Effect of dilution in sperm maturation media and time of storage on sperm motility and fertilizing capacity of cryopreserved semen of sex-reversed female rainbow trout.
Masculinized females, also called neomales or sex-reversed females have a male phenotype but retain the female genotype (XX). Therefore, all spermatozoa produced in their functional testes carry an X chromosome, which is desired for the production of all-female rainbow trout populations. Semen of sex-reversed female rainbow trout is of low quality and in vitro maturation is required, which includes dilution of sperm suspensions with specially formulated maturation solutions. The aim of this study was to determine the effect of dilution in different maturation media on sperm quality (sperm motility characteristics and fertilizing capacity) of frozen/thawed sperm of sex-reversed female rainbow trout. The effect of time of post-thaw storage (0, 15, 60 and 120min) on semen quality was also tested. Sperm motility parameters and fertilization rate at the eyed and hatching stages were assessed for post-thaw semen diluted in different media. The cryopreservation procedure resulted in high post-thaw sperm motility of about 57% and did not differ from fresh semen. Unexpectedly, maturation media decreased sperm activation capacity immediately after dilution; however, sperm motility increased over time. Fertilization rates of frozen/thawed semen were high (71-87%) and did not differ significantly between experimental variants at any of tested periods of storage. Our results demonstrated that the effect of the maturation media on frozen/thawed sperm is different from that of fresh sperm. The progressive increase in post-thaw sperm motility in maturation media can potentially be applied to routine hatchery practice.
Department of Gametes and Embryo Biology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland.
Sylwia
S
Judycka
Department of Gametes and Embryo Biology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland.
Andrzej
A
Ciereszko
Department of Salmonid Fish Research, Inland Fisheries Institute, Rutki, 83-300 Żukowo, Poland.
Stefan
S
Dobosz
Department of Salmonid Fish Research, Inland Fisheries Institute, Rutki, 83-300 Żukowo, Poland.
Tomasz
T
Zalewski
Department of Gametes and Embryo Biology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland. Electronic address: g.dietrich@pan.olsztyn.pl.
Grzegorz J
GJ
Dietrich
D000818:Animals; D017756:Aquaculture; D015925:Cryopreservation / Q000662:veterinary*; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro / Q000662:veterinary; D005615:Freezing; D008297:Male; D017686:Oncorhynchus mykiss / Q000502:physiology; D012099:Reproductive Techniques / Q000662:veterinary; D012661:Semen / Q000502:physiology*; D055101:Semen Analysis / Q000662:veterinary*; D012662:Semen Preservation; D013079:Sperm Maturation; D013081:Sperm Motility / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects
Cryopreservation; Sex-reversed rainbow trouts; Sperm fertilizing capacity; Sperm maturation; Sperm motility; Spermatozoa