In this study of the unique stability of the marsupial acrosome, experiments were carried out on the acrosomes of spermatozoa of the tammar wallaby (Macropus eugenii), common brushtail possum (Trichosurus vulpecula) and grey short-tailed opossum (Monodelphis domestica). Light microscopy showed that 4% of opossum and 15% of possum and wallaby spermatozoa lost their acrosomes after freeze-thawing. Electron microscopy revealed that freeze-thawing also induced changes in the acrosomal matrix of some acrosome intact spermatozoa. In both possum and wallaby, freeze-thawing increased the number of spermatozoa with vesiculation of the acrosomal matrix. Freeze-thawing disrupted the plasma membrane of spermatozoa but the acrosomal membranes remained intact. Immediately on addition of high concentrations of TX-100 (0.02% and 0.04%) there was significant loss of acrosomes and motility in possum and wallaby spermatozoa. Lower concentrations of TX-100 (< or = 0.01%) did not affect motility for up to 30 min in all three species, and there was no significant loss of acrosomes. Although loss of acrosomes did not occur under mild detergent treatment, 56% of wallaby and 70% of possum spermatozoa had altered acrosomes after 30 min in 0.01% TX-100. Electron microscopy revealed that acrosomes were undergoing a vesiculation process similar to that seen after freeze-thawing. Often the plasma membrane of detergent-treated spermatozoa was disrupted and had formed plasma membrane vesicles. However, the acrosomal membranes remained intact despite major changes to the acrosomal matrix. The study confirmed the remarkable stability of the marsupial acrosome and suggested that this is probably based in the acrosomal membranes.
The diacylglycerol DiC8 (1,2-dioctanoyl-sn-glycerol; 100 mumol l-1) was found to induce acrosomal loss in 70% of wallaby spermatozoa and 40% of possum spermatozoa after incubation for 120 min. If 10 mumol calcium ionophore l-1 was present, the time required to reach these end points was reduced to 30 and 60 min, respectively. The diacylglycerol OAG (1-oleoyl-2-acetyl-sn-glycerol; 100 mumol l-1) produced some acrosomal loss, particularly when 10 mumol calcium ionophore l-1 was present, but when the ionophore was absent, results were equivocal. The other diacylglycerol tested DOG (1,2-dioleoyl-sn-glycerol; 100 mumol l-1) did not induce significant acrosomal loss in possum or wallaby spermatozoa. The concentration of DiC8 required to induce acrosomal loss in marsupial spermatozoa (50-100 mumol l-1) was relatively high compared with that for placental mammals, suggesting a less specific mode of action than enzyme activation. Of the diacylglycerols tested alone, only DiC8 led to significant loss of motility. In wallabies, this was detectable after incubation for 60 min and in possums after incubation for 120 min. The ultrastructure of the DiC8-induced acrosomal loss was essentially identical to the acrosome reaction described for a broad range of placental mammals. A membrane vesicle shroud covered the acrosomal surface of the sperm head. The vesicles appeared to be formed by multiple point fusions between the plasma membrane and the outer acrosomal membrane. The mechanism of DiC8-induced acrosomal loss remains to be established.(ABSTRACT TRUNCATED AT 250 WORDS)
Probiotics MEP + can increase fowl weight and weft efficiency. Therefore it is important to determine probiotics MEP + effect at different dosages toward reproduction aspect. This research aimed to examine duck reproduction organ size after fed supplemented with probiotics MEP + at four different dosages within 30 days. This research used Completely Randomized Design (CRD). Four dosages applied in this research i.e.; (K) without probiotic's application or control, (P1) 0.75 ml/kg, (P2) 1,5 ml/kg, and (P3) 3 ml/kg. Each treatment repeated eight times. A total of 40 ducks raised on the floor of dry cage system. At the 31 st day of the treatment duck reproduction system organ was measured. Whole results show increase average data (±SD) for weight of both right and left testis, and liver weight with highly probiotics dosage it, however the analysis result statistic not significant (P > 0,05) except weight of right left testis with duck weight or gonadosomatic index (GSI) were very significant (P < 0,01) among all treatment at different dosages was compared control. The results is confirmed that probiotic's MEP + treatment with different dosages within 30 days gave no effect towards duck reproduction system organ size except to gonadosomatic index (GSI) male duck.
