DNA Throughout the Single Mitochondrion of a Kinetoplastid Flagellate: Observations on the Ultrastructure of Cryptobia vaginalis (Hesse, 1910)

SYNOPSIS. Cryptobia vaginalis (Hesse 1910) occurs as long thin and short broad forms in the vagina of the gnathobdelliform leeches Haemopis sanguisuga (Linnaeus) and Hirudo medicinalis Linnaeus. Cytochemical staining for DNA and transmission electron microscopy of sectioned material indicate that in the thin forms the kinetoplast DNA (kDNA) is dispersed irregularly through the mitochondrial network ( pankinetoplastic condition) rather than concentrated in the adbasal region of the mitochondrion ( eukinetoplastic condition) as in trypanosomatids and most other kinetoplastid flagellates. Light-microscopic studies on the rare broad forms, however, suggest that these have conventional adbasal location of the kinetoplast. Binary fission appears to occur in the thin forms, suggesting that the dispersed kinetoplast is either highly polyenergid or lacks a genetic function. In other features of its microanatomy, C. vaginalis is a conventional kinetoplastid. The flagellate has an incomplete corset of pellicular microtubules which may have a role in the cortical contractility characteristic of the genus Cryptobia . Feeding is by pinocytosis of vaginal colloids through a microtubule-lined cytopharynx, possibly after binding to a prominent filament-coated preoral ridge. A pulsatile (contractile) vacuole is present and appears to be responsible for defecation as well as osmoregulation. Some individuals have elongate bacterial epibionts attached to the body in parallel with the cortical microtubules. All individuals have 2–8 spheroplast-like endobiotic bacteria in the prenuclear cytoplasm.     

Revision of the Genus Askenasia Blochmann, 1895, with Proposal of Two New Species, and Description of Rhabdoaskenasia minima N. G., N. Sp. (Ciliophora, Cyclotrichida)

ABSTRACT. The planktonic ciliate genus Askenasia Blochmann, 1895 is reviewed and the new genus Rhabdoaskenasia n. gen. is established. Askenasia is characterized by three circumferential kinety belts and a circumoral wreath of paired argyrophilic granules without recognizable cilia and nematodesmata. A "brush" is absent. Askenasia apparently lacks the key characters of the Haptorida and is thus transferred to the Cyclotrichida, family Mesodiniidae. Rhabdoaskenasia differs from Askenasia in having single files of basal bodies in all kinety belts and club-shaped extrusomes. It possesses a circumoral kinety composed of dikinetids from which nematodesmata originate, forming a distinct rhabdos. Although very similar to Askenasia in its general appearance, R. minima n. sp. could belong to another order. Based on an extensive review of the literature and on silver impregnated specimens the following Askenasia species are recognized and described in detail: A. volvox (Eichwald, 1852) Kahl, 1930, A. stellaris (Leegaard, 1920) Kahl, 1930, A. acrostomia n. sp., and A. chlorelligera n. sp. Askenasia faurei Kahl, 1930 and A. humilis Gajewskaja, 1928 are transferred to the genus Cyclotrichium: C. faurei (Kahl, 1930) n. comb., C. humilis (Gajewskaja, 1928) n. comb. The systematic position of the genus Askenasia is discussed and keys to the genera of the Mesodiniidae and to the species of Askenasia are provided.     

Pollen morphology of the Dimorphandra group (Leguminosae,Caesalpinioideae)

The Dimorphandra group, as traditionally circumscribed, is a rather diverse assemblage of genera in Leguminosae subfamily Caesalpinioideae that share certain morphological characteristics with the basally branching lineages of subfamily Mimosoideae. It currently comprises 51 species in seven genera: Burkea (1 species), Dimorphandra (26 species), Erythrophleum (10 species), Mora (6 species), Pachyelasma (1 species), Stachyothyrsus (2 species) and Sympetalandra (5 species). This study investigates the pollen morphology of 25 samples from 19 species of all seven genera. Pollen of the Dimorphandra group is small, isopolar, trizonocolporate and released in monads. Apertures are almost equal to polar length, with correspondingly small apocolpial areas. The shape of the aperture apices varies from acute to wide and rounded. Surface ornamentation is psilate, perforate, microreticulate, or perforate‐rugulate. The wall structure is usually columellate with a well developed foot layer. The pollen is small and unspecialised, agreeing with a previously noted pattern of more fixed and homogenous pollen structure in the more derived clades in subfamily Caesalpinioideae, compared with the great diversity of pollen types found in the basally branching lineages.     

