Fallisia parasites (Haemosporidia: Plasmodiidae) from the flying lizard, Draco maculatus (Agamidae) in Thailand

Plasmodium (Fallisia) siamense n. sp. was described from the flying lizard Draco maculatus (Agamidae) collected near Bangkok, Thailand. Parasitic in thrombocytes, it produces 18-64 merozoites in schizonts that are larger than the usually oval gametocytes. Both gametocyte sexes showed a prominent nucleus, elongate in macrogametocytes and triangular in microgametocytes. This is the first Fallisia parasite described from a host outside the Neotropical Region, although presence of the genus in Australasia was reported 40 years ago, without formal taxonomic designation.     

Ultrastructural study of the gametocytes and merogonic stages of Fallisia audaciosa (Haemosporina: Garniidae) that infect neutrophils of the lizard Plica umbra (Reptilia: Iguanidae)

Little is known regarding the ultrastructure of the genus Fallisia (Apicomplexa: Haemosporina: Garniidae). This report describes the fine structure of some developmental stages of Fallisia audaciosa that infect neutrophils in the peripheral blood of the Amazonian lizard Plica umbra (Reptilia: Iguanidae). The parasites lie within a parasitophorous vacuole and exhibit the basic structures of members of the Apicomplexa, such as the pellicle and the cytostome. Invaginations of the inner membrane complex were seen in the gametocytes and may be concerned with nutrition. The meronts were irregularly shaped before division, a feature unusual among members of the Apicomplexa. The unusual presence of a parasitic protozoan within neutrophils, in some way interfering with or modulating the microbicidal activity of such cells, is discussed.     

Malarial Parasites of the "Jesu Cristo" Lizard Basiliscus basiliscus (Iguanidae) in Panama

SYNOPSIS. The iguanid lizard Basiliscus basiliscus in Panama is parasitized by Plasmodium basilisci and P. achiotense sp. nov. P. basilisci in this host is characterized by schizonts containing 4–14 merozoites, with schizonts parasitizing proerythrocytes containing more merozoites than those in erythrocytes. Asexual parasites lack cytoplasmic projections, while mature gametocytes are round or oval with regular margins.
P. achiotense is characterized by the combination of prominently pigmented, large schizonts containing 36–56 merozoites and oval or round gametocytes which are about 1/3 larger than those of P. basilisci.
EE-schizonts of P. basilisci were observed commonly in thrombocytes and occasionally in lymphocytes, and appeared early in experimental infections induced by blood inoculation.     

Asexual and Sexual Stages of a Malaria Parasite in the Thrombocytes of Tropidurus torquatus (Iguanidae) Infected with Plasmodium tropiduri*

SYNOPSIS. Sexual and asexual stages of a parasite found in the thrombocyte-like cells of some Tropidurus torquatus infected with Plasmodium tropiduri are described. The strong ultrastructural similarities between the gametocytes of this parasite and the gametocytes of P. tropiduri, and the finding of this parasite in lizards inoculated with P. tropiduri suggest that this malaria parasite can develop both in erythrocytes and thrombocytes. Evidence in favor of this hypothesis is discussed.     

The extravascular compartment of the bone marrow: a niche for Plasmodium falciparum gametocyte maturation?

ABSTRACT: BACKGROUND: Plasmodium falciparum immature gametocytes accumulate in the bone marrow, but their exact location in this tissue remains unclear. METHODS: The stage and deposition pattern of gametocytes was analysed on histological sections of a bone marrow sample collected in a patient with subacute P. falciparum malaria. RESULTS: A majority (89%) of immature stages II to IV gametocytes and a minority (29%) of mature stage V gametocytes were observed in extravascular spaces. Discussion and conclusion These observations represent a valuable step towards understanding sequestration patterns of P. falciparum gametocytes and may ultimately lead to novel transmission-blocking interventions.     

