Epigenetic Lamarck

Article : ”The Rate of Epigenetic Drift Scales with Maximum Lifespan Across Mammals,” by Emily M. Bertucci-Richter et al., Nature communications (11/23) Introduction Epigenetic drift , or the stochastic accumulation of DNA methylation changes over time, is a hallmark of aging. While the role of epigenetic drift in determining maximum lifespan across species has been debated, robust tests of this hypothesis are lacking. In this study Bertucci-Richter et al. investigated the relationship between epigenetic drift and maximum lifespan across four mammal species: humans, mice, rats, and elephants. Methods The researchers used whole-genome bisulfite sequencing to measure DNA methylation levels at various CpG sites (cytosine-guanine dinucleotide sequences) in blood samples from individuals of each species spanning a wide range of ages. They then calculated the epigenetic disorder, a measure of the deviation from the expected DNA methylation pattern, at different genomic resoluti...

The study “ Transposon wave remodeled the epigenomic landscape in the rapid evolution of X-Chromosome dosage compensation’” published in Genome Research, Metzger et al. delved into the evolutionary mechanisms underlying the rapid divergence of sex chromosomes in Poecilia picta, a species of freshwater fish. Their findings shed light on the remarkable ability of transposons (TE), mobile genetic elements, to drive rapid evolutionary change.  TE's were ignored as Junk DNA by neo darwinists for 30 years. Poecilia picta exhibits a unique pattern of sex chromosome dosage compensation, a mechanism that ensures equal expression of genes on the X chromosomes in both males and females, despite the presence of only one X chromosome in males. This study uncovered a striking wave of repetitive element (TE) insertions, particularly those carrying YY1 motifs, that swept across the X chromosome of Poecilia picta. These insertions dramatically remodeled the epigenomic landscape of ...

Article ; Small RNAs in the Transgenerational Inheritance of Epigenetic Information, Duempelmann et al. (1/21) Abstract Epigenetic information, which refers to heritable changes in gene expression that do not alter the DNA sequence as with neo-Darwinism, is increasingly recognized as a key player in development.  Small RNAs, a class of non-coding RNAs that are involved in RNA interference (RNAi), have emerged as important mediators of epigenetic inheritance.  Sadly due to NeoDarwinian theory the Junk DNA where nc RNA came from was ignored for 30 years. In this review authors highlight mechanistic studies in model organisms that advance our understanding of how small RNAs trigger long-lasting epigenetic changes in gene expression and discuss observations that lend support for the idea that small RNAs might participate in mechanisms that trigger epigenetic gene expression changes in response to environmental cues and the effects these could have on population adaptat...

Article  : Epigenetic Regulation and Epigenetic Memory Resetting during Plant Rejuvenation, by Liu et al (11/23) Abstract Plant rejuvenation, the reversal of plant developmental status from the mature to the juvenile phase, is a fascinating process with immense potential for agricultural and horticultural applications. It involves the restoration of juvenile characteristics, including morphology, physiology, and reproductive capabilities. While the mechanisms underlying plant rejuvenation are not fully understood, epigenetic regulation plays a crucial role. Epigenetic modifications, such as DNA methylation and histone modifications, provide an additional layer of control beyond the genetic code, influencing gene expression and developmental processes. Introduction Plants exhibit remarkable regenerative capacity, capable of producing new tissues and organs throughout their lifespan. This ability is particularly evident in the process of plant rejuvenation, where mature p...

Article "Hybrid Epigenomes Reveal Extensive Local Genetic Changes to Chromatin Accessibility Contribute to Divergence in Embryonic Gene Expression Between Species" , by Hannah R Devens et al., Molecular Biology and Evolution, November 2023 Chromatin Accessibility and Its Role in Gene Expression Chromatin, a complex of DNA and proteins, packages the genetic material within the cell's nucleus. The accessibility of chromatin, the ease with which proteins can interact with DNA, plays a crucial role in regulating gene expression.  Open chromatin allows transcription factors, proteins that bind to DNA and initiate gene transcription, to access and activate genes. Conversely, closed chromatin hinders transcription, effectively silencing genes. Investigating Genetic and Molecular Influences on Chromatin Configuration This study sought to unravel the genetic and molecular mechanisms that influence chromatin configuration, particularly its impact on embryonic gene expression diver...