Global producer responsibility for plastic pollution.

Brand names can be used to hold plastic companies accountable for their items found polluting the environment. We used data from a 5-year (2018-2022) worldwide (84 countries) program to identify brands found on plastic items in the environment through 1576 audit events. We found that 50% of items were unbranded, calling for mandated producer reporting. The top five brands globally were The Coca-Cola Company (11%), PepsiCo (5%), Nestlé (3%), Danone (3%), and Altria (2%), accounting for 24% of the total branded count, and 56 companies accounted for more than 50%. There was a clear and strong log-log linear relationship production (%) = pollution (%) between companies' annual production of plastic and their branded plastic pollution, with food and beverage companies being disproportionately large polluters. Phasing out single-use and short-lived plastic products by the largest polluters would greatly reduce global plastic pollution.

Marine Debris and Human Health: An Exposure Pathway of Persistent Organic Pollutants?

Although there are not any direct studies linking persistent organic pollutants (POPs) accumulated on marine debris to human health, there are numerous studies showing human health impacts from repeated and high-level POP exposure, as well as studies showing that POPs accumulate on plastic debris in the marine environment. With this knowledge, there is a need for greater awareness of the risks of POP exposure for those who handle marine debris regularly, especially in contexts of higher exposure such as those working in marine debris-concentrated areas. Among the scientific community, understanding of the exposure risk might be high, but others who handle marine debris, for instance, citizen groups in the Global South, are not necessarily aware of this exposure pathway. Moreover, global consumers who are marketed "ocean plastics" upcycled products are also not aware of potential POP exposure. Before marine plastics are accepted into the upcycled economy, these risks warrant further examination. This is a perspectives piece that aims to draw awareness to these emergent POP exposure pathways and considerations regarding marine plastic pollution. Environ Toxicol Chem 2022;41:263-265. © 2021 SETAC.

Meiotic cDNA libraries reveal gene truncations and mitochondrial proteins important for competitive fitness in Saccharomyces cerevisiae.

Gametogenesis is an evolutionarily conserved developmental program whereby a diploid progenitor cell undergoes meiosis and cellular remodeling to differentiate into haploid gametes, the precursors for sexual reproduction. Even in the simple eukaryotic organism Saccharomyces cerevisiae, the meiotic transcriptome is very rich and complex, thereby necessitating new tools for functional studies. Here, we report the construction of 5 stage-specific, inducible complementary DNA libraries from meiotic cells that represent over 84% of the genes found in the budding yeast genome. We employed computational strategies to detect endogenous meiotic transcript isoforms as well as library-specific gene truncations. Furthermore, we developed a robust screening pipeline to test the effect of each complementary DNA on competitive fitness. Our multiday proof-of-principle time course revealed 877 complementary DNAs that were detrimental for competitive fitness when overexpressed. The list included mitochondrial proteins that cause dose-dependent disruption of cellular respiration as well as library-specific gene truncations that expose a dominant negative effect on competitive growth. Together, these high-quality complementary DNA libraries provide an important tool for systematically identifying meiotic genes, transcript isoforms, and protein domains that are important for a specific biological function.

Dynamic sex chromosome expression in Drosophila male germ cells.

Given their copy number differences and unique modes of inheritance, the evolved gene content and expression of sex chromosomes is unusual. In many organisms the X and Y chromosomes are inactivated in spermatocytes, possibly as a defense mechanism against insertions into unpaired chromatin. In addition to current sex chromosomes, Drosophila has a small gene-poor X-chromosome relic (4th) that re-acquired autosomal status. Here we use single cell RNA-Seq on fly larvae to demonstrate that the single X and pair of 4th chromosomes are specifically inactivated in primary spermatocytes, based on measuring all genes or a set of broadly expressed genes in testis we identified. In contrast, genes on the single Y chromosome become maximally active in primary spermatocytes. Reduced X transcript levels are due to failed activation of RNA-Polymerase-II by phosphorylation of Serine 2 and 5.