New Paper by Kathrine: The cls Gene of Buchnera as a Key to Symbiosis

A study led by our lab member Kathrine Tan has been published in iScience. The research demonstrates that the cls gene, the sole remaining phospholipid biosynthesis enzyme gene in the aphid endosymbiont Buchnera aphidicola, plays a crucial role in maintaining symbiosis with its host.

While Buchnera has lost nearly all phospholipid biosynthesis genes, the cardiolipin synthase gene (cls) is conserved. By applying the PNA-based knockdown method she established in 2024, Tan successfully disrupted the function of cls. This led to a reduction in Buchnera cell numbers, morphological abnormalities, and, in rare cases, mislocalization of the bacteria to the gut instead of their designated symbiotic organ. Importantly, these disruptions were accompanied by a decline in aphid reproductive performance, underscoring the essential role of cls in host–symbiont interactions.

Future studies will aim to clarify the precise molecular function of cls. Notably, the loss of most phospholipid synthesis genes while retaining cls is not unique to Buchnera but is also a common feature across many insect symbionts. Thus, this work provides important insights into the evolutionary processes underlying symbiosis.

Reference

Tan, K.X.Y., and Shigenobu, S. (2025). Targeted disruption of the cls gene in Buchnera aphidicola impairs membrane integrity and host symbiont dynamics. iScience 28, 113178. https://doi.org/10.1016/j.isci.2025.113178