Strangest genetic scientific experiments
Contd. from last week
The fastest trees
 A tree that can reach 90 feet in six years and be grown as a row crop
on fallow farmland could represent a major replacement for fossil fuels.
Purdue University researchers are using genetic tools in an effort to
design trees that readily and inexpensively can yield the substances
needed to produce alternative transportation fuel.
The scientists are focused on a compound in cell walls called lignin
that contributes to plants’ structural strength, but which hinders
extraction of cellulose.
Cellulose is the sugar-containing component needed to make the
alternative fuel ethanol. With funding from the Department of Energy,
Clint Chapple and Rick Meilan are using genetic tools to find ways to
convert trees into ethanol as a replacement for fossil fuels.
Growing human eyeballs
A genetic switch that gives tadpoles three eyes could allow stem-cell
scientists to eventually grow human eyeballs or at least create
replacement parts needed for repair jobs. If scientists could grow
eyeballs from stem cells in the lab, the process would be a boon to
individuals with damage to cells within the eye, including retinal
disorders.
 Scientists had already established the amphibian genes that initiate
and direct eye development, which they refer to as Eye Field
Transcription Factors (EFTFs). How these genes get activated in the
right location at a certain time during development had been cloaked in
mystery. But in 2007, a new study suggested a nitrogen-bearing molecule
sets off a series of steps that result in eye formation in frogs.
When researchers injected a specific enzyme into frog embryos, the
resulting tadpoles showed an extra eye. The mechanism probably also
applies to humans and other animals with eyes.
Dale and University of Warwick developmental biologist Elizabeth
Jones, along with colleagues, discovered the eye-switch while
investigating how “ectoenzyme” molecules located on the external surface
of cells contributed to the development of locomotion in the African
clawed frog (Xenopus laevis).
The biologists injected the molecules into frog embryos that
comprised just eight cells. One of the ectoenzymes triggered wonky eye
development. When added to cells that would eventually form the head,
the resulting tadpole sported three eyes instead of two. An even
stranger sight resulted when they injected the ectoenzyme into other
developing body cells.
The molecule caused an additional “ectopic” eye, leading to tadpoles
with a spare peeper growing out of the side, abdomen or even along the
tail. |
