Tpl94D-eGFP transiently expressed in spermatids at the time when the switch from a histone-based to a protamine-based chromatin configuration occurs. It is first detected in early canoe stage spermatids shortly before the histones disappear. It is most strongly expressed at late canoe stage when protamines are visible and the histones have disappeared. It is no longer detected when the chromatin is completely condensed.