Abstract Detail

Comparative Genomics/Transcriptomics

Robison, Tanner [1], Hauser, Duncan [2], Nelson, Jessica [2], Lewis, Louise [3], Li, Fay-Wei [4].

Exploring the dynamic plastid and and mitochondrial genomes of a new species of green algae (Chaetopeltidales, Chlorophyceae).

Chaetopeltidales is a poorly characterized order in the Chlorophyceae of green algae, with only two complete plastid and no mitochondrial genomes published. Here we characterize the organellar genomes of a new, but yet to be described genus and species in this order. The mitochondrial genome, measuring 66,927bp, represents the first complete mitochondrial genome published for the order Chaetopeltidales. The chloroplast genome, measuring 428,981bp, is one of the largest plastid genomes published to date, and shares this large size with the other sequenced plastomes in Chaetopeltidales. In addition to its massive size, this new plastid genome shares with the other members of Chaetopeltidales an incredible number of short repeats which are dispersed throughout the intergenic regions of the plastid genomes. Despite these shared features, the plastid genomes of Chaetopeltidales appear to be highly rearranged when compared to one another, with inversions, translocations, and duplications, suggesting a particularly dynamic plastome. Finally, both the plastid and mitochondrial genomes of this new algae contain a number of mobile group I and group II introns, which appear to have occurred in separate waves of invasion. Interestingly, three of the introns within the mitochondrial genome encode homing endonucleases that show highest similarity to those found in fungi, rather than algae, suggesting a possible case of horizontal gene transfer. These results help to shed light on a less understood group of algae and their unusual organellar genomes and raise additional questions about the unique patterns of genome evolution within Chaetopeltidales.

1 - Cornell University, Plant Biology, 533 Tower Road, Ithaca, NY, 14853, United States
2 - Maastricht University, Maastricht Science Programme, PO Box 616, 6200 MD, Maastricht, Netherlands
3 - University of Connecticut, Department of Ecology and Evolutionary Biology, 200 Pharmacy/Biology Building, Storrs, CT, 06269, USA
4 - Boyce Thompson Institute, 533 Tower Rd, Ithaca, NY, 14853, United States

none specified

Presentation Type: Oral Paper
Session: CG3, Functional & Comparative Genetics/Genomics III
Location: Virtual/Virtual
Date: Friday, July 31st, 2020
Time: 4:15 PM
Number: CG3006
Abstract ID:356
Candidate for Awards:Margaret Menzel Award

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