For some people dark chocolate or coffee are just too bitter to stomach. For others they're heavenly. While culinary experiences throughout life certainly shape food preferences, the main reason for these stark differences may lie in our genetic make-up. This is because the shape and density of bitter taste buds called fungiform papillae (the rough patch in this microscope image of a rat's tongue) varies enormously between individuals. Having greater quantities of these sensors will exaggerate the characteristic bitterness of coffee and make it unbearably strong. Scientists now know that a minute difference in a single gene (called gustin) determines how many of these bitter buds coat our tongues. Fungiform papillae also pick up sweet, sour and spicy flavours so an aversion to dessert or curry for example, may have similar genetic foundations.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.