title: Lack of transmission of murine norovirus to mice via in vitro fertilization, intracytoplasmic sperm injection, and ovary transplantation.
abstract: Since its discovery in 2003, murine norovirus (MNV) is still endemic in many rodent animal facilities. Our aim was to determine the risk of transmission of MNV (91% homology to MNV3) to embryo recipients and pups via assisted reproductive technologies, especially those which compromise the integrity of the zona pellucida. In vitro fertilization (IVF), assisted in vitro fertilization (AIVF) with reduced glutathione, intracytoplasmic sperm injection, and ovary transplantation were performed. Murine norovirus was detected by qualitative and quantitative reverse transcription polymerase chain reaction. After natural infection of immunocompetent C57BL/6NTacCnrm and immunodeficient athymic nude mice with MNV, the mesenteric lymph nodes, small intestine, spleen, liver, lung, brain, ovary, and testis were infected at specific intervals for more than a 1-year period. At Week 12, the number of viral genomes per milligram of gonad from both strains was 20 to 50. Murine norovirus strictly adhered to spermatozoa collected from infected mice because three washes did not remove MNV from the sperm. After using MNV-positive sperm for IVF, AIVF, and intracytoplasmic sperm injection, 27 to 30 genomes were detected in IVF (n = 100) and AIVF (n = 100) embryos from both mouse strains. Approximately 87% of MNV detected in these embryos was found in the zona pellucida. However, all embryo transfer recipients, pups, and ovary recipients were MNV-negative. The results indicate that manipulation of the germplasm through assisted reproductive technologies did not lead to transmission of MNV to mice. This may be because of the absence of an infectious dose or failure of the MNV strain to replicate effectively in developing embryos and the reproductive tract.
authors.affiliation: National Research Council (IBCN), CNR-Campus International Development (EMMA-INFRAFRONTIER-IMPC), Monterotondo Scalo, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Raspa
authors.affiliation: Comparative Medicine, Center for Molecular Medicine, University of Cologne, Cologne, Germany.
authors.forename: Esther
authors.initials: E
authors.lastname: Mahabir
authors.affiliation: Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Fray
authors.affiliation: Department of Pediatric Oncology and Hematology, Children's Hospital, University of Cologne, Cologne, Germany.
authors.forename: Ruth
authors.initials: R
authors.lastname: Volland
authors.affiliation: National Research Council (IBCN), CNR-Campus International Development (EMMA-INFRAFRONTIER-IMPC), Monterotondo Scalo, Italy. Electronic address: ferdinando.scavizzi@cnr.it.
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Scavizzi
mesh_terms: D000818:Animals; D017250:Caliciviridae Infections / Q000635:transmission* / Q000821:virology; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects*; D051379:Mice; D029322:Norovirus / Q000145:classification*; D016377:Organ Transplantation / Q000009:adverse effects*; D010053:Ovary / Q000637:transplantation*; D020554:Sperm Injections, Intracytoplasmic / Q000009:adverse effects*
keywords: Assisted reproductive technology; Embryo transfer; Intracytoplasmic sperm injection; In vitro fertilization; Murine norovirus; Transmission