Analysis of an improved Cyanophora paradoxa genome assembly

• Main Authors: Price, Dana C., Goodenough, Ursula W., Roth, Robyn, Lee, Jae-Hyeok, Kariyawasam, Thamali, Mutwil, Marek, Ferrari, Camilla, Facchinelli, Fabio, Ball, Steven G., Cenci, Ugo, Chan, Cheong Xin, Wagner, Nicole E., Yoon, Hwan Su, Weber, Andreas P. M., Bhattacharya, Debashish
• Other Authors: School of Biological Sciences
• Format: Article
• Language: English
• Published: 2020
• Subjects: Science::Biological sciences; Cyanophora Paradoxa; Archaeplastida
• Online Access: https://hdl.handle.net/10356/142287
• Institution: Nanyang Technological University

Glaucophyta are members of the Archaeplastida, the founding group of photosynthetic eukaryotes that also includes red algae (Rhodophyta), green algae, and plants (Viridiplantae). Here we present a high-quality assembly, built using long-read sequences, of the ca. 100 Mb nuclear genome of the model glaucophyte Cyanophora paradoxa. We also conducted a quick-freeze deep-etch electron microscopy (QFDEEM) analysis of C. paradoxa cells to investigate glaucophyte morphology in comparison to other organisms. Using the genome data, we generated a resolved 115-taxon eukaryotic tree of life that includes a well-supported, monophyletic Archaeplastida. Analysis of muroplast peptidoglycan (PG) ultrastructure using QFDEEM shows that PG is most dense at the cleavage-furrow. Analysis of the chlamydial contribution to glaucophytes and other Archaeplastida shows that these foreign sequences likely played a key role in anaerobic glycolysis in primordial algae to alleviate ATP starvation under night-time hypoxia. The robust genome assembly of C. paradoxa significantly advances knowledge about this model species and provides a reference for exploring the panoply of traits associated with the anciently diverged glaucophyte lineage.