Optimization of Curimba (Prochilodus lineatus) Sperm Cryopreservation: Efficacy of Trehalose as a Cryoprotectant

Abstract

ABSTRACT Semen cryopreservation is essential for the conservation and maintenance of germplasm stocks from several species, each of which has specific requirements for successful cryopreservation. The objective of this study was to develop a sperm preservation protocol for Prochilodus lineatus (curimba) using the sugars trehalose, sucrose, lactose, and raffinose. Because synergy among cryoprotectants is not always beneficial, each cryoprotectant was tested separately at three concentrations (50, 100, and 150 mM), and dimethyl sulfoxide (DMSO) was used as the control. After thawing, sperm kinetic parameters were analyzed using computer-assisted sperm analysis (CASA), and cellular functional parameters were assessed by flow cytometry. In the sperm kinetic analyses, only the amplitude of lateral head displacement did not differ statistically from the control (p > 0.05), whereas the other parameters were lower than those of the control. In the motility-period analysis, 100 mM trehalose was superior to the control (p < 0.05), supporting its use in the protocol. However, the results for the different parameters analyzed showed that the other sugars tested were not superior to the control (10% DMSO), indicating that they were not effective for cryopreservation. Trehalose at 100 mM showed the most favorable response among the tested sugars for P. lineatus sperm cryopreservation.