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.