The potential for nanomaterial toxicity affecting the male reproductive system.

With the development of nanotechnology, nanomaterials offer great advantages in a wide variety of industrial and consumer products, and show promise for biomedical applications. However, with these new products, nanomaterial pollutants may enter the human body to cause adverse health effects, including hazards to the male reproductive system. Nanomaterials can enter the body through inhalation, oral exposure, or intravenous injection, and reach the testis via the blood, penetrate the Sertoli cell barrier, and directly or indirectly elicit toxicopathological changes to the testicles. These may then trigger hormone disorders, inhibit spermatogenic cell proliferation, and induce apoptosis, ultimately leading to a decrease in sperm motility and number, ultimately diminishing male reproductive capacity. This review will discuss the toxicological effects of nanomaterials on the male reproductive system, including inflammation, the impact on the hypothalamic-pituitary-gonadal axis (HPG axis), lipid peroxidation, and free ion release relevant to germ cells, Sertoli cell tight junctions, and the gonadal endocrine system. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials.

Genetic diversity and population structure of Camellia huana (Theaceae), a limestone species with narrow geographic range, based on chloroplast DNA sequence and microsatellite markers.

Camellia huana is an endangered species with a narrow distribution in limestone hills of northern Guangxi and southern Guizhou provinces, China. We used one chloroplast DNA (cpDNA) fragment and 12 pairs of microsatellite (simple sequence repeat; SSR) markers to assess the genetic diversity and structure of 12 C. huana populations. A total of 99 alleles were detected for 12 polymorphic loci, and eight haplotypes and nine polymorphic sites were detected within 5200 bp of cpDNA. C. huana populations showed a low level of genetic diversity (n = 8, Hd = 0.759, Pi = 0.00042 for cpDNA, N A  = 3.931, H E  = 0.466 for SSRs), but high genetic differentiation between populations (F ST  = 0.2159 for SSRs, F ST  = 0.9318 for cpDNA). This can be attributed to the narrow distribution and limestone habitat of C. huana. STRUCTURE analysis divided natural C. huana populations into two groups, consistent with their geographical distribution. Thus, we suggest that five natural C. huana populations should be split into two units to be managed effectively.