The reproductive characters provide information about the gonad maturity of eel. The prepubertal stage occurs in the yellow eel, and the pubertal stage achieves in the silver eel. This study aimed to evaluate the reproductive characters of tropical eel, Anguilla bicolor McClelland in the different developmental stages. Eels with 33 - 81 cm ± 13.54 length, and weight of 98 - 1062 g ± 262.99 were used to determine their reproductive characters. The variables observed were the total length, body weight, Gonadosomatic Index (GSI), eye index and estradiol levels. The results showed that total length, body weight and GSI of silver eels were higher than yellow eels (P < 0.01). Total length, body weight, and GSI were 66.09 cm ± 9.34, 556.83 g ± 236.24, and 2.12% ± 1.88 respectively. The eye index and plasma estradiol level of yellow eel, pre-silver, and silver eel were similar (P > 0.05). In conclusion, there are many differences in reproduction characteristics between a yellow and silver eels. The gonad of silver eel is more mature than that of a yellow eel.
In vitro spermatogenesis has many clinical applications and hopefully with improvement of research findings this technique will solve the applied fisheries era 4.0. This research aimed to evaluate the effects of testosterone and type of serum on the in vitro spermatogenesis of shark-minnow fish (Osteochilus hasselti). In the present research, four concentrations of testosterone (0, 5, 10 and 15 ng/mL) were tested. The types of serum used were autologous serum and Fetal Bovine Serum (FBS). The results showed that the use autologous serum in the culture medium capable of maintaining the consistency of the tissue culture in culture period and maintaining in vitro spermatogenesis of shark-minnow. This study shown that stage-specific of spermatogenic cells needed certain testosterone concentration. The stage of secondary spermatocyte needed testosterone concentration of 5ng/mL i.e. 50.81±9.29% in medium with autologous serum and 36.47±15.49% in medium with FBS, while stage of spermatid and spermatozoa needed testosterone concentration of 10ng/mL i.e. 36.66±19.81% and spermatozoa 43.45±23.44% in autologous serum and the proportion of spermatid i.e. 42.35±9.09% and spermatozoa 35.25±14.0% in medium with FBS. This study proven that in-vitro spermatogenesis, already demonstrated in shark-minnow fish, offered great promises to cope with reproductive issues in the aquaculture and applied fisheries biotechnology.
Eel population in nature reaches critical number, so that culture strategy is urgently needed to fulfil the high demand of this fish. A shortcut to get functional male, which proven difficult to be founded from natural catching, is masculinization. This research aimed to induce masculinization of tropical eel, Anguilla bicolor McClelland supplemented with various doses of 17α-methyltestosterone during a month culture in freshwater (0 ppt) or brackish water (10 ppt). The eel was grouped and fed with supplementation of 17α-methyltestosterone at various doses, depending upon treatments, namely 0 mg Kg-1 diet (control), 40, 80 or 120 mg Kg-1 diet. Eels size were similar, at approximately 16,78 g ± 0,62 in weight and 25,38 cm ± 0,15 in length were either culture in freshwater or brackish during the experiment for eight weeks. Sex gonad, based on anatomical histological structures, Eye Index and Fin Index were measured after time culture treatment achieved, as well as body length, weight, eye diameter and the length of the pectoral fin were measured. Results showed that supplementation 17α-methyltestosterone 80 mg/Kg diet culture in brackish water has the highest number of male (90%). This study proven that, the hormone was effective for masculinization in eels, It useful for masculinization in eels. Results proved that the 17α-methyltestosterone highly significant (P<0.01) effect on the Eye index (3.63 – 5.14) and Fin Index (3.03 – 4.08) of eels. This study concluded, that 17α-methyltestosterone more effective in improving the number of males in brackish water than in freshwater culture.
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