scholarly journals A lizard with two tales: what diversification within Sceloporus occidentalis teaches us about species formation

2021 ◽  
Author(s):  
Ricardo J Pereira ◽  
Sonal Singhal
Keyword(s):  
Sceloporus Occidentalis ◽  
Species Formation

scholarly journals Evidence for ephemeral ring species formation during the diversification history of western fence lizards ( Sceloporus occidentalis )

2021 ◽  
Author(s):  
Nassima M. Bouzid ◽  
James W. Archie ◽  
Roger A. Anderson ◽  
Jared A. Grummer ◽  
Adam D. Leaché
Keyword(s):  
Sceloporus Occidentalis ◽  
Species Formation ◽  
History Of ◽  
Ring Species

scholarly journals A lizard with two tales: what diversification within Sceloporus occidentalis teaches us about species formation

2021 ◽  
Author(s):  
Ricardo Pereira ◽  
Sonal Singhal
Keyword(s):  
Gene Flow ◽  
Genetic Drift ◽  
Charles Darwin ◽  
Molecular Ecology ◽  
Genetic Interactions ◽  
Sceloporus Occidentalis ◽  
Genome Data ◽  
Species Formation ◽  
Ring Species ◽  
Natural Laboratory

In 1859, Charles Darwin proposed that species are not fundamentally different from subspecies or the varieties from which they evolve. A century later, Dobzhansky (1958) suggested that many such lineages are ephemeral and are likely to revert differentiation through introgression (Fig. 1A); only a few evolve complete reproductive isolation and persist in sympatry. In this issue of Molecular Ecology, Bouzid et al. (2021) show how new analytical methods, when applied to genome data, allow us to more precisely determine whether or not species formation follows the paths outlined by Darwin and Dobzhansky (Fig. 1B). The authors study the diversification of the lizard Sceloporus occidentalis, finding a continuum of genetic interactions between the preservation of genetic identity to genetic merger, analogous to what is exemplified by ring species. In doing so, they teach us two tales on species formation: that lineages are fractal byproducts of evolutionary processes such as genetic drift and selection, and that lineages are often ephemeral and do not always progress into species. Studying ephemeral lineages like those in S. occidentalis allows us to capture divergence at its earliest stages, and potentially to determine the factors that allow lineages to remain distinct despite pervasive gene flow. These lineages thus serve as a natural laboratory to address long standing hypotheses on species formation.

Increased Demethylmenaquinone‐Dependent Reactive Oxygen Species Formation by Β-Lactams in Enterococcus Faecalis

2018 ◽  
Author(s):  
Loïc Léger ◽  
Aurélie Budin-Verneuil ◽  
Margherita Cacaci ◽  
Abdellah Benachour ◽  
Axel Hartke ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Enterococcus Faecalis ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Reactive Oxygen Species Formation ◽  
Species Formation

Compounds from Ilex paraguariensis extracts have antioxidant effects in the brains of rats subjected to chronic immobilization stress

2017 ◽  
Vol 42 (11) ◽  
pp. 1172-1178 ◽  
Author(s):  
Ana C. Colpo ◽  
Maria Eduarda de Lima ◽  
Marisol Maya-López ◽  
Hemerson Rosa ◽  
Cristina Márquez-Curiel ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Immobilization Stress ◽  
Brain Regions ◽  
Protective Role ◽  
Ilex Paraguariensis ◽  
Protective Effects ◽  
Species Formation ◽  
Lipid And Protein Oxidation ◽  
Response To Stress ◽  
Chronic Immobilization Stress

Immobilization induces oxidative damage to the brain. Ilex paraguariensis extracts (Mate) and their major natural compound, chlorogenic acid (CGA), exert protective effects against reactive oxygen species formation. Here, the effects of Mate and CGA on oxidative damage induced by chronic immobilization stress (CIS) in the cortex, hippocampus, and striatum were investigated. For CIS, animals were immobilized for 6 h every day for 21 consecutive days. Rats received Mate or CGA by intragastric gavage 30 min before every restraint session. Endpoints of oxidative stress (levels of lipid peroxidation, protein carbonylation, and reduced (GSH) and oxidized (GSSG) forms of glutathione) were evaluated following CIS. While CIS increased oxidized lipid and carbonyl levels in all brain regions, CGA (and Mate to a lesser extent) attenuated lipid and protein oxidation as compared with control groups. GSH/GSSG balance showed a tendency to increase in all regions in response to stress and antioxidants. Taken together, our results support a protective role of dietary antioxidants against the neuronal consequences of stress.

Perching Behavior of Sceloporus occidentalis in Recently Burned Chaparral

Copeia ◽  
1974 ◽  
Vol 1974 (1) ◽  
pp. 256 ◽  
Author(s):  
Harvey B. Lillywhite ◽  
F. North
Keyword(s):  
Sceloporus Occidentalis

scholarly journals Effect of Novel Marine Nutraceuticals on IL-1α-Mediated TNF-αRelease from UVB-Irradiated Human Melanocyte-Derived Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Visalini Muthusamy ◽  
Lynn D. Hodges ◽  
Theodore A. Macrides ◽  
Glen M. Boyle ◽  
Terrence J. Piva
Keyword(s):  
Antioxidant Properties ◽  
Mitogen Activated Protein Kinase ◽  
Uvb Radiation ◽  
Reactive Oxygen Species Formation ◽  
Mapk Signalling Pathway ◽  
Species Formation ◽  
Human Melanocyte ◽  
Mapk Signalling ◽  
Mitogen Activated Protein ◽  
Necrosis Factor

UV-induced inflammation and reactive oxygen species formation are involved in the development of melanoma. Natural products like 5β-scymnol and CO2-supercritical fluid extract (CO2-SFE) of mussel oil contain anti-inflammatory and antioxidant properties that may aid in reducing the deleterious effects of UV radiation. Therefore, their effect on the release of the proinflammatory cytokine, tumour necrosis factor-α(TNF-α), from UVB-irradiated human melanocytic cells was examined. Human epidermal melanocytes (HEM) and MM96L melanoma cells were exposed to UVB radiation and IL-1α. Cell viability and TNF-αlevels were determined 24 hours after-irradiation while p38 mitogen-activated protein kinase (MAPK) activation was observed at 15 min after-irradiation. Whenα-tocopherol, CO2-SFE mussel oil, and 5β-scymnol were added to the UVB-irradiated HEM cells treated with IL-1α, TNF-αlevels fell by 53%, 65%, and 76%, respectively, while no inhibition was evident in MM96L cells. This effect was not due to inhibition of the intracellular p38 MAPK signalling pathway. These compounds may be useful in preventing inflammation-induced damage to normal melanocytes.

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