Characterization of sperm motility in sea bass: the effect of heavy metals and physicochemical variables on sperm motility

Abstract

Computer assisted sperm analysis (CASA) was used to characterize the motility of sea bass Dicentrarchus labrax spermatozoa and to study the effect of several physicochemical variables and heavy metals on sperm swimming performance. Duration of sperm motility in sea bass was very short (<50 s). During the first 20 s all the motility variables measured remained approximately constant, the velocity and linearity of the movement being maximum during this period, while both variables decreased sharply later. While slight variations in pH did not significantly modify sperm swimming performance, changes in osmolality affected all the measured motility variables. Two of the heavy metals tested, Cu 2þ and Pb 2þ , did not affect sperm motility when the activating media contained up to 100 ppm of the metal salts. In contrast, Hg 2þ modified the morphology of post-swimming spermatozoa at 0Á4-1 ppm (sperm dilution rate 1:39) and completely arrested sperm motility at concentrations as low as 0Á1 ppm (sperm dilution rate 1:2500). Assuming a covalent binding to sperm cells, this revealed a finite number of c. 10 million Hg 2þ binding sites per spermatozoon. Complementary results using demembranated spermatozoa suggested that the main target of HgCl 2 would be located in the plasma membrane and that HgCl 2 would inhibit water channels, hence preventing sperm motility.

Marine fish spermatozoa: racing ephemeral swimmers

“…In fish spermatozoa, the putative presence of aquaporins comes from observations where sperm motility is sensitive to low concentrations of inhibitors of aquaporins such as HgCl 2 , Abascal et al 2007. In turbot sperm, the effect of HgCl 2 , supposedly targeted to aquaporins, is chronologically double: first, inhibiting initiation of motility and secondly, inducing a 'twist' of the flagellum (Fig.…”

“…This impression is confirmed by many quantitative assessments of motility parameters (Cosson 2007a). Experimental values of the initial sperm speed of forward displacement in various species confirm a high velocity (expressed in mm/s): 150-180 in halibut , Vermeirssen et al 2004, 160 in fugu (Takai & Morisawa 1995), 130 (Cosson et al 2008a) or 65-100 (Trippel & Morgan 1994) in cod, 130 in hake (Cosson et al 2008a, Groison et al 2008, 215-230 in tuna (Cosson et al 2008b), 220 in turbot , Dreanno et al 1999c, and 120 (straight line velocity) in sea bass (Dreanno et al 1999a(Dreanno et al , 1999b, similar to values published by Abascal et al (2007). However, these velocity characteristics may be modulated by sperm microenvironment and particularly pH and osmolality of the SM.…”

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“…In study, since spermatozoa motility of sea bass is very short (<50s), all of spermatozoa motility parameters declined at the first 20 s. Moreover, it was observed that Cu 2+ and Pb 2+ did not affect spermaotoza motility when the activation solution contained up to 100 ppm o f the metal salts. However, 0.4-1 pp m (sperm d ilution rate 1:39) of Hg Cl 2 changed the morphology of postswimming spermatozoas and their motility co mpletely arrested at concentrations as low as 0.1 pp m (sperm dilution rate 1:2500) of HgCl 2 (Abascal, Cosson, & Fauvel, 2007). The modified sperms of rainbow trout using Hg (1-10 mg/ l) and Cd (10 mg/l) and reported changes in their spermatozoa motility after 4 h incubation (Dietrich et al, 2010).…”

“…However, in recent years, several studies have been carried out to investigate in vitro sperm to xicity of some toxic materials using CASA systems (Abascal, Cosson, & Fauvel, 2007;Chyb, Kime, M iko lajczy k, Szczerbik, & Epler, 2000;Chyb, Kime, Szczerb ik, Miko lajczyk, & Ep ler, 2001;Dietrich et al, 2010;Fabbrocini et al, 2012;Kime et al, 1996;Li, Li, Dzyuba, & Randak, 2010;Van Loo k, & Kime, 2003). Recently, in vitro sperm to xicity attract researcher's attention, thus, there are limited studies on toxicity of nanoparticles for risk assessment of nanomaterials.…”

Sperm motility, fertilization, and larval development of silver catfish (Rhamdia quelen) in copper-contaminated water

“…Even sublethal concentrations may have medium-and long-term consequences such as reduced reproduction in fish. In the water, gametes are exposed to pollutants (ABASCAL et al, 2007) that can modify their features (DIETRICH et al, 2012), reducing or preventing natural or artificial propagation (WITECK et al, 2011).…”