Plasmodium kentropyxi n.sp. (Apicomplexa: Haemosporina: Plasmodiidae) and a Plasmodium tropiduri-like parasite in the lizard Kentropyx calcarata (Lacertilia: Teiidae) in north Brazil

Plasmodium kentropyxi n.sp. is described in the teiid lizard Kentropyx calcarata from north Brazil. Young asexual stages and gametocytes are at first polar in the erythrocyte but with elongation, move to a lateral position. Largest meronts seen contained from 30-40 nuclei and conspicuous greenish-black pigment granules located in a distinct vacuole. With growth the gametocytes eventually assume a smooth, curved cylindrical shape, with evenly rounded ends. Pigment is scattered or concentrated around a conspicuous vacuole which is slowly developed as the gametocytes mature. Mature male parasites measured 11.8 x 4.0 microns (9.6 x 4.2 - 13.2 x 3.6 microns), shape-index 2.9 (2.2 - 5.0), and females 13.5 x 4.5 microns (12.0 x 4.5 - 15.0 x 4.8 microns), shape-index 3.0 (2.2 - 3.8). Some larger meronts may slightly enlarge the erythrocyte, but most asexual stages and the mature gametocytes rarely do so. A second, P. tropiduri-like parasite encountered in K. calcarata possessed small rounded or fan-shaped meronts producing from 4-14 merozoites, and spherical to subspherical gametocytes of approximately 6.0 x 5.0 microns. The parasite was consistently polar in its position in the erythrocyte.     

Investigating species boundaries in the Giliopsis group of Ipomopsis (Polemoniaceae): Strong discordance among molecular and morphological markers

As a first step in elucidating mechanisms of speciation in the Giliopsis group of Ipomopsis (Polemoniaceae), we examined patterns of morphological and genetic differentiation and crossability. This group comprises three species that diverged very recently: two perennials, I. guttata and I. tenuifolia, and one annual, I. effusa. Analysis of phenotypic variation established that the three species are distinct for floral characters, and this differentiation is maintained in a locality containing both perennial species. Next, we assessed the genealogical relationships with AFLPs. All sampled individuals of I. effusa clustered together, a result in accord with its genetic isolation. The perennials, which retain interfertility, were not resolved as sister taxa. Rather, individuals sampled from the single I. guttata population that is sympatric with I. tenuifolia were genetically more similar to I. tenuifolia samples than they were to conspecifics. This pattern may be due to substantial introgression of I. tenuifolia genomic regions that do not contribute to floral phenotype in I. guttata. Our result adds to mounting evidence that plant species, as defined by morphological characters, are often not genomically cohesive. Taken together, our data warrant caution in delimiting species with genetic markers alone, and, importantly, suggest that selection on species-diagnostic morphological characters can be sufficiently strong to counteract extensive gene flow.     

斗嫁(虫戚)卵子发生和雌性性腺组织学研究

通过组织切片和活细胞涂片对斗嫁(虫戚)Cellana grata(GbuId)性腺和生殖细胞进行观察,研究雌性性腺特征及不同发育阶段雌性生殖细胞的形态特点与分布状况.观察与分析表明:(1)斗嫁(虫戚)雌性滤泡由卵原细胞及不同发育时期的初级卵母细胞填充,成熟的初级卵母细胞位居滤泡腔中央区域;(2)性细胞发育不同步,属分批产卵类型;(3)卵子发生中,细胞、核及核仁大小变化的总体趋势是随着发育进程而逐渐增大,常见1-2个核仁;(4)卵质的酸碱特性变化与卵黄的出现相关;(5)成熟卵母细胞大小约为(120-140)μm×150μm,外被约5-12 μm厚的胶质膜;(6)胶质膜的均一性、厚度、酸碱性随卵发育而变化,胶质膜与卵膜之间出现间隙可以作为卵开始成熟的标志,而胶质膜由嗜酸性转化为嗜碱性可以作为卵成熟即将排放的标志.     

Shape transformation and cytoskeletal reorganization in activated non-mammalian thrombocytes

The nucleated thrombocytes of non-mammalian vertebrates are partially flattened, ovoid cells morphologically distinct from mammalian platelets, and the extent of their functional equivalence is unknown. To test whether they resemble platelets in having similar F-actin-based post-activation stages, rapid fixation/extraction/labeling methods were developed to reveal cytoskeletal organization in dogfish thrombocytes by confocal microscopy. Unactivated cells contained cortical F-actin plus denser F-actin co-localizing with outer marginal band (MB) microtubules. In the post-activation sequence, determined for the first time by continuous observation of individual thrombocytes following thrombin perfusion, cells rounded and blebbed, spread, and eventually flattened extensively. The MB twisted and then became disorganized, with microtubule bundles remaining centrally located and associated with nuclear clefts. In contrast, F-actin occupied blebs and outward-spreading cytoplasm, initially in spiky projections, then predominantly in stress fibers, and inhibitors of F-actin assembly or myosin ATPase blocked shape changes. Thus, the post-activation stages and cytoskeletal events observed in nucleated thrombocytes were found to parallel those of platelets.     

