Graph polynomials derived from Tutte-Martin polynomials

A graph polynomial q(G;ζ) has recently been studied by Arratia et al. [The interlace polynomial: a new graph polynomial, in: Proceedings of the Eleventh Annual ACM-SIAM Symposium on Discrete Mathematics, San Francisco, CA, 2000, North-Holland, Amsterdam, pp. 237-245]. That polynomial can be derived from the restricted Tutte-Martin polynomial of an isotropic system, which we introduced [A. Bouchet, Tutte-Martin polynomials and orienting vectors of isotropic systems, Graphs Combin. 7 (1991) 235-252] in order to prove a conjecture of Las Vergnas on the Tutte polynomial of a binary matroid. It follows that (i) |q(G;-1)| is equal to a power of 2 and (ii) q(G;3) is the same power of 2 times an odd integer. Neither (i) or (ii) appears in [R. Arratia et al., The interlace polynomial: a new graph polynomial, in: Proceedings of the Eleventh Annual ACM-SIAM Symposium on Discrete Mathematics, San Francisco, CA, 2000, North-Holland, Amsterdam, pp. 237-245].