A research team led by Prof. Hwan Su Yoon (Department of Biological Sciences at Sungkyunkwan University), together with the research team of Prof. Bhattacharya published a paper on the evolutionary process of chloroplasts in the photosynthetic amoebae, Paulinella micropora.

Chloroplasts are the powerhouses of many aquatic and terrestrial ecosystems. The chloroplast in algae and plants originated more than 1 billion years ago and therefore offers limited insights into the initial stages of chloroplast evolution. To address this issue, we focused on the photosynthetic amoeba Paulinella micropora that acquired chloroplast recently (∼124 million years ago) from the independent cyanobacterial origin.

Paulinella genome revealed how foreign genes from cyanobacteria and other bacteria affected during the evolution of the chloroplast. In plant cells, proteins involved in photosynthesis are targeted to the chloroplast. Short amino acid sequences called signal peptides are involved in this process. The research team discovered a unique chloroplast signal peptide in Paulinella, which has a plant-independent origin. Moreover, most of the chloroplast targeted proteins were originated from amoeba host, suggesting dominant host contribution to chloroplast evolution.

As a model organism showing what happened in the early evolution process of plants, the research on photosynthetic Paulinella is important. Paulinella genome information can be used as basic data for research on applied fields such as synthetic biology and genetic engineering that maximize photosynthesis efficiency.

[Image] photosynthetic Paulinella

Published article: Duckhyun Lhee, JunMo Lee, Khaoula Ettahi, Chung Hyun Cho, Ji-San Ha, Ya-Fan Chan, Udi Zelzion, Timothy G Stephens, Dana C Price, Arwa Gabr, Eva C M Nowack, Debashish Bhattacharya, Hwan Su Yoon, Amoeba Genome Reveals Dominant Host Contribution to Plastid Endosymbiosis, Molecular Biology and Evolution, Volume 38, Issue 2, February 2021, Pages 344–357, https://doi.org/10.1093/molbev/msaa206