911 (Monopisthocotylea: Monocotylidae), with the first detailed description of a copulatory stylet in a monogenean. Parasitol Res 2018; 117:1503-1512. [DOI: 10.1007/s00436-018-5831-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/06/2018] [Indexed: 11/29/2022]
|
7
|
Ultrastructural aspects of spermatogenesis, testes, and vas deferens in the parthenogenetic tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea), a carp parasite from Slovakia. Parasitol Res 2010; 108:61-8. [PMID: 20838810 DOI: 10.1007/s00436-010-2038-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 08/25/2010] [Indexed: 11/28/2022]
Abstract
Spermatogenesis, testes, and vas deferens in the parthenogenetic monozoic tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea) from Slovakia, parasitizing the carp Cyprinus carpio L., have been investigated by means of transmission electron microscopy for the first time. The present results show that helminths with parthenogenetic and normal reproduction may share some common spermatology features, e.g., dense cytoplasm of the peripherally localized spermatogonia or a rosette type of spermatogenesis. In contrast to tapeworms with normal reproduction, the most prominent ultrastructural characteristic of the spermatocytes of A. huronensis is fragmentation of their nuclei. This clear feature of cell degeneration might be a consequence of the aberrant first meiotic division. Peripheral cortical microtubules and a single centriole, indicators of the ongoing spermiogenesis, were observed only very rarely in the early spermatids. Characteristics of normal spermiogenesis, i.e., apical dense material in the zone of differentiation in early stages of spermiogenesis, flagellar rotation, and proximo-distal fusion, were never found in the present study. The testes follicles are surrounded by a thin cytoplasmic sheath underlined by a basal lamina. Vas deferens is lined by flat epithelium with numerous surface lamellae and cilia. Mature, functional spermatozoa were not observed in the vas deferens of A. huronensis from Slovakia.
Collapse
|
8
|
Spermatological characters of the spathebothriidean tapeworm Didymobothrium rudolphii (Monticelli, 1890). Parasitol Res 2010; 106:1435-42. [DOI: 10.1007/s00436-010-1822-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Accepted: 03/02/2010] [Indexed: 10/19/2022]
|
9
|
Unified terminology for cestode microtriches: a proposal from the International Workshops on Cestode Systematics in 2002-2008. Folia Parasitol (Praha) 2009; 56:199-230. [DOI: 10.14411/fp.2009.025] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
10
|
Ultrastructure of the early gravid uterus of Corallobothrium fimbriatum (Cestoda: Proteocephalidea). Parasitol Res 2009; 105:989-96. [PMID: 19468751 DOI: 10.1007/s00436-009-1487-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Accepted: 05/10/2009] [Indexed: 10/20/2022]
Abstract
The ultrastructure of the uterine epithelium and underlying extracellular matrices has been studied in several cyclophyllideans, but relatively little has been published on uterine fine structure in other cestode orders. To develop comparative data, we initiated a study focusing on a common and widespread genus of the order Proteocephalidea. Adult specimens of Corallobothrium fimbriatum were removed from the small intestine of brown bullhead catfish, Ameiurus nebulosus, from the St. Lawrence River in North America. Early gravid proglottids were examined by light microscopy as whole mounts or diced in buffered glutaraldehyde, processed by standard techniques and examined by as stained sections by light microscopy and by transmission electron microscopy. Voucher specimens were deposited in the Museum of Comparative Zoology at Harvard University. The uterus consisted of an epithelial wall supported basally by an extracellular matrix and parenchyma cells, which together formed epitheliomesenchymal villi at many points. The uterine epithelium consisted of a single thin syncytial layer, folded distally into long epithelial villi that protruded into the lumen at some points. The epithelium's numerous nuclei were very close to the lumen, but bulged along with the perinuclear cytoplasm proximally into the surrounding medullary parenchyma. Each nucleus contained small amounts of evenly dispersed heterochromatin and euchromatin, with a central nucleolus. Numerous mitochondria occurred in the cytoplasm, which was densely filled with free ribosomes but contained scant endomembrane components and showed little evidence of secretory activity. The uterine cells possessed few of the apical microvilli that are typical of some cyclophyllidean species, but the apical plasma membrane and cortical cytoplasm were extensively developed into long microlamellae similar to other species. The basic syncytial nature of the epithelium is similar to that of other cestodes studied previously, but the specific combination of features is unlike any previously described. Based on this one proteocephalidean species, we discerned no pattern that would distinguish between Proteocephalidea and Cyclophyllidea based on uterine structure.
