Cassytha filiformis is a parasitic plant from the angiosperm family Lauraceae. According to NCBI nucleotide databases, cox1 sequences from C. filiformis and other Lauraceae species have been reported. A comparison of their sequences suggested that C. filiformis has an intron in its cox1, while other Lauraceae species have not. It is not clear whether the cox1 intron was acquired exclusively by C. filiformis, or whether it was lost in other members of the family.
Researchers from Xishuangbanna Tropical Botanical Garden (XTBG) investigated cox1 evolution in the parasitic Lauraceae species. They generated cox1 sequences from different C. filiformis samples collected from three distant places and from 32 other species from different lineages within the family Lauraceae, and analyzed the cox1 sequences from a wide diversity of angiosperms.
They identified two different copies of the gene cox1 in individual samples of C. filiformis. They also found two different copies of the cox1 gene in C. filiformis. In addition to the well-documented cox1 intron homing, they also identified exons involved in horizontal gene transfer.
The study demonstrated clearly the different origins of the two types of cox1 genes as well as the implications of two independent horizontal transfer events.
The study entitled “Horizontal Gene Transfer has Impacted cox1 Gene Evolution in Cassytha filiformis” has been published in Journal of Molecular Evolution.
LI Jie Ph.D Principal Investigator
Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China