| In the research, activation and artificial insemination of Bombyx mori female bursa copulatrix semen was studied, Bombyx mori bursa copulatrix semen was cryopreserved by different cryopreservation ways, DN A damage detection and artificial insemination of the thawed sperm was also studied. The research on the determination of superoxide dismutase, lactate dehydrogenase and acrosin were conducted. Finally, we discussed the change trends of the enzyme activity before and after cryopreserving, besides its relationship with the fertilization rate. The main research content and result were reported as follows:1 Activation and artificial insemination of Bombyx mori female bursa copulatrix semenBy giemsa's dye, direct observation of Bombyx mori bursa copulatrix sperm depending on microscope, and artificial insemination of the bursa copulatrix sperm, the studies showed: The semen in the female bursa copulatrix after mating 20 to 30 minutes was similar to that in the male moth seminal vesicle, and the spermatic fluid contained a large number of eupyrene sperm bundles and was not activated. The semen was treated with different trypsin concentrations, the result of microscope observation and artificial insemination showed that 0.2μ/mL trypsin in 50% semen solution, the fertilization rate is highest. The semen was treated with trypsin, plasmin, pepsin and succinic acid sodium respectively, only trypsin could dissociate the eupyrene sperm bundles and improve the motion of apyrene sperm synchronously, and also only the trypsin-treated semen had the ability of fertilization. The research also found that the optimum semen concentration for artificial insemination was double dilution.2 Cryopreserving, thawing of Bombyx mori female bursa copulatrix semen and DNA damage detection, artificial insemination of cryopreservation spermBursa copulatrix semen was preserved at -80°C as well as in liquid nitrogen respectively, and it was thawed after a certain time. DNA damage level of Bombyx mori cryopreservation sperm was inspected by the SCGE method. During the inspection, we found that parts of sperm electrophoresises presented apparent comet-shape after semen added no cryoprotectant undergo deep freezing, and the difference of DNA damage level was significant in contrast to the control, this indicated that DNA suffered damage to some degree; While whether semen added cryoprotectant preserved at -80°C or in liquid nitrogen, all of sperm, electrophoresises remained circular after freezing, and there was no significant difference between this and the control. Therefore, the results indicated that well freezing modes couldn't damage spermatozoon's DNA.Inactivated semen also could lay oosperm after it was cryopreserved both at -80℃ and in liquid nitrogen, but the semen lost the ability of fertilization after it was cryopreserved at -80℃ for three months, while the fertility of the semen preserved in liquid nitrogen for 1 year maintained at 82.2%. The study also found that the fertility of the sperm of Chinese strain was higher than Japanese's, hybrid and stock. Artificial inseminated female silkworm was hybridized with triploid sperm, the result was that the total laying number and the fertility of female silkworm were enhanced.3 The activity analysis on superoxide dismutase of Bombyx mori cryopreservation semenThe superoxide dismutase (SOD) acted as an important enzyme of organism antioxidation defense system. Both cryopreservation way and time could affect the activity of SOD. The activity measurement showed that the activity of SOD in the extracted semen changed indistinctivly within 5 hours; When the semen was cryopreserved at -80°C, the activity of SOD decreased linearly along with the time passing and after 3 months the activity was just approximate 23 percent of that before cryopreservation; After the semen was cryopreserved in liquid nitrogen, the activity of SOD decreased 55 percent, but the activity of SOD in the semen preserved for one day changed not too much in contrast with that preserved for 3 months; The increasing trend for the activity of SOD in the seminal plasma was related to the decreasing trend for the activity of SOD in the semen, therefore the activity of SOD could be adopted as an index evaluating the quality of the semen.4 The effect of cryopreservation on the activity of lactate dehydrogenase of Bombyx mori semenThe fittest bottom concentration in the course of activity measurement of lactate dehydrogenase (LDH) in Bombyx morVs semen was between 0.5 and 0.8mmol/L; When the LDH extract was preserved at 4℃, its activity decreased along with the time passing, so the activity of LDH should be measured within 15 hours after extraction; Bombyx morCs sperm was senously harmed after the semen was cryopreserved, LDH in the sperm spilled over to the seminal plasma, as a result, the activity of LDH in the sperm decreased and the activity of LDH in the seminal plasma increased; After the semen was cryopreserved at - 80"C for 90 days, the activity of LDH in sperm was just 23 percent of that before cryopersevation. When the semen was cryopreserved in liquid nitrogen, after one day. the activity of LDH in sperm decreased to 43 percent, but the activity changed a little during the following 90 days.5 The acrosin activity determination of Bombyx mori's sperm before and after cryopreserving as well as its relationship with the fertilization rateThe acrosin activity of Bombyx mori's sperm was determined using the improved Kennedy's...
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