Involvement of ABCB1 and ABCC1 transporters in sea urchin Echinometra lucunter fertilization

Abstract

Fertilization is an ordered sequence of cellular interactions that promotes gamete fusion to form a new individual. Since the pioneering work of Oskar Hertwig conducted on sea urchins, echinoderms have contributed to the understanding of cellular and molecular aspects of the fertilization processes. Studies on sea urchin spermatozoa reported the involvement of a plasma membrane protein that belongs to the ABC proteins superfamily in the acrosome reaction. ABC transporters are expressed in membranes of eukaryotic and prokaryotic cells, and are associated with the transport of several compounds or ions across biomembranes. We aimed to investigate ABCB1 and ABCC1 transporter activity in sea urchin spermatozoa and their involvement in fertilization. Our results indicate that Echinometra lucunter spermatozoa exhibit a low intracellular calcein accumulation (18.5% stained cells); however, the ABC blockers reversin205, verapamil, and MK571 increased dye accumulation (93.0-96.6% stained cells). We also demonstrated that pharmacologically blocking ABCB1 and ABCC1 decreased spermatozoa fertilizing capacity (70% inhibition), and this phenotype was independent of extracellular calcium. These data suggest that functional spermatozoa ABCB1 and ABCC1 transporters are crucial for a successful fertilization. Additional studies must be performed to investigate the involvement of membrane lipid homeostasis in the fertilization process.

Single Nucleotide Polymorphisms in SLC5A1, CCNA1, and ABCC1 and the Association with Litter Size in Small-Tail Han Sheep

“…CCNA1 is an important cell cycle regulator that plays an important regulatory role in germ cell meiosis, indicating that it plays an important role in animal reproduction [29,30,31,55]. ABCC1 is associated with the transport of several compounds or ions across biomembranes and is crucial for successful fertilization [56]. However, few studies have investigated the effect of the SLC5A1 , CCNA1 , and ABCC1 genes on litter size in sheep.…”

Mitochondrial permeability transition pore (MPTP) desensitization increases sea urchin spermatozoa fertilization rate

“…The inconsistent results can be attributed to calcein self‐quenching, which may be related to several reasons since the presence of ABC transporters activity (Silva‐Neta et al, ) to the small cell size or the small amount of cytoplasm compared to the large mitochondrion in the spermatozoa. Calcein‐AM is an ABC transporters substrate and CsA blocks the activity of several ABC proteins, which increases calcein concentration inside the cell (Hait et al, ; Tiberghien and Loor, ; Marques‐Santos et al, ; Hamdoun et al, ; De Souza et al, ; Silva‐Neta et al, ). Additionally, Hamann et al () demonstrated that calcein exhibits a strong self‐quenching that is responsible for the reduction in the fluorescence level according to the cell size.…”

ATP‐binding cassette transporters protect sea urchin gametes and embryonic cells against the harmful effects of ultraviolet light

“…The mapping of the sea urchin S. purpuratus genome revealed 65 genes encoding ABC transporters (Sodergren et al, ). Recently, our group characterized the activity of ABCB1 and ABCC1 proteins in the gametes, embryonic cells, and pluteus larvae of Echinometra lucunter , a widespread sea urchin that inhabits the tropical and temperate waters of the Atlantic Ocean (De Souza et al, ; Silva‐Neta et al, ; Torrezan et al, ). Our data suggest that ABC transporters act as a biochemical barrier that confers protection against chemical stress in E. lucunter embryos, but are also crucial to the fertilization process.…”