ALBERT

Notes: SYNOPSIS. Microstome →macrostome transformation in Tetrahymena vorax was induced by suspending microstomes in a transforming principle, stomatin, released by a potential prey, T. pyriformis. It was found that 70–90% of the microstomes formed macrostomes within 7 hours following suspension in this transforming principle. Macrostome formation occurred by the process of oral replacement. This process involved resorption of the microstome oral apparatus and its replacement with a larger (macrostome) one, which arose from an anarchic field that formed behind the resorbing oral area. Ninety-five percent of those microstomes which were destined to form macrostomes were in some stage of oral replacement 195 minutes after their suspension in stomatin. Several commercially produced products were tested over a wide range of concentrations to determine their ability to act as an inducer of macrostomes. Only 2, Trypticase and Bactocasitone, had any activity, and it was too small to be considered really effective. An attempt was also made to destroy the activity of stomatin by using enzymes. RNAse was effective but only in very high concentrations, so it was suggested that this activity might be related to the destruction of RNA within the transforming cell and not related to hydrolysis of stomatin. None of the other enzymes tested had any effect in reducing the activity of stomatin.

Notes: SYNOPSIS. A developmental sequence is proposed for the haplosporidan Minchinia nelsoni Haskin, Stauber and Mackin, 1966, based on study of oyster infections over the past 5 years in Chesapeake Bay. Uninucleate stages develop by nuclear division into multinucleate plasmodia which proliferate in the tissues by plasmotomy. Relatively small plasmodia containing what are considered to be gametic nuclei originate by unequal plasmotomy of large plasmodia. These have been interpreted to aggregate and fuse to form large plasmodia which contain prozygotes. Pairing and fusion of nuclei occur within each plasmodium to produce zygote nuclei (synkaryons) which undergo division, possibly meiotic, to form sporonts. Sporoblasts differentiate into spores with the development of spore walls and opercula. Cystoid plasmodia develop during times of unfavorable conditions. An anomalous but common sequence involving sexuality and mitosis is described, and the occurrence of various life cycle stages within the host thruout the year is discussed.

Notes: SYNOPSIS. Many of the sub-pellicular and infraciliary structures in protozoa have proved difficult to study with standard thin-sectioning technics. When these structures are viewed in isolated and fragmented form, many of the thin-sectioning difficulties are circumvented. Langmuir-trough isolation followed by critical-point drying, as well as thin sectioning, were used in this study to determine the patterns of sub-pellicular microtubules and fibrils interconnecting kinetosomes of membranelles and cirri of Euplotes eurystomus. The fibrillar network in the bases of these ciliary organelles is presented in some detail and apparent variations in pattern are noted. Functional aspects of some of the structures are discussed. With special preparation nearly whole Euplotes may be obtained for study in the electron microscope. Fused cilia were frequently obtained and their ultrastructure was studied.

Notes: SYNOPSIS. A technic is described for the quantitative assay of paramylum content of euglenoid flagellates. The method relies on the alkaline solubility of paramylum followed by treatment with the anthrone reagent. The intensity of the color developed by paramylum is about 14% greater than that developed by an equivalent amount of glucose. The method is sensitive down to about 10 μg.

Notes: SYNOPSIS. The development of three 8-liter and four 12-liter cultures of the photosynthetic dinoflagellate Gonyaulax monilata was followed for 4 months. Weekly estimates were made of population levels of this chain-forming flagellate, along with incidence of cells in chains and toxicity to fish. Guppies (Lebistes reticulatus) were used to assay toxicity. Populations reached a peak when cultures were 3–5 weeks old, declined during weeks 6–10, and tended to stabilize thereafter thru the 17th (final week). The percentage of cells in chains was related to the slope of the population curve; rapidly increasing populations had the highest proportion of long chains, suggesting that incidence of chains is an index of the growth phase in G. monilata. Peak toxicity was not reached until culture populations had been steadily declining for a month, indicating that most toxin is released by autolysis. The reproducibility of culture population and toxicity levels recommend the methods used for future studies.

Notes: SYNOPSIS. The pigments synthesized by Astasia ocellata include α- and ε-carotene, 4-keto-β-carotene (echinenone), and 4,4′-diketo-β-carotene (canthaxanthin); 4-keto-α-carotene, accounting for about half the pigment in the cells, was tentatively identified; a strongly adsorbed keto-carotenoid, accounting for 25% of the pigments and bearing some similarities to astacin, polytomaxanthin and phoenicoxanthin, was also found.

Notes: SYNOPSIS. Blepharisma intermedium was cultured axenically. The organisms were freed of contaminating microorganisms by serial washing in a sterile salt solution. The major nutrients in the various media were: Freshly killed or lyophilized and autoclaved bacteria (Pseudomonas ovalis), yeast extract prepared from Fleischmann's baking yeast or Fleischmann's yeast autolysate, lettuce infusion or stigmasterol, 6 B-vitamins, and phosphate buffer at 2 times 10−3 M. The cultures were kept in the dark at 25 C. Altho the 1st division after transfer into fresh media was delayed, B. intermedium divided in approximately 32 hours thereafter in most of these media.

