The diploid anuran Xenopus tropicalis has emerged as a key research model in cell and developmental biology. To enhance the usefulness of this species, we developed methods for generating immortal cell lines from Nigerian strain (NXR_1018, RRID:SCR_013731) X. tropicalis embryos. We generated 14 cell lines that were propagated for several months. We selected four morphologically distinct lines, XTN-6, XTN-8, XTN-10 and XTN-12 for further characterization. Karyotype analysis revealed that three of the lines, XTN-8, XTN-10 and XTN-12 were primarily diploid. XTN-6 cultures showed a consistent mixed population of diploid cells, cells with chromosome 8 trisomy, and cells containing a tetraploid content of chromosomes. The lines were propagated using conventional culture methods as adherent cultures at 30°C in a simple, diluted L-15 medium containing fetal bovine serum without use of a high CO 2 incubator. Transcriptome analysis indicated that the four lines were distinct lineages. These methods will be useful in the generation of cell lines from normal and mutant strains of X. tropicalis as well as other species of Xenopus .
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Four Draft Single-Cell Genome Sequences of Novel, Nearly Identical Kiritimatiellaeota Strains Isolated from the Continental Deep Subsurface
ABSTRACT The recently proposed bacterial phylum Kiritimatiellaeota represents a globally distributed monophyletic clade distinct from other members of the Planctomycetes , Verrucomicrobia , and Chlamydiae (PVC) superphylum. Here, we present four phylogenetically distinct single-cell genome sequences from within the Kiritimatiellaeota lineage sampled from deep continental subsurface aquifer fluids of the Death Valley Regional Flow System in the United States.
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- Award ID(s):
- 1826734
- NSF-PAR ID:
- 10100768
- Date Published:
- Journal Name:
- Microbiology Resource Announcements
- Volume:
- 8
- Issue:
- 11
- ISSN:
- 2576-098X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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While nostocacean cyanobacteria are ubiquitous and play critical roles in terrestrial ecosystems, their taxonomy and biogeography still entail mysteries. We isolated two
Nostoc ‐like cyanobacteria from biological soil crusts of the Atacama (Chile) and Mojave (USA) Deserts. An initial 16S rRNA gene phylogeny placed both in monophyly withMojavia pulchra . Here, we describe two new species of the previously monotypicMojavia using a polyphasic approach including morphology, 16S rRNA phylogenies, secondary structure, and percent similarity of the 16S‐23S ITS region. LikeM. pulchra , both new species produce compact microcolonies, arthrospore‐like akinetes, and monocytes, traits characteristic of the genus.Mojavia aguilerae sp. nov. is morphologically distinct from both other species in producing bluntly conical end cells, abundant enlarged akinetes in multiseriate filaments, and gold‐colored cells during senescence.Mojavia dolomitestris sp. nov. exhibited distinctly firm, light‐colored, compartmentalized mucilage.M. dolomitestris is somewhat cryptic withM. pulchra , but has more densely packed microcolonies, rarity and later onset of brownish sheath pigmentation, and an origin from soils derived from dolomite. The two new species strengthened the position ofMojavia as a robust genus sister toNostoc. Although 16S rRNA gene data could not separate theMojavia species from each other, the three species showed distinct dissimilarities in secondary ITS structure and differed greatly fromNostoc sensu stricto. The high dissimilarities between their 16S‐23S ITS regions suggest a long evolutionary history of the three species as separate lineages.Mojavia is an evolutionary and ecologically unique nostocacean genus, and its rarity and restricted habitat point to an urgent need for recognition and protection. -
Schilder, Rudolf (Ed.)Abstract Closely related phytophagous insects that specialize on different host plants may have divergent responses to environmental factors. Rhagoletis pomonella (Walsh) and Rhagoletis zephyria Snow (Diptera: Tephritidae) are sibling, sympatric fly species found in western North America that attack and mate on plants of Rosaceae (~60 taxa) and Caprifoliaceae (three taxa), respectively, likely contributing to partial reproductive isolation. Rhagoletis zephyria evolved from R. pomonella and is native to western North America, whereas R. pomonella was introduced there. Given that key features of the flies’ ecology, breeding compatibility, and evolution differ, we predicted that adult eclosion patterns of the two flies from Washington State, USA are also distinct. When puparia were chilled, eclosion of apple- and black hawthorn-origin R. pomonella was significantly more dispersed, with less pronounced peaks, than of snowberry-origin R. zephyria within sympatric and nonsympatric site comparisons. Percentages of chilled puparia that produced adults were ≥67% for both species. However, when puparia were not chilled, from 13.5 to 21.9% of apple-origin R. pomonella versus only 1.2% to 1.9% of R. zephyria eclosed. The distinct differences in eclosion traits of R. pomonella and R. zephyria could be due to greater genetic variation in R. pomonella, associated with its use of a wider range of host plants than R. zephyria.more » « less
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Adenosine-to-inosine (A-to-I) RNA editing, catalyzed by ADAR enzymes, is a ubiquitous mechanism that generates transcriptomic diversity. This process is particularly important for proper neuronal function; however, little is known about how RNA editing is dynamically regulated between the many functionally distinct neuronal populations of the brain. Here, we present a spatial RNA editing map in the
Drosophila brain and show that different neuronal populations possess distinct RNA editing signatures. After purifying and sequencing RNA from genetically marked groups of neuronal nuclei, we identified a large number of editing sites and compared editing levels in hundreds of transcripts across nine functionally different neuronal populations. We found distinct editing repertoires for each population, including sites in repeat regions of the transcriptome and differential editing in highly conserved and likely functional regions of transcripts that encode essential neuronal genes. These changes are site-specific and not driven by changes inAdar expression, suggesting a complex, targeted regulation of editing levels in key transcripts. This fine-tuning of the transcriptome between different neurons by RNA editing may account for functional differences between distinct populations in the brain. -
null (Ed.)This study builds on recent treatments of the marine red algal family Gracilariaceae (Gracilariales) focusing in detail on Hydropuntia and Crassiphycus. Species in these two genera often present identification problems due to high levels of morphologial similarity among genetically distinct species, and high levels of phenotypic plasticity, leading to pseudocryptic speciation and homoplasies. In order to resolve long standing problems, clarify some species concepts and better understand the evolution of the group, we performed phylogenetic analyses of all plastid rbcL DNA sequences available for known Hydropuntia and Crassiphycus species, including newly sequenced specimens. Our results revealed the presence of potentially undescribed species, the existence of strong phylogeographic patterns below and above the species level and helped re-delineate morphologically similar taxa. New detailed morphological descriptions for three common yet poorly known Western Atlantic species are provided: C. secundus, C. usneoides and H. rangiferina. H. rangiferina from the Indo- Pacific is a distinct species from the true H. rangiferina and represents a putative undescribed species. We also provide a time-calibrated phylogeny for the six genera in the Gracilariales to identify past geological and climatic processes associated with their origin and diversification.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1128/MRA.01249-18
