Chinese researchers have made significant strides in understanding the molecular mechanisms that enable birds to tolerate highly acidic foods, a trait that has intrigued scientists for quite some time.

In a study published in the journal Science, the researchers identified a crucial mutation in the sour taste receptor known as the OTOP1 gene, which plays a vital role in allowing songbirds to consume acidic fruits without experiencing aversion.

Lai Ren, a researcher affiliated with the Kunming Institute of Zoology at the Chinese Academy of Sciences and the corresponding author of the paper, explained that a single amino acid change in the OTOP1 gene enhances sour tolerance in songbirds, a development crucial for their dietary expansion and subsequent species diversification.

Additionally, the research team uncovered a potential co-evolutionary connection between birds' ability to tolerate sour tastes and their perception of sweetness. This dual capability not only enables them to withstand the acids present in fruits but also allows them to accurately detect sugar levels, thus enhancing their resource exploitation.

Lai emphasized the novelty of the study, stating that it is the first to systematically reveal the molecular foundation of avian sour taste perception along with its evolutionary significance. This work proposes the hypothesis of a 'songbird sour-sweet co-evolution' that provides fresh theoretical insights into the adaptive interplay between complex sensory systems and their environmental challenges.

(Cover: VCG)