Notes: SYNOPSIS. The effects of temperatures of 12–18 C on cell division and oral primordium development were investigated in cultures of synchronized Tetrahymena pyriformis GL-C. If exposures to 12 or 15 C were initiated prior to a “transition point,” long delays of cell division were generated. After this transition point, cell division could no longer be substantially delayed by exposure to low temperature. The time of the transition point was somewhat earlier with 15 C than with 12 C treatments. At temperatures higher than 15 C long delays of cell division were not generated regardless of time of treatment.The effects of low temperature on oral morphogenesis were strongly dependent on the stage which was affected. (i) The further development of cells initially in the “anarchic field” stage (stage 1) was immediately blocked at both 12 and 15 C. (ii) Cells initially in the stages of incipient membranelle differentiation (stages 2 and 3) continued to develop at both 12 and 15 C, and formed oral primordia in which all 3 membranelles were clearly differentiated (stage 4). The subsequent progress of these stage 4 primordia depended on the temperature: at 12 C virtually all were resorbed (and cell division was blocked); at 15 C only about 1/3 were resorbed, while the remaining 2/3 completed their development (with the concomitant completion of cell division). (iii) Cells initially in intermediate stages of membranelle differentiation (early stage 4) developed to some extent at 12 C, and then underwent resorpton of oral primordia and blockage of cell division; at 15 C such cells completed their development and division normally. (iv) Cells in which the membranelles and undulating membrane were complete or nearly so (stage 5 and very late stage 4) at the time of the beginning of the cold treatment subsequently finished their development and went thru cell division, even at temperatures as low as 5 C.These results indicate that in addition to a “stabilization point” which occurs shortly before the completion of membranelle development, there is an earlier change in the primordium at the time of the onset of membranelle development, which renders development much less sensitive to direct interference by low temperature.

Notes: SYNOPSIS. Excysted sporozoites of Eimeria meleagrimitis, E. necatrix, E. acervulina, and E. gallopavonis were inoculated into monolayer cell cultures of bovine, ovine, porcine, and human kidney. E. meleagrimitis developed only in bovine embryonic kidney. Mature schizonts were found in the 11th, 16th, and 20th serial passages, but only immature schizonts were in the 4th and 6th passages. E. necatrix developed to mature schizonts in the 3rd, 4th, 6th, 11th, 16th, and 20th passages of bovine kidney and also to immature schizonts in the 175th and 189th passages of PK-15 (cell line porcine kidney). Schizonts, however, did not develop in the 140th and 145th passages of CCI-33 (cloned PK-15). Neither E. meleagrimitis nor E. necatrix developed in the primary, 1st or 2nd passages of bovine embryonic kidney, primary porcine kidney, 45th and 52nd passages of a human embryonic kidney cell line, or in the primary, 5th and 18th passages of ovine kidney. Eimeria acervulina and E. gallopavonis did not develop in any of the cultures. E. meleagrimitis and E. necatrix probably completed only one asexual generation in culture. The structure of mature schizonts of both species differed greatly from those in the natural host. Schizonts of E. meleagrimitis present at 48 hours were small (13–18 by 12–14 μ) and contained only 12–28 merozoites that were 3.2–3.8 μ long. At 48 hours, E. necatrix schizonts were 15–18 μ in diameter or less and contained only 15–20 merozoites (2.0–3.5 μ long); at 96 hours they were 50–70 by 10–35μ and contained either hundreds of small merozoites (2.0–3.5 μ long) or a lesser number of larger merozoites (9–11 μ).

Notes: SYNOPSIS. In heavily endemic collecting sites in Panamá and Colón Provinces, Republic of Panama, 14.7% of Ameiva ameiva and 8.5% of Basiliscus basiliscus were injected with Besnoitia darlingi. Single infected specimens of A. leptophrys and A. festiva were also taken, these being new host species records for this parasite. Infections were found only in the older lizards.Initially, virulence of the lizard parasites for white mice was low but increased with successive mouse passages. Concomitantly, the cyst-forming capacity of the strain diminished with successive mouse passages. No relation between initial virulence of the lizard parasites for mice and subsequent virulence after 16 or 17 mouse passages was recorded.The original description of B. panamensis (a synonym of B. darlingi) is emended on the basis of extensive material to include cyst diameters of 200–500 μ; also, the liver, mesentery, and tunica propria of the testis occasionally contain cysts. Cysts are frequently macroscopic and on the surface of organs so that they can be seen on casual inspection. B. sauriana Garnham, 1966 is a synonym of B. darlingi.

