Cases. A total of 111 strains, including 81 BXD strains, both parental strains (C57BL/6J and DBA/2J) and both reciprocal F1 hybrids (B6D2F1 and D2B6F1), and 26 other common inbred strains were quantified. In most cases, two arrays were processed per strain--one for males and one for females. All tissue and RNA was extracted by Lu Lu and colleagues. Samples were pooled by sex and usually include at least two cases per sex and strain.

Sex Balance. XX strains have matched male and female samples. XX strains have male only samples (BXDX, XX, XX, XXX and XXX). XX strains have only female samples (BXDXX, XX, and XX.) Please review the expression data for Xist probe set 10606178. This non-coding RNA is expressed highly only in females and can be used to check the sex of a sample or pool of tissue. Ddx3y probe set 10608138 can also be used. This is a Y chromosome gene that is expressed abundantly in male samples and at background levels in female samples.