A coffee berry borer (Hypothenemus hampei) genome assembly reveals a reduced chemosensory receptor gene repertoire and male-specific genome sequences.

Coffee berry borer-CBB (Hypothenemus hampei) is a globally important economic pest of coffee (Coffea spp.). Despite current insect control methods for managing CBB, development of future control strategies requires a better understanding of its biology and interaction with its host plant. Towards this objective, we performed de novo CBB genome and transcriptome sequencing, improved CBB genome assembly and predicted 18,765 protein-encoding genes. Using genome and transcriptome data, we annotated the genes associated with chemosensation and found a reduced gene repertoire composed by 67 odorant receptors (ORs), 62 gustatory receptors (GRs), 33 ionotropic receptors (IRs) and 29 odorant-binding proteins (OBPs). In silico transcript abundance analysis of these chemosensory genes revealed expression enrichment in CBB adults compared with larva. Detection of differentially expressed chemosensory genes between males and females is likely associated with differences in host-finding behavior between sexes. Additionally, we discovered male-specific genome content and identified candidate male-specific expressed genes on these scaffolds, suggesting that a Y-like chromosome may be involved in the CBB's functional haplodiploid mechanism of sex determination.

Effect of maintaining apical patency on irrigant penetration into the apical two millimeters of large root canals: an in vivo study.

INTRODUCTION: Factors such as complex root canal anatomy and the vapor lock phenomenon have been shown to limit the penetration of irrigating solutions into the apical third in both in vivo and in vitro studies involving small and wide canals. Hence, the aim of this study was to determine whether the use of a patency file is related to the presence of a radiopaque irrigating solution in the apical 2 mm of large human root canals. METHODS: Forty-three large human root canals were randomly divided into 2 groups. Apical patency was maintained in 1 group (P, n = 22) during shaping and cleaning procedures with a no. 10 K-file 1 mm beyond the working length (WL) but not in the other group (no patency [NP], n = 21). In both groups, the canals were shaped with the K3 system. Irrigation was performed with 1 mL of a solution prepared with a radiopaque contrast medium and 5.25% sodium hypochlorite. Digital images were taken, and 2 calibrated readers determined the presence or absence of the irrigating solution in the apical 2 mm of the root canals. RESULTS: There were significantly more canals with irrigant in the apical 2 mm when apical patency was maintained with a no. 10- Kfile 1 mm beyond the WL than when apical patency was not maintained throughout the cleaning and shaping procedures (P = .04). CONCLUSIONS: Maintaining apical patency improves the delivery of irrigants into the apical third of large human root canals.