Light and Electron Microscopic Observations on Encystment of Acanthamoeba palestinensis, Reich

SYNOPSIS. The ultrastructural changes occurring during encystment of Acanthamoeba palestinensis have been investigated. The cyst wall consists of endocyst and exocyst, both having the same fine structure. At irregular intervals in the cyst wall ostioles occupied by opercula are present. The nuclear membrane forms bulb-shaped projections and releases vesicles bounded by double membranes into the cytoplasm. Dense nucleolus-like bodies of different sizes and variable numbers are found in the nucleus of every cyst. The importance of the cyst structure as a taxonomic criterion is discussed.     

PALMELLOPSIS MURALIS SP. NOV. (CHLOROPHYCEAE,TETRASPORALES, PALMELLACEAE)1

A new member of the chlorophycean, tetrasporalean genus Palmellopsis Korschikov (1953), Palmellopsis muralis Bold and King, is described from limestone in Austin, Texas, U.S.A. Certain details of ultrastructural organization are included.     

Absence of non-target effects of two Bacillus thuringiensis coleopteran active δ-endotoxins on the bulb mite, Rhizoglypus robini (Claparède) (Acari, Acaridae)

Transgenic crops with plant‐incorporated protectants are often more specific than synthetic insecticides and have the potential to reduce impacts on non‐target organisms. In this study we assessed the impact of Cry3Aa and Cry3Bb1 coleopteran‐active δ‐endotoxins on the bulb mite, Rhizoglypus robini. The effect of Cry3Aa prototoxin in solutions of the biopesticide Novodor^® on mite survival was assessed in laboratory studies. Survival of R. robini exposed to Cry3Aa in a short‐term contact and ingestion experiment was not affected, although R. robini was significantly affected by the insecticide Fipronil^® used as a positive control. Similarly, R. robini exposed in a longer duration feeding trial to the Cry3Aa toxin in artificial diet were also not significantly affected. When Cry3Aa was tested on the positive control insect, Leptinotarsa decemlineata, reduced weight of larvae and increased mortality was recorded. The effect of Cry3Bb1 toxin in transgenic corn tissues on R. robini food choice was assessed in a laboratory study. In no‐choice tests a greater proportion of R. robini were found on garlic roots than on Cry3Bb1 transgenic corn and a near‐isogenic non‐transgenic corn. In a choice test, more R. robini was recovered on garlic roots than on either corn variety, and on Cry3Bb1 corn than on non‐transgenic corn. In large field plots using specific mite traps across the growing season, R. robini mite populations were not significantly different between Cry3Bb1 corn and non‐transgenic corn alone or non‐transgenic corn treated with different combinations of two insecticides. Our results, combined with results from other studies, suggest that transgenic plants expressing the Cry3Aa or Cry3Bb1 Bacillus thuringiensis toxins are likely to have negligible impact on R. robini mite populations.     

THE CONTRACTILE VACUOLE AS AN ENDOCYTIC ORGANELLE OF THE CHLAMYDOMONAD FLAGELLATE GLOEOMONAS KUPFFERI (VOLVOCALES,CHLOROPHYTA)1

The endomembrane system of the chlamydomonad flagellate, Gloeomonas kupfferi Skuja, consists of a complex network of endoplasmic reticulum, Golgi bodies, and various vacuoles. One of the more distinct vacuolar components is the contractile vacuole (CV) complex, which consists of two anterior contractile vacuoles that expand/contract approximately every 30 s. In this study, experimental cytochemical labeling was performed to help elucidate possible endocytic/membrane recycling mechanisms in Gloeomonas and the possible role of the contractile vacuole in this process. When incubated with 0.5 mg · mL^?1 cationic ferritin for short periods of time (2–60 min), labeling follows this route: inner membrane of CV, globular deposits in the CV and associated vesicles, and ultimately the terminal trans face cisternae of the Golgi apparatus (GA). Similar incubations with Lucifer yellow and concanavalin A—gold conjugates support distinct uptake of exogenous ligands by the CV and associated vesicles. Our results suggest that the contractile vacuole may be a site of endocytosis and that the trans GA loci may be a key site of membrane recycling.     

Eurycea bislineata (Green), the Two-Lined Salamander, a New Host of Myxidium serotinum Kudo & Sprague, 1940 (Myxosporida, Myxidiidae)

SYNOPSIS. Myxidium serotinum was found in 51 of 58 (87.9%) specimens of the two-lined salamander, Eurycea bislineata , from West Virginia. This constitutes a new host record. No specimens of the order Salientia, or other species of the order Caudata were infected. Eurycea bislineata appears to be the normal host of M. serotinum , which is specific for the gallbladder in a variety of amphibian hosts. Apparently, larval E. bislineata becomes infected with M. serotinum , and the parasite does not become a mature trophozoite until after the tadpoles metamorphose to the adult salamander. Certain host hormonal factors may be important to the maturation of M. serotinum.     

