Oxygen consumption as related to the development of the extraembryonic membranes and cardiovascular system in the European pond turtle (Emys orbicularis) embryogenesis

Nechaeva, M. V.; Vladimirova, I. G.; Алексеева, Т. А.

doi:10.1016/j.cbpa.2007.08.005

Cited by 22 publications

(19 citation statements)

References 34 publications

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“…Deoxygenated afferent and oxygenated efferent blood sup- plies for the CAM are derived from chorioallantoic artery and vein, respectively. General patterns of growth and differentiation in the CAM and heart have been described for the European pond turtle, Emys orbicularis (Nechaeva et al, 2007). Increase in mass of both the CAM and heart are closely correlated with oxygen consumption prior to day 50 (total incubation time $ 100 days at 258C; Ewert, 1985).…”

Section: Chorioallantoic Membrane Vasculature Developmentmentioning

confidence: 94%

Development of cardiac form and function in ectothermic sauropsids

Crossley

Burggren

2009

Journal of Morphology

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Evolutionary morphologists and physiologists have long recognized the phylogenetic significance of the ectothermic sauropsids. Sauropids have been classically considered to bridge between early tetrapods, ectotherms, and the evolution of endotherms. This transition has been associated with many modifications in cardiovascular form and function, which have changed dramatically during the course of vertebrate evolution. Most cardiovascular studies have focused upon adults, leaving the development of this critical system largely unexplored. In this essay, we attempt a synthesis of sauropsid cardiovascular development based on the limited literature and indicate fertile regions for future studies. Early morphological cardiovascular development, i.e., the basic formation of the tube heart and the major pulmonary and systemic vessels, is similar across tetrapods. Subsequent cardiac chamber development, however, varies considerably between developing chelonians, squamates, crocodilians, and birds, reflected in the diversity of adult ventricular structure across these taxa. The details of how these differences in morphology develop, including the molecular regulation of cardiac and vascular growth and differentiation, are still poorly understood. In terms of the functional maturation of the cardiovascular system, reflected in physiological mechanisms for regulating heart rate and cardiac output, recent work has illustrated that changes during ontogeny in parameters such as heart rate and arterial blood pressure are somewhat species-dependent. However, there are commonalities, such as a beta-adrenergic receptor tone on the embryonic heart appearing prior to 60% of development. Differential gross morphological responses to environmental stressors (oxygen, hydration, temperature) have been investigated interspecifically, revealing that cardiac development is relatively plastic, especially, with respect to change in heart growth. Collectively, the data assembled here reflects the current limited morphological and physiological understanding of cardiovascular development in sauropsids and identifies key areas for future studies of this diverse vertebrate lineage.

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Section: Chorioallantoic Membrane Vasculature Developmentmentioning

confidence: 94%

Development of cardiac form and function in ectothermic sauropsids

Crossley

Burggren

2009

Journal of Morphology

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“…We then took advantage of this new methodology to test for thermal acclimation of heart rate of embryos in four reptilian species representing different phylogenetic lineages. In reptiles, the relationship between heart rate and test temperature shows very little change from early development all the way through to immediately prior to hatching when the eggs are incubated at a constant temperature [9], [11], [12], [13], unlike the situation in some birds [14], [15]. Thus, if reptilian embryos acclimate to incubation conditions, the relationship between test temperature and heart rate should differ between conspecific embryos incubated at different temperatures – regardless of the stage of embryonic development at which we make these comparisons.…”

Section: Introductionmentioning

confidence: 99%

Thermal Acclimation of Heart Rates in Reptilian Embryos

Hua

Zhao

et al. 2010

PLoS ONE

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In many reptiles, the thermal regimes experienced by eggs in natural nests vary as a function of ambient weather and location, and this variation has important impacts on patterns of embryonic development. Recent advances in non-invasive measurement of embryonic heart rates allow us to answer a long-standing puzzle in reptilian developmental biology: Do the metabolic and developmental rates of embryos acclimate to local incubation regimes, as occurs for metabolic acclimation by post-hatching reptiles? Based on a strong correlation between embryonic heart rate and oxygen consumption, we used heart rates as a measure of metabolic rate. We demonstrate acclimation of heart rates relative to temperature in embryos of one turtle, one snake and one lizard species that oviposit in relatively deep nests, but found no acclimation in another lizard species that uses shallow (and hence, highly thermally variable) nests. Embryonic thermal acclimation thus is widespread, but not ubiquitous, within reptiles.

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“…Therefore changes in ventricular volume and blood oxygen carrying capacity together with changes in oxygen extraction, could account for the higher rates of VO 2 in relation to f H during the later periods of embryonic development (Tazawa andWhittow, 1994, Burggren andPinder, 1991;Reiber, 1996, Crossley andAltimiras, 2000). So far, embryonic Vs has not been measured directly but heart mass is often used as a correlated index for its prediction (Burggren and Pinder, 1991;Birchard and Reiber, 1996;Nechaeva et al, 2007). In the iguana heart mass in embryos and hatchlings represents 0.2 to 0.3% of the body mass, approximately half of the 0.6% proportion typically found in adult mammals (Schmidt-Nielsen, 1984).…”

Section: Discussionmentioning

confidence: 99%

“…There have been some determinations of heart rate (f H ) during embryonic development in reptiles (see Taylor et al, 2014) that showed unchanging or even decreasing values during the final stages of incubation. Thus f H is clearly failing to match increasing rates of VO 2 (Nechaeva et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Rates of oxygen uptake increase independently of changes in heart rate in late stages of development and at hatching in the green iguana, Iguana iguana

Sartori

Abe

Crossley

et al. 2017

Comparative Biochemistry and Physiology Part A: Molecular &

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Oxygen consumption (VO), heart rate (f), heart mass (M) and body mass (M) were measured during embryonic incubation and in hatchlings of green iguana (Iguana iguana). Mean f and VO were unvarying in early stage embryos. VO increased exponentially during the later stages of embryonic development, doubling by the end of incubation, while f was constant, resulting in a 2.7-fold increase in oxygen pulse. Compared to late stage embryos, the mean inactive level of VO in hatchlings was 1.7 fold higher, while f was reduced by half resulting in a further 3.6 fold increase in oxygen pulse. There was an overall negative correlation between mean f and VO when data from hatchlings was included. Thus, predicting metabolic rate as VO from measurements of f is not possible in embryonic reptiles. Convective transport of oxygen to supply metabolism during embryonic incubation was more reliably indicated as an index of cardiac output (CO) derived from the product of f and M. However, a thorough analysis of factors determining rates of oxygen supply during development and eclosion in reptiles will require cannulation of blood vessels that proved impossible in the present study, to determine oxygen carrying capacity by the blood and arteriovenous oxygen content difference (A-V diff), plus patterns of blood flow.

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Oxygen consumption as related to the development of the extraembryonic membranes and cardiovascular system in the European pond turtle (Emys orbicularis) embryogenesis

Cited by 22 publications

References 34 publications

Development of cardiac form and function in ectothermic sauropsids

Development of cardiac form and function in ectothermic sauropsids

Thermal Acclimation of Heart Rates in Reptilian Embryos

Rates of oxygen uptake increase independently of changes in heart rate in late stages of development and at hatching in the green iguana, Iguana iguana

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