00:00 Dr. Oded Rahavi discusses the concept of genetic inheritance, including the idea that experiences and traits can be passed on from one generation to the next, and explains the basics of DNA, RNA, and inheritance.

07:59 Dr. Oded Rechavi explains that while every cell type in the body expresses different genes and assumes a unique identity, the important distinction is between somatic cells and germ cells, with only germ cells contributing to the next generation and somatic cells unable to transfer information or traits to the next generation, which is a barrier for the inheritance of acquired traits and memories.

16:08 The belief that acquired traits can be inherited and passed on to future generations, known as Lamarckism, led to dangerous consequences and was discredited by Darwin's theory of natural selection, with examples such as the long necks of giraffes and the fraudulent experiments of Paul Cameron illustrating the flaws in Lamarckism.

24:35 Paul Cameron's fraudulent experiments and the controversy surrounding his work led to the investigation of McConnell's research on memory transfer in planaria, which was later partially replicated by researchers from Boston.

32:20 McConnell's experiments in the 70s and 80s showed that memories can be transferred through different fractions of animals, with the RNA fraction being the one that transmits the memory, which is now supported by current research on feeding worms with RNA.

40:33 Epigenetics is the inheritance of traits across generations through mechanisms other than changes to the DNA sequence, with RNA molecules being the most interesting players in transmitting this information.

48:52 The effects of starvation or hardship during pregnancy can lead to differences in birth weights, glucose sensitivity, and neurological diseases in the next generation, but the mechanism behind this is not well understood and may not necessarily involve epigenetics.

57:20 Exposure of both mothers and fathers to stress or environmental factors can affect the transmission of genetic information and potentially lead to epigenetic effects in future generations, although the evidence for this in mammals is still limited and controversial.

01:05:28 Model organisms, such as C. elegans nematodes, are important for studying biology and human health because they share many functions and genes with humans, and they can be experimented on in ways that are not possible with humans.

01:13:43 C. elegans worms are advantageous model organisms for studying genetics and inheritance of acquired traits due to their transparent bodies, short generation time, and ability to be manipulated using optogenetics and gene activation techniques.

01:22:05 In a study with C. elegans worms, it was shown that the worms can transmit information in the form of RNA molecules to the next generation, specifically in the context of resistance to viruses, where the worms inherit small RNAs that match the viral genome and protect them from viral replication.

01:30:25 In worms, small RNAs are passed on to multiple generations through a mechanism called RNA dependent RNA polymerase, which amplifies the small RNAs and prevents dilution, and there are also genes that regulate the duration of the inheritance of these small RNAs.

01:38:07 The question of whether memory can be transferred between generations, specifically in the brain, is still unknown, but there is evidence that RNA can be transferred between tissues and affect the next generation's behavior and responses.

01:45:44 The brain uses a different language than the language of inheritance, and while it is unclear how information from the brain can be translated into heritable molecular form, it is possible that very specific memories or behaviors could be transmitted to the next generation through the manipulation of RNA.

01:53:31 Perturbing the production of small RNAs in the brain affects the expression of a gene in the germline, which can then impact behavior and be transmitted across multiple generations through the transfer of RNA.

02:00:56 Stressing hermaphrodite worms with high temperatures leads to the secretion of a pheromone that attracts males, increasing the probability of mating and diversifying the genome.

02:08:08 The possibility of using three-parent IVF to prevent chromosomal abnormalities and mitochondrial damage in embryos is being explored, and there is potential to manipulate and change aberrant inheritance through exercise and altering the composition of heritable RNAs.

02:15:56 Worms placed on ice after being taught an association don't forget, and the breakdown of memory happens slower in low temperatures, but it's not just the temperature, it's the changing of the internal state of the worms that affects memory kinetics, and the genes that change when worms become cold tolerant on and off ice can be manipulated to extend memory, and the one pair of neurons in C. elegans that is sensitive to lithium is tied to memory extension, as lithium switches the forgetfulness mechanism on and off, and this mechanism may be related to the release of adrenaline in the body and may be RNA dependent.

02:23:45 The episode concludes with a thank you to the guest and a reminder to subscribe to the podcast and support the sponsors.