Complete Mitochondrial Genome of a Gymnosperm, Sitka Spruce (Picea Sitchensis), Indicates a Complex Physical Structure
This week we profile a recent publication in Genome Biology and Evolution from the laboratory
of Dr. Inanc Birol (pictured) at Canada’s Michael Smith Genome Sciences Centre at BC Cancer,.
Could you provide a brief overview of your lab’s current research focus?
The Bioinformatics Technology Lab at Canada’s Michael Smith Genome Sciences Centre (GSC) at BC Cancer, led by GSC Distinguished Scientist Dr. Inanc Birol, is a computational biology research group. We develop novel algorithms, data structures and genome analysis software and offer a complete and scalable solution for de novo genome assembly. The bioinformatics tools we build find applications in cancer research, and are the foundation of our genome research program at the GSC.
What is the significance of the findings in this publication?
In this study, we made use of both long- and short-read sequencing technologies to determine the complete sequence and physical structure of the Sitka spruce mitochondrial genome. Our analyses revealed that, similar to the genome of the Sitka spruce itself, the mitochondrial genome of the Sitka spruce is very large—one of the largest mitochondrial genomes sequenced to date—and has a complex and intricate physical structure. Rather than the typical circular mitochondrial chromosome seen in many species, the mitochondrial genome of the Sitka spruce is comprised to two components, the larger of which exhibits a branching rosette-like structure.
How these branched mitochondrial genomes are replicated during cellular division remains to be determined, and the complete sequence of the Sitka spruce mitochondrial genome will be an invaluable resource for future investigations into the genome structure and mechanism of replication.
Spruce trees are the most significant forest resources in Canada, producing high quality wood and fibre. But due to new challenges including climate change, acceleration of spruce breeding programs to ensure future forest health and productivity is crucial. Sequencing the Sitka spruce mitochondrial genome was part of the Spruce-Up project, a Canadian initiative aiming to produce genomics and socioeconomic knowledge to accelerate spruce breeding programs, working together to ensure the future of spruce trees in Canada.
What are the next steps for this research?
Like the trees themselves, spruce genomes are big, complex, and full of surprizes. We continue to refine the genomics resources for several spruce species and are preparing a series of follow-on publications describing spruce genomes in unprecedented detail and completeness.
This work was funded by:
This work was supported by Genome Canada, Genome Quebec, Genome British Columbia and Genome Alberta for the Spruce-Up project (243FOR).