Insights into the biology and phylogeny of Chloromonas polyptera (Chlorophyta), an alga causing orange snow in Maritime Antarctica

2013 ◽  
Vol 25 (5) ◽  
pp. 648-656 ◽  
Author(s):  
Daniel Remias ◽  
Hans Wastian ◽  
Cornelius Lütz ◽  
Thomas Leya
Keyword(s):  
Soluble Carbohydrates ◽  
Outer Cell ◽  
Geographical Distance ◽  
Nutrient Input ◽  
Maritime Antarctica ◽  
Closely Related Species ◽  
Close Relationship ◽  
Relationship Of ◽  
The Antarctic ◽  
Outer Cell Wall

AbstractIn Antarctica, mass accumulations of psychrophilic algae cause striking phenomena like green, orange, or red snow. This occurs during summer, when coastal snowfields start to melt, become waterlogged and photoautotrophs can thrive. Chloromonas polyptera (Fritsch) Hoham, Mullet & Roemer is a unicellular species that causes orange snow in the vicinity of penguin rockeries. It has been recognized for many decades because of the distinct habitat and the characteristic morphology of cysts with elongated flanges on the outer cell wall. However, closer investigations concerning the ecology or physiology have been sparse so far. Field material was collected from two sites on the Antarctic Peninsula to find out more about metabolic and cellular strategies. The results were compared with a closely related species from high alpine locations, Chloromonas nivalis (Chodat) Hoham & Mullet. Despite the geographical distance, C. polyptera shares several physiological strategies with the alpine relative, such as the formation of cyst stages, saccharose and glycerol as main soluble carbohydrates and the abundant accumulation of the carotenoid astaxanthin. Moreover, photosynthesis is adapted to temperatures of about 1°C. The molecular phylogeny confirmed a close relationship of C. polyptera to other Chloromonas species isolated from snow. Chloromonas polyptera seems to be exclusive to coastal Antarctic ecosystems influenced by animal nutrient input.

Description of new chiactine-bearing sponges provides insights into the higher classification of Calcaronea (Porifera: Calcarea)

Zootaxa ◽  
2019 ◽  
Vol 4615 (2) ◽  
pp. 201
Author(s):  
ADRIANA ALVIZU ◽  
JOANA R. XAVIER ◽  
HANS TORE RAPP
Keyword(s):  
New Species ◽  
Phylogenetic Reconstruction ◽  
Molecular Data ◽  
Phylogenetic Study ◽  
Two New Species ◽  
Close Relationship ◽  
New Material ◽  
Relationship Of ◽  
The Antarctic

A recent phylogenetic study revealed a close relationship between chiactine-bearing (family Achramorphidae, order Leucosolenida) and pugiole-bearing (order Baerida) calcaronean sponges as well as new putative taxa within Achramorphidae. In this study, we present a revision of chiactine-bearing sponges based on morphological re-examination of type material and recently collected specimens, in addition to new molecular data for the ribosomal 18S and C-region of the 28S. We provide re-descriptions for all known chiactine-bearing species, and further describe two new species from the Antarctic (Achramorpha antarctica sp. nov. and Megapogon schiaparellii sp. nov.) and two new species and a new genus from the Nordic Seas (Achramorpha ingolfi sp. nov. and Sarsinella karasikensis gen. nov. sp. nov.). The new phylogenetic reconstruction based on ribosomal 18S and C-region of the 28S confirms previous findings about the close relationship of some members of Baerida and the family Achramorphidae of the order Leucosolenida. However, new material and the addition of molecular data from the type species of both taxa would be required to formally propose changes at (sub-)ordinal levels within the classification of Calcaronean sponges. 

scholarly journals Reevaluation of Host Specificity of the Closely Related Species Pseudoperonospora humuli and P. cubensis

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 55-61 ◽  
Author(s):  
Fabian Runge ◽  
Marco Thines
Keyword(s):  
Closely Related Species ◽  
Bryonia Dioica ◽  
Virulence Potential ◽  
Pseudoperonospora Humuli ◽  
Host Jump ◽  
High Virulence ◽  
Close Relationship ◽  
Internal Transcribed Spacer Sequences ◽  
Relationship Of ◽  
Limited Possibility

Pseudoperonospora cubensis causes some of the most devastating diseases of cucurbitaceous crops, while P. humuli is an important pathogen of hop (Cannabaceae). Although parasitic to different Angiosperm orders, these pathogens are highly similar, both in morphology and based on molecular comparisons. Considering the close relationship of P. humuli and P. cubensis, it was hypothesized that cross infectivity of the pathogens between their optimum hosts might be possible. Two strains of P. humuli and one of P. cubensis used in this study were able to reproduce on the two wild cucurbit relatives Bryonia dioica and Sicyos angulatus. Interestingly, limited infectivity of the P. cubensis strain to hop was also observed, and the P. humuli strain was also able to infest Cucumis sativus. The cross infections were verified by comparing the nuclear ribosomal-internal transcribed spacer sequences of newly produced sporangiophores from the different hosts. Morphologically the two pathogens could be distinguished by statistical analyses on their original hosts but these differences diminished on some alternate hosts. The ability of P. cubensis to infest the perennial Bryonia dioica and Humulus lupulus might offer a limited possibility for overwintering in temperate regions and needs to be evaluated in future studies. The ability of P. humuli to complete its life cycle on all the tested cucurbits provides evidence that the host jump across orders may continue and points to the high virulence potential of this pathogen.

