猪卵母细胞玻璃化冷冻后细胞骨架的变化

Oocytes were collected from 2~5mm size follicle of slaughtered porcine ovaries. Immature (GV stage) oocytes were cumulus-oocyte complex (COC) and mature oocytes were derived from in vitro maturation of GV stage oocytes. Either GV stage or MII stage oocytes were individually divided into three groups: the control, treated with vitrification solution and vitrified group. Oocytes used for the experiment were fixed and stained by immunofluorescence and then were observed under laser-scanning confocal microscopy (LSCM). The results showed that the normal rates of meiotic spindle organization, chromosome alignment and actin filaments (F-actin) of GV stage oocytes treated with vitrification solution were 42.9%, 26.3% and 28.6%, respectively and the normal rates from vitrified group were 10.1%, 36.4% and 16.9%, respectively. There was significant difference among these two groups and between them and the control (P＜0.05). Normal rate of spindle, chromosome and microfilament of MⅡstage oocytes treated with vitrification solution and vitrified with OPS method were respectively 34.4% versus 12.9%, 61.3% versus 56.7%, and 47.9% versus 37.2% and all of them were significantly lower than that from the control. The results indicated that spindles, chromosomes and microfilaments of porcine oocytes at different stages were nonreversible damaged obviously followed exposion to freezing medium or vitrification, which may be the main reason affecting the maturation, fertilization and development of oocytes.