What Mothers Eat Matters We use rats as a model for how humans work because we can control their diet and they quickly have many offspring. Rats are also very similar to humans physiologically. Studying this relationship using a rat model How did we measure potential fertility? Females are born with a limited number of eggs; all waiting halfway through meiosis. Each month some will go through four developmental stages and be ready for fertilisation. We counted the number of eggs developing in each treatment group to determine whether diet influenced egg development. An egg at the primordial stage The primary stage The secondary stage A mature antral egg follicle ready to be released for fertilisation Analysing changes in gene expression could explain these differences in egg development Thanks very much to the government-funded NZ Mathematics and Sciences Teacher fellowship scheme, administered by the Royal Society of NZ, that has allowed me to contribute to this research. I have had fantastic support from the scientists at the Liggins Institute, my host Dr Deborah Sloboda in particular; without her enthusiasm and encouragement I could not have done any of this! Also, a huge thank you to Jacquie Bay and Helen Mora for opportunities to participate in their amazing LENS programme. Jane Cunningham teaches science, biology and chemistry at Avondale College. Teacher Fellow 2008, hosted by the Liggins Institute, University of Auckland Evidence suggests our health is influenced by conditions we experienced in our mother’s womb Results suggest pregnant rats fed a high-fat diet programmed their daughters to go through puberty early and also use up their eggs more quickly. Research already suggests that if our mother ate a high-fat diet when pregnant it increases our risk of obesity, diabetes and heart disease later in life - even if we eat a healthy diet! Back in the classroom... Examples in Junior Science: Nature of science: experimental design, using animal models and ethical issues Food and digestion: importance of a healthy diet Reproduction : early puberty and the problems this can cause for our teenagers. Jane Cunningham, Avondale College Acknowledgements Mother ate balanced diet Mother ate high-fat diet Mother ate high-fat diet only during pregnancy With many women making choices about nutrition during pregnancy, high-fat diets may be contributing to difficulties getting pregnant and also harm their babies long term health. Results Examples in Year 13 Biology: How the environment affects our phenotype by changing gene expression Hormones and the control of gene expression in eukaryotes How biotechnologies are being used in current research Epigenetics and how it is changing our understanding of inheritance and evolution. For more information or resources, please me: Crush up the ovaries and extract all the RNA. Copy the RNA into cDNA which is more stable Use PCR to make multiple copies of the cDNA Use quantitative PCR to calculate differences in gene expression across the rat groups Use gel electrophoresis to check that cDNA is not contaminated Daughters fed a balanced diet Daughters fed a high- fat diet Daughters fed a balanced diet Daughters fed a high-fat diet Mothers ate a balanced diet Mothers ate high- fat diet when pregnant Mothers always ate high- fat diet Daughters fed a balanced diet Daughters fed a high fat diet Some of the rats weighed up to 1.5kg! We also investigated low-fat diets This research provides an interesting context for many skills and concepts: This graph demonstrates that if pregnant rats are fed a high-fat diet during pregnancy and lactation their pups will go into puberty earlier. This may be the case in human studies. So, is the fertility of these children affected? Age (days) Mother fed a balanced diet Mother fed a high-fat diet during pregnancy Mothers fed high- fat diet from birth Percentage of offspring who have reached puberty Do maternal diets also influence reproduction? Age at puberty