Fig. 3

At the RTL1 locus an ancestral A allele has a single copy of a partially palindromic sequence (indicated in red) and the derived A* allele has a tandem duplication of this sequence which is processed as a microRNA from the maternal antisense transcript. a In AA homozygotes the maternal allele (above) is expressed as RTL1-antisense noncoding RNA and the paternal allele (below) is expressed as sense RTL mRNA. No microRNAs inhibit translation of RTL1 mRNA. b In A*A heterozygotes, the maternal A* allele produces a microRNA that binds to the mRNA transcribed from the paternal A allele which possesses a single-copy of the partially palindromic sequence. Translation of RTL1 protein is inhibited. c In AA* heterozygotes, the A maternal allele does not produce the microRNA and the paternal A* mRNA is translated. d In A*A* homozygotes, the maternal A* allele is processed as a microRNA that binds to both copies of the palindromic sequence of the mRNA transcribed from the paternal A* allele. Translation of RTL1 protein is inhibited