Notes: SYNOPSIS. An electron microscope study of microgametocytes and macrogametes of Eimeria nieschulzi Dieben, 1924 revealed that they lie within vacuoles bounded by a host unit membrane. The vacuole surrounding the microgametocyte contains granular material. The vacuole around the macrogamete is narrower and contains vesicles and membranes. Micropores were seen on the surface of the plasma membrane of microgametocytes and macrogametes. Microtubules were seen in macrogametes. Young microgametocytes and macrogametes have a similar cytoplasmic matrix, mitochondria and nuclei. Glycogen granules apparently develop around vacuoles in both microgametocytes and macrogametes. Glycogen granules were also seen along the margins of parallel bundles of fibers in microgametocytes. As nuclei of the microgametocyte divide, they move to the periphery of the parasite. Three basal bodies, each with 9 fibers in triplet form, develop in association with each nucleus. Microgametes have 2 free flagella and a central short, attached flagellum. Basal granules lie along the outer fibers of the central flagellum. Each microgamete has an elongate mitochondrion in close contact with the nucleus. In macrogametes wall-forming bodies develop in lacunae in the cytoplasm. Smaller dark bodies with areas of low density were also seen. Wall-forming bodies and dark bodies move to the periphery of mature macrogametes.

Notes: SYNOPSIS. In the nearly mature macrogametes of Eimeria auburnensis, the cell membrane is a unit membrane, with underlying and overlying osmiophilic layers usually present. Cup-shaped micropores were occasionally seen. Smaller, V-shaped invaginations were also found in considerable numbers at the surface. At the deepest point, these invaginations were bounded only by a unit membrane. Immediately adjacent to this point, vesicles with homogenous electron-pale contents bounded by a similar unit membrane, were frequently seen. Pinocytosis evidently occurs at the site of these invaginations. Numerous folds of the host cell membrane bordering the vacuole in which the parasite lay extended about 0.1–0.7 μ into the vacuole. These “intravacuolar folds” varied in depth and number in different specimens. In some, the majority of folds had apparently become disconnected from the host cell membrane. A highly developed smooth endoplasmic reticulum occurred in the adjacent host cell cytoplasm. The intravacuolar folds may assist in transfer of nutrients, including membrane material, from the host cell to the parasite. The evidence indicates that in this species of Eimeria nutrients are taken into the parasite primarily as fluids by pinocytosis and possibly other processes.

Notes: SYNOPSIS. Sexual reproduction of up to 50% of the cells from 9 cultures of Stentor coeruleus was observed repeatedly for several months. Photomicrographs were taken of mating pairs, and a number of new observations were made, including the ability of well fed cells (containing food vacuoles) to conjugate, the ability of a high percentage of cells (approaching 50%) in a culture to mate at one time, a more detailed description of the region of cell attachment as viewed from the frontal fields of the partner cells, and the ability of one partner to twist off and leave its oral area attached to the other member of the pair.

Notes: SYNOPSIS. Comparison of RNA molecules between certain protozoa using the technic of nucleic acid hybridisation revealed that there are complementary sequences for ribosomal RNA molecules in the genomes of such cells. Furthermore the genes for ribosomal RNA have been conserved during evolution in this group of organisms. On the other hand, RNA molecules from these protozoa which can be considered to be “messengers” show little in the way of sequence relationships. By utilising the technic of hybridisation it was found that Oxytricha can compete effectively against Paramecium ribosomal RNA for Tetrahymena DNA but the ribosomal RNA sequences of the latter could not compete completely against Paramecium ribosomal RNA for Oxytricha DNA. The result is interpreted to show that different ribosomal sequences were hybridising with each of the DNA samples from Tetrahymena and Oxytricha. A general interpretation of this result in terms of ribosome evolution is presented.

Notes: SYNOPSIS. Strains of Tetrahymena pyriformis, including amicronucleate strain GL and representatives of 9 syngens, have been examined to determine the patterns whereby cortical features vary with numbers of ciliary meridians. The characteristics scored were the positions of the contractile vacuole pores (CVP's), the extent of the area within which CVP's develop, the incidence of supernumerary CVP's, and the number of postoral meridians. Intrasyngenic comparisons were possible in 6 syngens and permitted an assessment of intrasyngenic variation for these characteristics. Only the CVP positions appear to be reasonably constant within syngens in the strains examined. On the basis of this criterion the syngens can be arrayed in an approximate order of 1, 3, 7, 6, 8, 9, 2, 5, GL and 4; the angle formed between the central axis, the stomatogenic meridian and the CVP's is most acute in syngen 1.

Notes: SYNOPSIS. The bionomics of Labyrinthula Cienkowski and the validity of the family Labyrinthulidae Haeckel are reviewed. The structure, physiology (including nutrition), locomotion, ecology, and possible pathogenicity for eel-grass (Zostera marina L.) are discussed. The uniqueness of its gliding motility along slime tracks, lack of phagotrophy, and poorly understood congregation tendencies emphasize the present taxonomic isolation of the group. Further interest attaches to some species because of their steroid requirements.

