Expression profiles in testis of mouse inter-subspecific hybrids

According to Dobzhansky-Muller model, hybrid sterility is a consequence of independent evolution of related taxa resulting in incompatible interaction during gametogenesis of their hybrids. We proposed that asynapsis of heterospecific chromosomes in meiotic prophase provides a general and recurrently evolving trigger for the meiotic arrest of interspecific F1 hybrids. We used genome-wide expression profiling to quantify misexpression of Chr X and Chr Y genes. The total RNA (20–30 ng) samples were extracted from 14.5 days juvenile testes (pool of 4 samples), converted to cDNA using the Affymetrix 3 IVT Express Kit and hybridized to Affymetrix Mouse Gene 1.0ST GeneChips (core facility of the Institute of Molecular Genetics AS CR, Prague, Czech Rep.) We visually checked intensity histograms, boxplots and PCA graph and excluded one PWDxPWK sample that was a clear outlyer on all QC graphs (not shown).