Section of tropical taxonomy: Seven new species and one new record of Polygala (Polygalaceae) from Somalia

The following new species are described: Polygala gypsophila (northern, central and southern Somalia, on gypsum), P. bariensis (northern Somalia, on limestone), P. hamarensis (coastal dunes near Mogadishu), P. argentea (central Somalia, on limestone near coast), P. gawenensis (central Somalia, on limestone), P. effusa (central Somalia and eastern Ethiopia, on sand), P. citrina (southern Somalia, on granitic outcrops). P. meonantha is reported for the first time from Somalia.     

Plasmodium spp. (Apicomplexa: Plasmodiidae) of the flying lizardDraco volans (Agamidae)

The agamid lizardDraco volans from Palawan, Republic of the Philippines, was found to be parasitised by threePlasmodium species:P. draconis n. sp.,P. volans n. sp. andP. vastator, Laird 1960. BothP. draconis andP. volans, but notP. vastator, were also present inD. volans from Sarawak. The species are readily distinguished by schizont size, merozoite number, and gametocyte size and shape.P. volans has schizonts approximately one-half the size of those ofP. draconis and produces 4–6 merozoites in comparison to 4–16 in the larger species. Gametocytes of both new species are predominantly oval in the Palawan sample and elongate in that from Sarawak.P. draconis gametocytes are approximately twice the size ofP. volans gametocytes, but on average no more than one-half the size of gametocytes ofP. vastator.     

Studies of growth and development of gametocytes in Haemoproteus columbae Kruse.

As determined by their ability to exflagellate and round up, it took the macrogametocyte and the microgametocyte of Haemoproteus columbae in pigeons 68 and 116 h, respectively, after patency to reach maturity. Pigment granules appeared in the undifferentiated gametocytes 8 h after invasion of blood. Vacuoles were observed in young gametocytes and persisted in the older forms. The growth curve of H. columbae is close to the sigmoidal curve for growth in protozoa. Multiple infection was noticed in pigeons with high levels of parasitemia, but no more than 2 gametocytes reached maturity; such multiple infections were rare in relapses. The sex ratio of the gametocytes was 1:1. Strong lateral displacement of the nuclei of infected erythrocytes was the rule; hypertrophy was negligible.     

Molecular phylogenetic analysis of circumnuclear hemoproteids (Haemosporida: Haemoproteidae) of sylviid birds, with a description of Haemoproteus parabelopolskyi sp. nov

Haemoproteus spp., with circumnuclear gametocytes and tentatively belonging to Haemoproteus belopolskyi, are widespread and prevalent in warblers belonging to the Sylviidae, with numerous mitochondrial cytochrome b (cyt b) lineages detected among them.We sampled the hemoproteids from 6 species of warblers adjacent to the Baltic Sea. Parasites were identified to species based on morphology of their gametocytes, and a segment of the parasite's cyt b gene was sequenced. Sixteen mitochondrial cyt b lineages of hemoproteids with circumnuclear gametocytes were recorded. Two clades of lineages (clade A in species of Acrocephalus and Hippolais and clade B in species of Sylvia) with sequence divergence between their lineages >5% are distinguished in the phylogenetic tree. Within the clades A and B, the genetic distance between the lineages is < or = 3.9 and < and = 2.8%, respectively. We compared the morphology of gametocytes of 3 lineages (hHIICT1, hMW1, and hSYAT2) in detail. The lineages hHIICTI and hMW1 (clade A) belong to the morphospecies H. belopolskyi. Parasites of the lineage hSYAT2 (clade B) are described as a new species Haemoproteus parabelopolskyi, which can be readily distinguished from H. belopolskyi by the significantly smaller nuclei of its macrogametocytes. Lineages closely related to H. belopolskyi and H. parabelopolskyi are identified. The sequence divergence between lineages of these 2 morphospecies ranges between 5.3 and 8.1%. It seems probable that avian Haemoproteus spp. with a genetic differentiation of > or =5% in mitochondrial cyt b gene might be morphologically differentiated at the stage of gametocytes. This study establishes the value of both PCR and morphology in identification of avian hemoproteids.     

