No, invece è proprio cosi', a quanto pare hanno scoperto una "variante fosforosa" di DNA!!
Cita:
But Wolfe-Simon found that GFAJ-1 can go a step further. When starved of phosphorus, it can instead incorporate arsenic into its DNA, and continue growing as though nothing remarkable had happened.
http://www.space.com/scienceastronomy/a ... 01202.htmlRiassunto di come funziona il DNA (dallo stesso link sopra):
Cita:
The DNA molecule is shaped like a spiral ladder. The "rungs" of the ladder are comprised of pairs of nucleotides, which spell out the genetic instructions of life. The sides of the DNA ladder, referred to as its backbone, are long chains of alternating sugar and phosphate molecules. A phosphate molecule contains five atoms: one of phosphorus, four of oxygen. No phosphorus, no phosphate. No phosphate, no backbone. No backbone, no DNA. No DNA, no life.

Gruppo fosfato:

Pero', sempre nello stesso articolo, si dice che non è ancora sicuro al 100% che l'Arsenico individuato sia nel DNA, serviranno ovviamente controverifiche:
Cita:
If you "replace all the phosphates by arsenates," in the backbone of DNA, he said, "every bond in that chain is going to hydrolyze [react with water and fall apart] with a half-life on the order of minutes, say 10 minutes."
So "if there is an arsenate equivalent of DNA in that bug, it has to be seriously stabilized" by some as-yet-unknown mechanism, Benner said.
Benner suggests that perhaps the trace contaminants in the growth medium Wolf-Simon uses in her lab cultures are sufficient to supply the phosphorus needed for the cells' DNA. He thinks it's more likely that arsenic is being used elsewhere in the cells, in lipids for example.
La cosa intrigante è chbe questa obiezione propone in realtà involontariamente un'altra ipotesi: forse gli organismi con "DNA fosforoso" non hanno bisogno dell'acqua per vivere, o meglio, per loro l'acqua sarebbe addirittura tossica!