A genotyping array for the globally invasive vector mosquito, Aedes albopictus

[[abstract]]BACKGROUND: Although whole-genome sequencing (WGS) is the preferred genotyping method for most genomic analyses, limitations are often experienced when studying genomes characterized by a high percentage of repetitive elements, high linkage, and recombination deserts. The Asian tiger mosquito (Aedes albopictus), for example, has a genome comprising up to 72% repetitive elements, and therefore we set out to develop a single-nucleotide polymorphism (SNP) chip to be more cost-effective. Aedes albopictus is an invasive species originating from Southeast Asia that has recently spread around the world and is a vector for many human diseases. Developing an accessible genotyping platform is essential in advancing biological control methods and understanding the population dynamics of this pest species, with significant implications for public health. METHODS: We designed a SNP chip for Ae. albopictus (Aealbo chip) based on approximately 2.7 million SNPs identified using WGS data from 819 worldwide samples. We validated the chip using laboratory single-pair crosses, comparing technical replicates, and comparing genotypes of samples genotyped by WGS and the SNP chip. We then used the chip for a population genomic analysis of 237 samples from 28 sites in the native range to evaluate its usefulness in describing patterns of genomic variation and tracing the origins of invasions. RESULTS: Probes on the Aealbo chip targeted 175,396 SNPs in coding and non-coding regions across all three chromosomes, with a density of 102 SNPs per 1 Mb window, and at least one SNP in each of the 17,461 protein-coding genes. Overall, 70% of the probes captured the genetic variation. Segregation analysis found that 98% of the SNPs followed expectations of single-copy Mendelian genes. Comparisons with WGS indicated that sites with genotype disagreements were mostly heterozygotes at loci with WGS read depth  20, indicating that the chip more accurately detects heterozygotes than low-coverage WGS. Sample sizes did not affect the accuracy of the SNP chip genotype calls. Ancestry analyses identified four to five genetic clusters in the native range with various levels of admixture. CONCLUSIONS: The Aealbo chip is highly accurate, is concordant with genotypes from WGS with high sequence coverage, and may be more accurate than low-coverage WGS

TiO2 nanotubes enriched with calcium, phosphorous and zinc: promising bio-selective functional surfaces for osseointegrated titanium implants

The lack of osseointegration and implant-related infections are two major complications leading to failure of dental and orthopedic implants. Therefore, the development of effective titanium (Ti) implant surfaces able to display enhanced osteogenic activity and antimicrobial properties is required. In particular, titanium dioxide (TiO2) nanotubes (NTs) have demonstrated promising features to modulate biological responses, as they may be easily tailored to achieve multiple functions. This work aims to study the ability of bio-functionalized TiO2 NTs to induce osseointegration, and concomitantly, to avoid infection. TiO2 NTs were bio-functionalized with calcium (Ca), phosphorous (P) and zinc (Zn), by reverse polarization anodization. Morphological and topographical features of NTs were observed through scanning electron microscopy (SEM), while surface chemistry was investigated by X-ray photoelectron spectroscopy (XPS). Biocompatibility studies were conducted with MG-63 and human mesenchymal stem cells (hMSCs) through MTT assay. Furthermore, cell morphology and cytoskeleton organization were observed by SEM and laser scanning confocal microscopy (LSCM). The osteoblastic differentiation capacity of hMSCs was studied by real-time PCR, as well as their angiogenesis ability by measuring the total release of vascular endothelial growth factor (VEGF). Finally, viability of Staphylococcus aureus (S. aureus) was assessed by live/dead bacterial viability assay. Results show that bio-functionalized TiO2 nanotubular surfaces are biocompatible and modulated cell morphology. In particular, NTs enriched with Ca, P, and Zn, induced to significantly up-regulated levels of bone morphogenetic protein 2 (BMP-2) and osteopontin (OPN) genes of hMSCs, when compared to conventional NTs. TiO2 nanotubular surfaces induced hMSCs to release a higher amount of VEGF, and significantly reduced the bacterial viability, both when compared to adequate Ti controls. In conclusion, the superimposition of TiO2 nanotubular-textured surfaces and their enrichment with Ca, P, and Zn, is a very promising approach for the development of novel bio-selective implant surfaces able to improve osseointegration and avoid infection.The authors acknowledge the financial support from FCT by the doctoral grant (Ref. SFRH/BD/88517/2012), CAPES (Proc. 99999.008666/2014-08), CNPq (Proc. 490761/2013-5) and UNESP. Also, the authors would like to thank Rio de Janeiro cell bank (BCRJ, Rio de Janeiro, Brasil) for all the support provided for biological experiments, as well Fernando Almeida for technical assistance at confocal microscope in CENABIO-UFRJ (Rio de Janeiro, Brasil). Tolou Shokuhfar especially thanks to US National Science Foundation NSF-DMR CAREER award # 1564950.info:eu-repo/semantics/publishedVersio