ON PROPAGATION OF CORTICLA FACTOR AND CYTOPLASMIC FACTOR PARTICIPATING IN CLEAVAGE FURROW FORMATION OF THE NEWT'S EGG*

From Cynops pyrrhogaster eggs just after the start of the first cleavage, a fragment of cortical layer with a small entire cleavage furrow was cut out. In the fragment, the cortex had already acquired susceptibility to and the subcortical cytoplasm had already accquired inducibility for furrow formation. The fragment was transplanted to the animal hemisphere of uncleaved fertilized eggs or eggs immediately after the onset of the first cleavage, from which a portion of the host cortex was removed. Observation was made on division of the graft, and on propagation of the cortical susceptibility and the cytoplasmic inducibility of the graft onto the host egg. The transplant divided succesively on the host egg in many cases, but the furrow of the graft never advanced to the surface of the host egg. Neither the cortical factor nor the cytoplasmic factor was transmitted across the graft to the recipient egg.     

Ciliate Protozoa in the Rumen of Sassaby Antelope, Damaliscus lunatus lunatus, Including the Description of a New Species and Form

ABSTRACT. Composition of rumen ciliate fauna in five Zambian, sassaby antelopes was determined. Six genera, 18 species, and four forms were identified. One new species and form, belonging to the subfamily Diplodiniinae, were found, then labeled Ostracodinium damaliscus n. sp. and Diplodinium bubalidis f. aspinosum n. f., respectively. Only ophryoscolecid species were present while isotrichids were absent. Twelve of 18 total species are commmonly found in African antelopes. Three of those 12 species, Entodinium fyferi, Enoploplastron garstangi and Opisthotrichum janus , are only found in African antelopes. Percentage composition was low in the genera ml of rumen fluid, and the average number of ciliate species per host was 17.2.     

CHANGES OF THE MEMBRANE POTENTIAL AT THE TIME OF FERTILIZATION IN THE SEA URCHIN EGG WITH SPECIAL REFERENCE TO THE FERTILIZATION-WAVE

An experimental device was developed from the work of U ehara and S ugiyama (1969), in order to study the electrical phenomena accompanying the fertilization-wave in the sea urchin egg.
The change in membrane potential upon fertilization consists of 2 peaks (I to et al. , 1970), being preceded by a shoulder. The shoulder appears within the "latent period" (A llen and G riffin , 1958), and the 2 peaks correspond to the breakdown of the cortical granules and the formation of the fertilization membrane.
When the equatorial region of the egg surface was exposed to a detergent-sea water, the breakdown of the cortical granules and the formation of the fertilization membrane are induced only in this ring-shaped area. Sperm is then added to one of the polar regions. The fertilization-wave, starting from the point of sperm-entry, propagates across the detergent-treated region, and the membrane is formed on the whole egg surface. During such an experiment, changes of the membrane potential in the detergent-treated region were measured. 1 to 3 sudden transient depolarizations appear, followed by a delayed small depolarization. It is presumed that the initial depolarization corresponds to the fertilization-wave. The pattern of the potential change at normal fertilization may be explained by complexity of the cortical change, and the initial depolarizing shoulder is considered to correspond to the fertilization-wave, which is isolated by the above-mentioned device.     

INDUCTION OF CELLULAR PROCESSES CONTAINING COLLAGENASE AND RETINOID BY INTEGRIN-BINDING TO INTERSTITIAL COLLAGEN IN HEPATIC STELLATE CELL CULTURE

Cultered hepatic stellate cells were induced to elongate long, multipolar cellular processes by interstitial collagen gel used as a substratum, as compared to flattened or round cell shapes on polystyrene surface or on Matrigel containing the basement membrane components, respectively. The process induction was inhibited by several reagents as follows: (1) anti-integrin α2 antibody; (2) an oligopeptide, DGEA, an integrin-binding sequence in type I collagen molecule; (3) wortmannin, a phosphatidylinositol 3-kinase inhibitor. Protein tyrosine phosphorylation was enhanced throughout cells including cellular processes by culturing on type I collagen gel. Dual fluorescence staining showed that the core of the processes contained microtubules, whereas the periphery of the processes comprised fibrillar actin. Thus, the process extension was found to depend on integrin-binding to type I collagen fibres, followed by signal transduction and cytoskeleton assembly. The cellular processes included interstitial collagenase and vitamin A-containing lipid droplets. The lipid droplets and vitamin A-autofluorescence were increased by retinyl acetate addition to the culture medium, suggesting an important role of processes in hepatic stellate cell function.     

Scanning Electron Microscopy of the Adoral Ciliary Zone of Cycloposthium Bundle (Ciliophora,Entodiniomorphida)1

The adoral ciliary zone of Cycloposthium spp., inhabiting the large intestine of the horse, was studied by scanning electron microscopy. It could be divided into four parts: outer, inner, left, and right zones. The outer zone, extending on the anterior periphery of the apical cone of the body, had 20 tuft-like syncilia arranged radially around the longitudinal axis. Each ciliary tuft consisted of about 170 cilia, and in cross section it had a rectangular shape. The cilia of the inner zone, situated at the top of the apical cone, were aggregated irregularly to form shorter bundles than the tufts of the outer zone. The innermost cilia of this zone were shorter than the outermost. There was a distinct non-ciliated border between the outer and inner zones. A horseshoe-like operculum having no cilia was present at the center of the adoral ciliary zone, and the opening of the vestibulum was situated as a cleft crossing from the center to the right periphery of this zone. No cilia extended onto the vestibular wall. The left ciliary zone was situated beneath the outer zone and consisted of five short rows of barren kinetosomes of which only the central row possessed very short cilia. The right ciliary zone, consisting of a few rows of cilia situated at the bottom of the inner adoral lip, was also easily distinguished from the other ciliary zones. This zone was interpreted as an extension of the outer adoral zone passing along the right side of the apical cone. These ciliary zones were considered to be highly differentiated and useful for both movement of and ingestion of food.     

Ciliate Protozoa in the Rumen of Kafue Lechwe, Kobus leche kafuensis, in Zambia, with the Description of Four New Species

ABSTRACT The composition of the rumen ciliate fauna in 76 Kafue lechwe inhabiting a limited area in Zambia was surveyed and five genera containing 24 species with 16 formae belonging to the family Ophryoscolecidae were identified. Four new species belonging to Diplodiniinae were recognized and described as Diplodinium lochinvarense n. sp., Diplodinium leche n. sp., Diplodinium zambiense n. sp., and Metadinium ossiculi n. sp. In addition, Ostracodinium gracile form fissilaminatum Dogiel, 1932 was found for the second time and described as Metadinium fissilaminatum n. comb. The species composition was fairly unusual. Seven of the species have been found only in African wild antelopes and these species were found more frequently than cosmopolitan species. There was no evidence of isotrichid species. The average density of ciliates per 1 ml of the rumen fluid was 25.7 times 10⁴, and the number of ciliate species per head of host was 10.8.