Levka"Female mice grow testes after this single DNA tweak
Small changes in the non-coding part of the genome have a key role in sex determination.
Female mouse embryos with a single letter change in a specific region of their DNA develop male reproductive organs, finds a study1 published today in Nature Communications.
Typically, female mouse embryos with two X chromosomes develop ovaries because a gene called Sox9 is suppressed. In male mouse embryos with XY chromosomes, the expression of Sox9 triggers testis development.
In male mice, Sox9 is controlled by a segment of non-coding DNA — part of the genome that does not encode proteins — called enhancer 13 (Enh13). Studies have shown that deleting Enh13 causes mice with XY chromosomes to develop female organs2, but until now, modifying Enh13 was not known to have any effects in female (XX) mice."