Description de Quelques Espèces de Ciliés Hyménostomes des Genres Sathrophilus Corliss, 1960, Cyclidium O. F. Müller, 1786, Histiobalantium Stokes, 1886

RESUME. Les structures buccales de Sathrophilus vernalis Dragesco & Grolière, 1969 sont détaillées. La morphogenèse buccale de l'opisthe, semi-autonome, avec participation du scuticus et d'une cinétie postorale droite, s'accompagne d'une re-constitution de l'appareil buccal du proter. La morphologie buccale de Cyclidium sphagnetorum Šràmek-Hušek, 1949 est comparée à celles de Cyclidium citrullus Cohn, 1865 et Cyclidium glaucoma O. F. Müller, 1786. La stomatogenèse Histiobalantium majus Kahl, 1933 débute par une prolifération du scuticus vers la gauche.
SYNOPSIS. Buccal structures of Sathrophilus vernalis Dragesco & Grolière, 1969 are described. The semiautonomous buccal morphogenesis of the opisthe, involving the participation of the scuticus and the right postoral kinety, is accompanied by the reconstitution of the buccal apparatus of the proter. The buccal structure of Cyclidium sphagnetorum Šràmek-Hušek, 1949 is compared to those of Cyclidium citrullus Cohn, 1865 and Cyclidium glaucoma O. F. Müller, 1786. Stomatogenesis of Histiobalantidium majus Kahl, 1933 starts with a proliferation of the scuticus towards the left.     

Ultrastructure de Quelques Stades de la Microsporidie Octosporea muscaedomesticae Flu, Parasite de Ceratitis capitata (Wiedemann) (Diptère, Trypetidae)

La présence de diplocaryons à tous les stades de la sporulation d'Octosporea muscaedomesticae Flu, 1911 est mise en évidence ainsi qu'une membrane pansporoblastique autour des sporoblastes en développement et des spores. Le problème présenté par ces 2 faits est discuté. Une évolution étrange des ribosomes périnucléaires et démontrée. Une telle étude ultrastructurale est nécessaire et intéressante car O. muscaedomesticae est l'espèce-type du genre Octosporea.     

Observations on a Rare Ciliate, Discomorphella pectinata (Levander, 1894) Corliss, 1960

ABSTRACT. Specimens of the rare ciliate Discomorphella pectinata (Levander, 1894) Corliss, 1960 were impregnated with silver nitrate in 1963. The body is discoid, about 60 μ m long, laterally compressed and adorned with long spines. The somatic kineties on the right and left sides are sparse, sometimes disorganized, and locally without cilia. The oral zone has a complex infraciliature that lies above two series of ventral kineties and below a large, visor-like, epistomial fringe. The arrangement of this fringe is similar to that observed in some other heterotichous ciliates, notably members of the Metopidae and Caenomorphidae.     

Silk formation mechanisms in the larval salivary glands of<Emphasis Type="Italic">Apis mellifera</Emphasis> (Hymenoptera: Apidae)

The mechanism of silk formation inApis mellifera salivary glands, during the 5th instar, was studied. Larval salivary glands were dissected and prepared for light and polarized light microscopy, as well as for scanning and transmission electron microscopy. The results showed that silk formation starts at the middle of the 5th instar and finishes at the end of the same instar. This process begins in the distal secretory portion of the gland, going towards the proximal secretory portion; and from the periphery to the center of the gland lumen. The silk proteins are released from the secretory cells as a homogeneous substance that polymerizes in the lumen to form compact birefringent tactoids. Secondly, the water absorption from the lumen secretion, carried out by secretory and duct cells, promotes aggregation of the tactoids that form a spiral-shape filament with a zigzag pattern. This pattern is also the results of the silk compression in the gland lumen and represents a high concentration of macromolecularly well-oriented silk proteins.     

Redescription of Antetintinnidium mucicola (Claparède and Lachmann, 1858) nov. gen., nov. comb. (Alveolata,Ciliophora, Tintinnina)

Tintinnid ciliates have traditionally been described and classified exclusively based on their lorica features. Although information on the cell characters is urgently needed for a natural classification, more molecular than cytological data has been accumulated over recent years. Apparently, the tintinnids developed in the marine environment and entered freshwater several times independently. Typical freshwater tintinnids belong to the genera Tintinnidium and Membranicola. The species are comparatively well‐known regarding their morphology and characterised by two unusual de novo originating ciliary rows, the ventral organelles. In contrast, the cell features in the marine/brackish Tintinnidium species, specifically their somatic ciliary patterns, are insufficiently known or not known at all. Therefore, the morphology of a common marine/brackish representative, Tintinnidium mucicola, is redescribed based on live observation and protargol‐stained material. Furthermore, biogeographical and autecological data of the species are compiled from literature and own records. The phylogenetic relationships of T. mucicola are inferred and the diversity of the family Tintinnidiidae is assessed from 18S rDNA sequences. The study shows that T. mucicola is not only molecularly distinct, but also characterised by many plesiomorphic features, for instance, it does not possess a verifiable homologue to the ventral organelles. Hence, a new genus, Antetintinnidium nov. gen., is established for T. mucicola. The new insights into the diversity of Tintinnidiidae shed light on the early evolution of tintinnids and might provide clues on their adaptions to freshwater.     

