Insect Molecular Biology and Biochemistry

Insect Transposable Elements Part 3

Detection of in vivo Transposition Events by TE Display TE display (Van den Broeck et al., 1998; Casa et al., 2000; Biedler et al., 2003) is a sensitive and reproducible experimental method to detect TE insertions (Figure 5). TE display is a powerful tool for genome-wide analysis of TE insertions, and for detection of new […]

Insect Transposable Elements Part 4

Impact of TEs in Insects TEs and Genome Size and Organization As described in the introduction, TEs are integral and significant components of eukaryotic genomes. For example, at least 46% of the human genome (Lander et al., 2001) is TE-derived sequences. It has been proposed that the differing TE abundance may account for the "C-value […]

Transposable Elements for Insect Transformation Part 1

Summary The germ-lines of more than 35 species from five orders of insects have been genetically transformed, using vectors derived from Class II transposable elements. Initially the P and hobo vector systems developed for D. melanogaster were not applicable to other species, but four transposons found in other species, Hermes, Minos, Mosl, and piggy-Bac, were […]

Transposable Elements for Insect Transformation Part 2

Transformation Marker Systems The availability and development of selectable marker systems has played a large part in recent advancements in insect transformation, which have been equal in importance to vector development. The rapid implementation and expansion of P transformation in Drosophila was possible, in large part, due to the availability of several eye-color mutant-rescue systems. […]

Transposable Elements for Insect Transformation Part 3

Detection methods for fluorescent proteins Once heterologous expression of GFP in nematodes was discovered, it was realized that use of the marker for whole body analysis of gene expression would require an optical system allowing a large depth of field and a stage with working space for culture plates. Up to this time, most epifluorescence […]

Transposable Elements for Insect Transformation Part 4

piggyBac Discovery of piggyBac and other TTAA-specific elements Similar to several other insect transposable element systems, the piggyBac element was discovered fortuitously in association with a mutant phenotype. However, unlike all the other transposons used for insect transformation, the mutant phenotype was the result of a functional element that had transposed into an infectious organism. […]

Transposable Elements for Insect Transformation Part 5

Minos The first germ-line transformation of a non-drosophilid insect mediated by a transposon-based vector system was achieved with the Minos element. Minos was originally isolated as a fortuitous discovery in D. hydei during the sequencing of the non-coding region of a ribosomal gene (Franz and Savakis, 1991). Minos was found to be a 1.4-kb element […]

Cuticular Proteins (Insect Molecular Biology) Part 1

Introduction In the first edition of this series, Silvert (1985) outlined several major areas of uncertainty regarding cuticular proteins. The questions raised were: Were proteins extracted from cuticle authentic cuticular proteins, or might some be contaminants of adhering cells and hemolymph? Was the epidermis the sole site of synthesis of cuticular proteins, or were some […]

Cuticular Proteins (Insect Molecular Biology) Part 2

Classes of Proteins Found in Cuticles Non-Structural Proteins Some representative non-structural proteins that have been identified in cuticle are listed in Table 2. Pigments Proteins from three classes of pigments used in cuticle – insecticyanins and two different yellow proteins – have been sequenced. The insecticyanins are blue pigments made by the epidermis and secreted […]

Cuticular Proteins (Insect Molecular Biology) Part 3

CPR family: Proteins with the R&R consensus By far the most common family of cuticular proteins is that containing the R&R Consensus. The name comes from a 28-aa motif, first recognized by Rebers and Riddiford (1988) in six cuticular proteins. The original R&R Consensus is part of a longer conserved sequence, pfam00379. A valuable website, […]