Eurasian reed warblers compensate for virtual magnetic displacement

sperm to penetrate the ZP and fuse with the egg plasma membrane [6]. Vaccination with solubilized ZP or isolated ZP proteins can bring about infertility. Sometimes the effects are transient; alternatively, they can be long-lasting, but may be associated with reproductive tissue damage, due to the induction of antibody-and/or T-cell-mediated responses [7]. We cloned rat IE3, a monoclonal antibody that binds the amino terminus of mouse ZP2, a critical ligand for taxon-specifi c sperm binding [8] (Figure S2A). IE3 transiently inhibits female mouse fertility when introduced as ascites fl uid through intraperitoneal injection [9]. Recombinant IE3 localized to the egg ZP in vitro and in vivo (Figure S2B). When mating was initiated 5 weeks after injection of AAV-IE3, seven out of twelve mice expressing IE3 were infertile, while fi ve were fertile, but with reduced litter sizes compared with controls (mean ± SEM, 3.8 ± 1.35 vs 14.7 ± 0.94; p < 0.01) (Figure 1I, Figure S2C). However, over subsequent months all AAV-IE3 mice (titer range between 2.8 and 19.3 g/ml) failed to produce progeny, with the exception of one of the initially fertile group of fi ve, who delivered a second litter of one during month three of mating (Figure S2D). Importantly, ovaries from infertile females expressing IE3 for 6 months (Figure 1, compare panels K and J), as with those exposed to IE3 transiently [9], appeared histologically normal, and contained follicles at multiple stages of development, as well as multiple corpora lutea. This, in conjunction with the observation that comparable numbers of eggs can be superovulated from control and AAV-IE3 females (Figure S2B), suggests that vectored expression of anti-ZP antibodies can induce long-term infertility without disrupting normal follicular maturation. Supplemental information, including background , discussion, hurdles that must be overcome in implementation of vectored contraception, possible strategies for bringing about reversibility, experimental procedures , two fi gures and one table, can be found with this article online at ACKNOWLEDGEMENTS We thank Janet Baer and Karen Lencioni for providing advice on a number of aspects of this work relating to mouse husbandry and reproduction. Shirley Pease provided help with mouse superovulation and Ken Chan with microscopy of eggs. Alejandro B. Balazs and Rachel Galimidi provided help with AAV. Jost Vielmetter and the Caltech Protein Expression Center provided assistance with protein production and SPR measurements. Cynthia Besch-Williford (IDEXX Bioresearch) provided analysis of mouse histology. This work did not receive specifi …