Ascoma Development in Neophyllis melacarpa (Lecanorales, Ascomycota), with Notes on the Systematic Position of the Genus

1999 ◽  
Vol 47 (5) ◽  
pp. 783 ◽  
Author(s):  
Heidi Döring ◽  
Aino Henssen ◽  
Mats Wedin
Keyword(s):  
Developmental Stages ◽  
Systematic Position ◽  
Secondary Product ◽  
Generic Type ◽  
Characteristic Features ◽  
Product Chemistry

The ascoma ontogeny of Neophyllis melacarpa (F.Wilson)F.Wilson is described and similarities toAustropeltum glareosum Henssen, Döring & Kantvilas are pointed out. Neophyllis is shown to formtrue podetia as well as pseudopodetia, and an unpigmented boundary tissue ofthin-walled, plasma-rich hyphae. Characteristic features include the formationof a boundary tissue separating a hypophysiate pseudopodetium from theascomatal tissue, a large subglobose hypothecium, and a cortical covering ofyounger developmental stages. Ascus structure and conidiophore anatomy aredescribed and similarities to Austropeltum arediscussed. The secondary product chemistry of Neophyllisis described in detail, and two chemical taxa, corresponding to the currentlyaccepted species N. melacarpa andN. pachyphylla (MÜll.Arg.) Schneider, aretentatively accepted. The systematic position ofNeophyllis is discussed, and the generic distinctnessfrom Gymnoderma is clarified. It is concluded thatNeophyllis is closely related toAustropeltum, and that there is no support for regardingNeophyllis as closely related toCladonia, the generic type of Cladoniaceae. The possibleaffinities of Neophyllis to Stereocaulaceae andSphaerophoraceae are discussed, but it is pointed out that the delimitation ofall three families needs further investigation.

Report of Acineta euchaetae Sewell, 1951 from new locality of the Arabian Sea with notes on their taxonomy and distribution

Zootaxa ◽  
2021 ◽  
Vol 5039 (2) ◽  
pp. 291-298
Author(s):  
TAPAS CHATTERJEE ◽  
IGOR DOVGAL ◽  
VERONICA FERNANDES ◽  
AMRITA BHAUMIK ◽  
MANDAR NANAJKAR
Keyword(s):  
Adult Male ◽  
Arabian Sea ◽  
Calanoid Copepod ◽  
Developmental Stages ◽  
Systematic Position ◽  
Inland Waters ◽  
Ciliate Species ◽  
Rear Part

The article deals with the data about new find of the rare suctorian species Acineta euchaetae Sewell, 1951 on calanoid copepod host Euchaeta marina (Prestandrea, 1833) from the Arabian Sea. Seven young (sub-adult) individuals of the ciliate were observed on rear part of cephalothorax and on abdomen of adult male of copepod. The data about all known finds of A. euchaetae are discussed as well as the information on different developmental stages of the ciliate species. It is suggested that A. euchaetae is euryhaline species distributed in Eurasian coastal and inland waters and have preference for calanoid copepod hosts, but do not show specificity to any calanoid genus or species. The summarized diagnosis and refined systematic position of A. euchaetae are also provided.   

Clarification of the systematic position ofCercariaeum crassumWesenberg-Lund, 1934 (Digenea), based on karyological analysis and DNA sequences

2011 ◽  
Vol 86 (3) ◽  
pp. 293-301 ◽  
Author(s):  
R. Petkevičiūtė ◽  
V. Stunžėnas ◽  
G. Stanevičiūtė
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Developmental Stages ◽  
Sequence Divergence ◽  
Sister Group ◽  
Systematic Position ◽  
Life Cycles ◽  
Significant Information ◽  
Rdna Sequences ◽  
Species Specific

