Scientists Sequencing the Christmas Tree

Researchers in Sweden say they’ve captured most of the genes found in a Christmas tree. It’s part of a wider set of international projects aiming to one day sequence the conifer family.

A study at the University of Laval suggests that the genome of conifers has changed very little in the past 100 million years, while flowering plants have changed dramatically. This partly explains why dinosaur-era fossils often show evidence of plants looking remarkably like conifers.

It seems the explanation is that conifers quickly found and established a natural home, particularly in cold climates, while flowering plants had to adapt to changing circumstances and fight for space. That’s also why there are comparatively few variations in the conifer family: the Laval’s Professor Jean Bousquet pegs the number of conifer species at 600, compared with more than 400,000 flowering plants.

Conifers have become of particular interest to scientists looking at DNA because they fill an important gap in the list of plants that have been genetically sequenced: their historical stability means they can help explain wider patterns of plant evolution over history.

Although a conifer such as a Christmas tree might look very simple to humans, they actually have about 50 percent more genes in some cases. Capturing and sequencing them is particularly complicated because the plants are so much larger than humans and contain much more DNA, much of it non-gene DNA. It could be compared to playing Battleships with only a few extra ships but a board six times bigger.

Researchers hope that not only genetic projects involving conifers help in research into forestry management, but it may throw up new insight into genetic sequencing itself.

The Laval team have already come up with a partial sequence of a loblolly pine covering about a million pieces of DNA, thought to be half the total, taken from a single pine nut. They hope to have completed genomes of the loblolly, sugar pine and Douglas-fir by 2016.

Meanwhile the Swedish researchers have captured around two million DNA pieces from a Norway spruce, better known as a Christmas tree. They think they have most of the 35,000 or so genes thought to be in the tree, but now need to work on correctly sequencing the genome.