Scientists have been able to identify a number of cases, including the well-known monarch butterfly, where genes have ‘jumped’ naturally between totally different organisms. Does this make our own GMO experiments more acceptable?
Published last week in PLOS Genetics, the study found genes from parasitic wasps in two species of butterflies. Genes are usually only transferred vertically – that is from a parent to a child but scientists have found it’s possible for genes to transfer horizontally – from one species to another.
When a parasitic wasp lays eggs inside a host caterpillar’s body, at the same time it injects a virus that immobilises the caterpillar’s immune response so that the emerging wasp larvae can eat the caterpillar without interference. The caterpillar then dies and there is no gene transfer. But occasionally parasitic wasps make a mistake and lay their eggs in the wrong host. Although the wasp eggs then don’t survive, the caterpillar does, and some of the wasp DNA is transferred into the caterpillar’s DNA and subsequently passed on to its young.
Researchers have found wasp DNA when sequencing the genome of both Monarch butterflies and 3 species of moth.
They hypothesise that the wasp DNA survives in the butterflies as it produces an evolutionary advantage – it encourages the production of proteins that protect the caterpillars from being infected by bracovirus.
Although the creation of GMOs by humans is widely criticised as being ‘unnatural’, this discovery shows that gene transfer between organisms happens readily in nature. As study co-author Salvador Herrero of the University of Valencia says:
“You realise that nature is creating genetically modified organisms all the time”
More at PLOS
Citation: Gasmi L, Boulain H, Gauthier J, Hua-Van A, Musset K, Jakubowska AK, et al. (2015) Recurrent Domestication by Lepidoptera of Genes from Their Parasites Mediated by Bracoviruses. PLoS Genet 11(9): e1005470. doi:10.1371/journal.pgen.1005470