Facultative mobilization of eggshell calcium promotes embryonic growth in an oviparous snake RESEARCH ARTICLE

James R. Stewart, Rebecca A. Pyles, Kaitlyn A. Mathis, and Tom W. Ecay The mineralized eggshell of Reptilia was a major innovation in the evolution of the amniotic egg. Inorganic components strengthen the eggshell and are a potential source of nutrients to developing embryos. Embryos of oviparous reptiles do extract calcium from eggshells but vary interspecifically in exploitation of this resource. The pattern of embryonic calcium nutrition of the corn snake, Pantherophis guttatus, is similar to a diversity of squamate species: embryos obtain most calcium from yolk, yet also mobilize calcium from the eggshell. We tested the hypothesis that embryonic development is not dependent on eggshell calcium by manipulating calcium availability. We peeled away the outer calcareous layer of the eggshell of recently oviposited eggs; control eggs were left intact. Eggs were sampled periodically and calcium content of egg compartments (embryo, yolk, eggshell) was measured. We also analyzed skeletal development and size of hatchlings. There was no difference in survivorship or length of incubation between treatments. However, hatchlings from intact eggs contained more calcium and were larger in mass and length than siblings from peeled eggs. There were no observable differences in ossification but hatchlings from intact eggs had larger skeletal elements (skull, vertebrae). Our results indicate that mobilization of eggshell calcium is not a requirement for embryonic development of P. guttatu...
Source: Journal of Experimental Biology - Category: Biology Authors: Tags: RESEARCH ARTICLE Source Type: research

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Source: Expert Review of Anti-Infective Therapy - Category: Infectious Diseases Tags: Expert Rev Anti Infect Ther Source Type: research
Authors: Rombauts A, Abelenda-Alonso G, Cuervo G, Gudiol C, Carratalà J Abstract INTRODUCTION: Despite adequate antibiotic coverage, community-acquired pneumonia (CAP) remains a leading cause of hospitalization and mortality worldwide. It induces both a local pulmonary and a systemic inflammatory response, particularly significant in severe cases. The intensity of the dysregulated host response varies from patient to patient and has a negative impact on survival and other outcomes. AREAS COVERED: This comprehensive review summarizes the pathophysiological aspects of the inflammatory response in CAP, brie...
Source: Expert Review of Anti-Infective Therapy - Category: Infectious Diseases Tags: Expert Rev Anti Infect Ther Source Type: research
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Source: Expert Review of Anti-Infective Therapy - Category: Infectious Diseases Tags: Expert Rev Anti Infect Ther Source Type: research
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Source: Expert Review of Anti-Infective Therapy - Category: Infectious Diseases Tags: Expert Rev Anti Infect Ther Source Type: research
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Source: Journal of Hazardous Materials - Category: Environmental Health Source Type: research
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