Silk protein sericin pretreatment enhances osmotic tolerance and post-thaw sperm quality but reduces the ability of sperm cells to undergo in vitro induced acrosome reaction in rabbit

• Published in: Cryobiology Vol. 90; pp. 1 - 7
• Main Authors: Raza, Sanan, Uçan, Uğur, Aksoy, Melih, Erdoğan, Güneş, Ceylan, Ahmet, Serin, Ilker
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01-10-2019
• Subjects: Acrosome - drug effects; Acrosome Reaction - drug effects; Animals; Cryopreservation - methods; Cryoprotective Agents - pharmacology; Female; Fertility; Freezing; Insemination, Artificial - methods; Male; Pregnancy; Rabbits; Semen - drug effects; Semen Analysis; Semen Preservation - methods; Sericins - pharmacology; Sperm Motility - drug effects; Spermatozoa - drug effects
• ISSN: 0011-2240; 1090-2392
• DOI: 10.1016/j.cryobiol.2019.09.008

Effect of sericin pretreatment of sperm cells on the osmotic tolerance, ability to undergo acrosome reaction induced by calcium ionophore (CI), heparin (H) or lysophosphatidylcholine (LPC), post-thaw sperm quality and in vivo fertility was evaluated in four successive experiments in rabbit. In experiment 1, fresh semen was pretreated with sericin (0, 0.1% or 0.5% w/v) before exposing to fructose solutions adjusted to either 50, 100, 290, 500 or 1000 mOsm/L. Sericin pretreatment increased sperm livability in addition to live-membrane intact and total membrane intact sperm rates (P < 0.05) in 50 and 290 mOsm/L groups. In experiment 2, sperm samples were pretreated by either 0.1 or 0.5% sericin after removal of the semen plasma. CI, H or LPC were used to induce acrosome reaction in pretreated sperm samples. Sericin pretreatment, reduced the ability of sperm cells to undergo acrosome reaction (P < 0.05) in vitro. In experiment 3, ejaculates were frozen with or without sericin pretreatment in DMSO-sucrose extender. In post-thaw samples sericin pretreatment improved total and progressive motility, livability, membrane and acrosome integrity in a dose dependent manner (P < 0.05). In vivo fertility trials by artificial inseminations revealed contradictory results in experiment 4. Although 0.5% sericin pretreatment totally inhibited fertility, 0.1% sericin provided high pregnancy rates. In conclusion; sericin pretreatment enhances osmotic tolerance and post-thaw sperm quality, but reduces the ability of rabbit sperm cells to undergo in vitro induced acrosome reaction, but this effect is restored in vivo by dose dependent manner.