Polyethylene terephthalate nanoparticles effect on RAW 264.7 macrophage cells

AbstractPlastic pollution is a major environmental concern due to its pervasiveness which continues to increase year on year, as a result of a continuing acceleration in global plastic production and use. Polyethylene terephthalate (PET) is among the most produced plastics, commonly used as food and beverage containers. Once released in the environment, the degradation of plastic materials produces micro-and nano-plastics, with a particular concern about potential toxicological effects if they cross epithelial barriers via inhalation or ingestion. In this work, the effect of PET nanoparticles (PET-NPs) (≤ 250 d.nm) was assayed on mouse macrophages cell line (RAW 264.7) in in vitro experiments. Results showed that PET nanoparticles were easily internalized by the cells, 15 μg/mL of nanoparticles concentration had exhibited effects in cell proliferation and a slightly increased production of Reactive Oxygen Species (ROS), which seems to trigger cell response as foreign particles related to upregulation of PCDH12, IGH-V10, ROBO1 genes, and cell maintenance functions, related to FTSJ2 gene upregulation. Thus, the RAW 264.7 results showed here are useful towards for a preliminary and understanding of the potentially toxic effects related to PET nanoparticles and complementary to other in vitro assays, as the first step into the development of the risk assessment framework

Dominance of African racial ancestry in honey bee colonies of Mexico 30 years after the migration of hybrids from South America

Abstract The Africanized honey bee, a hybrid of Apis mellifera scutellata from Africa with European subspecies, has been considered an invasive species and a problem for beekeeping. Africanized bees arrived in Mexico in 1986, 30 years after their accidental release in Brazil. Although government programs were implemented for its eradication, Africanized populations persist in Mexico, but precise information on the patterns of genetic introgression and racial ancestry is scarce. We determined maternal and parental racial ancestry of managed and feral honey bees across the five beekeeping regions of Mexico, using mitochondrial (mtDNA, COI‐COII intergenic region) and nuclear markers (94 ancestrally informative SNPs), to assess the relationship between beekeeping management, beekeeping region, altitude, and latitude with the distribution of maternal and parental racial ancestry. Results revealed a predominantly African ancestry in the Mexican honey bees, but the proportion varied according to management, beekeeping regions, and latitude. The Mexican honey bees showed 31 haplotypes of four evolutionary lineages (A, M, C, and O). Managed honey bees had mitochondrial and nuclear higher proportions of European ancestry than feral honey bees, which had a higher proportion of African ancestry. Beekeeping regions of lower latitudes had higher proportions of African nuclear ancestry. Managed and feral honey bees showed differences in the proportion of maternal and nuclear racial ancestry. Managed honey bees from the Yucatan Peninsula and feral honey bees had a higher mtDNA than nuclear proportions of African ancestry. Managed honey bees, except those on the Yucatan Peninsula, had a higher nuclear than mtDNA proportion of African ancestry. Our study demonstrates that Africanized honey bee populations are genetically diverse and well established in Mexico, which highlights the limitations of management and government programs to contain the Africanization process and demands the incorporation of this lineage in any breeding program for sustainable beekeeping