Fig 3. zipt-7.1 controls sperm activation.

(A) DIC photomicrographs of wild-type spermatids in standard SM medium (left) or SM medium supplemented with zinc (middle) or Pronase (right). Activation (or spermiogenesis) results in the extension of pseudopods, which are indicated with dotted white lines. (B,C) Using these morphological criteria, spermatids were scored in multiple small batches to determine which were active or inactive, with the average for each batch yielding one data point (N = 8–48 batches). Box and whisker conventions are described in Fig 2, and the Mann-Whitney U test was used for statistical comparisons. Alleles were fem-3(q96gf), a mutation that causes hermaphrodites to produce sperm throughout their lives so as to increase sample sizes [15], him-5(e1490), a mutation that increases the frequency of male progeny but has no other developmental effects [16], and zipt-7.1(ok971). The individual numerical values for panels B and C can be found in S1 Data. DIC, differential interference contrast; SM, Sperm Medium.