Notes: SYNOPSIS. Sporozoites of L. simondi were maintained in a viable state for 7 months in liquid nitrogen. Comparison of parasite development initiated with fresh and frozen sporozoites showed a delay in development of each stage studied. Comparisons of prepatency, first elongate gametocytes, peak density of round and elongate forms, anemia and disappearance of megaloschizonts were made. In each phase there was a delay of 2–3 days in ducks infected with frozen sporozoites.

Notes: SYNOPSIS. Ten strains of Acanthamoeba from freshwater habitats were isolated in clonal cultures. Studies were made of trophic structure, nuclear division, cyst structure, some aspects of cytochemistry, and other characteristics. One strain was identified as A. castellanii (Douglas, 1930), one as A. astronyxis (Ray and Hayes, 1954), and 8 as A. polyphaga (Puschkarew, 1913). Strains of Acanthamoeba isolated by other workers were also examined comparatively.The pattern of nuclear division in all strains resembled that in metazoan cells, with the exception that centrioles were never found. Trophic amoebae had a PAS-positive surface outline. Cyst walls were strongly PAS-positive and also gave a positive test for cellulose with zinc chloroiodide.The genus Acanthamoeba Volkonsky, 1931 is re-defined, being distinguished from Hartmannella Alexeieff, 1912, emend. Volkonsky, chiefly by the formation of tapering, hyaline pseudopods (acanthopodia) and by a cyst made up of an ectocyst and a polyhedral or stellate endocyst, with excystment by removal of opercula. Other characteristics found in all strains include a distinctive food cup, the presence of many small refractile globules in the cytoplasm of trophic amoebae, and a cyst wall containing cellulose. The degree of spindle convergence, employed by Volkonsky as a generic criterion, was unusable.Differential diagnoses based principally on cyst structure are offered for A. castellanii, A. astronyxis, and A. polyphaga. The strain previously called Mayorella palestinensis Reich, 1933 is a distinct species of Acanthamoeba.

Notes: SYNOPSIS. Parauronema virginianum n. g., n. sp., a marine hymenostome ciliate is described from the Virginia coast. Structural studies were made on specimens treated with the Chatton-Lwoff silver impregnation technic and on animals observed with the phase microscope. Particular attention was given to the buccal ciliature and its importance to generic assignment in the order Hymenostomatida.

Notes: SYNOPSIS. Large numbers of sessile ciliates were successfully collected in plastic petri dishes with tight-fitting lids, transported in the water-filled dishes without disturbance. Each species within the transparent dishes was identified with a dissecting microscope and the position on the dish surface of each sessile individual was located and recorded on graph paper for further quantitative comparisons. This method was used for numerous experiments on the ecology and behavior of sessile ciliates and their responses to toxins.

Notes: SYNOPSIS. Structure and morphogenesis, and cytochemical data on Cochlodinium heterolobatum, a new species of unarmored dinoflagellate, were derived from living and fixed material from culture. C. heterolobatum is characterized by the torsion of the girdle which descends in a left-hand spiral 1.8 turns; the sulcus having a torsion of 0.8 turn; a sulcus loop in the epicone; a tongue-shaped lobe in the right hypocone; nucleus in the epicone; and a stigma in the left epicone. Trichocysts and behavior of the nucleus during typical and atypical divisions are described in cells from cultures of different ages. A small form with the specific characters was found. Intracellular bacteria were seen and their growth followed in individuals from cultures of different ages. A possible relationship between those bacteria and the accumulation of metabolites inside old cells is discussed.

Notes: SYNOPSIS. Species of sessile Stentor, Vorticella and colonial peritrichs were collected in boxtype plastic petri dishes. Thru a hole in the wall of the dish, various concentrations of mercuric chloride, a standard bactericidal agent, were introduced. Following a 3-hour exposure to the toxicant, the death of the sessile ciliates followed a set pattern with a clearcut toxicity threshold of 0.1–0.5 parts per million with an LD 50 of about 0.25 ppm. Furthermore, the sessile ciliates were not dislodged when the natural pond water in the dish was poured out and replaced with water from other sources. Various responses were elicited by 4-hour exposure to 4 changes of environment. By this procedure, the protozoan community was subjected to new sets of conditions. Such a technic could serve as a method of detecting and assessing water pollution.

Notes: SYNOPSIS. From characteristics of binary fission, conjugation, size and number of micronuclei, body size and incidence of giantism, a Blepharisma isolate hitherto called B. undulans is classified as B. dawsoni sp. nov. Binary fission in B. wardsi differs from fission in B. dawsoni in that the strand connecting the macronuclear nodes is severed; in B. dawsoni the strand persists.

Notes: SYNOPSIS. Experiments with mixtures of latex-tagged cultures of amoebae of strains, species and genera of the Dictyosteliaceae indicate little specificity in engulfment. This is in sharp contrast to the decided specificity for compatibility in completion of morphogenesis in the same organisms. Lack of specificity in engulfment is considered additional evidence favoring engulfment as a normal feeding activity rather than a process associated with syngamy in the cellular slime molds.

