Zur feinstruktur der Chorda dorsalis niederer Chordaten [Dendrodoa grossularia (v. Beneden) und Oikopleura dioica Fol]

1968 ◽  
Vol 93 (4) ◽  
pp. 547-559 ◽  
Author(s):  
Ulrich Welsch ◽  
V�lker Storch
Keyword(s):  
Oikopleura Dioica ◽  
Chorda Dorsalis

scholarly journals Phosphorylation of the histone H3.3 variant in mitosis and meiosis of the urochordate Oikopleura dioica

2007 ◽  
Vol 15 (2) ◽  
pp. 189-201 ◽  
Author(s):  
Alexandra Schulmeister ◽  
Martina Schmid ◽  
Eric M. Thompson
Keyword(s):  
Oikopleura Dioica ◽  
Histone H3.3 ◽  
Mitosis And Meiosis

scholarly journals Simple Procedure for Sperm Cryopreservation in the Larvacean Tunicate Oikopleura dioica

2011 ◽  
Vol 28 (1) ◽  
pp. 8 ◽  
Author(s):  
Kazuaki Ouchi ◽  
Atsuo Nishino ◽  
Hiroki Nishida
Keyword(s):  
Simple Procedure ◽  
Sperm Cryopreservation ◽  
Oikopleura Dioica

scholarly journals Capture efficiency for small dominant mesozooplankters (Copepoda, Appendicularia) off Buenos Aires Province (34ºS-41ºS), Argentine Sea, using two plankton mesh sizes

2009 ◽  
Vol 57 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Rosana Di Mauro ◽  
Fabiana Capitanio ◽  
María Delia Viñas
Keyword(s):  
Buenos Aires ◽  
Developmental Stages ◽  
Fish Larvae ◽  
Abundant Species ◽  
Accurate Estimation ◽  
Buenos Aires Province ◽  
Oikopleura Dioica ◽  
Great Loss ◽  
Argentine Sea ◽  
Significant Difference

Two plankton mesh sizes of 67 µm and 220 µm were compared to evaluate their efficiency in the capture of the smallest copepods and appendicularians present in the Buenos Aires coastal area (Argentine Sea). A total of 12 copepod species and one appendicularian species were recorded in this study. The copepods were separated into 4 groups: harpacticoids, cyclopoids, small calanoids and large calanoids and their developmental stages. Among the cyclopoids, Oithona nana was the most abundant species, being 96.29 % underestimated by the 220 µm mesh, whereas Microsetella norvegica dominated the harpacticoids and was captured exclusively by the smaller mesh. Similar results were found for copepodites I-III of small calanoids, whose net sampled underestimation reached 99.70%. On the other hand, no significant difference between meshes was found for adults and copepodites IV-V of small calanoids or any of the developmental stages of large calanoids. A great loss of biomass was observed for O. nana when applying the larger mesh. In regards to the appendicularian Oikopleura dioica, all size ranges below 1,000 µm length were better estimated by the 67 µm mesh in terms of abundance and biomass. Our results clearly show that the 67 µm mesh was more efficient in the capture of early stages of small copepods thus providing a more accurate estimation of the fish larvae prey field.

scholarly journals Evolution of CDK1 paralog specializations in a lineage with fast developing planktonic embryos

2019 ◽  
Author(s):  
Xiaofei Ma ◽  
Jan Inge Øvrebø ◽  
Eric M Thompson
Keyword(s):  
General Rule ◽  
Embryonic Cell ◽  
Cyclin B ◽  
Gene Duplications ◽  
Structural Elements ◽  
Oikopleura Dioica ◽  
Cell Cycles ◽  
Protein Levels ◽  
Binding Interface ◽  
M Phase

