title: Active immunization against the proregions of GDF9 or BMP15 alters ovulation rate and litter size in mice.
abstract: The transforming growth factor β (TGFB) superfamily proteins bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9), are essential for mammalian fertility. Recent in vitro evidence suggests that the proregions of mouse BMP15 and GDF9 interact with their mature proteins after secretion. In this study, we have actively immunized mice against these proregions to test the potential in vivo roles on fertility. Mice were immunized with either N- or C-terminus proregion peptides of BMP15 or GDF9, or a full-length GDF9 proregion protein, each conjugated to keyhole limpet hemocyanin (KLH). For each immunization group, ovaries were collected from ten mice for histology after immunization, while a further 20 mice were allowed to breed and litter sizes were counted. To link the ovulation and fertility data of these two experimental end points, mice were joined during the time period identified by histology as being the ovulatory period resulting in to the corpora lutea (CL) counted. Antibody titers in sera increased throughout the study period, with no cross-reactivity observed between BMP15 and GDF9 sera and antigens. Compared with KLH controls, mice immunized with the N-terminus BMP15 proregion peptide had ovaries with fewer CL (P<0.05) and produced smaller litters (P<0.05). In contrast, mice immunized with the full-length GDF9 proregion not only had more CL (P<0.01) but also had significantly smaller litter sizes (P<0.01). None of the treatments affected the number of antral follicles per ovary. These findings are consistent with the hypothesis that the proregions of BMP15 and GDF9, after secretion by the oocyte, have physiologically important roles in regulating ovulation rate and litter size in mice.
authors: School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand. joy.mcintosh@vuw.ac.nz
authors: C Joy
authors: CJ
authors: McIntosh
authors: Steve
authors: S
authors: Lawrence
authors: Peter
authors: P
authors: Smith
authors: Jennifer L
authors: JL
authors: Juengel
authors: Kenneth P
authors: KP
authors: McNatty
mesh_terms: D000818:Animals; D055430:Bone Morphogenetic Protein 15 / Q000737:chemistry / Q000276:immunology*; D005260:Female; D055429:Growth Differentiation Factor 9 / Q000737:chemistry / Q000276:immunology*; D057809:HEK293 Cells; D006801:Humans; D008098:Litter Size / Q000187:drug effects; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010060:Ovulation / Q000187:drug effects / Q000502:physiology; D034445:Ovulation Inhibition / Q000276:immunology; D011247:Pregnancy; D011498:Protein Precursors / Q000737:chemistry / Q000276:immunology*; D017434:Protein Structure, Tertiary; D014611:Vaccination / Q000379:methods*; D022642:Vaccines, Contraceptive / Q000276:immunology / Q000494:pharmacology
chemical_list: C525902:Bmp15 protein, mouse; D055430:Bone Morphogenetic Protein 15; C525898:Gdf9 protein, mouse; D055429:Growth Differentiation Factor 9; D011498:Protein Precursors; D022642:Vaccines, Contraceptive