Notes: SYNOPSIS. Eimeria colchici sp. n. is described from English pheasants Phasianus colchicus. It has cocysts measuring 19–33.5 (27.4) by 13–21 (16.7) μ, having both micropyle and polar granule. The large 1st and 2nd generation schizonts occur in the glands of the small intestine, 3rd generation schizonts occur deep in the glands of the ceca, and gametocytes occur in the epithelial cells of the ceca. The prepatent period is 6 days. In young pheasants the parasite causes coccidiosis characterized by formation of white cores in the ceca. Mortality is high in experimental infections. Zoalene (0.0125%) in the feed almost completely suppressed the infection; Amprolium (0.0125%) also gave good control, but sulfaquinoxaline (0.0125%) was not so effective. Sulfaquinoxaline, Saquadil and Sulfamezathine in the drinking water controlled mortality, but treatment had to be applied early to avoid weight losses.

Notes: SYNOPSIS. Monolayer primary and secondary cultures of embryonic bovine kidney, spleen, intestinal and testicle cells, and secondary cultures of embryonic bovine thymus, maintained in lactalbumin hydrolysate, Earle's balanced salt solution and ovine serum were observed for a maximum of 21 days after inoculation of E. bovis sporozoites. The sporozoites entered the cells in all of these cultures but underwent development only in primary cultures of kidney and intestinal cells and in secondary cultures of kidney, spleen, thymus, intestinal, and testicle cells. In acellular media, the sporozoites retained motility no longer than 21 hr. In the cell cultures, free motile sporozoites were seen for as long as 18 days after inoculation. Sporozoites entered cells anterior end first; the process of penetration required a few seconds to about a minute. Sporozoites were also observed leaving host cells. Intracellular sporozoites were first seen 3 min after inoculation; they were observed at various intervals up to 18 days after inoculation. In transformation of sporozoites into trophozoites a marked change in size and appearance of the nucleus took place before the change in shape of the body occurred. Trophozoites were first found 7 days after inoculation, multinucleate schizonts after 8 days, and schizonts with merozoites after 14 days. Schizonts containing merozoites were seen only in kidney, spleen, and thymus cells. The mature schizonts were smaller and represented a much lower proportion of the total number than in comparable stages of infections in calves. Schizonts with many nuclei occurred in intestinal cells; the most advanced stage seen in testicle cells was the binucleate schizont. Nuclear and cytoplasmic changes were observed in the infected cells.

Notes: SYNOPSIS. Peritoneal macrophages from hamsters were monolayered on coverslips in Leighton tubes. Twenty-four hours later these were transferred to a perfusion chamber. Leptomonads were added with fresh medium and the infection process observed with the aid of phase contrast. In the perfusion chamber free-swimming leptomonads attached to the macrophage by the tip of their flagella. Shortly after this initial attachment the macrophage extended a narrow pseudopodium around the flagellum which eventually reached and enveloped the body of the parasite. Upon complete envelopment the pseudopod containing the leptomonad was retracted into the central body of the macrophage. When first seen in the granular endoplasm of the macrophage, most of the leptomonads appeared to be surrounded by vacuoles. In most cases these vacuoles disappeared in a few minutes making it difficult to distinguish the parasite from the host cell cytoplasm.Leptomonads also were added directly to Leighton tube cultures, and the coverslips with the adherent macrophages and parasites were removed, fixed and stained periodically during the infection process. In these preparations most of the parasites were in clumps in the vicinity of macrophages. Details of the ingestion of the clumps could not be seen, but occasionally a single organism was seen with its flagellum and part of its body enclosed by an extended pseudopod. Most of the intracellular leptomonads were in large vacuoles. Forms intermediate between elongate leptomonads and LD bodies were surrounded by smaller vacuole-like spaces. The halo-like vacuoles most frequently seen around LD bodies may have been fixation artifacts. Under favorable conditions the leptomonads transformed to LD bodies in 1–4 hours, but it was 48 hours before a population increase could be found.

Notes: SYNOPSIS. Coccidia-free beagle puppies were experimentally infected with a cloned culture of Isospora rivolta oocysts. The endogenous stages were found in the posterior 1/2 of the small intestine, and rarely in the cecum and colon. Maximum numbers of all stages occurred just anterior to the ileocecal valve. Endogenous stages were found in the distal third of the villi, predominantly parasitizing subepithelial cells of the lamina propria; however, stages were occasionally present in epithelial cells. The number of asexual generations could not be determined from their structure, but evidence based on oocyst production suggested that there were at least 2 asexual generations. The schizonts were 17–24 by 12–25 μ and contained 4–24 merozoites, the most common number being 4 or 8. Schizonts with mature merozoites were found as early as 72 hr, but were present in maximum numbers at 96 hr. Merozoites had slender curved bodies and were 10.5–13.4 by 2.3–3.0 μ. Mature gamonts were found by 144 hr. Mature microgametocytes were 13.4 by 8.7 μ and contained 50–70 microgametes. Microgametes had slightly curved tapering bodies (5.8–6.4 by 0.6 μ) with 2 posteriorly directed flagella 11–14 μ long. Mature macrogametes had reticular cytoplasm and a uniformly large nucleus and nucleolus.The prepatent period was 142–146 hr. The patent period was 13–23 days with an average of 19 days.

