ARS | Publication request: Isolation and characterization of a novel family (Mild-4) of miniature subterminal inverted repeat transposable element from the Colorado potato beetle, Leptinotarsa decemlineata

Submitted to: Genbank
Publication Type: Other
Publication Acceptance Date: December 7, 2006
Publication Date: December 16, 2006
Citation: Yocum, G.D. 2006. Isolation and characterization of a novel family (Mild-4) of miniature subterminal inverted repeat transposable element from the Colorado potato beetle, Leptinotarsa decemlineata. Genbank. Accession number EF121856.

Technical Abstract: Determining the genomic structure of DAT-2 and -3 led to the isolation of four novel families of miniature subterminal inverted repeat transposable elements (MSITE): Mild-1, -2, -3 and -4. Mild-1a is inserted within the first intron of diapause protein-1. Mild-1a is 284 bp in length, has a 14 bp target site duplication and three sets of subterminal inverted repeats. The second element, Mild-2a, is inserted within the 3' terminus of Mild-1a. Mild-2a is 29 bp in length with a 3 bp target site duplication and one set of subterminal inverted-repeats. Mild-3a shares 60% identity with Mild-1a, is 253 bp in length, has an 9 bp target site duplication and has one set of subterminal inverted repeats. Mild-4a is 227 bp in length with an 12 bp target site duplication. Mild-4a appears to be an intermediate form between a true MITE and a true MSITE because the 5' inverted repeat is terminal (i.e., adjacent to the target site duplication) as in MITEs, but the 3' inverted repeat is separated (in this case, by 38 bp) from the 3' target site duplication as in MSITEs. The target site duplications of Mild-1, -3 and -4 families share a common conserved core of AATTT. All four families of transposable elements are AT rich and are able to form hairpin structures. Within the promoter region of DAT-3 is a 131 bp sequence that shares 77% identity to the 3' terminus of Mild-1a. Mild-4a has identity to a 24 and a 53 bp regions within the promoter of the juvenile hormone esterase B gene. Probes based on these regions within the JHEB promoter revealed differential expression during the prediapause phase in the small RNA fraction with the highest level of expression in day 1 prediapause adults. Accession number: EF121856.