Skip to main content
Fig. 5 | BMC Biology

Fig. 5

From: Transposon-induced epigenetic silencing in the X chromosome as a novel form of dmrt1 expression regulation during sex determination in the fighting fish

Fig. 5

A transposon, drbx1 inserted into the X linked dmrt1 leads to epigenetic changes. A Genomic location of transposon drbx1 in the X linked dmrt1 locus and genomic feature of the transposon, where fixed variants, SNP and InDels, are shown with black and red vertical lines. For InDels, sequence variation in X allele relative to Y allele is denoted with positive and minus numbers for insertions and deletions, respectively. The transposon is characterized by 10-bp direct repeats at both ends. One copy of the 10-bp repeat element is also identified in the Y allele (representing the “target sequence duplication” of transposon insertion), leading to a 180-bp difference in length between X and Y alleles. The transposon is 61-bp and 291-bp, respectively, away from two predicted conserved non-coding elements (CNEs): CNE.078772 and CNE.078773. B Methylation levels of XX relative to XY pooled genotypes in predicted genomic elements including promoter, exon and conserved noncoding elements, throughout dmrt1 genomic region, at 3, 5, 12, 20, and 30 dph, as examined using McrBC-based real-time PCR. Red arrow indicates the location of drbx1. C Relative methylation levels in the dmrt1 promoter region of XX, XY, and YY genotypes at 3 dph, as examined using McrBC-based real-time PCR. Three independent pools for each genotype were analysed (Mann-Whitney test, *P < 0.05 and **P < 0.01). D The inverse relationship between methylation and expression for dmrt1 at 5 dpf, examined based on pooled XX and XY genotypes. E Luciferase assay for transcriptional activation from the X and Y alleles. X allele containing both CNE.078772 and CNE.078773 and with the transposon drbx1 insertion between the two CNEs was cloned into pGL3-Promoter vector and showed reduced luciferase activity in rainbow trout gonad cell line, in comparison to Y allele without the transposon insertion (Mann-Whitney test, *P < 0.05)

Back to article page