skip to primary navigationskip to content
 

B333: You are what your mother ate: how maternal nutrition impacts offspring health (Lead Supervisor: Sinead English, Zoology)

Supervisors: Sinead English (Zoology), Rebecca Kilner (Zoology), John Terblanche (Stellenbosch University) and Lee Haines (Liverpool School of Tropical Medicine)

Importance of the area of research:

Environmental stress has a major effect on how individuals allocate nutrients among components of fitness, e.g. self-maintenance versus reproduction. When individuals are food-limited, they prioritize their own survival over that of their offspring, and this shift in allocation has long-term consequences for offspring quality. However, the mechanisms by which females adjust their nutrient allocation are poorly understood and vary across species with different diets. This project focuses on an important disease vector, the blood-feeding tsetse fly. Female flies give birth to live young and the larvae rely on maternal milk for nutrition. Tsetse live in sub-Saharan Africa where droughts are occurring with increasing frequency and severity as a result of climate change. Understanding how environmental stress, such as a decline in host abundance or quality, influences maternal nutrient allocation and offspring fitness is thus essential for predicting vector population dynamics and disease risk faced by these regions in coming years.

Project summary:

This project will investigate the influence of food stress on how individuals allocate and utilize nutrients across two generations in the live-bearing tsetse fly. Using a combination of diet manipulation experiments and cutting-edge stable isotope marker tracing, we will trace how specific macronutrients are utilized by mothers and transferred to their young depending on the degree of maternal nutritional stress. We will use the same isotopic markers to examine how offspring, when exposed to stressful conditions, use maternally-derived versus directly-derived nutrients for metabolism and survival. Our findings will feed into current population dynamic models of disease transmission.

What the student will do:

The student will use a novel method of spiking bloodmeals with isotopic markers to trace nutrient transfer from tsetse mothers to their offspring under conditions of food stress. Experimental stress manipulations will be achieved by increasing the plasma to red-blood-cell ratio of bloodmeals to mimic undernourished, dehydrated or anaemic mammalian hosts. Control and undernourished meals will be provided to pregnant females and subsequently to their adult offspring following a fully-factorial design. Using a newly developed method of non-invasive insect breath testing, the student will follow the fate of nutrients and their metabolic products across generations depending on the food stress experienced by mothers, offspring or both. This experimental design will allow the student to ask whether females experiencing food stress reduce their nutrient allocation to larvae, and subsequently whether offspring exposed to food stress are more reliant on maternally-derived nutrients than those which they obtain from blood feeding.

Please contact the lead supervisor directly for further information relating to what the successful applicant will be expected to do, training to be provided, and any specific educational background requirements.

References:

Boggs, C. L., and K. Niitepõld. 2014. Insights from Stable Isotopic Tracers on Reproductive Allocation under Stress. Integr. Comp. Biol. 54:1–10. DOI:10.1093/icb/icu074

McCue, M. D., R. Marena Guzman, C. A. Passement, and G. Davidowitz. 2015. How and when do insects rely on endogenous protein and lipid resources during lethal bouts of starvation? A new application for 13C-Breath testing. PLoS One 10:1–18. DOI:10.1371/journal.pone.0140053

McCue, M. D., L. Boardman, S. Clusella-Trullas, E. Kleynhans, and J. S. Terblanche. 2016. The speed and metabolic cost of digesting a blood meal depends on temperature in a major disease vector. J. Exp. Biol. 1893–1902. DOI:10.1242/jeb.138669

Follow this link to find out about applying for this project

Filed under: