Table 1. Differential expression of cyclin K during postnatal testis development.

Cell Type	day 1	day 3	day 7	day 10	day 15	day 21	day 35
gonocytes	−/+	+++	N/A
undiff. permatogonia	N/A		++	++	++	++	++
diff. spermatogonia	N/A		−	−	−	−	−
spermatocytes	N/A			−/+	+++	+++	+++
round spermatids	N/A					+	+
elongated spermatids	N/A					−
spermatozoa	N/A						−
sertoli cells	−	−	−/+	−/+	+	+	+

Footnote: N/A: not applicable. −: no expression. −/+: weak or no expression. +: detectable expression. ++: strong expression. +++: strongest expression.