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A C Pinkerton

Publications and source records attributed to A C Pinkerton.

9 recordsLinked to original sources
PubMed2003

Patterns of Hermes transposition in Drosophila melanogaster.

Transposable elements are being developed as tools for genomics and for the manipulation of insect genotypes for the purposes of biological control. An understanding of their transposition behavior will facilitate the use of these elements. The behavior of an autonomous Hermes transposable element from Musca domestica in the soma and germ-line of Drosophila melanogaster was investigated using the method of transposon display. In the germ-line, Hermes transposed at a rate of approximately 0.03 jumps per element per generation. Within the soma Hermes exhibited markedly non-random patterns of integration. Certain regions of the genome were distinctly preferred over others as integration targets, while other regions were underrepresented among the integration sites used. One particular site accounted for 4.4% of the transpositions recovered in this experiment, all of which were located within a 2.5-kb region of the actin5C promoter. This region was also present within the Hermes element itself, suggesting that this clustering is an example of transposable element "homing". Clusters of integration sites were also observed near the original donor sites; these represent examples of local hopping. The information content (sequence specificity) of the 8-bp target site was low, and the consensus target site resembles that determined from plasmid-based integration assays.

Animals↗
PubMed2001

Hermes-mediated germ-line transformation of the Mediterranean fruit fly Ceratitis capitata.

We report the use of the Hermes transposable element for germ-line transformation of the Mediterranean fruit fly, Ceratitis capitata. Hermes was able to genetically transform this insect at an estimated frequency between 0.6 and 1.1%, which is comparable to the transformation frequencies obtained for this species when using other transposable elements. Hermes integrates into the medfly genome by a cut-and-paste mechanism and the sequences integrated into the genome are delimited by the terminal nucleotides of the Hermes inverted terminal repeats. Integration resulted in the generation of 8 bp target site duplications, the sequences of which conformed to the target site duplications generated by hAT element transposition in insects. The Hermes element is one additional genetic tool that can be deployed in manipulating and characterizing the medfly genome.

Animals↗
PubMed2001

Genetic transformation systems in insects.

The past 5 years have witnessed the emergence of techniques that permit the stable genetic transformation of a number of non-drosophilid insect species. These transposable-element-based strategies, together with virus-based techniques that allow the expression of genes to be quickly examined in insects, provide insect scientists with a first generation of genetic tools that can begin to be harnessed to further increase our understanding of gene function and regulation in insects. We review and compare the characteristics of these gene transfer systems and conclude that, although significant progress has been made, these systems still do not meet the requirements of robust genetic tools. We also review risk assessment issues arising from the generation and probable release of genetically engineered insects.

Animals↗
PubMed2000

Green fluorescent protein as a genetic marker in transgenic Aedes aegypti.

We report here the use of the enhanced green fluorescent protein (EGFP) from the jellyfish, Aequorea victoria, as a genetic marker for the genetic transformation of mosquitoes. The EGFP gene, under the control of the actin5C promoter of Drosophila melanogaster was inserted into the Hermes transposable element. Preblastoderm embryos of a wild-type strain of the yellow fever mosquito, Aedes aegypti, were microinjected with this plasmid, together with a helper plasmid containing the Hermes transposase placed under the control of the D. melanogaster hsp70 promoter. Somatic EGFP expression was observed during early instars in approximately one-half of all G0 individuals. Two G1 individuals arising from a G0 female displayed high levels of EGFP gene expression during all stages of development. EGFP was transmitted in a Mendelian fashion to the G2 and G3 generations and molecular analysis confirmed the presence of the Hermes[actin5C:EGFP] gene in these insects. These results clearly demonstrate that EGFP can be used as an effective genetic marker in wild-type Ae. aegypti and most likely in other mosquito species as well.

Aedes↗
PubMed1999

The Queensland fruit fly, Bactrocera tryoni, contains multiple members of the hAT family of transposable elements.

Members of the hAT transposable element family are mobile in non-host insect species and have been used as transformation vectors in some of these species. We report that the Queensland fruit fly, Bactrocera tryoni, contains at least two types of insect hAT elements called Homer and a Homer-like element (HLE). The Homer element is 3789 bp in size and contains 12-bp imperfect inverted terminal repeats. The Homer element contains a long open reading frame (ORF) that encodes a putative transposase. Three different copies of this long ORF were recovered from the B. tryoni genome and, upon transcription and translation in an in vitro system, all produced transposase. The HLE is an incomplete element since no 3' inverted terminal repeat (ITR) was found. Homer and the HLE are as related to one another as either is to the other insect hAT elements such as Hermes, hobo, hermit and hopper. The structure and distribution of these two Homer elements is described.

Amino Acid Sequence↗
PubMed1996

Mobility of hAT transposable elements in the Old World bollworm, Helicoverpa armigera.

The P, hobo, Hermes, Minos and mariner transposable elements have been successfully used as gene vectors to achieve genetic transformation of Drosophila melanogaster. The hobo transposable element of D. melanogaster, a member of the hAT family of transposable elements, can also transpose in other dipteran species including the house fly Musca domestica and the Queensland fruit fly, Bactrocera tryoni. Another hAT element, Hermes, can also transpose in a wide range of insect species. We report here that both of these hAT elements are also capable of mobility and accurate transposition in the noctuid Helicoverpa armigera and thus may be able to be used as gene vectors that will enable the genetic transformation of this important pest species. Significantly, the ability of hobo to excise in this species is independent of the presence of an exogenous source of hobo transposase, which suggests that H. armigera may possess an endogenous hobo-like transposable element.

Animals↗
PubMed1983

Rehabilitation outcomes in females with spinal cord injury: a follow-up study.

A follow-up study was carried out on patients with spinal cord injury discharged from the G. F. Strong Rehabilitation Centre, Vancouver, British Columbia, Canada over a five year period with a minimum time from discharge to follow up of 18 months. Those no longer residing in the province, under the age of sixteen years on discharge, or who had made a substantial recovery were eliminated from the study. All of the patients included required a wheelchair or other aids for ambulation and had loss of normal bowel and bladder control. Twenty-four patients out of 37 who met the criteria were interviewed and details of medical, social, vocational and psychological outcomes are presented. In addition there were four deaths, the causes of which are discussed. Interesting comparisons between tetraplegic and paraplegic patients are given. Some differences between the findings in female and male patients are included.

Accidents, Traffic↗