Ferns finally get a genome, revealing a history of DNA hoarding and kleptomania: Ferns are notorious for containing massive amounts of DNA and an excessively large number of chromosomes. Defying all expectations, a fern no larger than a dinner plate currently holds the title for highest chromosome count, with a whopping 720 pairs crammed into each of its nuclei. This penchant of ferns for hoarding DNA has stumped scientists, and the intractable size of their genomes has made it difficult to sequence, assemble and interpret them.
Now, two papers published in the journal Nature Plants are rewriting history with the first full-length genomes for homosporous ferns, a large group that contains 99% of all modern fern diversity. “Every genome tells a different story,” said co-author Doug Soltis, a distinguished professor with the Florida Museum of Natural History. “Ferns are the closest living relatives of all seed plants, and they produce chemical deterrents to herbivores that may be useful for agricultural research. Yet until now, they’ve remained the last major lineage of green life without a genome sequence.”
Two teams of researchers separately unveiled the genome of Ceratopteris (Ceratopteris richardii) this Thursday and that of the flying spider monkey tree fern (Alsophila spinulosa) last month.
Gardening at Last 