Figure 3.

RT-PCR analysis of cortactin transcript expression. Cortactin transcripts are seen in rat round spermatids and adult rat testis but not in rat pachytene spermatocytes. The following primers were used: Cortactin-Forward 1, ₂₈₃ATC GGG GCA CCA GGA ACA CAT CAA₃₀₆; Cortactin-Reverse 1, ₁₀₂₉GAC GGC ACC TGG ACC ACT TCT TCA₁₀₀₅; Five isoforms of cortactin are expressed in mice; two isoforms of cortactin are expressed in rat and Xenopus; and three isoforms of cortactin are expressed in human. The primers were selected to span a stretch of 111 bp cDNA (spliced from some transcripts) to determine which cortactin form is expressed in spermatogenic cells and testis. The spliced sequence corresponds to nucleotides 864–974. The expected sizes of the fragments were 746 bp for the not spliced form and 635 bp for the spliced form. The transcript form expressed in round spermatids and testis is the non-spliced form. Actin primers were used as control. The construction of rat pachytene spermatocyte and round spermatid cDNA libraries was reported in reference ⁴⁹.