Monday, August 2, 2021
Sunday, August 1, 2021
In this article, the OKINAWA INSTITUTE OF SCIENCE AND TECHNOLOGY (OIST) GRADUATE UNIVERSITY, discusses the origins and molecular make up of venom, and how evidence shows mammal salivary glands and snake venom glands share a common genetic foundation.the team searched for genes that work alongside and interact strongly with the venom genes. The scientists used venom glands collected from the Taiwan habu snake from Asia. Agneesh Barua said, "The role of these genes in the unfolded protein response pathway makes a lot of sense as venoms are complex mixtures of proteins. So to ensure you can manufacture all these proteins, you need a robust system in place to make sure the proteins are folded correctly so they can function effectively.".
It seemed that other mammals like humans, dogs, and rodents also have their own version of these genes in the same pattern. Due to this, scientists believe this supports the theory that that venom glands evolved from early salivary glands. In a few thousand years we might encounter an evolutionary event where mice and even humans are venomous and this is definitely something worth studying further for the future of our ecosystem and understanding the evolutionary effects in genetics.
New Genetic Comparison Technique Developed At Stanford University Enables Further Study of the Human Brain and Face Evolution
In order for scientists to study human evolution, they often compare the human genome with the genomes of other species. The closeness between the species can be hard to navigate and make it difficult for scientists to define the causes of human evolution and development. A new technique developed at Stanford University allow researchers to better compare the DNA of humans to that of other species. This technique requires fusing human cells with skin cells of the other species that have been modified to act as STEM cells, allowing for the activities of the two cells to be analyzed side by side to learn more about the history and function of human DNA. In one trial, scientists found new genetic differences in the expression of the SSTRI gene that modulates neuron activity in the cerebral cortex. This discovery can help better understand diseases like Alzheimer's and Schizophrenia. In another trial of this new technique showed differences between the EVC2 gene in chimpanzees and humans, which gives clues about how the human face evolved. Researchers at Stanford University are specifically interested in how the levels of cis-regulatory elements that affect the expression of nearby genes in humans compares to the levels of cis-regulatory elements in other animals. One hurdle encountered during these experiments were any potential differences in the development between the two compared species. This difficulty was combatted by housing the DNA of the two compared animals in the same nucleus. The Human-Chimpanzee comparison experiment showed which gene expression pathways are more active in one species then the other. Since chimpanzees and humans are evolutionarily related, these comparisons can give us an insight into just how humans evolved. The new DNA comparison technique from Stanford University not only allows for evolution tracing within humans but can also help us to better understand the way neurological and genetic diseases function and are passed on.
Article Link: https://news.stanford.edu/2021/03/17/new-technique-reveals-genes-underlying-human-evolution/
Related Link: https://news.stanford.edu/news/2015/november/trace-invention-tools-112315.html
In our society today the term "inbreeding" is typically only used when it pertains to animals. For example, a dog having blue eyes is a recessive trait to the dominant brown eyes. The most efficient way to reproduce a generation of dog offspring with blue eyes is breed a male and female dog that carry the blue eyed phenotype, meaning they are homozygous recessive for it. As illustrated in the flow chart, it is possible for an offspring to inherit the homozygous recessive trait from parents who do not physically show it. These are the risks that are posed when inbreeding occurs amongst humans. Hypothetically, imagine the recessive trait in this instance was a chronic auto-immune disease, skeletal abnormality, or chronic genetic disorder. According to a study done in 2011, inbreeding practically doubles a person's susceptibility to inheriting a genetic disorder. If a person were to mate with someone outside of their family gene pool, if they do not carry the recessive trait for the unfavorable disease the offspring can resist being born with that phenotype.
There are many undesirable traits that put an offspring at risk when inbreeding. The offspring is susceptible to reduced fertility, birth rate, and immune function. They also have increased risk of cardiovascular disease, facial asymmetry, and risk of genetic disorders. The rates of child mortality is higher, and the growth of the human body as an adult is smaller. The most common genetic disorders that inbreed offspring face are schizophrenia, limb malformation, blindness, congenital heart disease, and neonatal diabetes.
Advanced microscope technology has allowed for the tertiary structure of DNA strands to better be understood and allowed for scientists to visualize how the genome organizes into these 3D structures. This new machinery uses high power lasers alongside chemical conditions that track fluorescent molecules to provide 10 times higher resolution than conventional microscopy. Prior to this new microscope technology it was not possible to analyze the tertiary structures of DNA closely. The new microscopes helped scientists draw correlations between the specific way DNA is transcribed and how it supercoils to form tertiary structures. Transcription was found to generate a force that moves across DNA strands like ripples through water. This is due to structural proteins known as cohesions that "surf" across DNA strands changing the shape of the genome in the process. Researchers believe that the discovery of the way cohesions affect the structure of DNA can help understand more about genetic and developmental disorders as it may be possible to draw correlations between diseases and tertiary structure folds. As DNA is condensed within a cell it forms many loops and coils which cause different sections of the DNA to interact with one another, allowing for individual cells to switch different information on and off. This new advancement shows that transcription aids in the process of determining which parts of the DNA fold to interact with each other. Until recently scientists were only able to predict where tertiary DNA loops were located but not their shape or what caused the coiling to form. The possibilities for this advanced form of microscopy are still being discovered.
Article Link: https://www.sciencedaily.com/releases/2021/07/210722113007.htm
Related Link: https://www.ncbi.nlm.nih.gov/books/NBK26880/
Saturday, July 31, 2021
Alzheimer's is a very complex and heartbreaking disease, with no great understanding of how it develops or how to cure it, causing no forms of any type of treatment. Scientists at the Salk Institute decided to grow neurons that resemble brain cells in older patients, and it shows that they start to lose their identity. They are shown to be markers of stress, and tend to resemble cancer cells which is also linked to aging.
In the study they conducted comparing skin cells with Alzheimer's affected patients, they discovered that the Alzheimer's cells had a lack of synaptic structures, which are important for sending signals to each other. They also had changes in their signaling pathways, which control cell function, indicating that the cells were stressed. Additionally, they found the Alzheimer's neurons had very similar molecular signatures to immature nerve cells found in the developing brain, meaning they lose their mature identity.
Hopefully with these new insights and further research, there can be a new therapeutic treatment for Alzheimer's patients. This could substantially change the path for the patient and for their families when dealing with this life-changing disease.