| 1. |
- Bernander, Rolf, et al.
(författare)
-
An archaeal origin for the actin cytoskeleton : implications for eukaryogenesis
- 2011
-
Ingår i: Communicative & Integrative Biology. - : Landes Bioscience. - 1942-0889. ; 4:6, s. 664-667
-
Tidskriftsartikel (refereegranskat)abstract
- A hallmark of the eukaryotic cell is the actin cytoskeleton, involved in a wide array of processes ranging from shape determination and phagocytosis to intracellular transport and cytokinesis. Recently, we reported the discovery of an actin-based cytoskeleton also in Archaea. The archaeal actin ortholog, Crenactin, was shown to belong to a conserved operon, Arcade (actin-related cytoskeleton in Archaea involved in shape determination), encoding an additional set of cytoskeleton-associated proteins. Here, we elaborate on the implications of these findings for the evolutionary relation between archaea and eukaryotes, with particular focus on the possibility that eukaryotic actin and actin-related proteins have evolved from an ancestral archaeal actin gene. Archaeal actin could thus have played an important role in cellular processes essential for the origin and early evolution of the eukaryotic lineage. Further exploration of uncharacterized archaeal lineages is necessary to find additional missing pieces in the evolutionary trajectory that ultimately gave rise to present-day organisms.
|
|
| 2. |
- Brusselaers, N
(författare)
-
Prescribed Drugs and the Microbiome
- 2019
-
Ingår i: Gastroenterology clinics of North America. - : Elsevier BV. - 1558-1942 .- 0889-8553. ; 48:3, s. 331-
-
Tidskriftsartikel (refereegranskat)
|
|
| 3. |
- Dahl, Tais W., et al.
(författare)
-
Do large predatory fish track ocean oxygenation?
- 2011
-
Ingår i: Communicative & Integrative Biology. - : Informa UK Limited. - 1942-0889. ; 4:1, s. 92-94
-
Tidskriftsartikel (refereegranskat)abstract
- The Devonian appearance of 1-10 meter long armored fish (placoderms) coincides with geochemical evidence recording a transition into fully oxygenated oceans. A comparison of extant fish shows that the large individuals are less tolerant to hypoxia than their smaller cousins. This leads us to hypothesize that Early Paleozoic O2 saturation levels were too low to support >1 meter size marine, predatory fish. According to a simple model, both oxygen uptake and oxygen demand scale positively with size, but the demand exceeds supply for the largest fish with an active, predatory life style. Therefore, the largest individuals may lead us to a lower limit on oceanic O2 concentrations. Our presented model suggests 2-10 meter long predators require >30-50% PAL while smaller fish would survive at <25% PAL. This is consistent with the hypothesis that low atmospheric oxygen pressure acted as an evolutionary barrier for fish to grow much above ~1 meter before the Devonian oxygenation.
|
|
| 4. |
- Eskilsson, Anna, 1986-, et al.
(författare)
-
Prostaglandin production in brain endothelial cells during the initiation of fever
- 2023
-
Ingår i: Communicative & Integrative Biology. - : Informa UK Limited. - 1942-0889. ; 16:1
-
Tidskriftsartikel (refereegranskat)abstract
- The initiation of fever has been a matter of controversy. Based on observations of little or no induction of prostaglandin synthesizing enzymes in the brain during the first phase of fever it was suggested that fever is initiated by prostaglandin released into the circulation from cells in the liver and lungs. Here we show in the mouse that prostaglandin synthesis is rapidly induced in the brain after immune challenge. These data are consistent with our recent findings in functional experiments that prostaglandin production in brain endothelial cells is both necessary and sufficient for the generation of all phases of fever.
|
|
| 5. |
- Ettema, Thijs, et al.
