Quality assessment of cryopreserved black-lip pearl oyster Pinctada margaritifera spermatozoa

Abstract

High quality of sperm is essential to a high fertilization rate, especially post-cryopreservation. Assessment of sperm integrity, motility and energy reserves before cryopreservation is necessary for selection of milt with optimal fertilizing potential. We describe the effect of cryopreservation on the quality of black-lip pearl oyster, Pinctada margaritifera var. cumingii sperm. Evaluated quality indices of fresh and frozen/thawed P. margaritifera spermatozoa, included morphology, ultrastructure and motility characteristics relative to the energy content (ATP) and its capacity to be sustained by mitochondrial respiration. Morphology and ultrastructure were quantitatively evaluated using images obtained by optical microscopy assisted by the Image J software and TEM, respectively. Sperm motility was assessed using Image J software combined with a computer assisted sperm analysis plugin adapted for assessing P. margaritifera spermatozoa. Other sperm quality parameters evaluated included O 2 consumption, ATP content, and creatine kinase activity. Frozen/thawed spermatozoa exhibited damage to the head but retained a compact spherical shape. Sperm motility indicators showed a significant decrease in quality resulting from the freeze/thaw process. The percent of motile cells was 54% compared to 84% in fresh sperm, O 2 consumption was 4.8 compared to 44 nanomol min −1 , ATP content was 0.72 nmol/10 9 spermatozoa in the activating medium compared to 4.54 nmol/10 9 spermatozoa, and creatine kinase activity was 9.06 × 10 −5 IU mg −1 protein compared to 12.5 × 10 −5 IU mg −1 protein. The cryopreservation protocol allowed obtaining an acceptable motility rate after thawing, confirming the predictive value of sperm motility measurements before cryopreservation in terms of their ability to withstand freezing process. Highlights ► Quality of the frozen/thawed black-lip pearl oyster Pinctada margaritifera spermatozoa. ► Progress to an efficient cryoconservation method for P. margaritifera spermatozoa. ► Preservation of P. margaritifera through the durable development of the pearl oyster culture in French Polynesia.

Hdh-Tektin-4 Regulates Motility of Fresh and Cryopreserved Sperm in Pacific Abalone, Haliotis discus hannai

“…The ATP levels in sperm during peak breeding seasons and in different cryopreserved sperm showed a trend of variation similar to that observed for sperm motility and mRNA expression of Hdh-TEKT4 in the same sperm sample. It has been reported that the motility and ATP content of oyster sperm can be significantly affected by the freeze–thaw process of cryopreservation ( Demoy-Schneider et al, 2018 ). A significant decrease in the ATP content in the cryopreserved sperm of Pacific oyster than in fresh sperm has been reported ( Suquet et al, 2010 ).…”

Effect of Trehalose and Sucrose in Post-thaw Quality of Crassostrea angulata Sperm

“…This protective effect of sugars in post-thaw sperm was also reported for several species such as boar, Salmonidae fish, and Australian flat oyster ( Gómez-Fernández et al, 2012 ; Nynca et al, 2016 ; Hassan et al, 2017a ). Trehalose and sucrose have shown an important role as supplement of the freezing medium during cryopreservation of bivalves, being mainly applied in larvae ( Choi et al, 2008 ; Labbé et al, 2018 ) and less in sperm ( Hassan et al, 2017a ; Demoy-Schneider et al, 2018 ). Moreover, studies in bivalve sperm were performed with a low number of quality analyses both in the fresh and post-thaw samples, being these analyses focused mainly on sperm motility, plasma membrane integrity, and fertilization success ( Vitiello et al, 2011 ; Horváth et al, 2012 ; Suquet et al, 2016 ; Hassan et al, 2017a , b ), thus lacking important information on sublethal damage.…”

Sperm cryopreservation of the noble Scallop Chlamys nobilis by a programmable freezing method: Effect of cryoprotectant

“…Studies on the mollusc sperm biological characteristics, cryopreservation and quality assessment have become more numerous since reviewed by Gwo (Gwo, ; Hassan, Qin, & Li, ). These studies concerned oyster species (Boulais et al, ; Suquet et al, ; Suquet, Rimond, et al, ), pearl oyster species (Demoy‐Schneider, Levêque, Schmitt, Le Pennec, & Cosson, ; Demoy‐Schneider, Schmitt, Le Pennec, Suquet, & Cosson, ; Zheng et al, ) and so on. However, studies for scallop species were limited to Pecten maximus (Suquet, Arsenault‐Pernet, Ratiskol, & Mingant, ; Suquet, Gourtay, et al, ; Suquet, Malo, et al, ; Suquet, Quéré, et al, ), Argopecten purpuratus (Lamarck, 1819) (Dupré, Covarrubias, Goldstein, Guerrero, & Rojas, ; Espinoza, Valdivia, & Dupre, ), Chlamys farreri (Li, Li & Xue, 2000; Xue, ) and Patinopecten yessoensis (Yang et al, ; Yang, Yang, Liu, & Zhou, , ).…”