Morphological and molecular characterisation of Aporcelaimellus nigeriensis sp. n. (Dorylaimida: Aporcelaimidae), a remarkable dorylaim from Nigeria

Nematology ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 867-877
Author(s):  
Milad Rashidifard ◽  
Tesleem T. Bello ◽  
Hendrika Fourie ◽  
Danny L. Coyne ◽  
Reyes Peña-Santiago
Keyword(s):  
New Species ◽  
Related Species ◽  
Ventral Side ◽  
Molecular Characterisation ◽  
Neck Length ◽  
Closely Related Species ◽  
Close Relationship ◽  
Relationship Of ◽  
The Relationship ◽  
A New Species

Summary A new species of Aporcelaimellus, collected in a watermelon field in Nigeria, is described, including its morphological and molecular (D2-D3 28S-rDNA, 18r-DNA) characterisation. Aporcelaimellus nigeriensis sp. n. is distinguishable by its 2.76-3.55 mm length, very coarse ventral body pores, lip region offset by deep constriction and 24-27 μm broad odontostyle 30-36 μm long at its dorsal and 28-31 μm at its ventral side, neck 648-779 μm long, pharyngeal expansion occupying 54-60% of total neck length, uterus 300-473 μm or 2.1-3.2 body diam. long and tripartite, V = 49-54, tail short and convex conoid (27-41 μm, c = 72-115, c′ = 0.5-0.7), spicules 108-137 μm long, and 9-10 spaced ventromedian supplements with hiatus. LSU analysis revealed a close relationship of A. nigeriensis sp. n. with other Aporcelaimellus species and questioned, once more, the monophyly of Aporcelaimidae. SSU phylogenetic tree was not able to resolve the relationship between the new species and other closely related species.

Ruthenium red and alcian blue effects on outer structures of methanotrophic bacteria

1988 ◽  
Vol 46 ◽  
pp. 72-73
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
C.C. Remsen
Keyword(s):  
Research Effort ◽  
Ruthenium Red ◽  
Outer Cell ◽  
Methanotrophic Bacteria ◽  
En Bloc ◽  
Methylosinus Trichosporium ◽  
Wall Structures ◽  
Methylomonas Albus ◽  
Type Strains ◽  
Outer Cell Wall

Methane, a contributor to the “greenhouse effect”, is oxidized in the natural environment by methanotrophic bacteria. As part of a comprehensive research effort, we have been examining the ultrastructure of methanotrophs. These microorganisms have complex outer cell wall structures similar to those frequently found in other chemol itho- trophic bacteria. (1,2)In our work, we have focused on the “type” strains of Methylomonas albus BG8 and Methylosinus trichosporium OB3b. Between Spurr and LR White embedding resins, we found a difference 1n the preservation of an outer cup layer of BG8 external to the peripheral membranes. Cells from the same sample embedded in Spurr consistently lacked this feature (FIG. 1). This effect was overcome by an en bloc ruthenium red (RR) protocol that resulted in successful retention of the cup layer in Spurr resin (FIG. 2). For OB3b cells, the en bloc RR protocol resulted in an exterior bead feature distinguishable in thin section (FIG. 4) that previously was seen only by SEM.

NOTES ON THE GENUS PROTARCHOIDES (HYMEN., ICHNEUMONIDAE)

1938 ◽  
Vol 70 (11) ◽  
pp. 230-232 ◽  
Author(s):  
C. Stuart Walley
Keyword(s):  
North American ◽  
North American Species ◽  
Close Relationship ◽  
Relationship Of

The following notes were assembled in arranging the Protarchoides material in the National Collection. In establishing the identity of Protarchoides mellipes (Prov.) it has been found necessary to synonymize one species. A species allied to mellipes is described as new and a table is provided for the separation of the four known North American species. The recording of Trichiosoma as host for a member of this genus is further evidence of the close relationship of the genus with Protarchus Foer.

scholarly journals Study of the 49 kDa excretory-secretory protein gene of Trichinella nativa and Trichinella spiralis

2007 ◽  
Vol 44 (3) ◽  
pp. 120-125 ◽  
Author(s):  
B. Zheng ◽  
L. Xiao ◽  
X. Wang ◽  
D. Li ◽  
Y. Lu ◽  
...  
Keyword(s):  
Prokaryotic Expression ◽  
Protein Gene ◽  
Trichinella Spiralis ◽  
Secretory Protein ◽  
Rt Pcr ◽  
Prokaryotic Expression Vector ◽  
Close Relationship ◽  
Bamhi Site ◽  
Relationship Of ◽  
Trichinella Nativa

AbstractTo study the function of the 49 kDa excretory-secretory (ES) protein gene (P49) of Trichinella, the genes was amplified by RT-PCR from RNA of Trichinella spiralis and Trichinella nativa and several Chinese Trichinella isolates of domestic animals, and sequenced after being cloned. The amplified products of these parasites produced bands of about 950 bp. The 97.2 % to 100 % nucleotides identity and 94.3 % to 100 % identity of deduced amino acids among P49 gene of these Trichinella strains showed the close relationship of these parasites. The P49 gene of T. nativa was cloned into the BamHI site of the prokaryotic expression vector pET-30a, and the recombinant vector was expressed. The expressed product was 40.8 kDa in size. In Western blot analysis, the expressed product was reactive to sera of mice infected with T. nativa, T. spiralis and their Chinese geographical strains.

Sign in / Sign up

Export Citation Format

Share Document