Applying “Gold Standards” to In-Vitro-Derived Germ Cells

(Cell 157, 1257–1261; June 5, 2014) In the original version of Figure 1 in the above Essay, we have noted some fundamental errors. In the box labeled ‘‘Haploid,’’ the three oocyte metaphase chromosomes are erroneously depicted in their meiosis I configuration as paired homologous chromosomes, each with two chromatids. However, this oocyte should be at meiosis II, post homolog segregation, with only three chromosomes depicted, each with two chromatids. Also, in the original figure, the recombination proteins were colored the same as the centromeres, but there is no implied relationship between the two. The corrected figure appears below and with the article online to clarify these issues. We regret these mistakes and confusion they may have caused.