Re: Naruto Manga 499 Spoilers / Summaries
About Kushina being the Kyuubi Jinchuuriki before Naruto.
If she had given birth to a newborn Naruto...WHILE the Kyuubi was attacking the village, then Naruto had the Kyuubi sealed into him at childbirth, HOW would she be the Kyuubi jinchuuriki before Naruto? She would have died during the extraction, then Naruto would have more than likely died, unless he was old enough by then to not depend on his mother for a few hours. But even so, I believe that if the mother dies, so does the child...
I also thought of the idea of the chains just being a representation of Kushina's ability to control the Kyuubi, but it wouldn't surprise me if it was a Kekkai Genkai. The thing is though, does it HAVE to be a nature-type Kekkai Genkai? Not ALL Kekkai Genkais are nature types. The Sharingan, Shikomyatsu (Kimmimaro's KG), Byakugan, the 3rd Kazekage's Iron Sand (hasn't been confirmed to be earth and lightning), and the Rinnegan don't have Nature types. If Kushina does indeed have a Kekkai Genkai, she might just be able to change her chakra into a special metal like Kimmimaro could change his bone density, and make bones into weapons.
Kimmimaro was a beast...Wish we could have seen more of him.