Studies of Growth and Development of Gametocytes in Haemoproteus columbae Kruse*

SYNOPSIS As determined by their ability to exflagellate and round up, it took the macrogametocyte and the microgametocyte of Haemoproteus columbae in pigeons 68 and 116 h, respectively, after patency to reach maturity. Pigment granules appeared in the undifferentiated gametocytes 8 h after invasion of blood. Vacuoles were observed in young gametocytes and persisted in the older forms. The growth curve of H. columbae is close to the sigmoidal curve for growth in protozoa. Multiple infection was noticed in pigeons with high levels of parasitemia, but no more than 2 gametocytes reached maturity; such multiple infections were rare in relapses. The sex ratio of the gametocytes was 1:1. Strong lateral displacement of the nuclei of infected erythrocytes was the rule; hypertrophy was negligible.     

Effect and Localization of Trifluralin in Plasmodium falciparum Gametocytes: An Electron Microscopic Study1

Trifluralin, a herbicide which is known to bind to plant and algal tubulin, induced ultrastructural changes in the microtubules of the mature Plasmodium falciparum gametocytes in vitro. Trifluralin treatment led to disassembly of the well ordered subpellicular microtubules, whereas it had no effect on microtubules of human platelets or of rat neuronal cells in vitro. The disassembled microtubules showed fragmented large tubular structures, which frequently were associated with the pellicular membranes. Electron microscopic autoradiography showed radioactive trifluralin associated with the microtubule fragments. These results provide evidence that trifluralin selectively binds to microtubules in malaria parasites and causes disruption of their structure.     

Hepatozoon ursi n. sp. (Apicomplexa: Hepatozoidae) in Japanese black bear (Ursus thibetanus japonicus)

Morphological and genetic features of a new Hepatozoon species, Hepatozoon ursi n. sp., in Japanese black bear (Ursus thibetanus japonicus) were studied. Schizogonic developmental stages were observed in the lungs of Japanese black bears. The schizonts were sub-spherical in shape and 45.7+/-4.6 x 42.7+/-4.5 microm in size. Each mature schizont contained approximately 80-130 merozoites and 0-5 residual bodies. The merozoites were 7.0+/-0.7 x 1.8+/-0.3 microm in size. Intraleukocytic gametocytes were slightly curved, cigar-like in shape and had a beak-like protrusion at one end. The size of the gametocytes was 10.9+/-0.3 x 3.3+/-0.2 microm. The analyses of the18S rRNA gene sequences supported the hypothesis that H. ursi n. sp. is different from other Hepatozoon species. Mature Hepatozoon oocysts were detected in two species of ticks (Haemaphysalis japonica and Haemaphysalis flava) collected on the bears infected with H. ursi n. sp. Two measured oocysts were 263.2 x 234.0 microm and 331.8 x 231.7 microm, respectively. The oocysts contained approximately 40 and 50 sporocysts, respectively. The sporocysts were sub-spherical in shape and 31.2+/-2.5 x 27.0+/-2.9 microm in size. Each sporocyst contained at least 8-16 sporozoites, with the sporozoites being 12.2+/-1.4 x 3.5+/-0.5 microm in size. H. ursi n. sp. is the first Hepatozoon species recorded from the family Ursidae.     

Genome Sequence of n-Alkane-Degrading Hydrocarboniphaga effusa Strain AP103T (ATCC BAA-332T)

Hydrocarboniphaga effusa strain AP103(T) (ATCC BAA-332(T)) is a member of the Gammaproteobacteria utilizing n-alkanes as the sole source of carbon and energy. Here we report the draft genome sequence of AP103(T), which consists of 5,193,926 bp with a G + C content of 65.18%.