Notes: SYNOPSIS. Rabbit antisera to strains of different mating types of Chlamydomonas moewusii and to one strain of C. eugametos were tested against strains of C. reinhardti, C. eugametos, and C. moewussi, and against strains of 2 varieties and 6 mutant types of C. moewusii. Technics of double diffusion, absorption, and immunoelectrophoresis revealed marked serological differences between the sexually incompatible, distinct genetic species C. moewusii and C. reinhardti. Less distinct serological differences were resolved between C. moewusii and the so-called “species”C. eugametos, which is sexually compatible with the former, thus reconfirming the conspecificity between the 2 strains as suggested by Gowans. Marked serological differences were noted between C. moewusii and 2 of its varieties (C. moewusii var. tenuichloris and C. moewusii var. rotunda) which constitute 2 additional genetic species because of sexual incompatibility between themselves and with C. moewusii. Wild types and certain mutants of C. moewusii were compared serologically and could be distinguished on this basis. Strains of different mating types as well as certain mutant strains (e.g., paralyzed flagella, flagella-less, twins and monsters) could be differentiated serologically altho differences were often very subtle. Some antigens were common to organisms tested.

Notes: SYNOPSIS. Optimal growth of the colorless flagellate, Astasia longa, in terms of generation time occurred at 25–30 C. Above and below this interval, generation time increased. In contrast, length of the lag phase was constant over a wide temperature range, 18–32 C. At 13 C dry weight of Astasia was 15% greater than at 28.5. Alcohol-ether soluble material accounted for 72% of the dry weight increase at 13, while RNA and protein contents of the cells were the same at both temperatures. Rates of synthesis of dry weight, RNA, protein and lipid per μl oxygen consumed were all reduced at 13 C; however, lipid synthesis was the least affected. Cell division in Astasia was synchronized repetitively by cold (13–15 C) and warm (28.5 C) temperature cycles. Under best conditions, cell division began immediately at the onset of the warm period. Cellular preparations for cytokinesis apparently were at least partially completed in the cold, and raising the temperature released a block to cell division.

Notes: SYNOPSIS. Isolated rumen protozoan species (Entodinium) were incubated in vitro with starch, antibiotics and Na214CO3. 14C-carbonate was incorporated into amino acids of the Entodinium protein. Arginine, aspartic acid, alanine, and glutamic acid had the highest specific activities. Carbonate was incorporated into the TCA-soluble fraction, into cell polysaccharides, and into ether and acetone extracts of TCA-precipitates.

Notes: SYNOPSIS. Light-dependent incorporation of acetate occurs in an obligate phototrophic strain of Euglena gracilis (strain L). Assimilation is into all major biochemical fractions. Acetate does not induce operation of the glyoxylate by-pass as it does in heterotrophic strains; neither does it stimulate oxygen consumption. Acetate will not replace CO2 in phototrophic growth. A number of carbon sources tested would not support growth in the dark, and glucose was not incorporated either in the light or the dark.

Notes: SYNOPSIS. The uptake, distribution and turnover of phosphorus have been studied for the culture form of Trypanosona cruzi. Following exchange reactions, phosphorus was accumulated at an approximate rate of 1.9 μg/108 trypanosomes/hour in Krebs-Ringerphosphate. Of 3.8 mg P/g trypanosomes (wet weight), 60% occurred in acid-soluble, 13% in phospholipid, 22% in nucleic acid, and 5% in phosphoprotein fractions. Acid-soluble and phosphoprotein fractions incorporated P32 more rapidly than phospholipid and nucleic acid fractions, the phosphoprotein fraction having the highest specific activity by 8 hours of incubation.

Notes: SYNOPSIS. Sulfaquinoxaline and ethopabate are 2 chemically distinct types of antagonist of PABA with anticoccidial action. Reversal experiments with PABA and synergism studies with pyrimethamine indicated that both compounds interfered with the PABA-folic acid metabolic sequence. Six pure strains of Eimeria brunetti responded differently to the 2 compounds. The strain most sensitive to ethopabate was one of 2 strains most resistant to sulfaquinoxaline. Conversely, the strain most sensitive to sulfaquinoxaline was unresponsive to the highest doses of ethopabate employed. Hypotheses to explain the differences in biological effects of the 2 compounds were considered.

Notes: SYNOPSIS. Stationary cultures of Ochromonas danica accumulated lipids as they aged. The bulk of the increase in fatty acids was in the unsaturates, particularly the polyunsaturates. The quantity of lipid peroxides (thiobarbituric acid-positive material) also increased with age. Aging was also associated with increase in sensitivity to inhibitory compounds. The implications of lipid accumulation for cell sensitivity are discussed.

