Sdic is a new gene that evolved recently in the lineage of @entity238 . It was formed from a duplication and fusion of the gene @entity69161 , which encodes @entity69161 , and @entity62891 , which encodes the intermediate polypeptide chain of the cytoplasmic dynein. The fusion joins @entity69161 exon 4 with @entity62891 intron 3, which brings together three putative promoter elements for testes-specific expression of Sdic: the distal conserved element (DCE) and @entity1062 ( @entity1062 ) are derived from @entity69161 , and the proximal conserved element (PCE) from @entity62891 intron 3. Sdic transcription initiates within the PCE, and translation is initiated within the sequence derived from @entity62891 intron 3, continuing through a 10 base pair insertion that creates a new splice donor site that enables the new coding sequence derived from intron 3 to be joined with the coding sequence of @entity62891 exon 4. A novel protein is created lacking 100 residues at the @entity1472 end that contain sequence motifs essential for the function of cytoplasmic dynein intermediate chains. Instead, the @entity1472 end is a hydrophobic region of 16 residues that resembles the @entity1472 end of axonemal dynein intermediate chains from other organisms. The downstream portion of Sdic features large deletions eliminating @entity62891 exons v2 and v3, as well as multiple frameshift deletions or insertions. The new protein becomes incorporated into the tail of the mature sperm and may function as an axonemal dynein intermediate chain. The new Sdic gene is present in about 10 tandem repeats between the wildtype @entity62891 and @entity69161 genes located near the base of the X chromosome. The implications of these findings are discussed relative to the origin of new gene functions and the process of speciation.

Origin and evolution of a new gene expressed in the XXXX sperm axoneme.

@entity1472 :: ('CHEBI:46882', 'Chemical') :: ['amino'] @entity69161 :: ('33019(Tax:7227)', 'Gene') :: ['AnnX', 'annexin X'] @entity1062 :: ('MESH:D013736', 'Disease') :: ['TSE', 'testes-specific element'] @entity62891 :: ('44160(Tax:7227)', 'Gene') :: ['Cdic'] @entity238 :: ('7227', 'Species') :: ['Drosophila melanogaster']
@entity238 :: (7227,Species) :: ['Drosophila']
