Elsa
Vaughn
Biology
1610 - Blog Assignment
Professor
Dr. Michaela Gazdik
December
12, 2016
SCIENTIFIC
AMERICAN –naturenews
Topic
1
Biochemists’
Discovery Could Lead to Vaccine Against ‘Flesh-Eating’ Bacteria.-
Biochemists
at the University of California San Diego have uncovered patterns in the outer
protein coat of group A Streptococcus that could finally lead to a vaccine
against these highly infectious bacteria.
The
term flesh-eating bacteria refer to a necrotizing fasciitis. It starts in the tissues just below the skin
and spreads along the flat layers of tissue (fascia) that separate different
layers of soft tissue, such as muscle and fat, which produce a necrotizing
infection that could result in the loss of the affected part.
Flesh-eating
disease, caused by the bacterium known as Streptococcus pyogenic, Streptococcus
pyogenic, produces toxins that destroy
tissues such as muscles, skin, and fat, and are commonly responsible for mild
sore throat (pharyngitis) and skin infections. Rarely, this form of strep
bacterium causes severe illnesses such as toxic shock syndrome and necrotizing
fasciitis.
“When
we become infected with a particular strain of group A Strep, we generally
mount an immune response against the particular M protein displayed by that strain,”
explains Ghosh. “But this immunity works only against the infecting strain. We
remain vulnerable to infection by other group A Strep strains that display
other types of M proteins on their surfaces.
Biochemists
detailed four crystal structures of four different M protein types, each bound
to human C4BP, with common pattern sequences hidden within the differences that
linked all these proteins together. The idea is to have antibodies do the same
thing as C4BP—that is to recognize many different M protein types. Ghosh says:
“That way, the antibody response will not be limited to one M protein and one
stain of group A strep. With that purpose chemists are now working on
developing a vaccine that will be protective against all strains of group A
strep.
Comment 1.-
General Comment. -Because our immune system must recognize the different
proteins before launching an immune response with antibodies, our immunity
system works only against the infected strain. The researchers want to combat
C4BP binding a broad variety of M protein types.
Comment 2.-
Question.- If M proteins of different types appear to be unrelated in sequence
to one another, and the antibody
response is specific and limited to a
single M protein type, how do they are
going to get the effective vaccine?
Comment
3.-Answer. - By blocking the complex interaction between M proteins and C4BP.
Two graduate students Sophia Hirakis and Rommie Amaro are studying protein
structures by computer. It allowed the researchers to understand that there are
common sequence pattern. This sequence pattern is used to recruit C4BP to the
surface of group A strep by the different M protein types.
I
found this article very interesting because this job is going to help,
individuals who are infected with “flesh-eating bacteria”
Topic
2
Accelerating
Tomato Engineering
Source:
Cornell University.
Tomatoes
are already an ideal model species for plant research. Scientists at the Boyce
Thompson Institute (BTI) just made them even more useful by cutting the time
required to modify their genes by six weeks, it means procedure from 17 weeks
to just 11. They developed a better method for "transforming" a
tomato--a process that involves inserting DNA into the tomato genome and
growing a new plant. By adding the plant hormone auxin to the medium that
supports growth of tomato cells, they can speed up the plant's growth.
Typically,
transformation works by using a soil bacterium called Agrobacterium
tumefactions to insert a new segment of DNA into the cells of tomato seedling
tissues. The transformed cells are transplanted onto plant regeneration medium,
which contains nutrients and hormones that cause the tissue to grow into a tiny
new plant.
Researchers
in the Van Eck lab perform tomato transformations routinely, as a research
method to understand how individual genes affect tomato growth and development
“We’re looking at the genes and gene networks involved in stem cell
proliferation, meristem development and flowering and branching,” says Van Eck,
“with the end goal being that maybe genes that we identify in tomato, which is
strictly being used as a model, might help us understand what can be done to
increase yield in other crops.”
Comment
1.-
General Comment. -While looking for ways to make tomatoes more productive, the
researcher’s goal is to use the tomato as a model, to increase yield in other
crops.
Comment
2.-
Question. -How individual DNA affect tomato grow and development; and, how do
the researchers work to insert DNA into the cells of tomato and how do they
grow them`` .?
Comment
3.-
Answer. - Cuts the time from 17 to11 weeks, and saves money. They use a soil bacterium called
Agrobacterium tumefactions to insert a new segment of DNA into the cells of
tomato seedling tissues. The transformed cells are transplanted onto plant
generations medium, which contains nutrients and hormones that cause the tissue
to grow into a tiny new plants. These plantlets are then transferred to root
induction medium where they grow roots, before being planted in soil and
hardened in the greenhouse.
I
found this article very interesting, because it causes me curiosity to know how
do they work; and because in Biology class we were talking about DNA.
