| 1. |
- Zuntini, Alexandre R., et al.
(författare)
-
Phylogenomics and the rise of the angiosperms
- 2024
-
Ingår i: NATURE. - 0028-0836 .- 1476-4687. ; 629, s. 843-850
-
Tidskriftsartikel (refereegranskat)abstract
- Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods(1,2). A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome(3,4). Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins(5-7). However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes(8). This 15-fold increase in genus-level sampling relative to comparable nuclear studies(9) provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.
|
|
| 2. |
- Karawita, Anjana C., et al.
(författare)
-
The swan genome and transcriptome, it is not all black and white
- 2023
-
Ingår i: Genome Biology. - : BioMed Central (BMC). - 1465-6906 .- 1474-760X. ; 24:1
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe Australian black swan (Cygnus atratus) is an iconic species with contrasting plumage to that of the closely related northern hemisphere white swans. The relative geographic isolation of the black swan may have resulted in a limited immune repertoire and increased susceptibility to infectious diseases, notably infectious diseases from which Australia has been largely shielded. Unlike mallard ducks and the mute swan (Cygnus olor), the black swan is extremely sensitive to highly pathogenic avian influenza. Understanding this susceptibility has been impaired by the absence of any available swan genome and transcriptome information.ResultsHere, we generate the first chromosome-length black and mute swan genomes annotated with transcriptome data, all using long-read based pipelines generated for vertebrate species. We use these genomes and transcriptomes to show that unlike other wild waterfowl, black swans lack an expanded immune gene repertoire, lack a key viral pattern-recognition receptor in endothelial cells and mount a poorly controlled inflammatory response to highly pathogenic avian influenza. We also implicate genetic differences in SLC45A2 gene in the iconic plumage of the black swan.ConclusionTogether, these data suggest that the immune system of the black swan is such that should any avian viral infection become established in its native habitat, the black swan would be in a significant peril.
|
|
| 3. |
|
|
| 4. |
- Sobotka, Kristina, et al.
(författare)
-
Single Sustained Inflation followed by Ventilation Leads to Rapid Cardiorespiratory Recovery but Causes Cerebral Vascular Leakage in Asphyxiated Near-Term Lambs
- 2016
-
Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background A sustained inflation (SI) rapidly restores cardiac function in asphyxic, bradycardic newborns but its effects on cerebral haemodynamics and brain injury are unknown. We determined the effect of different SI strategies on carotid blood flow (CaBF) and cerebral vascular integrity in asphyxiated near-term lambs. Lambs were instrumented and delivered at 139 +/- 2 d gestation and asphyxia was induced by delaying ventilation onset. Lambs were randomised to receive 5 consecutive 3 s SI (multiple SI; n = 6), a single 30 s SI (single SI; n = 6) or conventional ventilation (no SI; n = 6). Ventilation continued for 30 min in all lambs while CaBF and respiratory function parameters were recorded. Brains were assessed for gross histopathology and vascular leakage. CaBF increased more rapidly and to a greater extent during a single SI (p = 0.01), which then decreased below both other groups by 10 min, due to a higher cerebral oxygen delivery (p = 0.01). Blood brain barrier disruption was increased in single SI lambs as indicated by increased numbers of blood vessel profiles with plasma protein extravasation (p = 0.001) in the cerebral cortex. There were no differences in CaBF or cerebral oxygen delivery between the multiple SI and no SI lambs. Ventilation with an initial single 30 s SI improves circulatory recovery, but is associated with greater disruption of blood brain barrier function, which may exacerbate brain injury suffered by asphyxiated newborns. This injury may occur as a direct result of the initial SI or to the higher tidal volumes delivered during subsequent ventilation.
|
|
| 5. |
- Zander, Ivo, et al.
(författare)
-
Born globals and international business : Evolution of a field of research
- 2015
-
Ingår i: Journal of International Business Studies. - : Springer Science and Business Media LLC. - 0047-2506 .- 1478-6990. ; 46:1, s. 27-35
-
Tidskriftsartikel (refereegranskat)abstract
- Knight and Cavusgil's award-winning article has played an important role in the development of the growing body of research on companies that internationalize early and rapidly. These "born global" firms represent important contributors to many economies, often as key players in ecosystems that support large multinational enterprises. Despite their growing importance, our understanding of how and why these firms develop and implement their internationalization strategies, and what makes them successful, remains incomplete. Addressing such questions has contributed substantially to the development of the research domain of international entrepreneurship (IE), which focuses on entrepreneurial aspects of doing business across borders, in the context of both small and large firms. While IE is much broader than born globals, these firms are central to the IE domain and the impact of the Knight and Cavusgil paper has helped to develop a stronger awareness of the important linkages and intersections between IF and the wider international business research. community. We reflect on the important contribution of this paper, and suggest some directions for the future development of research into firms that choose to operate internationally practically from the start of their operations.
|
|