Collapse
|
11
|
Ultrastructure of the cirrus sac of echinophallid tapeworms (Cestoda, Bothriocephalidea) and the terminology of cirrus hard structures. Int J Parasitol 2009; 39:381-90. [DOI: 10.1016/j.ijpara.2008.07.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Revised: 07/03/2008] [Accepted: 07/14/2008] [Indexed: 10/21/2022]
|
12
|
An immunocytochemical, histochemical and ultrastructural study of the nervous system of the tapeworm Cyathocephalus truncatus (Cestoda, Spathebothriidea). Parasitol Res 2008; 104:267-75. [DOI: 10.1007/s00436-008-1187-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 08/28/2008] [Indexed: 11/29/2022]
|
13
|
Sem and Tem Study of the Armed Male Terminal Genitalia of the Tapeworm Paraechinophallus japonicus (Cestoda: Bothriocephalidea). J Parasitol 2008; 94:803-10. [DOI: 10.1645/ge-1474.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Accepted: 01/09/2008] [Indexed: 11/10/2022] Open
|
14
|
A standardised terminology of the embryonic envelopes and associated developmental stages of tapeworms (Platyhelminthes: Cestoda). Folia Parasitol (Praha) 2008; 55:42-52. [PMID: 18578166 DOI: 10.14411/fp.2008.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Over the past 40 years, much has been published on the ultrastructure and cellular development of embryonic structures in a wide range of cestodes. However, the literature contains many discrepancies in both terminology and interpretations because of the facts that these organisms are phylogenetically diverse within their respective orders and families, the habitats that affect embryonic envelope structure are diverse, and the work has been done in various laboratories around the world. This review and synthesis was initiated by a working group of biologists from around the world convened at the Fifth International Workshop on Cestode Systematics and Phylogeny in Ceské Budejovice, at the Institute of Parasitology of the Biology Centre, Academy of Sciences of the Czech Republic. It brings together the data from published work and establishes a uniform terminology and interpretation based on the data as they are presented. A consensus was reached for standardised definitions of the oncosphere, hexacanth, coracidium, embryonic envelopes, outer envelope, inner envelope, embryophore, vitelline capsule, shell, and outer coat. All of these are defined as components of the embryo or its vitellocyte-derived or uterine-derived coatings.
Collapse
|
15
|
SPERMIOGENESIS AND SPERM ULTRASTRUCTURE OF CYATHOCEPHALUS TRUNCATUS (PALLAS, 1781) KESSLER, 1868 (CESTODA: SPATHEBOTHRIIDEA). J Parasitol 2006; 92:884-92. [PMID: 17152927 DOI: 10.1645/ge-718r1.1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Spermiogenesis and sperm ultrastructure of adult Cyathocephalus truncatus, a member of presumably basal group of "true" cestodes (Eucestoda), have been examined for the first time by using transmission electron microscopy. The process of sperm formation corresponds in basic pattern to that of the Pseudophyllidea. In addition, the 2 pairs of electron-dense attachment zones are present in median cytoplasmic process of C. truncatus. However, mature spermatozoa of C. truncatus differ significantly from those of the pseudophyllideans, especially in the morphology of the proximal and distal spermatozoon extremities. The proximal extremity of the mature spermatozoon lacks a crested body, which is present in more derived cestodes and some pseudophyllideans. The distal end of the mature spermatozoa exhibits different morphology in the gametes from testes and those from receptaculum seminis. New for the Eucestoda is a finding that a lateral cytoplasmic extension creates the distal end of the spermatozoa from testes, resembling sperm of some Monogenea and Digenea. In contrast, the distal extremity of the spermatozoa from receptaculum seminis contains only a nucleus. Despite the above-mentioned peculiarities, the ultrastructural data on sperm/spermiogenesis suggest close relationships of the Spathebothriidea and Pseudophyllidea.
Collapse
|
16
|
Fine structure of the female reproductive ducts of Cyathocephalus truncatus (Cestoda: Spathebothriidea), from salmonid fish. Folia Parasitol (Praha) 2006; 52:323-38. [PMID: 16405296 DOI: 10.14411/fp.2005.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
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.
Collapse
|
17
|
Abstract
Vitellogenesis in two spathebothriidean tapeworms, dixenous adult Cyathocephalus truncatus and monoxenous progenetic Diplocotyle olrikii, has been examined using transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for glycogen. Each vitelline follicle consists of vitellocytes at various stages of development and one irregularly shaped interstitial cell. Projections of the interstitial cell enclose the vitellocytes and extend as a cytoplasmic sheath on the follicular periphery. An outer thin fibrous layer (= extracellular lamina) covers the cytoplasmic sheath in C. truncatus, but lacks in D. olrikii. Maturing and mature vitellocytes contain vitelline material in the form of single small shell globules that gradually fuse and give rise to the large shell globule clusters. Morphology of shell globule clusters differs slightly in both species. In addition, single "lamellar" granules are present in the cytoplasm of vitellocytes of C. truncatus, but not in D. olrikii. Both electron lucent and electron dense lipid droplets are present in the vitellocytes of C. truncatus, whereas only electron dense lipids occur in D. olrikii. A single lipid droplet turns up occasionally in the nuclei of some of the vitellocytes of C. truncatus. The ultrastructural features of vitellogenesis in spathebothriideans resemble those reported previously in "lower" cestodes, especially in pseudophyllideans.
Collapse
|