Board Thread:Theories and Speculation/@comment-3965545-20160511191323/@comment-5407586-20160511194628

We know for sure that Nagato is an Uzumaki, and Zetsu stated he was from the Senju lineage. Either Zetsu meant Senju=Uzumaki, or Nagato was half-Senju half-Uzumaki (Tsunade and Nawaki would be 1/4-Senju 1/4 Uzumaki, due to being Hashirama's grandchildren). It was stated Nagato was a perfect host for the Rinnegan, as evidenced by the fact that he could handle both eyes as a child, while an adult Obito despite having half of his body made of Hashirama-imbued White Zetsu matter couldn't handle more than one Rinnegan (though I suspect Madara somehow lessened the burden of his eyes before giving them to Nagato). But I think Nagato was a pure-blooded Uzumaki, mainly because Uzushiogakure was destroyed while Konohagakure, the Senju clan's home, wasn't.