Recombination between snowhoe hare and La Crosse bunyaviruses

Area of Science:

• Virology
• Molecular Biology
• Genetics

Background:

• Previous studies demonstrated heterologous genetic recombination in La Crosse (LAC) and snowshoe hare (SSH) viruses.
• Specific reassortant viruses with defined RNA segment genotypes were previously obtained.

Purpose of the Study:

• To investigate reciprocal genetic crosses between LAC and SSH virus mutants.
• To identify and characterize novel reassortant viruses resulting from backcrosses.
• To explore the reasons for the absence of certain expected reassortant viruses.

Main Methods:

• Utilizing temperature-sensitive (ts) mutants of LAC group I and SSH group II viruses.
• Performing reciprocal crosses and backcrosses between LAC and SSH ts mutants.
• Analyzing the genotypes of resulting reassortant viruses.
• Developing a screening procedure for SSH-LAC reassortant viruses based on N polypeptide differences.

Main Results:

• Reciprocal crosses between SSH group II and LAC group I ts mutants did not yield expected LAC/SSH/SSH or LAC/SSH/LAC reassortants.
• Backcrosses produced novel reassortants: LAC/LAC/SSH and SSH/SSH/LAC.
• Further backcrosses failed to produce specific expected reassortant genotypes (LAC/SSH/SSH and LAC/SSH/LAC).

Conclusions:

• The study highlights limitations in achieving all possible reassortant genotypes through heterologous recombination between LAC and SSH viruses.
• Specific genetic combinations may be less viable or difficult to produce, influencing viral evolution.
• A method for screening SSH-LAC reassortants based on N polypeptide variations was established.