Total antioxidant capacity, catalase activity, and lipid peroxidation changes in seminal plasma of sex-reversed female and male rainbow trout (Oncorhynchus mykiss) during spawning season.

The advantages of gender-related characteristics are used in aquaculture practice to improve production. For instance, all-female stock is preferable than mixed or all-male stock in salmonid culture. The most effective way to obtain all-female populations is the using of sex-reversed (SR) female trouts, genotypically female but phenotypically male, by masculinizing androgen hormones as breeders in artificial insemination. This study was conducted to evaluate changes in the total antioxidant capacity (TAC), protein concentration, catalase (CAT) activity, lipid peroxidation level (LPO; malondialdehyde), and Fourier transform infrared spectra of seminal plasma of SR female and normal (N) male trouts during the spawning season. Seminal plasma TAC values of N male and SR female trouts were determined as 0.015 ± 0.004 and 0.116 ± 0.033 mM of Trolox equivalents, respectively, in the middle of the spawning season. Some regions related to aromatic rings in seminal plasma Fourier transform infrared spectra of SR female trouts differed from N male trouts were indicated to the higher TAC values. At the middle of the spawning season, protein concentrations were determined as 569.5 ± 139.4 mg/dL in SR female trouts and 66.3 ± 22.7 mg/dL in N male trouts. LPO levels in seminal plasma of N male trouts varied from 46.33 ± 12.05 × 10(-3) to 270.02 ± 70.64 × 10(-3) nmol/mg protein, whereas from 13.87 ± 4.98 × 10(-3) to 48.49 ± 17.31 × 10(-3) nmol/mg protein in SR female trouts throughout the spawning. CAT activities of seminal plasma in N male trouts ranged from 0.38 ± 0.26 to 0.47 ± 0.32 kU/mg protein, whereas those values in SR female trouts varied between 0.21 ± 0.10 and 0.43 ± 0.15 kU/mg protein. Moreover, there were the pairwise significant correlations among all variables except between CAT and TAC (P > 0.05). Remarkable correlations were found between LPO-protein (r = -0.922, P < 0.05, n = 190), LPO-TAC (r = -0.859, P < 0.05, n = 98), and TAC protein (r = +0.879, P < 0.05, n = 98). Similar to seminal plasma of N male trouts, TAC values, protein concentrations, and CAT activities in seminal plasma of SR female trouts have shown decline, whereas LPO levels increased toward the end of the spawning seasons. Seminal plasmas of SR female trouts were characterized by higher protein concentrations and TAC values and lower LPO levels than that from N male trouts.

EFFECTS OF SEMEN EXTENDER SUPPLEMENTED WITH L-METHIONINE AND PACKAGING METHODS (STRAWS AND PELLETS) ON POST-THAW GOLDFISH (Carassius auratus) SPERM QUALITY AND DNA DAMAGE.

BACKGROUND: Amino acids protect spermatozoa against cell damage during cryopreservation due to have antioxidant property and found in seminal plasma at high concentration. OBJECTIVE: The aim of the present work was to analyse the effect of extender supplementation with L-methionine on post-thawed sperm motility, duration and DNA damage and also it was tested the feasibility of using straws and pellets method for the cryopreservation of goldfish (Carassius auratus) sperm. MATERIALS AND METHODS: Extenders were supplemented with different L-methionine concentrations of 1 mM; 1.5 mM; 3 mM; 6 mM. Semen samples diluted at the ratio of 1 to 9 by the extenders were subjected to cryopreservation. After dilution the semen was aspirated into 0.25 ml straws and 0.1 ml pellets, the straws and pellets were placed on the tray, frozen in nitrogen vapor and plunged into liquid nitrogen. DNA damage was determined with comet assay after cryopreservation. RESULTS: Our results indicated that an increase in the concentration of L-methionine caused a significant increase in the motility rate and duration of sperm in goldfish (C. auratus) (p<0.05). In addition, duration and percentage of motility in pellets were higher than in straws. Comparing all concentrations of L-methionine, the best concentration of L-methionine was 1.5 mM. Highest post-thaw motility (45.00 +/- 7.07%) and duration of motility (17.00 +/- 0.71s) were obtained with the extender at concentration 1.5 mM in pellets. Addition of the extender with L-methionine was reduced DNA damage compared to control group. CONCLUSION: Consequently, pellets could be used for goldfish sperm cryopreservation and the tested amino acid affected the motility parameters, and semen extenders could be supplement with L-methionine.

Effect of butylated hydroxytoluene (BHT) on the cryopreservation of common carp (Cyprinus carpio) spermatozoa.

The aim of the present study was to test the effects of butylated hydroxytoluene (BHT) on the cryopreservation of common carp spermatozoa. BHT is widely used in the cryopreservation of the spermatozoa of different animal species and successfully sustains the characteristics of spermatozoa during freezing and thawing, but it has not previously been used with fish. After sampling, common carp spermatozoa were diluted with an extender composed of modified Kurokura's extender, 10% DMSO, and 10% egg yolk containing 0.0001, 0.001, 0.01, 0.1, 1, 2.5, 5, or 10mM BHT and subsequently frozen in liquid nitrogen. The post-thaw spermatozoa characteristics (i.e., progressive motility percentage (%), duration of progressive motility (s), fertilization rate (%), and eyed-eggs rate (%)) were evaluated and compared with those of the control group. There were significant increases in the percentage of progressive motility and the duration of progressive motility at the concentrations of 0.1 and 0.001mM BHT (P<0.05). The duration of post-thawed spermatozoa progressive motility at 0.001mM BHT was significantly greater than that of the other groups (39.6±0.4s, P<0.05), and the fertilization rates and eyed-eggs rates were also higher following the 0.1 and 1mM BHT treatments. BHT at concentrations of more than 1mM caused sperm immobility during the preparatory stages of the sperm freezing. We concluded that 0.001-0.1mM BHT can be beneficial for the cryopreservation of common spermatozoa.

Evaluation of cryoprotective effect of Turkish pine honey on common carp (Cyprinus carpio) spermatozoa.

BACKGROUND: The cryopreservation procedures that allow preserving sperm cells have been applied for sperm of many species. A sugar like glucose, fructose and sucrose were frequently used in cryomedia but up to the present pine honey was not used for cryopreservation of sperm cells. OBJECTIVE: The objective of present study is to investigate the effect of pine honey in various concentrations of 100, 200, 300, 400 and 500 mg/ml solutions on cryopreservation and fertilization ability of spermatozoa of common carp (Cyprinus carpio). MATERIALS AND METHODS: Totally 12.5 % (v/v) Me2SO as a cryoprotectant and 10 % (v/v) egg yolk added all extenders. Pine honey also compared with sugars as glucose, fructose (monosaccharide) and sucrose (disaccharide). Collected semen samples were diluted at the ratio of 1:9 with the extenders. After dilutions, the sperm motility was assessed for each group and then the diluted semen samples were cryopreserved. RESULTS: The extenders containing 300 mg ml-1 pine honey group showed both highest post thaw motility 75.3 ± 5.1 %, motility duration (s) 47.3 ± 2.5 % and hatching ratio 42.6 ± 4.2 % than other cryopreserved groups (P<0.05). CONCLUSION: Using the pine honey in cryomedia is effective for cryopreservation especially about hatching success of egg fertilized by frozen-thawed sperm of common carp.