Why Women Are Stripey

Epigenetics means women have different active xchromosomes in different cells. Animation courtesy of Music by Amarante: Animation: Etsuko Uno Art and Technical Direction: Drew Berry Sound Design: Francois Tetaz Emma Bortignon Scientific Consultation: Marnie Blewitt Courtesy of Walter and Eliza Hall Institute of Medical Research: When a female embryo is four days old it consists of just 100 cells. At this point the xchromosome from Mom and the one from Dad are both active. But in order for proper development to occur, one of the x chromosomes must be switched off. Through a tiny molecular battle within each cell, one of the xchromosomes wins and remains active while the loser is deactivated. This is done by wrapping the DNA tighter around proteins, modifying histone tails, and DNA methylation molecular markers to indicate this DNA should not be read. What s surprising is that it s pretty rand