MHC-genotype of progeny influenced by parental infection

Area of Science:

• Immunogenetics
• Reproductive Biology
• Virology

Background:

• Previous in vitro experiments indicated non-random major histocompatibility complex (MHC) haplotype combinations in early mouse embryos.
• Two selection mechanisms were proposed: egg sperm selection and sperm influence on egg meiosis.
• Embryo MHC heterozygosity varied over time, suggesting an external factor, potentially mouse hepatitis virus (MHV), influenced fertilization.

Purpose of the Study:

• To test the hypothesis that MHV infection influences MHC haplotype selection during fertilization.
• To determine if viral infection affects the non-random combination of MHC haplotypes in early embryos.

Main Methods:

• Randomly chosen mice were infected with MHV or sham-infected as controls five days before mating.
• Two-cell embryos were recovered from oviducts and cultured to the blastocyst stage.
• Blastocyst genotypes were determined using polymerase chain reaction (PCR).

Main Results:

• Virus-infected mice produced a significantly higher proportion of MHC-heterozygous embryos compared to sham-infected controls.
• The observed pattern of MHC heterozygosity aligned with previous experimental findings.
• This indicates a correlation between MHV infection status and non-random MHC haplotype combination.

Conclusions:

• Parental MHV infection promotes the selection of specific MHC-haplotype combinations during fertilization.
• This suggests a parental mechanism to enhance offspring heterozygosity and potentially immune response in the presence of viral infection.