AP Biology class blog for discussing current research in Biology

Author: jervissystem

The First “in vivo” CRISPR-Cas9 Gene Editing

At the start of the new year all of the scientists working in different fields being to create a schedule of perceived accomplishments that will occur in regard to their specific field of study. In the term of the people working with CRISPR, they speculate that the first in body injection in order to conduct real time genome editing will occur in 2020. Prior to this year, CRISPR has been used to edit and alter the DNA of red blood cells outside of the body, but the scientists working with this new form of biological technology belief that this year it will be used the way it is intended to be used.

CRISPR was originally found in 2012 inside bacteria in order to help stop viruses from infecting them. Scientists saw the possible benefit of this in humans and through years of research discovered that CRISPR can help place another enzyme Cas9, which snips out parts of DNA, in a correct spot on the genome to alter and edit a person’s DNA code. While over time some scientists have wondered about the ethics of this new discovery, most are excited by all of the possibilities that CRISPR has on curing diseases.

Currently, the reason that CRISPR-Cas9 has become a talking point recently was due to the fact and difference between gene editing “in vivo” versus gene editing “ex vivo”, meaning within the body or outside the body. Scientists working with CRISPR have been able to understand how editing “ex vivo” works. They are able to see the genes they want to edit and watch the process occur. This is also easier for the scientists because if the editing messes up, they do not need to reinsert the altered cell back into the body. On the other hand, “in vivo” gene editing is much more efficient and can be completed through a simple injection, but may cause dangerous consequences, such as cancer, if a mistake is made in both the scientists’ coding of the CRISPR or in the process done by the CRISPR itself.

Now that scientists are starting to attempt to move from “ex vivo” editing to “in vivo” editing, all of these questions and issues are being brought up. With lots of labs around the country working on moving into “in vivo” editing and an FDA approval for the procedure, the first CRISPR-Cas9 “in vivo” gene editing is bound to happen soon. Hopefully, this new biological technology does its job properly and gives hope to those who have various currently seemingly incurable disease. If successful, CRISPR could revolutionize medicine itself to make it more efficient and effective. Feel free to comment about how you think CRISPR will do in the first “in vivo” test and how it could effect life later on.

The Human Gut Microbiome: Cooperation or Competition within Our Bodies

The human gut microbiome is home to many different types of small bacteria which help the human system function. These intestinal bacteria hold millions of genes that assist with human metabolic function. However, over time scientist have become more interested in the interaction between these bacteria and the human system in regards to diseases that they may prevent through their creation of micronutrients. The most common of these micronutrients are B-vitamins. These B-vitamins specifically, B-1,2,3,5,6,7,9, and 12 are all produced by the bacteria in the human gut microbiome. Along with queuine, these micronutrients allow the gut microbiomes to grow and assist in human bodily functions. In the study lead by Andrei Osterman, the goal was to investigate these microbiomes more and their influence on the human body through their creation of micronutrients.

The scientists on the study’s first objective was to determine the way that the microbiomes created their micronutrients. There are two methods in which the microbiomes can produces these vitamins, de novo or dependent. The ones that produce it de novo mean that they create with own micronutrients through their own process, while the others are dependent on the micronutrients of other microbiomes either older ones or ones close in distance to it. This idea brought about the question as to do the two types of microbiomes compete for these resources or do they coexist. Surprisingly, through research, the scientists discovered that the two types of microbiomes actual peacefully coexist and cooperate in the sharing of the resources. Instead of the dependent microbiomes stealing from the de novo ones, they actually understand the importance of their providers and work with them in return for their micronutrients.

This fact of the peaceful coexistence between the two types of microbiomes then caused Osterman and his team to wonder how the de novo microbiomes are able to distribute the vitamins to both the dependent microbiomes and its human host. To learn more about this process, the researchers looked at the genome of the two different types of microbiomes and marked them separately. The de novo type was given a variant code “P” which stood for prototrophic and the others were given a variant code “A” for auxotrophic. These two codes help them distinguish between the different types of microbiomes and their district pathways. It was discovered that the pathway that the auxotrophic microbiomes used to receive nutrients was called the downstream pathway. This pathway is a flow of vitamins from the phototrophic microbiomes downstream into an area in which the auxotrophic microbiomes can uptake the food.

As the scientists learned more about the pathways in between the different types of microbiomes, they also discovered that some of their original predictions were incorrect. While they believed to have discovered through the phenotype which microbiome was de novo and dependent, with more information on the subject, they began to see the flaw in their original thinking. They discovered that some of the predetermined microbiomes actually were both part de novo and dependent. They had a place to create micronutrients while having downstream pathways to receive it.

Through their research, Osterman and his team were able to discover facts about the way the human gut microbiomes transfer and create nutrients and vitamins to transport to other microbiomes and the human host itself. While very important to our bodies, it is strange to think about the different types of bacteria living in ourselves and their over microbiomes that they have within us. Please feel free to comment your ideas regarding the whole entire world that lives within ourselves in septic our human gut microbiomes.

Is Training Your Dog Useless?

For about 100 years, humans have been trying to train the domestic animals, such as dogs, that they live with. They put in lots of time and effort for teach their dogs simple tricks such as sitting, lying down, and staying in place. While it is rewarding to have a dog listen to commands after teaching and training them, this may not as great of an accomplishment as previously thought. As a dog owner myself, this had me worried, but as a recent ScienceNews post says, the answer to how to train a dog may just lie in their genetics. 

Training Dogs May Be an Outdated Practice

This was the hypothesis that Noah Snyder-Mackler had as he and a few other colleagues from the University of Washington in Seattle attempted to prove its legitimacy. Primarily, the group collected data about 101 different breeds of dogs from two dog genotypes databases and a survey titled C-BARQ, a survey where dog owners submit information about behavior from their dogs such as aggressiveness or ability to listen. As the data came in, there were over 14,000 submissions and they were all scored on 14 different traits. Overall, Snyder-Mackler and his group found that poodles and border collies had higher traits of trainability and Chihuahuas and dachshunds had higher traits of aggressiveness. However this does not means that training a dog is rendered useless since there was about a small correlation, 50%, between energy level and fearfulness.

Aggression Could Have Been Caused from Genetics

Next the researchers tried to see if certain traits correlated with certain genes. After doing more research they found that no genes specially aligned with a breeds behaviors, but this does not mean that the research is useless since even though this  does not show that a gene brings about a behavioral trait, but it shows that this subject needs more research to be able to determine the validity of Snyder-Mackler’s original hypothesis.

Dogs are very complex genetically and therefore behavioral traits are both a combination of genetics and training. As Carlos Alvarez, a researcher at the Nationwide Children’s Hospital in Columbus, Ohio, says, “Dogs are a really powerful system to investigate the genetics of many traits and diseases because generations of domestication and breeding have simplified their genomes. This study shows that behavior is no different.” Overall while this research is just the start and is incomplete in totality, it shows that there is much more to discover regarding this topic. If you have any traits that you think correlate with either your dog’s genes or breed, please post a comment a explain why.


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