Heterozygous Rnpc3-deficient mice exhibit a normal lifespan but complete loss of Rnpc3 is indispensable for preimplantation development. (A) The initial targeted allele (Rnpc3neo) used in this study contained an IRES:LacZ and a loxP-flanked promoter-driven neo cassette inserted into intron 3 of the Rnpc3 gene, thereby disrupting its function. (B) Mice harboring conditional alleles in which exons 4 and 5 are flanked by loxP sites were generated by crossing Rnpc3neo mice with an embryonic Flp deleter transgenic line. (C) A germline null allele (Rnpc3−) was generated by crossing Rnpc3neo mice with mice carrying a Cre deleter transgene. Diagram modified from Skarnes et al. (2011) with permission from Springer Nature. (D) Longevity of Rnpc3+/− mice is the same as WT littermate controls: n = 58–62, Student's t-test P = 0.1131. (E) Pituitary gland weights of Rnpc3+/− mice (60–70 wk) are comparable to WT littermate controls (n = 11–17, Student's t-test P = 0.4822). (F) Several litters of mice were generated from in-crossing Rnpc3+/− parents and no Rnpc3−/− mice were born or hatched in culture from E3.5 blastocysts. (G) Genotyping of E3.5 blastocysts that had been cultured for 24 h identified all potential genotypes. Rnpc3+/+ and Rnpc3+/− blastocysts appeared normal while Rnpc3−/− exhibited an arrested morula phenotype (right panel). Scale bar in G = 100 µm.
