Dr. Rehavi explains how our genes and different patterns of inheritance shape our experience of life and who we are
DNA, RNA and germ cells
- DNA is the genetic instructions contained in every cell of the body, condensed into chromosomes
- RNA is the instructions to make one particular protein based on the entire set of possibilities
- Somatic cells are all the cells that are not germ cells and should not contribute to the next generation
- Germ cells are the only cells that contribute to the next generation
Model organisms
Model organisms are organisms that many people work on to learn about biology, including humans
C. elegans is a model organism that is a small worm, 1mm long, found in rotten fruits and leaves
- It has a fixed number of cells, 302 neurons, and each neuron has a name
- It has a connectome, a map of which neurons talk to each other
- It is transparent, so neurons can be seen firing
- It has a short generation time of 3 days and produces hundreds of progeny
- It is easy to manipulate and study, and does not require a sensitive environment
Memory transmission
- Bandwidth of inheritance can be very specific or very general
- Brain activity can be transferred to the next generation in worms, but not in mammals
- Memories encoded in the brain cannot be transferred transgenerationally due to the different languages of the brain and inheritance
- Memories that are very specific may be able to be transferred through the production of small RNAs
Memory Transfer
- McConnell was an American psychologist who studied Planaria, a type of flatworm
- He claimed to be able to teach them certain things and transfer memories through feeding
- His research was controversial and could not be replicated
- Recently, a researcher from Boston replicated some of McConnell’s experiments
- McConnell also claimed to be able to transfer memories through fractions of the worm, such as DNA, RNA, fats, proteins, and sugars
- His research was popular knowledge and was considered pseudoscience for many years
Epigenetics
- Epigenetics is the interaction between genes and their products that bring about the phenotype or consequences and how genes influence development
- DNA can be chemically modified, such as methylation, acetylation, and serotonin
- Identical twins can look different due to epigenetic changes or other mechanisms
- Epigenetics is the inheritance of traits across cell division or generations without changes to the DNA sequence