AbstractChromosome set and rDNA sequences of the larval digeneanCercariaeum crassumwere analysed in order to clarify its systematic position and possible adult form. Parasites were obtained from the sphaeriid bivalvePisidium amnicum, collected in Lithuanian and Finnish rivers. The karyotype is shown to consist of five pairs (2n = 10) of large, up to 14 μm, chromosomes. Complement, composed of a low diploid number of exclusively bi-armed elements, presumably arose through Robertsonian fusions of acrocentric chromosomes. Consistent with a Robertsonian-derived karyotype, one or two small, metacentric, mitotically stable B chromosomes were detected in the cells of parthenitae isolated from some host individuals. A phylogenetic analysis using rDNA internal transcribed spacer 2 (ITS2) and 28S sequences corroborates the allocation ofC. crassumto the family Allocreadiidae. In neighbour-joining and maximum parsimony phylogenetic treesC. crassumclusters into one clade withAllocreadiumspp., and is the closest sister group in relation toA. isoporum; the level of rDNA sequence divergence between them (2.67% for ITS2 and 1.16% for 28S) is consistent with the level expected for intrageneric variation. The present study adds significant information to a database for establishing species-specific characters for confident characterization of different developmental stages of allocreadiid species, clarification of their life cycles and evaluation of intra- and interspecific variability.

Thelopsis challenges the generic circumscription in the Gyalectaceae and brings new insights to the taxonomy of Ramonia

2021 ◽  
Vol 53 (1) ◽  
pp. 45-61
Author(s):  
Damien Ertz ◽  
Neil Sanderson ◽  
Marc Lebouvier
Keyword(s):  
Phylogenetic Analyses ◽  
Saint Paul ◽  
Morphological Characters ◽  
Systematic Position ◽  
Sister Species ◽  
Phylogenetic Position ◽  
Generic Type ◽  
The Family ◽  
Fungal Dna ◽  
First Time

AbstractThe genus Thelopsis was classified in the family Stictidaceae but its systematic position has never been investigated by molecular methods. In order to determine its family placement and to test its monophyly, fungal DNA of recent collections of Thelopsis specimens was sequenced. Phylogenetic analyses using nuLSU, RPB2 and mtSSU sequences reveal that members of Thelopsis form a monophyletic group within the genus Gyalecta as currently accepted. The placement of Thelopsis, including the generic type T. rubella, within the genus Gyalecta challenges the generic circumscription of this group because Thelopsis is well recognized by the combination of morphological characters: perithecioid ascomata, well-developed periphysoids, polysporous asci and small, few-septate ellipsoid-oblong ascospores. The sterile sorediate Opegrapha corticola is also placed in the Gyalectaceae as sister species to Thelopsis byssoidea + T. rubella. Ascomata of O. corticola are illustrated for the first time and support its placement in the genus Thelopsis. The hypothesis that O. corticola might represent the sorediate fertile morph of T. rubella is not confirmed because the species is phylogenetically and morphologically distinct. Thelopsis is recovered as polyphyletic, with T. melathelia being placed as sister species to Ramonia. The new combinations Thelopsis corticola (Coppins & P. James) Sanderson & Ertz comb. nov. and Ramonia melathelia (Nyl.) Ertz comb. nov. are introduced and a new species of Gyalecta, G. amsterdamensis Ertz, is described from Amsterdam and Saint-Paul Islands, characterized by a sterile thallus with discrete soralia. Petractis luetkemuelleri and P. nodispora are accommodated in the new genus Neopetractis, differing from the generic type (P. clausa) by having a different phylogenetic position and a different photobiont. Francisrosea bicolor Ertz & Sanderson gen. & sp. nov. is described for a sterile sorediate lichen somewhat similar to Opegrapha corticola but having an isolated phylogenetic position as sister to a clade including Gyalidea praetermissa and the genera Neopetractis and Ramonia. Gyalecta farlowii, G. nidarosiensis and G. carneola are placed in a molecular phylogeny for the first time. The taxonomic significance of morphological characters in Gyalectaceae is discussed.

