Improved reference genome of the arboviral vector Aedes albopictus

BACKGROUND

The Asian tiger mosquito Aedes albopictus is globally expanding and has become the main vector for human arboviruses in Europe. With limited antiviral drugs and vaccines available, vector control is the primary approach to prevent mosquito-borne diseases. A reliable and accurate DNA sequence of the Ae. albopictus genome is essential to develop new approaches that involve genetic manipulation of mosquitoes.

RESULTS

We use long-read sequencing methods and modern scaffolding techniques (PacBio, 10X, and Hi-C) to produce AalbF2, a dramatically improved assembly of the Ae. albopictus genome. AalbF2 reveals widespread viral insertions, novel microRNAs and piRNA clusters, the sex-determining locus, and new immunity genes, and enables genome-wide studies of geographically diverse Ae. albopictus populations and analyses of the developmental and stage-dependent network of expression data. Additionally, we build the first physical map for this species with 75% of the assembled genome anchored to the chromosomes.

CONCLUSION

The AalbF2 genome assembly represents the most up-to-date collective knowledge of the Ae. albopictus genome. These resources represent a foundation to improve understanding of the adaptation potential and the epidemiological relevance of this species and foster the development of innovative control measures.

SU-E-T-226: Clinical Implementation of a Gravity-Oriented Wedge for Total Body Irradiation

PURPOSE

To describe a TBI technique designed within the limits of a small-room geometry and its clinical implementation.

METHODS

Following construction of the universal treatment devices, including the double-wedge, beam spoiler table, and patient support table, commissioning consists of measurements to determine the output, tissue-phantom ratio, effective source distance, and off-axis factor. Dose is calculated by applying these factors per patient-specific measurements to arbitrary point in the patient. Typically, ten calculation points are located at mid-separation along the mid-sagittal plane from the head to the ankles. When areas of unacceptably high dose are calculated, custom compensators are constructed from 5-mm sheets of PMMA and placed over the patient on top of the beam spoiler table. The typical dose homogeneity of the planning calculations is within 2% of the prescribed dose.

RESULTS

To verify the accuracy of the technique, an anthropomorphic phantom was simulated and treated. In total, 128 thermoluminescent dosimeters (TLDs) were irradiated within the phantom. Concentrations of TLDs were located in the planes of selected calculation points, i.e. the head, neck, sternum, lung, umbilicus, and pelvis. Results showed the average dose to these locations differed from the intended dose by -3.5%, 3.4%, 2.6%, 9.5%, 2.8%, and 0.5%, respectively. Due to its heterogeneous material, a higher discrepancy in the lung dose was anticipated. To demonstrate the dosimetric size of the radiation field, ionization chamber measurements were taken on one lateral side of the treatment area at a constant depth of 5 cm. A few measurements on the contralateral side were within 1 %, verifying the field's lateral symmetry. The approximate treatment area for the current technique is approximately 180×50 cm.

CONCLUSIONS

We have demonstrated a small-room technique capable of meeting the dosimetric goal of TBI. To improve the dosimetric characteristics, new universal treatment devices are currently being designed and constructed.