Chronological and Morphological Progression of Nucleus during Mouse Oocyte Maturation and Fertilization in vitro

The chronological and morphological changes of the nucleus during mouse oocyte maturation and fertilization were systematically studied. Although most oocytes went through GVBD 2-4 hrs after culture, 13.6% remained at GV stage 8 hrs after culture.TEM observation revealed that nucleoli of oocytes which failed to go through GVBD were composed of fibrillar-granular component,small vacuoles and fibrillar centers or showed small vacuoles on nuclear surface. During GVBD, the nucleoli became smaller and smaller and finally disappeared with the nuclear-associated chromatin dislocated to the periphery. Nuclear membrane with attached chromatin became folded and electronic dense cores appeared in the center of chromatin clumps at the same time.The last event of GVBD was the disruption of nuclear membrane.At the end of the 5th hr after culture, meiosis progressed to prometaphase I.Chromosomes,distributed in the original GV area free of organelles,were surrounded by large quantity of mitochondria and small SER vesicles. At the end of the 12th hr after culture,48. 1% of the oocytes emitted PB1.Decondensing sperm head and early male pronuclcus(mPN)with condensed nucleoli were found 1-2 hrs after insemination.The formation and enlargement of female PN(fPN) occurred a little earlier than that of mPN. 33.3% finished syngamy at 8-9 hrs after insemination.The process of nucleolus formation was reverse to that in GVBD. The oolemma modification caused by cortical reaction could effectively inhibit polyspermy.in contrast,there were sperm binding to the oolemma where CGs failed to be released. In addition, PB2 was emitted 2-5 hrs after insemination. The difference between PB1 and PB2 as well as the abstriction of polar body were also discussed.

Role of animal pole protuberance and microtubules during meiosis in sea cucumber Apostichopus japonicus oocytes

Fully grown oocytes of Apostichopus japonicus have a cytoplasmic protuberance where the oocyte attaches to the follicle. The protuberance and the oolamina located on the opposite side of the oocyte indicate the animal-vegetal axis. Two pre-meiotic centrosomes are anchored to the protuberance by microtubules between centrosomes and protuberance. After meiosis reinitiation induced by DTT solution, the germinal vesicle (GV) migrates towards the protuberance. The GV breaks down after it migrates to the oocyte membrane on the protuberance side. The protuberance then contracts back into the oocyte and the first polar body extrudes from the site of the former protuberance. The second polar body forms beneath the first. Thus the oocyte protuberance indicates the presumptive animal pole well before maturation of the oocyte.

The Polar φ-Brunn-Minkowski Inequalities

A general framework of polar Brunn-Minkowski theory that unifies the Orlicz Brunn-Minkowski inequality, the Lp Brunn-Minkowski inequality for p ∈(0,1) and the logBrunn-Minkowski inequality all for polar bodies is provided. It is shown that this general polar φ Brunn-Minkowski inequality is equivalent to a general polar φ Minkowski mixed volume inequality.

A Characterization of the Polarity Mapping for Convex Bodies

In this paper,we establish a characterization of the polarity mapping for convex bodies for 1-dimensional convex bodies,which is a supplement to the result for such a characterization obtained by B?r?czky and Schneider.

Rescue ICSI: Choose the Optimal Rescue Window before Oocyte Aging

Objective To evaluate the application value of rescue ICSI in fertilization failure after conventional IVF and choose the best rescue window before oocyte aging according to the results of rescue ICSI performed in different time. Methods The data of 93 IVF cycles were analyzed retrospectively. Rescue ICSI was performed in these cycles after conventional IVF failure. Because of the different rescue time, these cycles were divided into two groups： early rescue group （group A, 77 cycles, rescue ICSI performed 4-8 h after conventional IVF） and late rescue group （group B, 16 cycles, rescue ICSI performed 20-22 h after conventional IVF）. Results There were no statistically significant differences in age of female, duration of infertility, number of oocytes retrieved every cycle. The normal fertilization rate, pregnancy rate and implantation rate were decreased in group B compared with those in group A （P〈0.05）. In group A, the normal fertilization rate of rescue ICSI performed 4-6 h after conventional IVF （group A1） was increased compared with that of rescue ICSI performed 6-8 h （including 6 h） after conventional IVF （group A2）（66.5% vs 55.9%）（P〈0.05）; while the abnormal fertilization rate in group A1 was decreased compared with group A2 （9.0% vs 14.4%）（P〈0.05）. Clinical pregnancy rate was slight higher in group A1 than in group A2, though this failed to be significantly different. Conclusion Rescue ICSI is effective if fertilization was failure after conventional IVF, the most important thing is to choose the reasonable rescue window before oocyte aging when ICSI is performed.

Lp-dual Quermassintegral sums

In this paper,we first introduce a concept of L_p-dual Quermassintegral sum function of convex bodies and establish the polar projection Minkowski inequality and the polar projection Aleksandrov-Fenchel inequality for L_p-dual Quermassintegral sums.Moreover,by using Lutwak’s width-integral of index i,we establish the L_p-Brunn-Minkowski inequality for the polar mixed projec- tion bodies.As applications,we prove some interrelated results.