Notes: SYNOPSIS. The size of the population of Naegleria gruberi at the time the amoebae are offered the opportunity to become flagellated is not a critical factor in the morphogenesis of this organism. Small populations (1-15 cells) readily become flagellated. Small populations (1-5 cells) washed several times also become flagellated. Clonal populations (25) have been established. All clones yield flagellates under the usual conditions. It is suggested that the physiological state of the amoebae is a factor in determining the number of cells that will undergo morphogenesis at any given time.

Notes: SYNOPSIS. Frame by frame analysis of cinephotomicrographs of the evacuation of the water excretory vesicle of Amoeba proteus shows that this organelle (commonly called the “contractile vacuole”) does not contract as the water is expelled. Instead, pressure exerted by the underlying endoplasmic “gel” pushes the vesicle against the plasmalemma, bulging the latter until a pore opens through it. The cell membrane and apposed vesicular membrane both rupture through the plasmalemmar pore; the fluid rushes out; and the vesicle collapses against and inverts into itself, but does not contract. There is therefore no systole of the vesicle due to any contraction of it. A survey of the literature shows that others who have studied the evacuation of these water excretory vesicles in amebas, suctorians, and ciliates have also described them as collapsing, not contracting. Recent electronmicrographs of a number of protozoa also indicate that the water excretory vesicle collapses, and does not contract as it evacuates its contents; and that there are no fibrils surrounding the organelle which might promote its contraction. We suggest that the term “contractile vacuole” be discarded as a descriptive and identifying term for such organelles; and that they be called “water expulsion” organelles. We further suggest that the term “vacuole,” which implies that the structure is empty, be replaced by the term veside, implying its function as a small container, and that the organelle be preferentially called the water expulsion vesicle. We also suggest that the terms “systole” and “diastole” be discarded and be replaced with enlargement and evacuation so that the erroneous implication of a contraction and relaxation cycle may be dispelled.The succeeding new water expulsion vesicle in Amoeba proteus seldom forms at the site of the old one, but usually forms at a new site in the sol anterior to the gel of the tail region, to which it is transferred prior to expulsion. A tentative suggestion of how this transfer may occur is offered.

Notes: SYNOPSIS. Adenosine triphosphate (ATP) with pyruvate, or adenosine diphosphate with phosphoenolpyruvate, favor the development of Plasmodium lophurae removed from its host erythrocytes and kept extracellularly in vitro. It seemed possible that the parasites might be deficient in enzymes of the glycolytic cycle concerned with the generation of ATP. The ATP content of duck erythrocytes infected with P. lophurae was lower than that of uninfected cells. Infected erythrocytes, however, had somewhat higher contents of both pyruvic kinase and phosphoglyceric kinase than did uninfected ones. Both of these enzymes could be found in the free parasites. Furthermore, the pyruvic kinase of the free parasites was inactivated by freezing and thawing, whereas that of the host erythrocyte was not affected. It will be necessary, therefore, to look further for the basis for the favorable effect of ATP with pyruvate on parasites developing extracellularly in vitro.

Notes: SYNOPSIS. Properties and cellular location of acid phosphatase in Trypanosoma gambiense were studied. Activity was found in both the sediment (32,000 ×g) and the supernatant of homogenates. Cenrifugation in 0.3 M sucrose showed activity principally in the lowspeed fraction (4,000 ×g). One min of sonication released most of this activity. Several phosphomonoesters were hydrolyzed at acid H's. Enzymatic activity was relatively specific for pyrophosphate and p-nitrophenylphosphate at pH 3.6. At pH 5.2, purine and pyimidine nucleotide 5′-triphosphates as well as adenosine di- and ono-5′-phosphates were hydrolyzed nonspecifically. Activity with yrophosphate at pH 3.6 had a temperature optimum of 60-70 C while that for adenosine 5′-triphosphate (pH 5.2) was 50 C. These ctivities of the sediment required no metal co-factors and were inibited by Fe++, inhibition at the lower pH being greater.Glucose 6-phosphate was hydrolyzed by the supernatant with maximum activity between pH 6.0 and 7.2 and a temperature optimum of 50 C. This pH range showed a broad plateau with 2 or 3 minor peaks. The hydrolysis of p-nitrophenylphosphate showed a similar pH curve. In glucose 6-phosphate hydrolysis, Mg++ was a required co-factor but could be replaced by Ni++ or Co++. Ammonium sulfate fractionation precipitated most of the supernatant activity between 50 and 75% saturation.A modified Gomori technic produced spherical deposits of PbS thruout the cytoplasm of the intact cell. With the electron microscope, Pb phosphate deposition was observed in membrane-bound vesicles (i.e., lysosomes) approximately 100-150 mμ in diameter. These organelles were common in the region of the reservoir at the base of the flagellum. Acid phosphatase activity specific for glucose 6-phosphate as substrate was localized within this basal pocket.