Ultrastructure of Prorodon (Ciliophora, Prostomatida) I. Somatic Cortex and Some Implications Concerning Kinetid Evolution In Prostomatid and Colpodid Ciliates

ABSTRACT. This study describes the ultrastructure of the somatic cortex of Prorodon aklitolophon and Prorodon teres. the meridionally arranged somatic kineties of both species can be separated into two parts: a short anterior part, which consists of a few somatic dikinetids (in which both kinetosomes are ciliated), and a longer posterior consisting of monokinetids. the somatic monokinetids are associated with a convergent postciliary microtubular ribbon, a transverse microtubular ribbon flatly inserted in front of the kinetosome, a short and steeply extending kinetodesmal fibre attached to kinetosomal triplet 5 and 7, and a desmose anterior to triplet 3. From this desmose, two to five prekinetosomal microtubules originate and extend anteriorly. the posterior kinetosome of the somatic dikinetids is associated with the same microfibrillar and microtubular structures as the somatic monokinetid, except that no prekinetosomal microtubules originate from the desmose. the anterior kinetosome has a single postciliary microtubule and a tangentially oriented transverse microtubular ribbon. the permanent collecting canals of the unique contractile vacuole system extend parallel and adjacent to the somatic kinetics of Prorodon . the collecting canals are supported by the prekinetosomal microtubules. A similarly organized contractile vacuole system is not yet known from any other ciliate group. One of the most surprising results of this investigation was finding a significant similarity between the somatic dikinetid pattern of Prorodon and the colpodid dikinetid pattern. A hypothesis is presented to illustrate the evolution of the somatic kinetid patterns in colpodid and prostomatid ciliates.     

Life Cycle of Eimeria ferrisi Levine & Ivens, 1965 in the Mouse, Mus musculus

SYNOPSIS. The life cycle of Eimeria ferrisi is described from experimentally infected Mus musculus. The prepatent period was 3 days and the patent period was 3–4 days. The endogenous stages were found only in the cecum and colon. Three generations of schizonts were found. Mature 1st-generation schizonts first seen 24 hr postinoculation (PI) measured 10.9 (7–14) × 10.2 (6–13) μm and had 9.6 (7–14) merozoites. Some 2nd-generation schizonts had uninucleate merozoites and others had multinucleate merozoites. The former were first seen in small numbers 36 hr PI and were most abundant 48 hr PI. They measured 9.6 (5–13) × 7.9 (6–12) μm and had 18 (6–25) merozoites. Schizonts with multinucleate merozoites were seen 72 hr PI. Mature 3rd-generation schizonts were seen 72 hr PI. They measured 14.0 (12–18) × 11-0 (9–13) μm and had 12.5 (5–16) merozoites. Macrogamonts were first seen in 72 hr sections. Each young macrogamont had a large nucleus with a prominent nucleolus. Only one type of cytoplasmic granule appeared to be involved in the formation of the oocyst wall. Mature macrogamonts were 11.0 (5–14) × 10.0 (6–13) μm. Crescent-shaped bodies were observed in the parasitophorous vacuole of trophozoites and young macrogamonts. Early microgamonts were first recognized at 96 hr by the presence of darkly stained and irregularly shaped nuclei. Usually, mature microgametes were arranged in long, narrow whorls at the periphery of the microgamont or in whorls at the surface of 2–5 compartments.     

Structure of the Cuticle of Metadasynemoides cristatus (Chromadorida: Ceramonematidae)

Structure of the cuticle of Metadasynemoides cristatus (Chromadorida: Ceramonematidae) is examined by light, scanning, and transmission electron microscopy. The nematode has more than 600 annuli, and each annulus has eight cuticular plates. Eight longitudinal ridges, beginning on the cephalic capsule, extend the whole length of the body. Where a ridge traverses an annulus, it forms a complicated articulating structure of overlapping vanes. Within the electron-dense cortical layer, from which the cuticular plates are formed, there are spaces crossed by fine fibrillae, forming what have been termed "vacuoles" by light microscopists. There is an epicuticle and a continuous lucent basal layer. There appears to be no median layer. The cuticle lining of the esophagus and that forming the circum-oral ridge is of much simpler construction.