Regional differences in shell conductance and pore density of avian eggs

Rokitka, M. A.; Rahn, Hermann

doi:10.1016/s0034-5687(87)80021-x

Cited by 44 publications

(28 citation statements)

References 13 publications

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“…Similar observations have been recorded in Blue Tits (Cyanistes caeruleus) where pigmentation ''spread'' was significantly correlated with daily rate of mass loss during incubation (Sanz and García-Navas, 2009). Despite the evidence that eggshell pores tend to have a higher density (pores per mm 2 ) at the shoulder and blunt end of the egg (Rokitka and Rahn, 1987), eggs with pigment spots spread evenly across the eggshell had a lower rate of mass loss than eggs that had the maculation distribution more over the blunt pole. The presence of the spots was seen as the factor reducing rates of mass loss although there was no significant relationship between pigment intensity and rates of mass loss (Sanz and García-Navas, 2009).…”

Section: Wild Bird Speciesmentioning

confidence: 92%

A Review of the Relationship between Eggshell Colour and Water Vapour Conductance

Deeming

2011

Avian Biology Research

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This review brings together the available literature that examines the effect of variations in pigmentation on the water vapour conductance of avian eggshells. Pheasant and Houbara bustard eggs provide some evidence that shell abnormalities can impact upon colour and water vapour conductance. By contrast, data from wild birds suggest that neither the degree of maculation or intensity of background colour impact upon conductance. Those studies that purport to show variation in rates of water loss in eggs with different degrees of pigmentation may have been confounded by variation in natural nesting conditions. This emerging field of research remains very much in its infancy.

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Section: Wild Bird Speciesmentioning

confidence: 92%

A Review of the Relationship between Eggshell Colour and Water Vapour Conductance

Deeming

2011

Avian Biology Research

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“…Quantification of angiogenic effects in ovo was done in the planar part of CAM under the egg's air cell. This CAM part seems interesting in connection with earlier findings related to regional variations of shell pore density and gas conductance (Rokitka and Rahn 1987) as well as blood vessel morphometry (Reizis et al 2005). The capacity for CAM gas exchange can be assessed by the ratio between the eggshell pore density and CAM blood vessel density.…”

Section: Discussionmentioning

confidence: 55%

“…The capacity for CAM gas exchange can be assessed by the ratio between the eggshell pore density and CAM blood vessel density. Rokitka and Rahn (1987) found regional differences in shell pore density and shell gas conductance in six different avian species. All species displayed a decrease in regional shell conductance and pore density from the blunt end to the pointed end.…”

Section: Discussionmentioning

confidence: 89%

Angiogenic Effect of Leptin in the Quail Chorioallantoic Membrane

et al. 2010

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Leptin, the product of ob gene, beside its key role in the control of body weight and food consumption, can be involved in the control of embryonic development. Leptin administration in ovo accelerated the embryonic and post-embryonic development in Japanese quail. Although the mechanisms of leptin effects on growth and development acceleration are not clear, stimulation of angiogenesis represents one of plausible explanations. Therefore, the aim of the present study was to investigate the pro-angiogenic effect of leptin in vivo in the quail chorioallantoic membrane (CAM). The recombinant murine leptin (10, 100, and 1000 ng) was applied either ex ovo on the CAM surface of ex ovo incubated embryos at embryonic day 7 (ED7) or in ovo into the egg albumen at ED5. Changes in blood vessels were quantified by the fractal analysis providing the fractal dimension (Df) estimate. Leptin administered in ovo was more efficient in stimulation of angiogenesis than the ex ovo treatment, since 10 ng dose elicited significantly higher (P < 0.001) stimulation of vessel development of the CAM under the air cell than it did after ex ovo cultivation. Our study confirmed that exogenously applied leptin was able to stimulate angiogenesis in CAM. Leptin-mediated stimulation of angiogenesis may improve nutrient utilization from the yolk and explain at least partially the accelerating effect of leptin on avian embryo growth and development.

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“…Thus, among other factors, an optimal exchange rate for both O 2 and CO 2 through the shell to and from the blood vessels of the CAM should exist. This suggests that an area of the shell, which potentially evaporates relatively more water, can potentially exchange more respiratory gases (Rokitka and Rahn, 1987). In addition, the CAM blood flow supplying/carrying away the respiratory gases should be regulated, and this requires an appropriate development of blood vessels.…”

Section: Discussionmentioning

confidence: 99%

“…Rokitka and Rahn (1987) measured water vapor diffusive conductance of eggshells of six avian species and found an average decline of 88 and 63% of blunt end values, for the middle and the pointed end, respectively. These relationships corresponded to the changes in regional eggshell pore density.…”

mentioning

confidence: 99%

Regional and developmental variations of blood vessel morphometry in the chick embryo chorioallantoic membrane

Reizis

Hammel

2005

Journal of Experimental Biology

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Avian eggs contain all the necessary materials for embryonic development except for oxygen, which diffuses in from the environment via pores in the hard, calcified eggshell to the chorioallantoic membrane (CAM), the respiratory organ, which is rich in blood vessels. An air cell is formed at the blunt pole of the egg between the two membranes of the eggshell and enlarges during incubation due to water vapor loss. In this study of the CAM of chicken eggs, we compared blood vessel numerical density Since the eggshell over the air cell has a relatively greater porosity, and the respiratory gas exchange ratio there is higher than at other areas of the egg, there is a correlation between all the above morphometric data and the eggshell porosity. This suggests optimization of embryonic gas exchange in the chicken egg. We would like to propose that, during natural incubation, an increased gas diffusion under the air cell, together with increased blood vessel numerical density, may compensate for covering of the central part of the eggshell by the incubating parent.

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Regional differences in shell conductance and pore density of avian eggs

Cited by 44 publications

References 13 publications

A Review of the Relationship between Eggshell Colour and Water Vapour Conductance

A Review of the Relationship between Eggshell Colour and Water Vapour Conductance

Angiogenic Effect of Leptin in the Quail Chorioallantoic Membrane

Regional and developmental variations of blood vessel morphometry in the chick embryo chorioallantoic membrane

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