Cricket Sperm In Vitro Capacitation And Acrosome Reaction

The sperm from spermatheca of cricket Telegryllus was used as experimental material. A new method has been established to keep the mature sperm alive in vitro. The sperm surviving time in Tc-100 medium is about 5.0h,in balanced saline is 2.0h,in PBS is about 1.5h.The factors causing the sperm to die are analysised. The surviving time in Tc-100 can meet our requirements. The in vitro cultural method is a rapid and convenient way to study the capaciation and acrosome reaction of insect sperm.There is a spermatheca to store sperm in female cricket, the sperm can live 3-4 months in it. So there are some insects that only breeding several times and the storing sperm in the spermatheca is enough for it's reproductivity.In order to study why insect sperm can live so long, while mammalian sperm if they didn't get the chance to fertilize with eggs, sperm can only keep several hours. Under transmission electronic microscope ,the structure of spermatheca is investigated and the spermatozoon in it present in groups. This phenomenon coincide with male cricket's spermiation by spermatophore sac. After observation the face that the spermetheca is formed by the outer embryonal layer,and it is mainly composed of gland cells.The effects of spermine on capaciation and acrosome reaction of cricket sperm have been determined under light microscope. For many years people try to determine the nature of decapaciation factors, but at present, it seems that decapaction factors are not some special substance. It is the cooperation of a series of inhibitory factors in seminal plasma. Spermine widely exists in mammalian organism and body fluids, but there are disputations about it's functions during reproductive process. There are three groups in contrast to determine the effects of spermine during reproductive process, one group is Tc-100 medium, the secondgroup is Tc-100 medium with spermine and the third group is Tc-100 medium with caffeine. According to the result of experiment, spermine can not only promote motive ability, but also greatly enhance capacition and acrosome reaction. FITC bound ConA and LCA are used as probes to distinguish the reacted sperm from the intact sperm, it is through fluorescent microscope and has been repeatedly scored for at least 10 times. Acrosome reacted sperm can be identified by lack of fluorescence on the head.The binding pafterns of the two lectins to the sperm surface were also photographed during capaciation and acrosome reaction process, it is a more detailed study about the lectin binding pattern during spermatogenesis process. From the time (1951) that Austin and Zhang firstly found capaciation, it has always been the active area in reproductive biology. Through lectins which can be specially bound to glycoconjugates, we found that glycoconjugates firstly appear in testis, and then modify in epididymis, and it have some kind of changes during capaciation process. We observed the changes of the binding pattern during capaciation and acrosome reaction, found that lectin receptors change a lot.The fact proves that lectin receptors are important factors during capaciation. Lectin receptor sites also undergo quantitative changes.