(författare)
-
Cell division and the ESCRT complex : A surprise from the archaea
- 2009
-
Ingår i: Communicative & Integrative Biology. - 1942-0889. ; 2:2, s. 86-88
-
Tidskriftsartikel (refereegranskat)abstract
- The Archaea constitute the third domain of life, a separate evolutionary lineage together with the Bacteria and the Eukarya.1 Species belonging to the Archaea contain a surprising mix of bacterial (metabolism, life style, genomic organization) and eukaryotic (replication, transcription, translation) features.2 The archaeal kingdom comprises two main phyla, the Crenarchaeota and the Euryarchaeota. Regarding the cell division process in archaeal species (reviewed in ref. 3), members of the Euryarchaeota rely on an FtsZ-based cell division mechanism4 whereas, previously, no division genes had been detected in the crenarchaea. However, we recently reported the discovery of the elusive cell division machinery in crenarchaea from the genus Sulfolobus.5 The minimal machinery consists of three genes, which we designated cdvA, B and C (for cell division), organized into an operon that is widely conserved among crenarchaea. The gene products polymerize between segregating nucleoids at the early mitotic stage, forming a complex that remains associated with the leading edge of constriction throughout cytokinesis. Interestingly, CdvB and CdvC were shown to be related to the eukaryotic ESCRT-III protein sorting machinery (reviewed in ref. 6), indicating shared common ancestry and mechanistic similarities to endosomal vesicle formation and viral (HIV) budding in eukaryotes. We also demonstrated that the cdv operon is subject to checkpoint-like regulation, and that the genes display a complementary phylogenetic distribution within the Archaea domain relative to FtsZ-dependent division systems.5 Here, the findings are further explored and discussed, and topics for further investigation are suggested.
|
|
| 6. |
|
|
| 7. |
- Hagman, Mattias
(författare)
-
Pheromone-induced life-history shifts : a novel approach to controlling invasive toads
- 2010
-
Ingår i: Communicative & Integrative Biology. - 1942-0889. ; 3:3, s. 238-239
-
Tidskriftsartikel (refereegranskat)abstract
- In a recent paper,1 we showed that recurrent exposure to alarm pheromones reduced development time and size at metamorphosis in larval cane toads (Bufo marinus). Subsequent measurements of post-metamorphic toads revealed larger parotoid glands relative to body size and increased amounts of bufalin (a toxic bufodienalide) in animals from the experimental treatment, suggesting increased investment in chemical defenses. These findings are of interest for evolutionary theory. But the study was also part of a larger conservation-based research program of which this pheromone work was an important component in the development of a management strategy for reducing the ecological impact of invasive cane toads in Australia. For example, our study1 aimed to quantify biochemical and life-history effects as well as assess the likely longterm impact of pheromone exposure on toads. In this addendum, I discuss the conservation potential of our research, with emphasis on exploiting alarm pheromones to induce viability reducing life-history shifts.
|
|
| 8. |
- Heijtz, RD
(författare)
-
Preface
- 2019
-
Ingår i: Gastroenterology clinics of North America. - : Elsevier BV. - 1558-1942 .- 0889-8553. ; 48:3, s. XI-XII
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 9. |
|
|
| 10. |
- Johansson, Fredrik, et al.
(författare)
-
Theoretical considerations for understanding a Purkinje cell timing mechanism
- 2014
-
Ingår i: Communicative & Integrative Biology. - : Informa UK Limited. - 1942-0889. ; 7:6, s. 994376-994376
-
Tidskriftsartikel (refereegranskat)abstract
- In classical conditioning, cerebellar Purkinje cells learn an adaptively timed pause in spontaneous firing. This pause reaches its maximum near the end of the interstimulus interval. While it was thought that this timing was due to temporal patterns in the input signal and selective engagement of changes in synapse strength, we have shown Purkinje cells learn timed responses even when the conditional stimulus is delivered to its immediate afferents.(1) This shows that Purkinje cells have a cellular timing mechanism. The cellular models of intrinsic timing we are aware of are based on adapting the rise time of the concentration of a given ion. As an alternative, we here propose a selection mechanism in abstract terms for how a Purkinje cell could learn to respond at a particular time after an external trigger.
|
|
