Allelic expression analysis of tammar PHLDA2. (A) The difference of genomic structure by the length polymorphism is described. The open boxes represent exonic regions. Each black arrow represents a single 31 bp repeat unit. The longer allele has two units as a tandem repeat while the shorter allele has no repeat. The gel picture shows the PCR results using genomic DNA extracted from three different individuals having each genotype. "S" represents shorter allele; "L": longer allele. (B) Electrophoresis of RT-PCR products. Two different bands correspond to the amplified products from the longer and shorter allele. "gDNA" represents genomic DNA; "mDNA": maternal DNA; "YSP": yolk sac placenta. Three independent RT-PCR results were shown for the fetus #3 and pouch young #1. (C) The results of direct sequencing for tammar IGF2 PCR products amplified the unspliced transcript.