In silico analysis of single‐cell RNA sequencing data from 3 and 7 days old mouse spermatogonial stem cells to identify their differentially expressed genes and transcriptional regulators

Combinatorial immune and stress response, cytoskeleton and signal transduction effects of graphene and triphenyl phosphate (TPP) in mussel Mytilus galloprovincialis

Owing to its unique surface properties, graphene can absorb environmental pollutants, thereby affecting their environmental behavior. Triphenyl phosphate (TPP) is a highly produced flame retardant. However, the toxicities of graphene and its combinations with contaminants remain largely unexplored. In this work, we investigated the toxicological effects of graphene and TPP to mussel Mytilus galloprovincialis. Results indicated that graphene could damage the digestive gland tissues, but no significant changes were found in the graphene + TPP co-exposure group. There was a significant decrease in the content of GSH and the activities of GST and CAT in the co-exposure group compared to that in graphene-exposed group. It seemed that the adsorption of TPP on graphene could inhibit the surface activity of graphene and thus reduced its tissue damage and oxidative stress in mussels. Expression levels of stress response (MyD88a), cytoskeleton (MHC1, PMyo and TMyo) and reproductive (CP450 and HSD) genes were up-regulated in the graphene-exposed group, but significantly down-regulated after combined exposure of graphene and TPP. Furthermore, PPI analysis proved that the interactions of HSP90AA1 with UNC45B and FKBP4/5/6/L contributed to the toxicity caused by the combined exposure. Because of the potential toxicity of graphene and TPP, government administrators should consider its risks prior to the widespread environmental exposure.

Isolation and molecular characterization of spermatogonia from male Sprague-Dawley rats exposed in utero and postnatally to dibutyl phthalate or acrylamide

The increased incidence of testicular disorders in young men and the possible influence of environmental chemicals, such as dibutyl phthalate (DBP) and acrylamide (AA), requires experimental models for identifying modes of action. Most published reproductive toxicologic studies use RNA samples from the total testis to evaluate testicular gene expression; however, analyses of isolated cell types could provide a more specific tool. Among testicular germ cells, spermatogonia are critical since they represent the onset of spermatogenesis. This study aimed, (1) to establish a technique for spermatogonia isolation; (2) to apply this isolation technique to verify possible gene expression alterations (Pou5f1, Kitlg, Mki-67, Bak1 and Spry4) in prepubertal post-natal day, (PND24) and pubertal (PND45) testes after in utero and postnatal exposure to DBP or AA. The technique was efficient for isolation of a majority of spermatogonia. In utero DBP exposure led to reduced litter body weight at birth, reduced anogenital distance of male pups on PND4, and increased frequency of male nipple retention on PND14 compared to controls. DBP-exposed relative testes weights were reduced only at PND24 compared to control but they did not differ at PND45. DBP-exposed animals showed reduced expression levels of Pou5f1 and Mki67 on PND24, and reduced expression of Pou5f1 and Spry4 on PND45. AA exposure reduced expression of Pou5f1, Mki67, and Spry4 at PND45 although not significantly. Our results suggest that DBP acts by reducing cell proliferation and impairing differentiation in prepubertal and pubertal testes.