Changes Of Sperm Ultrastructure Before And After Freezing And Freezing Of Blue Fox Semen

The introduction of Finnish high-quality blue fox,through the use of artificial insemination technology to expand and improve,so that China's blue fox breeding industry has developed rapidly in the past 20 years.At present,the blue fox uses a fresh insemination rate of more than 80%.However,due to the lack of corresponding breeding methods,the germplasm has been degraded year by year and has to be introduced repeatedly.In fact,semen freezing technology can preserve blue fox semen indefinitely,realize long-distance communication of semen,and has great application significance for the production of blue frost fox(Silver fox x blue fox python).However,the current blue fox semen freezing technology is not mature in the world,because the survival rate of sperm after freezing and thawing is low,which significantly affects the conception rate of female fox.In order to further understand the damage caused by ultra-low temperature freezing to the motility and internal structure of blue fox sperm,the experimental study was carried out by selecting a better cryoprotectant and a complete blue fox semen freezing process system.Test(1):The test was divided into 4 groups,French Kasu semen frozen dilution(?),Donglin ?-yolk frozen dilution(?),Tris-yolk frozen dilution(?)and control room temperature dilution Donglin ?(?).After freezing and thawing,the freezing effects of three kinds of frozen diluents were detected,and the sperm redness,hypotonic swelling method and Coomassie blue staining method were used to detect sperm survival rate,sperm plasma membrane integrity rate and sperm acrosome integrity rate.The survival time and survival index of sperm at 37? were measured and the optimal frozen dilution was selected by comparison with fresh essence.Test(2):The original sperm was divided into two groups,A and B,and group A was diluted at room temperature.The ? dilutions were divided into three groups:B1,B2,and B3.The blue fox semen was frozen.The IVOS sperm motion detection system was used to detect the movement of the sperm in the 4 groups.The internal structure of the sperm in the A and B1 groups was observed by transmission electron microscopy.(3):Semen test of 15 female blue foxes was carried out by selecting semen with a spenn motility rate higher than 0.3 after thawing.The results showed that ultra-low temperature freezing had great damage to blue fox sperm.Compared with group IV,the survival rate of sperm in group ?,? and ? decreased by 48.3%,and the rate of sperm membrane integrity decreased by 48%.The average rate of decline was 37.4%;the average survival time(13h)and average survival index(2.25)after freezing and thawing at 37? were much lower than the survival time(37h)and survival index(7.85)of the ? group.High recovery temperature stimulates sperm movement,but sperm survival time is shorter;in group ?,?,?,group ? sperm survival rate,plasma membrane integrity rate,acrosome integrity rate are higher than ?,? group;three blue foxes The effect of semen cryopreservation on the protection of blue fox sperm was:?>?>?;the sperm motility of group A and group B was extremely significant(P<0.01),and the sperm of group B with rapid movement accounted for 25.1%,medium-speed movement.The spermatozoa accounted for an average of 39.8%,the slow-moving sperm accounted for an average of 4.2%,and the non-sporting sperm accounted for an average of 30.9%;the Bl,B2,and B3 spermatozoa and the fast-moving sperm were significantly different(P<0.05).The freezing process has the influence of manual operation factors.It is recommended to use an automatic freezer to freeze.Using transmission electron microscopy,the most serious damage in the B1 group is the sperm head membrane structure,the acrosome integrity rate is only 25%,and the frozen to the equatorial section and neck.The damage of the minibus,tail,mitochondria and microtubules is small;although the sperm motility of the blue fox semen after freezing and thawing is above 0.3,which is in line with the standard of frozen spermatozoa,the sperm survival time at 37?after freezing and thawing of blue fox sperm The survival index was too low,resulting in the trial of 15 blue foxes with only one calving,and the fertilization rate of frozen insemination was only 6.7%.