Auxotrophy
The method of replica plating implemented by Joshua Lederberg and Esther Lederberg included auxotrophs that were temperature-sensitive; that is , their ability to synthesize was temperature-dependent . 
<triplet> Joshua Lederberg <subj> Esther Lederberg <obj> spouse <triplet> Esther Lederberg <subj> Joshua Lederberg <obj> spouse