Notes: SYNOPSIS. Trypanosoma occidentalis sp. n., a hemoflagellate encountered in the blood plasma of 3 freshwater teleosts, Cottus gulosus, C. rhotheus (Family Cottidae) and Gasterosteus aculeatus (Family Gasterosteidae) from Washington State, is described and recorded. Morphologic and morphometric features are detailed, and comparisons are made with other trypanosomes reported from North American fishes and from related species of teleosts from Eurasia. The relationship of the geographic isolation of parasite, hosts, and potential vector in the determination of the new species is discussed.

Notes: SYNOPSIS. By means of the ninhydrin-Schiff method for proteins a diffuse reaction as well as one localized in granular inclusions can be shown in the cytoplasm of fibroblasts, epithelial cells, and macrophages in trypsin-dispersed chick liver cell cultures. Nuclei and nucleoli also take the specific stain. A progressive loss of cytoplasmic and nuclear staining occurs in the fibroblasts in cultures infected with a relatively pathogenic strain of T. vaginalis. A loss occurs in epithelial cells in advanced stages of degeneration, but in less damaged cells, while the diffuse reaction disappears, the number and staining intensity of the cytoplasmic inclusions remain unchanged or possibly may increase somewhat. The intensity of the diffuse reaction and the number and size of the characteristic inclusions increase in the active, parasite-free, experimental macrophages, but phagocytes with trichomonads closely applied to their external surfaces and those containing the flagellates within their cytoplasm typically retain only a few weak-staining inclusions.Similar distribution of alkaline and acid phosphatases occurs in preparations treated according to Gomori's and Burstone's methods, except that no nuclear staining is obtained with the latter. Activity of both enzymes is localized primarily in inclusions which are dispersed thruout the cytoplasm of fibroblasts and epithelial cells and tend to accumulate along the cell membranes and around the nuclei. In the course of infection with T. vaginalis there is a progressive loss of alkaline phosphatase from both cell types; however, the acid phosphatase activity increases. In the control macrophages both enzymes are localized in mostly rather large, rounded cytoplasmic inclusions. The number of such inclusions increases in the parasite-free experimental macrophages, but only a few weak-staining granules remainin phagocytes with engulfed trichomonads and in those whose external surfaces are in direct contact with the parasites. The loss of the inclusions is less apparent in macrophages containing degenerated flagellates than in the ones with healthy trichomonads, but regardless of the condition of the parasites, the highest enzymatic activity is found around them.ATPase and 5′-nucleotidase are localized in small granules dispersed thruout the cytoplasm of fibroblasts and epithelial cells. The granules tend to accumulate along the periphery of the cells and around the nuclei. A diffuse cytoplasmic reaction is present in preparations processed for 5′-nucleotidase. Nuclei and nucleoli give positive reactions for both enzymes. In the course of infection with trichomonads, activity of the 2 enzymes declines in both culture cell types. Control macrophages have diffuse cytoplasmic reaction for ATPase and 5′-nucleotidase and these enzymes are localized also in rounded cytoplasmic inclusions. Activity of both enzymes increases in the parasite-free experimental phagocytes, but little if any diffuse staining and only a few characteristic inclusions are left in macrophages with engulfed healthy trichomonads and in those whose external surfaces are invested with the flagellates.The ninhydrin-Schiff-positive inclusions found in the macrophages appear to be the same as some of those which have acid phosphatase activity and may well be identical with the glycolipoprotein bodies noted by us previously. On the grounds of their chemical constitution and behavior it seems likely that the inclusions are lysosomes.

Notes: SYNOPSIS. Chilomonas paramecium developed significant resistance to INH at concentrations up to 150 mg/100 ml. Once established, the resistant strains grew subnormally in drug-free medium and were more susceptible than the normal strain to sulfanilamide, but were much more resistant to PABA (10-20 mg/100 ml). In addition, INH-adapted strains were less responsive than the controls in PABA reversal of SA-inhibition. Strains adapted to sulfanilamide, sulfapyridine, and nicotinamide were less resistant to INH than the normal strain.

Notes: SYNOPSIS. The ultrastructure of the herbivorous amoeba Pelomyxapalustris was studied. Nuclear division is not understood in this amoeba, and evidence for the method of nuclear division was sought. This species typically has many spheroidal nuclei which are similar within a given cell. However, some amoebae from our collections differed from this common type in both the number and structure of their nuclei. This suggested stages associated with nuclear division. One current hypothesis of nuclear division in this organism is that of nuclear budding. Our evidence is more in accord with this method than with mitosis.The cytoplasm contained no mitochondria, Golgi bodies, contractile vacuoles or crystals. Most amoebae had 2 types of bacteria (bacteroids or endosymbionts) in their cytoplasm; a separate vesicle enclosed each of these. Characteristically, only 1 type of bacterium (Bn) surrounded the nucleus. Another type (B) was found elsewhere in the cytoplasm. Also in the cytoplasm were the following: food vacuoles enclosing various algae, relatively clear vacuoles and vesicles, glycogen, various electron-opaque particles, and occasional microtubules. The plasmalemma was smooth, lacking the external fringe which characterizes other large fresh-water amoebae.