Cyanobacteria reduce motility of quagga mussel (Dreissena rostriformis bugensis) sperm

Abstract

The temporal expansion of harmful algal blooms, primarily associated with cyanobacteria, may impact aquatic organisms at vulnerable life-history stages. Broadcast spawning species release gametes into the water column for external fertilization, directly exposing sperm to potential aquatic stressors. To determine if cyanobacteria can disrupt reproduction in freshwater broadcast spawners, we evaluated sublethal effects of cyanobacteria exposure on quagga mussel (Dreissena rostriformis bugensis) sperm. In laboratory studies, sperm were collected after inducing mussels to spawn using serotonin and exposed to 11 cultures of cyanobacteria including Anabaena flos-aquae, Aphanizomenon flos-aquae, Dolichospermum lemmermannii, Gloeotrichia echinulata, 5 cultures of Microcystis aeruginosa, M. wesenbergii, and Planktothrix suspensa. Sperm motility, using endpoints of cumulative distance traveled and mean velocity, was calculated for a minimum of 10 individual sperm using a novel optical biotracking assay method. The distance and velocity at which sperm traveled decreased when exposed to Aphanizomenon flos-aquae and 2 M. aeruginosa cultures. Our findings indicate that cyanobacteria impede the motility of quagga mussel sperm, which can potentially result in reproductive impairments to mussels and potentially other broadcast spawning species. Environ Toxicol Chem 2019;38:368-374. C 2018 SETAC

Multi-omics analysis reveals that iron deficiency impairs spermatogenesis by gut-hormone synthesis axis

“…Interestingly, we found that iron deficiency produced marked disturbances to the intestinal microbiota, and these disturbances dysregulated spermatogenesis. The extracts and exudates of Cyanobacteria have oestrogenic activity (Sychrová et al, 2012) and reduced sperm motility of the quagga mussel (Dreissena rostriformis bugensis) (Boegehold et al, 2019). The evidence suggests that Cyanobacteria is detrimental to spermatogenesis; however, we surprisingly found that the presence of Cyanobacteria is vital for normal spermatogenesis, as it was barely detectable in the gut of iron-deficient mice.…”

“…Mechanistically, defects in these activities appear to be a consequence of transcriptional mis-regulation of genes essential for testicular development. Moreover, iron deficiency impairs spermatogenesis indirectly by affecting hormone synthesis and testicular microbial homeostasis, evidenced by the DEGs, differentially expressed metabolites and functional prediction of differentially expressed microbiota (Zhang et al, 2022;Babakhanzadeh et al, 2020). Although we have deeply analysed the harm exerted by iron deficiency on spermatogenesis from different angles and have identified the regulation of ceRNA networks, we have not identified the key genes that are affected by iron deficiency and lead to spermatogenesis disorders.…”

“…Indeed, recent studies have confirmed that the gut microbiota is able to form a functionally complex and comprehensive three-dimensional network that regulates the reproductive, immune and metabolic systems. Moreover, the gut microbiota can act as protectors or invaders of the reproductive system (Boegehold et al, 2019;Zhang et al, 2021). Unfortunately, the characteristic changes in gut microbiota caused by iron deficiency have not been well described.…”

The combined effects of filter-feeding bivalves (Cristaria plicata) and submerged macrophytes (Hydrilla verticillate) on phytoplankton assemblages in nutrient-enriched freshwater mesocosms

“…Some functional traits of cyanobacteria, including cell size, life form (e.g. single celled, colonial, or filamentous), nutritional deficiency, and toxin production, can prevent them from being grazed by mussels ( White and Sarnelle, 2014 ; Boegehold et al, 2019 ). For example, Corbicula fluminea selectively filtered particles in the range of 0.2–2 µm ( Rong et al., 2021 ), Dreissena Polymorpha preferred food particles from 5 to 40 μm ( Sprung & Rose, 1988 ), and Venerupis corrugatus filtered out particles of 5 to 13 μm ( Stenton-Dozey and Brown, 1992 ).…”

Review and Development of Best Practices for Toxicity Tests with Dreissenid Mussels

“…Production and maintenance of early life stages in the laboratory can be laborious, and success depends on culture methods (e.g., pH and alkalinity of culture water; Fisher et al, 1994) and the ability to maintain adults in spawning condition (Stoeckel et al, 2004). For laboratory spawning and culture methods, see Fisher et al (1994); Nichols (1992); Ram & Nichols (1992); Ram et al (1996); Wright, Setzler‐Hamilton, Magee, Kennedy, & McIninch (1996); Wright, Setzler‐Hamilton, Magee, & Harvey (1996), Stoeckel et al (2004), and Boegehold, Alame, et al (2018); and Boegehold, Johnson, et al (2018).…”