Beginning in L4, SMA-1/βH is seen in both the spermathecal bag and SP-UTvalve with the strongest expression in the 4 cells most proximal to the SP-UT valve. Interestingly, this expression pattern changes during spermathecal development, and by adulthood, SMA-1/βH becomes restricted to a ring connecting the spermathecal bag and SP-UT valve.
LET-502 is only faintly expressed in the spermathecal bag cells and high levels of LET-502 are restricted to the distal neck and sp-ut valve cells. This is distinct from the expression pattern of MLCK-1, which is seen throughout the spermatheca including the distal neck, main bag cells, and sp-ut valve.
Strong expression of UNC-70/β in the spermatheca and SP-UT valve begins early in spermathecal development during larval stage 4 and continues into adulthood.
SPC-1/α is prominently expressed in both the spermatheca and SP-UT valvebeginning in L4 and extending into adulthood. In adults, SPC-1/α is also faintly expressed in the sheath.