Our new research confirms that lampreys experience rampant programmed genome rearrangement and losses during early development.
Dr Chris Amemiya
Studies of the sea lamprey, an eel-like parasitic vertebrate which preys on fish, have shown that more than a thousand genes are shed throughout the embryo in its early stages of development, apart from specialised compartments known as ‘primordial germ cells’, or PGCs.
These compartments are comparable to embryonic stem cells. Many of the genes lost had characteristics of ‘pluripotency’, indicating that they could be harmful to the body if they remained. The PGCs therefore could arguably be seen as making and protecting the next generation of sea lampreys.
The rearrangement of the genome and deletion of certain genes during embryogenesis ensures that the harmful genes containing possible diseases and mutations are restricted to the PGC compartment.
The research was undertaken at the Benaroya Research Institute (BRI) at Virginia Mason and recently appeared in the journal
Current Biology. The article was authored by Jeramiah Smith, PhD, a former postdoctoral fellow at BRI and now Assistant Professor of Biology at the University of Kentucky; Chris Amemiya, PhD, Principal Investigator at BRI and Professor of Biology, University of Washington; Evan Eichler, PhD, University of Washington Genome Sciences Professor; and Carl Baker, Research Scientist, University of Washington.
"Our new research confirms that lampreys experience rampant programmed genome rearrangement and losses during early development," said Dr Amemiya of their recent research. "The genes are restricted to the germ line compartment suggesting a deeper biological strategy in order to regulate the genome for highly precise, normal functioning. The strategy removes the possibility that the genes will be expressed in deleterious ways. Humans, on the other hand, must contain these genes through other ‘epigenetic’ mechanisms that are not fool-proof."
The results of this work could prove to have some positive implications. Further research into the process which is undergone in sea lamprey embryogenesis, the findings could be transferable to humans, in particular toward controlling and treating diseases. It is hoped that more work will also contribute to a better understanding of what makes genomes stable.
Sea lampreys will continue to be researched by the scientists at BRI, as they possess unique characteristics such as the ability to recover from a severed spinal cord due to an outstanding capacity for recovery and for regeneration.
As we are not nocturnal animals by nature, then we must benefit from sunlight, in several ways. It then follows that we can deal with sunlight - maybe we need to be more in touch with how to deal with exposure. This research shows that we do not know all the ways that we use sunlight naturally, which is probably true of other environmental factors. I will be very interested in outcomes of further research. Is there any research about sunlight and cognition?
That they might be harmful suggests some other subsequent potential mechanism (and almost a value judgement). What are the grounds for this belief? The implication seems beyond the data given at this point.
Donald Bligh - United Kingdom