Biochemical phenotypes in the accessory sex glands and plug formed by
PN-1+/+ and PN-1−/− males. (A
and C) PAGE of seminal vesicle-secreted proteins and
coagulating gland-secreted proteins from adult PN-1+/+ and
PN-1−/− mice. The collected seminal vesicle fluid was
separated by centrifugation into a liquid (L) and a viscous (V)
fraction. Wild-type seminal liquid phase revealed three major bands,
with estimated molecular masses of 38, 17, and 16 kDa
(A). In the corresponding PN-1−/− samples,
the 38-kDa component was strongly decreased and a component of around
28 kDa was observed. The same general pattern was found in the viscous
fraction, but in this case other bands of intermediate size were seen
in the mutant samples (A). There was no difference in
the coagulating gland protein patterns of PN-1+/+ and
PN-1−/− mice (C). (B and
D) Amount of thrombin-like protease and PN-1-like
inhibitor in the seminal vesicle and the coagulating gland of
14-day-old PN-1+/+ and PN-1−/− mice. In the
mutant mice, seminal fluid showed reduced thrombin inhibitory activity
(B), whereas coagulating gland fluid showed an excess of
unidentified thrombin-like protease activity (D). Notice
the different scales used in B and D.
(E) A decrease in plug size as well as a modified
appearance is clearly seen in PN-1−/− mice compared with
the plug generated by wild type. Plugs are oriented with their proximal
ends at the top. (Scale bar, 0.75 mm.) (F) Immunoblot
indicates that PN-1 is secreted during ejaculation and is then present
in plugs generated by PN-1+/+ males. (G)
Proteolytic activity assay in plugs homogenates in the presence of
added thrombin. The surplus proteolytic activity detected in plugs
generated by PN-1−/− males compared with the buffer
control with 0.1 nM added thrombin (see Materials and
Methods) indicates an endogenous PN-1-sensitive
proteolytic activity. (H) Coomassie blue
staining of PAGE-analyzed proteins contained in plugs generated by
PN-1+/+ and PN-1−/− mice. Each lane was
loaded with 5 μg protein.