AbstractThe active site of the essential, eukaryotic CDK1 kinase is generated by core structural elements, among which the PSTAIRE motif in the critical αC-helix, is universally conserved in metazoans. The CDK2 kinase, sharing the PSTAIRE, arose early in metazoan evolution and permitted subdivision of tasks along the S-M-phase axis. The marine chordate, Oikopleura dioica, is the only metazoan known to possess more than a single CDK1 ortholog, and all of its 5 paralogs show sequence divergences in the PSTAIRE. Through assessing CDK1 gene duplications in the appendicularian lineage, we show that the CDK1 activation loop substrate binding platform, ATP entrance site, hinge region, and main Cyclin binding interface, have all diversified under positive selection. Three of the 5 CDK1 paralogs are required for embryonic divisions and knockdown phenotypes illustrate further subdivision of functions along the S-M-phase axis. In parallel to CDK1 gene duplications, there has also been amplification in the Cyclin B complement. Among these, the CDK1d:Cyclin Ba pairing is required for oogenic meiosis and early embryogenesis and shows evidence of coevolution of an exclusive interaction. In an intriguing twist on the general rule that Cyclin B oscillations on a background of stable CDK1 levels regulate M-phase MPF activity, it is CDK1d protein levels that oscillate, rather than Cyclin Ba levels, to drive rapid, early embryonic cell cycles. Strikingly, the modified PSTAIRE of odCDK1d shows convergence over great evolutionary distance with plant CDKB, and in both O. dioica, and plants, these variants exhibit increased specialization to M-phase.

scholarly journals Widespread use of the “ascidian” mitochondrial genetic code in tunicates

F1000Research ◽  
2020 ◽  
Vol 8 ◽  
pp. 2072
Author(s):  
Julien Pichon ◽  
Nicholas M. Luscombe ◽  
Charles Plessy
Keyword(s):  
Genetic Code ◽  
Stop Codon ◽  
Mitochondrial Protein ◽  
Sequence Alignments ◽  
Additional Species ◽  
Multiple Sequence ◽  
Oikopleura Dioica ◽  
Mitochondrial Genetic Code ◽  
Mitochondrial Sequences ◽  
Mitochondrial Code

Background: Ascidians, a tunicate class, use a mitochondrial genetic code that is distinct from vertebrates and other invertebrates. Though it has been used to translate the coding sequences from other tunicate species on a case-by-case basis, it is has not been investigated whether this can be done systematically. This is an important because a) some tunicate mitochondrial sequences are currently translated with the invertebrate code by repositories such as NCBI GenBank, and b) uncertainties about the genetic code to use can complicate or introduce errors in phylogenetic studies based on translated mitochondrial protein sequences. Methods: We collected publicly available nucleotide sequences for non-ascidian tunicates including appendicularians such as Oikopleura dioica, translated them using the ascidian mitochondrial code, and built multiple sequence alignments covering all tunicate classes. Results: All tunicates studied here appear to translate AGR codons to glycine instead of serine (invertebrates) or as a stop codon (vertebrates), as initially described in ascidians. Among Oikopleuridae, we suggest further possible changes in the use of the ATA (Ile → Met) and TGA (Trp → Arg) codons. Conclusions: We recommend using the ascidian mitochondrial code in automatic translation pipelines of mitochondrial sequences for all tunicates. Further investigation is required for additional species-specific differences.

scholarly journals XV. On the chorda dorsalis

1841 ◽  
Vol 131 ◽  
pp. 195-199
Keyword(s):  
Whole Body ◽  
Chorda Dorsalis ◽  
Embryonic Structure

For the discovery of the remarkable structure in the embryo of some of the Vertebrata denominated the chorda dorsalis, we are indebted to Professor Baer. This naturalist considered it “the axis around which the first parts of the fœtus form,” and “the true virga mensoria for the whole body and all the chief systems.” Reichert supposes it to be that embryonic structure which serves as a “support and stay” for parts developed in two halves. In the course of my researches on the mammiferous ovum, an object was noticed which seems to correspond in appearance to the incipient chorda now referred to. I am desirous of drawing attention to this similarity in appearance, but more particularly to point out some important differences between my own observations and those of others, as to the mode of origin of the objects in question, and their relation to surrounding parts. For, should it be found that these objects are the same, my belief is that even the most recent views on the incipient growth of the embryo must undergo a change.

scholarly journals Spatiotemporal patterns of neurogenesis in the appendicularian Oikopleura dioica

2007 ◽  
Vol 311 (1) ◽  
pp. 264-275 ◽  
Author(s):  
Anne Mette Søviknes ◽  
Joel C. Glover
Keyword(s):  
Spatiotemporal Patterns ◽  
Oikopleura Dioica
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