Early development of twoCapitellaspecies (Annelida: Capitellidae) from the Gulf of Mexico

2019 ◽  
Vol 99 (7) ◽  
pp. 1557-1568
Author(s):  
Nuria Méndez ◽  
Justin Hilliard ◽  
Anja Schulze
Keyword(s):  
Gulf Of Mexico ◽  
Early Development ◽  
Developmental Stages ◽  
The Other ◽  
Pigmentation Pattern ◽  
Juvenile Mortality ◽  
Laboratory Conditions ◽  
Molecular Studies ◽  
Characteristic Features ◽  
Lecithotrophic Development

AbstractEarly development of the polychaetesCapitellasp. TF from Tampa, Florida andCapitellasp. TV from Tamiahua Lagoon, Veracruz was studied under laboratory conditions. Our observations indicate that hermaphrodites occur inCapitellasp. TF, but not inCapitellasp. TV. Length and volume of larvae and early juveniles were measured daily. Both species appear to have lecithotrophic development. Sizes and duration of the developmental stages varied widely, as in most known species ofCapitella. Characteristic features ofCapitellasp. TF include very small hermaphrodites with a distinct dorsal pigmentation pattern and characteristically shaped brood tubes with a centrally thickened region. Embryos forced to abandon the brood did not survive more than 3 days, and handling the brood produced alterations in timing. Ciliated metatrochophores fromCapitellasp. TV survived inside the brood without the female for at least 14 days and some larvae hatched and died during settling. Some of these larvae were abnormal, with two rounded protuberances in the two ends. Mortality was high. Fungi and protozoans appeared in the dishes and probably partially induced the production of thicker mucus in the brood tubes, delay in metamorphosis, juvenile mortality, worm length and failure in coupling. Size and duration of the developmental stages were distinctly different from the other putative lecithotrophic species of the complex. These differences and other characteristics of each species discard the possibility that they belong to a previously described species. Our results are applicable to future ecological, morphological and molecular studies of each species, habitat and phylogenetics.

Correlations between secondary-product chemistry and ecogeography in theRamalina siliquosa group (Lichens)

1977 ◽  
Vol 127 (2-3) ◽  
pp. 191-200 ◽  
Author(s):  
William Louis Culberson ◽  
Chicita F. Culberson ◽  
Anita Johnson
Keyword(s):  
Secondary Product ◽  
Product Chemistry

scholarly journals Molecular and genetic regulation of pig pancreatic islet cell development

2019 ◽  
Author(s):  
Seokho Kim ◽  
Robert L. Whitener ◽  
Heshan Peiris ◽  
Xueying Gu ◽  
Charles A. Chang ◽  
...  
Keyword(s):  
Pancreatic Islet ◽  
Developmental Stages ◽  
Islet Cells ◽  
Genetic Regulation ◽  
Human Islets ◽  
Human Islet ◽  
Human Pancreas ◽  
Pancreatic Islet Cell ◽  
Characteristic Features ◽  
Specific Regulation

AbstractReliance on rodents for understanding pancreatic genetics, development and islet function could limit progress in developing interventions for human diseases like diabetes mellitus. Similarities of pancreas morphology and function suggest that porcine and human pancreas developmental biology may have useful homologies. However, little is known about pig pancreas development. To fill this knowledge gap, we investigated fetal and neonatal pig pancreas at multiple, crucial developmental stages using modern experimental approaches. Purification of islet β-, α- and δ-cells followed by transcriptome analysis (RNA-Seq) and immunohistology identified cell- and stage-specific regulation, and revealed that pig and human islet cells share characteristic features not observed in mice. Morphometric analysis also revealed endocrine cell allocation and architectural similarities between pig and human islets. Our analysis unveiled scores of signaling pathways linked to native islet β-cell functional maturation, including evidence of fetal α-cell GLP-1 production and signaling to β-cells. Thus, the findings and resources detailed here show how pig pancreatic islet studies complement other systems for understanding the developmental programs that generate functional islet cells, and that are relevant to human pancreatic diseases.Summary StatementThis study reveals transcriptional, signaling and cellular programs governing pig pancreatic islet development, including striking similarities to human islet ontogeny, providing a novel resource for advancing human islet replacement strategies.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

Electron investigations of rhabdovirus-like particles in mexican bean beetles and crickets

