title: Purification and cDNA cloning of the ovigerous-hair stripping substance (OHSS) contained in the hatch water of an estuarine crab Sesarma haematocheir.
abstract: The egg attachment system of an estuarine crab Sesarma haematocheir is formed on the maternal ovigerous hairs just after egg laying, and slips off these hairs just after hatching. The stripping is caused by an active factor that we call OHSS (ovigerous-hair stripping substance), which is released by the embryo upon hatching. OHSS was purified, and its active form had a molecular mass of 25 kDa. The cDNA of OHSS cloned from an embryonic cDNA library was 1759 bp long, encoding 492 amino acids in a single open reading frame (ORF). The C-terminal part of the predicted protein was composed of a trypsin-like serine protease domain, with homology to counterparts in other animals of 33-38%. The predicted protein (54.7 kDa) secreted as a zymogen may be cleaved post-translationally, separating the C-terminal from the N-terminal region. The OHSS gene was expressed in the embryo at least 2 weeks before hatching. Expression was also detected in the zoea larva 1 day after hatching and in the brain of the female. However, it was not detected in the muscle, hepatopancreas or ovigerous seta of the female. Ultrastructural analysis indicated that the material investing maternal ovigerous hair, i.e. the outermost layer (E1) of the egg case, is attached at the special sites (attachment sites) arranged at intervals of 130-160 nm on the hair. It is suggested that OHSS acts specifically at these sites, lysing the bond with the coat, thus disposing of the embryo attachment system. This enables the female to prepare the next clutch of embryos without ecdysis.
authors.affiliation: Laboratory of Animal Behavior and Evolution, Graduate School of Natural Science and Technology, Okayama University, Tsushima 3-1-1, Okayama 700-8530, Japan.
authors.forename: Oleg
authors.initials: O
authors.lastname: Gusev
authors.forename: Hideki
authors.initials: H
authors.lastname: Ikeda
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Okochi
authors.forename: Jae Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Hatakeyama
authors.forename: Chiyoko
authors.initials: C
authors.lastname: Kobayashi
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Agata
authors.forename: Hidenori
authors.initials: H
authors.lastname: Yamada
authors.forename: Masayuki
authors.initials: M
authors.lastname: Saigusa
mesh_terms: D000595:Amino Acid Sequence; D000825:Animal Structures / Q000502:physiology*; D000818:Animals; D001483:Base Sequence; D001834:Body Water / Q000737:chemistry; D003386:Brachyura / Q000235:genetics* / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004625:Embryo, Nonmammalian / Q000737:chemistry*; D004792:Enzyme Precursors / Q000235:genetics* / Q000302:isolation & purification; D015870:Gene Expression; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D004792:Enzyme Precursors