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1. Down-regulation of gene expression between the diapause initiation and maintenance phases of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

Creator:
Yocum, George D., Rinehart , Joseph P. , and Larson, Marnie L.
Type:
article, model:article, and TEXT
Subject:
Chrysomelidae, Coleoptera, diapause, and gene expression
Language:
English
Description:
The diapause initiation and maintenance phases of the Colorado potato beetle, Leptinotarsa decemlineata, were screened. Eight transcripts were found to be downregulated as the beetles enter the diapause maintenance phase of diapause development after day 15 postemergence. These transcripts were also expressed in early nondiapausing adults. Using BlastX, the transcripts were placed into six broad categories: regulatory (serpin), structural (apidermin), protease (serine protease), retinol binding protein (CRALBP), carbohydrate metabolism (ß-glucosidase, ß-mannosidase, and cellulose II), and unknown function.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Environmental regulation of the purine synthesis enzyme purH transcript during adult diapause in Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

Creator:
Yocum, George D.
Type:
article, model:article, and TEXT
Subject:
Diapause, Colorado potato beetle, gene expression, and purine
Language:
English
Description:
A 1962 bp cDNA clone of 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (purH) was isolated from diapausing adults of Leptinotarsa decemlineata using RT-PCR and 3' and 5'-RACE. The probe generated from this clone hybridized to a transcript approximately 1960 bp in length on northern blots. The clone encodes for a deduced protein 594 amino acids in length with 73% identity, 83% similarity to purH from Drosophila melanogaster. Northern blot (total RNA) analysis determined that L. decemlineata purH (LdpurH) was downregulated in diapausing beetles stored at 10°C. Developmental studies revealed that LdpurH is expressed at nearly constant high levels in both nondiapausing and prediapause adults. LdpurH expression during the first 20 days of diapause is equivalent to that seen in nondiapausing beetles, after which expression decreases. Exposing 70 day old diapausing beetles to 20°C for 24 h induced an increase in expression of purH indicating that purH is regulated by temperature in diapausing/overwintering beetles.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

3. Insertion of miniature subterminal inverted repeat-like elements in diapause-regulated genes in the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

Creator:
Yocum, George D., Toutges, Michelle J., Roehrdanz, Richard L., and Dihle, Preston J.
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, entomologie, Chrysomelidae, Coleoptera, Leptinotarsa juncta, transposons, 2, and 59
Language:
English
Description:
Determining the genomic structure of diapause-associated transcripts (DAT) -2 and -3 led to the isolation of four novel miniature subterminal inverted repeat-like 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 long with a 3 bp target site duplication and one set of subterminal inverted repeats. Using primers based on Mild-1, genomic clones were developed leading to the isolation of Mild-3a. Mild-3a shares 60% identity with Mild-1a, is 253 bp long, has a 9 bp target site duplication and has one set of subterminal inverted repeats. Mild-4a is inserted within the first intron of DAT-2 and is 227 bp in length with a 12 bp target site duplication. Mild-4a appears to be an intermediate form between a miniature inverted repeat transposable element (MITE) and a 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 33 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 of the transposable elements are AT rich and are able to form hairpin structures. Within the promoter region of DAT-3 is a 163 bp sequence (Mild-1b) that shares 77% identity to the 3' terminus of Mild-1a. Mild-4a has identity to 25 and 53 bp regions within the promoter of the juvenile hormone esterase B gene. Southern blot analysis revealed the presence of Mild-1 and -3 elements in both Leptinotarsa decemlineata and Leptinotarsa juncta indicating that these elements are ancestral to the L. decemlineata, L. juncta separation. and George D. Yocum, Michelle J. Toutges, Richard L. Roehrdanz, Preston J. Dihle.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public