Most research carried out on the effects of the RN- allele
has been done on animals either classified as carriers or noncarriers
of the RN- allele. In Sweden for example, a common
commercial cross is the use of Hampshire sires on Landrace x
Large White cross bred sows, making slaughter pigs either
heterozygous RN-
/ rn+ or homozygous rn+/ rn+. However, in a
recent French study all three genotypes were studied, thus
making it possible to differentiate between pigs being homozygous
or heterozygous for the RN- allele (Lebret et al., 1999; Le
Roy et al., 2000a).
This paper summarises the main effects of the RN- allele
and how the gene was discovered including:
• Chemical composition and technological quality
• Enzyme activities and muscle fibre characteristic