1978 ◽  
Vol 36 (2) ◽  
pp. 378-379
Author(s):  
J. R. Adams ◽  
G. J Tompkins ◽  
A. M. Heimpel ◽  
E. Dougherty
Keyword(s):  
Biological Control ◽  
Integrated Pest Management ◽  
Pest Management ◽  
Developmental Stages ◽  
Management Program ◽  
Acheta Domesticus ◽  
Epilachna Varivestis ◽  
House Cricket ◽  
Similar Morphology ◽  
Bean Beetle

As part of a continual search for potential pathogens of insects for use in biological control or on an integrated pest management program, two bacilliform virus-like particles (VLP) of similar morphology have been found in the Mexican bean beetle Epilachna varivestis Mulsant and the house cricket, Acheta domesticus (L. ).Tissues of diseased larvae and adults of E. varivestis and all developmental stages of A. domesticus were fixed according to procedures previously described. While the bean beetles displayed no external symptoms, the diseased crickets displayed a twitching and shaking of the metathoracic legs and a lowered rate of activity.Examinations of larvae and adult Mexican bean beetles collected in the field in 1976 and 1977 in Maryland and field collected specimens brought into the lab in the fall and reared through several generations revealed that specimens from each collection contained vesicles in the cytoplasm of the midgut filled with hundreds of these VLP's which were enveloped and measured approximately 16-25 nm x 55-110 nm, the shorter VLP's generally having the greater width (Fig. 1).

The Fine Structure of the Sheath of Volvox Carteri f. Weismannia

1977 ◽  
Vol 35 ◽  
pp. 346-347
Author(s):  
Regina Birchem
Keyword(s):  
Developmental Stages ◽  
Ruthenium Red ◽  
Sulfated Polysaccharides ◽  
Volvox Carteri ◽  
High Voltage Electron Microscopy ◽  
Ultrastructural Studies ◽  
Voltage Electron ◽  
Sheath Formation ◽  
And Inversion ◽  
Sheath Material

Spheroids of the green colonial alga Volvox consist of biflagellate Chlamydomonad-like cells embedded in a transparent sheath. The sheath, important as a substance through which metabolic materials, light, and the sexual inducer must pass to and from the cells, has been shown to have an ordered structure (1,2). It is composed of both protein and carbohydrate (3); studies of V. rousseletii indicate an outside layer of sulfated polysaccharides (4).Ultrastructural studies of the sheath material in developmental stages of V. carteri f. weismannia were undertaken employing variations in the standard fixation procedure, ruthenium red, diaminobenzidine, and high voltage electron microscopy. Sheath formation begins after the completion of cell division and inversion of the daughter spheroids. Golgi, rough ER, and plasma membrane are actively involved in phases of sheath synthesis (Fig. 1). Six layers of ultrastructurally differentiated sheath material have been identified.

Ultrastructural modification of cellular interactions in cancer tumor

1978 ◽  
Vol 36 (2) ◽  
pp. 318-319
Author(s):  
N. P. Dmitrieva
Keyword(s):  
Cancer Cells ◽  
Human Thyroid ◽  
Adjacent Cell ◽  
Main Role ◽  
Cellular Interactions ◽  
Electron Microscopic ◽  
Cancer Tumor ◽  
Normal Human ◽  
Characteristic Features

One of the most characteristic features of cancer cells is their ability to metastasia. It is suggested that the modifications of the structure and properties of cancer cells surfaces play the main role in this process. The present work was aimed at finding out what ultrastructural features apear in tumor in vivo which removal of individual cancer cells from the cell population can provide. For this purpose the cellular interactions in the normal human thyroid and cancer tumor of this gland electron microscopic were studied. The tissues were fixed in osmium tetroxide and were embedded in Araldite-Epon.In normal human thyroid the most common type of intercellular contacts was represented by simple junction formed by the parallelalignment of adjacent cell membranees leaving in between an intermembranes space 15-20 nm filled with electronlucid material (Fig. 1a). Sometimes in the basal part of cells dilatations of the intercellular space 40-50 nm wide were found (Fig. 1a). Here the cell surfaces may form single short microvilli.

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