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Updated: Aug 29, 2026
Influenza Virus Propagation in Embryonated Chicken Eggs
Published on: March 19, 2015
Genetic characterization of a mumps virus isolate during passaging in the amniotic cavity of embryonated chicken eggs
Jelena Ivancic1, Dubravko Forcic, Tanja Kosutic Gulija
1Molecular Biomedicine Unit, Department of Research and Development, Institute of Immunology Inc., Rockefellerova 10, 10 000, Zagreb, Croatia. jivancic@imz.hr
Abstract:
The aim of this study was the molecular characterization of a historical mumps isolate (an alleged individual sample). After RNA extraction and cDNA synthesis, selective nested PCR amplification with specific primers, automated DNA sequencing and RFLP analyses were performed. The relative ratios of the detected virus sequences were determined by GeneScan electrophoresis. Phylogenetic tree based on the 316 nucleotide region of the SH gene of the mumps virus was generated by the neighbor-joining method. Results obtained by the described molecular approach show: (a) there are two mumps virus variants, A and B, detected in the fourth passage of wild type virus in the amniotic cavity of embryonated chicken eggs (ECE); (b) variants A and B belong to different genotypes; (c) variants A and B differ in the HN and NP genes which code for amino acid sequences comprising immunogenic epitopes; (d) variant B contains one or more minor variants. We discuss whether the observed differences between the two variants are a consequence of natural heterogeneity or of laboratory contamination in the early passages.
Insights
This study characterized a historical mumps virus isolate, revealing two distinct variants (A and B) belonging to different genotypes. The findings discuss potential natural heterogeneity versus laboratory contamination.
Area of Science:
- Virology
- Molecular Biology
- Genetics
Background:
- Mumps virus characterization is crucial for understanding its epidemiology and evolution.
- Historical isolates provide valuable insights into past viral strains.
Purpose of the Study:
- To perform molecular characterization of a historical mumps virus isolate.
- To identify and differentiate viral variants within the isolate.
Main Methods:
- RNA extraction and cDNA synthesis.
- Selective nested PCR amplification, automated DNA sequencing, and RFLP analysis.
- GeneScan electrophoresis for sequence quantification and phylogenetic analysis using the neighbor-joining method.
Main Results:
- Two distinct mumps virus variants, designated A and B, were identified in the fourth passage.
- Variants A and B belong to different genotypes and exhibit differences in HN and NP genes.
- Variant B contained minor variants, and the study discussed potential origins of observed differences.
Conclusions:
- The historical mumps isolate contains at least two genetically distinct variants.
- Observed genetic divergence may stem from natural viral heterogeneity or laboratory passage artifacts.
