Fig. 2

Structure of the ERV insertion associated with henny feathering (Hf_ERV). a) Schematic drawing of different CYP19A1 transcripts. Transcription start sites are indicated with red arrows. The top row is the structure of Hf_ERV induced transcription, identified by 5’RACE and submitted to GenBank (accession number MN124451). Middle row is the long transcript isoform present in wild-type chicken. The bottom row is the short wild-type isoform. Coding sequences, UTRs, and introns positions are based on NCBI and are indicated by dark green boxes, light green boxes, and light green lines, respectively; black arrows mark the orientation of transcription. Dash lines represents the shared 4 bp sequence of exon 1 between these 2 transcripts, other exons are identical. b) Positions and sizes of the two flanking LTRs and the internal retroviral gag, pro, pol, and env genes. TSD = target site duplication; PBS = primer binding site; SD = putative splice donor motif. c) Sequence and annotation of the two identical LTRs showing binding sites for EFIII and Ig/EBP, as well as a TATA box promoter