Supplementary Material for: Inactivation of the Anti-Müllerian Hormone Receptor Type 2 (<b><i>amhrII</i></b>) Gene in Northern Pike (<b><i>Esox lucius</i></b>) Results in Male-To-Female Sex Reversal

<b><i>Background:</i></b> The anti-müllerian hormone (Amh) pathway is crucial for sexual development in teleosts. A male-specific duplicate of anti-müllerian hormone (<i>amhby</i>) was previously identified as the northern pike (<i>Esox lucius</i>) master sex determination gene. However, the role of its putative cognate receptor, i.e., the anti-müllerian hormone receptor type 2 (<i>amhrII</i>) was unclear in this species. <b><i>Objective:</i></b> Here, we investigated the role of <i>amhrII</i> during sexual development of northern pike. <b><i>Method:</i></b> We generated stable mutants with deletions in exon 9 of <i>amhrII</i>, inactivating the AmhrII protein using a CRISPR-Cas9-mediated gene knockout strategy. <b><i>Result:</i></b> The inactivation of <i>amhrII</i> in northern pike results in a high level of male-to-female sex reversal. <b><i>Conclusion:</i></b> This result demonstrates that <i>amhrII</i> is necessary for male sexual development in northern pike and supports the idea that AmhrII is a conserved regulator of the teleosts sex differentiation network.