A recent paper published in the March 6, ’12 issue of Current Biology by Christin et al. at the Dept. of Ecology and Evolutionary Biology Brown University, USA and seven other authors have adduced strong evidence of Lateral Gene Transfer (LGT) in eukaryotes. The researchers studied the ancestry of the two genes encoding enzymes, namely, phosphoenolpyruvate carboxylase (PEPC) and phosphoenolpyruvate carboxykinase (PEPCK) that play a significant role in C4 photosynthesis. Four phylogenetically related species, three C4 and one C3 were studied intensively to learn the evolutionary history of the PEPC and PEPCK genes. The study on the phylogenetic analyses of nuclear genes and leaf transcriptomes, revealed that the basic elements of the C4 pathway in the grass lineage Alloteropsis evolved through a minimum of four independent LTGs from C4 taxa that distanced from the C3 group more than 20 million years ago. The transfer of genes that were already fully adapted for C4 function has occurred occasionally over a period of at least last 10 million years leading to the perfection of the C4 pathway. The study was possible due to the availability of the genomic data of the selected grass taxa, a good understanding of the enzymes involved in this metabolic pathway, high expression of the genes for C4 enzymes and finally due to earlier detection of a set of adaptive amino acid changes in the enzymes involved in the C4 pathway revealing the evolutionary importance of the genes acquired laterally. Please click here to read more.
summarized by Samsad Razzaque, a Biotechnology Graduate.