Figure 4

The E(spl)-C in Apis mellifera. A) A genomic region spanning about 250 kb (GroupUn.159; numbers are correspondingly) contains 3 presumptive E(spl) bHLH genes and one mα related gene. The gene at position ~250 kb encodes a bHLH protein with best overall identity to D.m.Mβ. This gene is disrupted by an intron inside the bHLH domain (dash and red arrowhead in B). Close by, at position 220 kb a mα related coding region is found. Based on high similarity to D.m.Mα and its close neighbourhood to A.m.mβ, we named it A.m.mα. A second intronless E(spl) like bHLH coding gene is located at position ~90 kb. We name it A.m.mγ since the encoded protein shows best overall identity to the D.m.Mγ. Approximately 50 kb away we detected sequences encoding an E(spl) like bHLH domain (A.m.Mβ') and a long open reading frame ending with a WRPW motif. The Ensembl honeybee database annotated a gene with five introns spanning 12 kb within this region but missed the respective motifs (GENSCAN00000025907). We propose a different gene structure; see Figure C for details. B) Alignment of the three putative honeybee bHLH proteins (A.m.Mβ', A.m.Mβ, A.m.Mγ) with D. melanogaster Mβ and Mγ proteins is shown. Identical residues are marked in blue; red shows highly related and yellow similar residues. Intron positions are marked with a triangle above and a dash in the respective A. mellifera sequence. C) Structure of the 12 kb GENSCAN00000025907 region. Black shows the Ensembl gene annotation, and blue the new ENSAPMG00000016895 annotation. Purple highlights a second exon that encodes part of the bHLH domain, the open reading frame extends into the predicted intron of GENSCAN00000025907 and terminates with WRPW.