Observation of synaptonemal complex during meiotic prophase in mouse primary spermatocytes

【Objective】 This study is aimed to display the morphological changes of synaptonemal complex during different substages of meiotic prophaseⅠ.【Method】 Seminiferous tubules were shredded from mouse testis and the released spermatocytes were spread evenly over microscope slides.Immunofluorescence staining of SCP3 was employed to exhibit the transformation in mophology of synaptonemal complexes occurring during different substages of meiotic prophaseⅠ in mouse primary spermatocytes.【Result】 Short,discontinuous and randomly converging SCP3 segments were observed in leptotene.In the subsequent zygotene,SCP3 appeared to be distinguishable,continuous and lineal,while no integral synaptonemal complexes were discerned.During pachytene,SCP3 became fully integral and clearly distinguishable.Totally 20 synaptonemal complexes were observed,including 19 autosomes and one XY bivalents.In diplotene,the SCP3 in two lateral elements began to expel and separate from each other,resulting in desynapsis while still retaining the distinguishable 20 bivalents.【Conclusion】 Immunofluorescence staining of SCP3 could be one powerful technique to exhibit the morphological changes of synaptonemal complex during different substages of meiotic prophaseⅠ.