  In this paper, for a Seifert loop (i.e., a knot in a Seifert three-manifold),
first we give a family of an explicit function $\Phi(q; N)$ whose special
values at roots of unity are identified with the Witten-Reshetikhin-Turaev
invariants of the Seifert loop for the integral homology sphere. Second, we
show that the function $\Phi(q; N)$ satisfies a $q$-difference equation whose
classical limit coincides with a component of the character varieties of the
Seifert loop. Third, we give an interpretation of the function $\Phi(q; N)$
from the view point of the resurgent analysis.
