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.
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