[hightiger]

I would call this. It isn't an easy position to play, but the UTG's actions make perfect sense for a pair of jacks. He could, of course, have flopped two pair or better. But you're getting 2.5 to one on the call, compensating you for this possibility. Also, his somewhat fast play makes a flopped straight a little unlikely. You have a smidgen of insurance from your inside straight draw, not much but a little bonus. And if he has two pair, you have six extra outs that counterfiet it.

Nevertheless, you may have saved the rest of your stack. It mostly depends on how UTG plays.