Prokaryotic species are sui generis evolutionary units

2019 ◽  
Vol 42 (2) ◽  
pp. 145-158 ◽  
Author(s):  
Marike Palmer ◽  
Stephanus N. Venter ◽  
Martin P.A. Coetzee ◽  
Emma T. Steenkamp
1990 ◽  
Vol 5 ◽  
pp. 13-30 ◽  
Author(s):  
D. A. Springer ◽  
A. I. Miller

The way we view species distribution patterns, particularly at the level commonly referred to as the “community”, has changed over the past 70 years in biology and, subsequently, in paleontology. Because the degree to which species associations can be interpreted as ecological and evolutionary units depends ultimately on recognition and interpretation of faunal spatial variability, we need to understand the nature of this variability at all levels of resolution before we can adequately address questions of “community” structure and dynamics. While it is possible to recognize spatial variability at several levels, from the distributions of individuals within a species to the overall pattern created by the global biota, we must ask whether these patterns really comprise a hierarchy with natural discontinuities (Fig. 1), or whether it is more realistic to view them as a continuous variability spectrum.


2015 ◽  
Vol 17 (2) ◽  
pp. 455-471 ◽  
Author(s):  
Luke B. Klicka ◽  
Barbara E. Kus ◽  
Pascal O. Title ◽  
Kevin J. Burns

2020 ◽  
Vol 49 (6) ◽  
pp. 659-667
Author(s):  
Franziska Trede ◽  
Anna Lemkul ◽  
Anagaw Atickem ◽  
Jacinta C. Beehner ◽  
Thore J. Bergman ◽  
...  

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 541
Author(s):  
Yunqi Ma ◽  
Chang-Joo Lee ◽  
Jang-Su Park

Bacteria can produce recombinant proteins quickly and cost effectively. However, their physiological properties limit their use for the production of proteins in their native form, especially polypeptides that are subjected to major post-translational modifications. Proteins that rely on disulfide bridges for their stability are difficult to produce in Escherichia coli. The bacterium offers the least costly, simplest, and fastest method for protein production. However, it is difficult to produce proteins with a very large size. Saccharomyces cerevisiae and Pichia pastoris are the most commonly used yeast species for protein production. At a low expense, yeasts can offer high protein yields, generate proteins with a molecular weight greater than 50 kDa, extract signal sequences, and glycosylate proteins. Both eukaryotic and prokaryotic species maintain reducing conditions in the cytoplasm. Hence, the formation of disulfide bonds is inhibited. These bonds are formed in eukaryotic cells during the export cycle, under the oxidizing conditions of the endoplasmic reticulum. Bacteria do not have an advanced subcellular space, but in the oxidizing periplasm, they exhibit both export systems and enzymatic activities directed at the formation and quality of disulfide bonds. Here, we discuss current techniques used to target eukaryotic and prokaryotic species for the generation of correctly folded proteins with disulfide bonds.


2014 ◽  
Vol 23 (9) ◽  
pp. 1220-1234 ◽  
Author(s):  
Jimin Pei ◽  
Wenlin Li ◽  
Lisa N. Kinch ◽  
Nick V. Grishin

2014 ◽  
Vol 9 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Christoph Schubart ◽  
Bianca Aichinger

AbstractBristle crabs of the genus Pilumnus (Brachyura: Heterotremata: Pilumnidae) are common inhabitants of European waters. They are easily identifiable as a genus, but with the exception of P. inermis, intrageneric classification turns out to be quite complex. There is no general agreement on the number and distinction of species. Therefore, this genus is well-suited for comparative molecular studies. Specimens of the Pilumnus hirtellus complex, here defined as including Pilumnus hirtellus, P. villosissimus, P. spinifer, P. aestuarii, and an undescribed species, were gathered from throughout the Mediterranean Sea and the eastern Atlantic Ocean. DNA sequence data were obtained from the barcoding region of the cytochrome oxidase 1 mitochondrial gene and used for reconstruction of a phylogenetic tree and a haplotype network. The morphology of the gastric ossicles was compared in the search of separating characters. Our results give evidence for five genetic clusters within the P. hirtellus complex. There is negligible geographic variation within these clusters. Unambiguous mtDNA sequences within morphologically variable local populations argue against possible hybridization. The here encountered evolutionary units are relatively young and possibly allow to study ongoing processes of morphological, genetic, and ecological differentiation, leading to speciation and radiations in the coastal marine environment.


RSC Advances ◽  
2016 ◽  
Vol 6 (114) ◽  
pp. 113000-113006 ◽  
Author(s):  
K. Mogi ◽  
C. Shirataki ◽  
K. Kihara ◽  
H. Kuwahara ◽  
Y. Hongoh ◽  
...  
Keyword(s):  

The vast majority of prokaryotic species are difficult or impossible to culture in laboratories, which makes it difficult to study these organisms using conventional biochemical techniques.


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