Whataretheethicalconcerns?
Chimerasareoftenmetwiththecriticismthat
theyare‘unnatural’creatures.Butis thata valid
reasontostoptheresearch?“Peoplethink,‘Oh,
weshouldn’tbeplayingGod,weshouldn’tbe
creatingthesethingsthatareunnatural,’”
explainsDrMackenzieGraham,a researchfellow
inneuroethicsat theOxfordUehiroCentrefor
Practical Ethics. However, he believes this2 experiments,histeamsuccessfullycreateda
ratwitha pancreasmadeofmousecells.The
pancreaswaslatertransplantedintoa mouse
engineeredtohavediabetes,andthemousewas
effectivelycured.Anyorgansthatcouldbeused
fortransplantationinhumanswouldhavetobe
grownina largeranimal,suchasa pigorsheep,
sothattheorganwouldbebigenoughforthe
patienttouse.Additionally,thechimerastendto
bemoresuccessful if the two species are closely
related.Havehumanhybridsbeencreatedbefore?
IzpisúaBelmonte’steamreportedthefirst
successfulhuman-animalchimerain2017,when
theycreatedpig-humanhybridembryos.The
researchersmodifiedthehumanstemcellsto
fluorescesothatanyhumancellsintheembryo
glowed.Afterdevelopingforthreetofourweeks,
onlyaround1 in100,000cellswashuman:far too
lowtobeuseful,and not localised in any
particular organ.
“Chimeras areoften met
with the criticism that they
are ‘unnatural’ creatures.
But is that a valid reason to
stop the research?”
GET T Y X 3, SCIENCE PHOTO LIBRARY, SALK INSTITUE