Details of Award
NERC Reference : NER/B/S/2003/00822
Differential maternal investment of yolk hormones: the importance of egg age and embryo development on yolk androgen concentration.
Grant Award
- Principal Investigator:
- Dr N Hazon, University of St Andrews, Biology
- Co-Investigator:
- Dr JA Graves, University of St Andrews, Biology
- Grant held at:
- University of St Andrews, Biology
- Science Area:
- Terrestrial
- Overall Classification:
- Terrestrial
- ENRIs:
- Environmental Risks and Hazards
- Biodiversity
- Science Topics:
- Environmental Physiology
- Conservation Ecology
- Behavioural Ecology
- Abstract:
- Environmental factors such as food availability and mate attractiveness can influence the value of individual offspring to the parents. As such, parents should invest differentially in different offspring depending on these environmental factors. Such invested resources include antioxidants, immunoglobulins or hormones deposited into the egg yolks by females. There is currently mounting interest in the adaptive value and the role of maternally-derived yolk androgens (testosterone and its derivatives) in egg-laying species. However, it is currently contentious whether maternally-derived yolk androgens are a valuable investment, a flexible tool to manipulate offspring fitness, or a sex-determination mechanism. Preliminary data we have shows that infertile eggs (i.e: those without embryo development) have higher yolk androgen concentration than eggs containing embryos. The first possible explanation of this is that high androgen levels inhibit embryo development, and we will test this hypothesis. This could have fascinating implications for female control of hatching success over individual eggs, and could function in sex ratio manipulation. The second possibility is that embryo development causes yolk androgen levels to drop dramatically. Therefore, a further aim of this study is to ascertain the effect of embryo development on yolk androgen content and to provide a standardised methodology for future studies of maternal investment of yolk androgens. This is crucially important because, so far, eggs of different ages have been analysed both between and within studies. We will breed zebra finches and incubate the eggs for different lengths of time. We will sex the embryos using molecular methods, and assay the yolks and albumen for androgens using radioimmunoassays. We will compare the androgen concentrations of i) infertile with fertile eggs of the same age, ii) male and female eggs, and iii) eggs of different age categories.
- NERC Reference:
- NER/B/S/2003/00822
- Grant Stage:
- Completed
- Scheme:
- Small Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Small Grants
This grant award has a total value of £30,687
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - T&S | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £16,340 | £2,173 | £4,658 | £7,516 |
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