Fig. 1

Sex-differential gene expression in late first trimester and term placentas are highly correlated. Sex differences in gene expression, log₂(CPM + 0.25/L), between 17 female and 22 male late first trimester (10.5–13.5 weeks) placentas on the left and 27 female and 23 male term (≥ 36.6 weeks) placentas shown on the right (A). Each point represents a gene. Genes that are sex differentially expressed, adjusted p value < 0.05, are indicated in purple for autosomal, orange for Y-linked, and green for X-linked. The number of uniquely sex-differentially expressed genes and shared between the late first trimester and the term placentas is shown in B. More genes are sex differentially expressed in the later first trimester (10.5–13.5 weeks) than in the term (≥ 36.6 weeks) placentas. There are 237 genes that are uniquely called as sex differentially expressed in the late first trimester placentas that are not called as sex differentially expressed in the term placentas; however, the log₂ female-to-male expression ratio for those genes are highly correlated between the later first trimester (Y-axis) and the term (X-axis) placentas r = 0.879 (C). There is also a high correlation for the 31 sex-differentially expressed genes that are called in both the late first trimester placentas and the term placentas, r = 0.986 and for the 22 genes uniquely called in the term placentas r = 0.982