Ovigerous-hair stripping substance (OHSS) in an estuarine crab: Purification, preliminary characterization, and appearance of the activity in the developing embryos

Ovigerous-hair stripping substance (OHSS) is an active factor in crab hatch water (i.e., filtered medium into which zoea larvae have been released). T his factor participates in stripping off the egg attachment structures (i.e ., egg case, funiculus, and the coat investing ovigerous hairs) that remain attached to the female's ovigerous hairs after larval release. Thus this a ctivity prepares the hairs for the next clutch of embryos. OHSS activity of an estuarine crab, Sesarma haematocheir, eluted as a single peak on molecu lar-sieve chromatography, but this peak still showed halo protein bands at 32 kDa and 30 kDa on SDS-PAGE. The two protein bands stained with a polyclo nal antiserum raised to the active fractions from molecular-sieve chromatog raphy. Moreover, antibodies purified from this polyclonal OHSS antiserum al so recognized both the 32-kDa and 30-kDa bands. OHSS immunoreactivity and b iological activity were associated with the attachment structures that rema ined connected to the ovigerous hairs after hatching. In developing embryos ,both protein bands could be stained immunochemically at least 10 days befo re hatching. But OHSS biological activity appeared only 3 days before hatch ing. The immunoreactive protein bands were nor observed in the zoea, but OH SS bioreactivity was present, though greatly reduced. The 32-kDa protein, a t least, is probably an active OHSS, and the 30-kDa protein band may also b e OHSS-related. The OHSS appears to be produced and stored by the developin g embryo. Upon hatching, most of the material may be trapped by the remnant structures, and the remainder is released into the ambient water.