Supplementary Material for: Overexpression of <i>Lis1</i> in Different Stages of Spermatogenesis Does Not Result in an Aberrant Phenotype

Previous studies showed that in the mouse mutant <i>Lis1</i><sup>GT/GT</sup> gene trap integration in intron 2 of <i>Lis1</i> gene leads to male infertility in homozygous <i>Lis1</i><sup>GT/GT</sup> mice. We further analyzed this line and could confirm the suggested downregulation of a testis-specific <i>Lis1</i> transcript in mutant animals in a quantitative manner. Moreover, we analyzed the gene trap mutation on different genetic backgrounds in incipient congenic animals and could exclude a genetic background effect. To gain further insights into the role and requirement of LIS1 in spermatogenesis, 3 transgenic lines were generated, that overexpress <i>Lis1</i> under control of the testis-specific promoters <i>hEF-1</i>α, which is exclusively active in spermatogonial cells, <i>PGK2</i>, which is active in pachytene spermatocytes and following stages of spermatogenesis, and <i>Tnp2</i> which is active in round spermatids and following stages of spermatogenesis, respectively. All 3 transgenic lines remained fertile and testis sections displayed no abnormalities. To overcome the infertility of <i>Lis1</i><sup>GT/GT</sup> males, these transgenic <i>Lis1</i>-overexpressing animals were mated with <i>Lis1</i><sup>GT/GT</sup> mice to generate ‘rescued’ <i>Lis1</i><sup>GT/GT</sup><i>/Lis1</i><sup>Tpos</sup> males. ‘Rescued’ animals from all transgenic lines remained infertile, thus overexpression of <i>Lis1</i> in different stages of spermatogenesis could not rescue the infertility phenotype of homozygous gene trap males.