Effects of Dilution Rate on the Motility and Acrosome Morphology of Boar Spermatozoa Stored at 15 °C

The objective of this investigation was to establish the optimal extent of dilution for storage of boar spermatozoa at 15°C in Kiev diluent. The dilution titers used for the sperm-rich fraction of ejaculates from 8 boars ranged from 1:2 to 1:50. Seminal doses were stored for 10 days. Motility and acrosome morphology were evaluated after 1, 3, 5, 7, and 10 days of storage. The percentages of motile spermatozoa after 24 and 72 hours of storage were significantly higher for dilution rates between 1:7 and 1:11 than for dilution rates lower than 1:7 or higher than 1:11 (p < 0.05). The percentages of spermatozoa with normal acrosomes after 24, 72, and 120 hours of storage were significantly higher for dilution rates between 1:8 and 1:11 than for dilution rates lower than 1:8 or higher than 1:11 (p < 0.01 ).     

促性腺释放激素对公兔繁殖性能的影响

本试验研究了促性腺释放激素对公兔繁殖性能的影响。试验结果表明促性腺释放激素可以显著提高公兔的性欲、精子浓度(P<0.05)、精子活力(P<0.05)和每次射精的活精子数(P<0.01)。射精量也有所增加,但差异不显著。     

Role of nitrergic nerves in the regulation of motility of the omasum and abomasum in healthy sheep <Emphasis Type="Italic">(Ovis aries)</Emphasis>

We examined the physiological role of nitrergic nerves in the regulation of omasal and abomasal motility in conscious healthy sheep and omasal muscle specimens. Nitric oxide (NO)-donor, S-nitroso-acethyl-dl-penicillamine (SNAP, 3-30 nmol/kg per min, i.v.) significantly inhibited omasal electromyographic (EMG) activity, whereas it did not alter EMG activity in the abomasal antrum. However, NO synthase inhibitor, Nomega-nitro-l-arginine-methyl ester (L-NAME, 0.3-3.0 micromol/kg per min, i.v.) did not alter EMG activity of the omasum and abomasum. In the in vitro experiments, SNAP application (6-200 micromol/l) significantly inhibited bethanechol (10 micromol/l)-induced contraction of longitudinal and circular muscles of the omasum. L-NAME application (0.03-3.0 mmol/l) enhanced electric field stimulation-induced contractions of the circular muscles. The results suggest that the omasal muscles are responsive to exogenous NO and that nitrergic nerves innervate the circular muscle layer of the omasum, however, nitrergic nerves are not or scarcely involved the physiological regulation of omasal and possibly abomasal motility in healthy sheep.     

Effects of Pentoxifylline,Caffeine, and Taurine on Post-Thaw Motility and Longevity of Equine Frozen Semen

Frozen semen provides several advantages to the breeder relative to fresh or cooled semen. However, some stallions are undesirable candidates for semen freezing due to poor post-thaw motility or longevity caused by membrane damage, osmotic stress, and oxidative stress during cryopreservation. The objective of this study was to determine the effect of post-thaw addition of pentoxifylline, caffeine, or taurine on sperm motility and longevity in equine frozen semen. Pentoxifylline, caffeine, or taurine was incorporated immediately into thawing frozen semen from nine warmblood stallions. Spermatozoa motility and longevity parameters were recorded and analyzed for each additive and for an untreated control. Of the three additives, only pentoxifylline improved total and progressive semen motility relative to that of untreated control. Pentoxifylline also increased semen curvilinear velocity, average path velocity, and straight line velocity relative to those of caffeine, taurine, or control. Semen treated with pentoxifylline also showed greater longevity relative to that of caffeine- or taurine-treated or untreated semen. Taurine improved linearity in comparison to that of semen treated with pentoxifylline, caffeine, or control but did not improve other parameters. Pentoxifylline may be useful in enhancing the quality of equine frozen semen and therefore improving its fertility. Additional studies are warranted that examine the effect of these additives on the conception rate. Pentoxifylline can be used to increase motility and longevity of equine frozen semen and theoretically increase probability of conception and overall breeding success rates.     

鸡蛋黄和鹌鹑蛋黄在崇明白山羊精液冷冻保存中效果比较

对崇明白山羊精液采取3种不同离心处理去除精清,比较添加鹌鹑蛋黄和鸡蛋黄对精液冷冻保存效果的影响.结果表明:崇明白山羊精液冷冻保存中以1 000 r/min离心5 min去除精清后,添加鸡蛋黄组解冻后精子活力为50.48%,鹌鹑蛋黄组解冻后精子活力为42.98%.添加鸡蛋黄组的效果显著优于鹌鹑蛋处理组.     

水稻白叶枯病菌fkbM基因对其运动性的影响

[目的]研究水稻白叶枯病菌fkb M基因对其运动性的影响。[方法]采用同源置换方法对水稻白叶枯病菌野生型菌株PXO99A的fkbM基因进行基因敲除,构建突变菌株ΔfkbM_(Xoo),同时构建互补菌株ΔfkbM_(Xoo)(C)。通过运动性试验,确定fkbM基因对运动性的影响。[结果]与野生型菌株PXO99~A相比,ΔfkbM_(Xoo)突变体运动性明显减弱,而互补菌株ΔfkbM_(Xoo)(C)能基本恢复水稻白叶枯病菌的运动性。[结论]水稻白叶枯病菌fkbM基因突变能减弱水稻白叶枯病菌的运动能力。     

Sperm quality and cryopreservation of Brazilian freshwater fish species: a review

The Brazilian freshwater fish diversity is the richest in the world. Only 0.7% of all Brazilian species have had any aspect of their sperm biology addressed up to this date. The majority of the fish species described in this review migrate during the spawning season (a phenomenon known as piracema). Urbanization, pollution, hydroelectric dams and deforestation are some of the causes of stock depletion or even local extinction of some of these species. The knowledge concerning sperm quality and minimum sperm:egg ratio is important to maximize the use of males without reducing hatching rates. Furthermore, sperm cryopreservation and gene banking can guarantee the conservation of genetic diversity and development of adequate breeding programs of native fish species. In this review, we present and evaluate the existing information on Brazilian fish species that have been subject to sperm quality and cryopreservation studies. The following parameters were evaluated: volume of extractable sperm, sperm motility, sperm concentration, freezing media, freezing methods, and post-thaw sperm quality. Although the existing protocols yield relatively high post-thaw motility and fertilization rates, the use of cryopreserved sperm in routine hatchery production is still limited in Brazil.