KLC3 protein expression. A) To confirm the KLC3 mRNA expression pattern in male germ cells and determine its apparent size, Western blot analysis was carried out using extracts from elongating spermatids, a mix of elongating spermatids and round spermatids, round spermatids, and pachytene spermatocytes (lanes 1–4, respectively) and epididymal spermatozoa (lane 5). KLC3 expression was probed using polyclonal antibodies. B) Monoclonal antibodies were raised against KLC3 for immunofluorescence studies. Specificities of the mAbs were analyzed by Western blots. Extracts from cells transfected with an HA-tagged KLC3 (lanes 1 and 3) or an unrelated control construct (lanes 2 and 4) were resolved by SDS-PAGE, transferred to membranes, and probed with anti-HA specific mAb (lanes 1 and 2) and anti-KLC3 mAb (lanes 3 and 4). Anti-KLC3 mAb specifically recognizes KLC3.