A-308

IN-VITRO MATURATION AFFECTS THE HISTONE ACETHYLA-TION MODIFICATION OF MOUSE OOCYTES AND EARLYCLEAVAGE EMBRYOS. N. Wang, M.-y. Dong, H.-f. Huang, F. Jin. Repro-ductive Endocrinology, Women’s Hospital, School of Medicine, ZhejiangUniversity, Hangzhou, Zhejiang, China.

OBJECTIVE: In-vitro fertilization and embryo transfer (IVF-ET) is a verysuccessful treatment for infertile couples. However, the high costs for gonad-otropin injections, the risk of ovarian hyperstimulation syndrome (OHSS)and the possible association between repeated ovarian stimulation and hor-mone-related cancers are the main drawbacks. In-vitro maturation (IVM) of-fers an alternative to conventional IVF treatment that minimizes drugadministration and avoids ovarian hyperstimulation. However, the safety ofIVM was questioned. Considering oocyte maturation is one of the most im-portant periods of epigenetic reprogramming, the changes of epigenetic mod-ification resulted from altered environments in IVM might be involved in. Toinvestigate the influences of IVM on epigenetic reprogramming and the pos-sible mechanisms, the expression of two regulatory enzymes for histone acet-ylation, histone acetyltransferase GCN5 (GCN5) and histone deacetylase 1(HDAC1) in mouse metaphase II (MII) oocytes and the preimplantation em-bryos were analyzed.

DESIGN: Experimental animal study.MATERIALS AND METHODS: Six-to-8-week-old ICR female mice

were divided into two groups, IVM and control group. In IVM group, imma-ture oocytes were collected from the ovaries of female mice without stimu-lation. MII oocytes were retrieved after 16-18h IVM of GV oocytes. Incontrol group, in-vivo matured MII oocytes were retrieved directly from ovi-ducts at post administration of HCG 7.5IU 13-15h after 7.5IU PMSG stimu-lation. Embryos in the two groups were recovered after 24-28h of IVF. RT-PCR was used to determine the gene expression of GCN5 and HDAC1 inmouse MII oocytes and 2-cell stage embryos.

RESULTS: The rates of fertilization and cleavage in IVM are lower thanthat in the control group (36.8%vs77.1%, p<0.01; 84.2%vs90.9%, p<0.01).The mRNA of GCN5 in MII oocytes and the two-cell embryos in IVM groupare similar to that in the control group (p >0.05).However, HDAC1 mRNAwas significantly decreased in both oocytes and embryos in IVM comparedwith the control group (P<0.05).

CONCLUSIONS: IVM environments could down-regulate the gene ex-pression of HDAC1 in MII oocytes and two-cell embryos. The culture con-ditions were inadequate to support the developmental capacity of someoocytes. The accurate mechanisms of those changes induced by IVM needfurther investigate.

Supported by: National Basic Research Program of China(2007CB948104).

A-309

ABNORMAL DISTRIBUTION OF CORTICAL GRANULES IN CYN-OMOLGUS MONKEY ONE-DAY OLD MII OOCYTES WHICHWERE IMMATURE AT OOCYTE RETRIVAL AFTER CON-TROLLED OVARIAN HYPERSTIMULATION. M. Yamanaka,S. Hashimoto, J. Okahara-Narita, J. Yamasaki, R. Torii, Y. Morimoto. IVFNamba Clinic, Osaka, Japan; Shiga University of Medical Science, Shiga,Japan.

OBJECTIVE: Developmental competence of cynomolgus monkey(macaca fascicularis) oocytes, which were immature at oocyte retrieval aftercontrolled ovarian hyperstimulation (COH) and reached to metaphase IIstage (MII, 1-day old MII oocytes) after overnight culture, were low com-pared with mature oocytes at oocyte retrieval (fresh MII oocytes). In thisstudy, ultrastructures of 1-day old and fresh MII oocytes were assessed.

DESIGN: An experimental study using a monkey model was performed.MATERIALS AND METHODS: Female cynomolgus monkey (5 years

old) was used for COH and oocyte retrieval was carried out using a laparo-scope. Cumulus cells were removed from oocyte using hyaluronidase.Some of immature (germinal vesicle (GV) and metaphase I (MI)) and mature(fresh MII) oocytes were fixed for control as below. Immature oocytes werecultured in TCM199 supplemented with 5% fetal calf serum for 24h. Controland 1-day old MII oocytes were prefixed by glutaraldehyde, postfixed by os-mium, dehydrated and embedded in EPON blocks. Ultrathin sections wereobserved by transmission electron microscope (TEM) after staining.

RESULTS: Fifty oocytes (14 GV, 21 MI, 9 MII and 6 degenerated oocytes,respectively) were retrieved. Immature oocytes (12 GV and 19 MI) were cul-

S472 Abstracts

tured. Seven mature oocytes were obtained. By observation using TEM, themorphological change of mitochondria during meiotic maturation was as-sessed. Mitochondria were oval at GV stage and some of them extended atMI stage. Flattened and crescent-shaped mitochondria which encircled smoothendoplasmic reticulum were observed in both fresh and 1-day old MII oocytes.However, in 1-day old MII oocytes, cortical granules were observed not only inthe surface but also inside of oocyte. In addition, large fragments were ob-served in the perivitelline space. Microvilli were observed in all oocytes.

CONCLUSIONS: These results suggest that cytoplasmic maturation is in-complete in 1-day old MII oocyte because of improper localization of corti-cal granules. The unbalance of maturation between nucleus and cytoplasmmay impair the developmental competence of 1-day old MII oocyte.

Supported by: None.

A-310

ANALYSIS OF MEIOTIC ABNORMALITIES OF IN VITRO MA-TURED OOCYTES FROM STIMULATED CYCLES OF NON-OBESEENDOMETRIOTIC AND PCOS PATIENTS: A PILOT STUDY.P. A. A. S Navarro, R. A. Ferriani, R. C. Vieira, E. M. Ferreira,A. C. J. S Rosa e Silva, I. D. E. S Barcelos. Department of Obstetrics and Gy-necology, Ribeirao Preto Medical School-USP, Ribeirao Preto, Brazil; Ri-beirao Preto Medical School-USP, Ribeirao Preto, Brazil.

OBJECTIVE: Endometriosis and Polycystic Ovarian Syndrome (PCOS)are major causes of human infertility. According to controversial data,both may be associated with worse outcomes of assisted reproduction tech-niques, which could be caused by an impairment of oocyte quality. Thus, wecompared meiotic spindle morphology and chromosomal distribution of invitro matured human oocytes from non-obese patients with endometriosisand PCOS submitted to ovarian stimulation for ICSI.

DESIGN: A prospective, controlled study.MATERIALS AND METHODS: Infertile patients aged up to 38 years un-

dergoing stimulated cycles for oocyte retrieval for ICSI were selected prospec-tively and consecutively and divided into endometriosis (20 patients) andPCOS (13 patients) groups. Immature oocytes (74 and 34 from endometriosisand PCOS patients, respectively) were submitted to in vitro maturation (IVM)for 19 hours� 1 hour (GV) or 4 hours� 30 minutes (MI) according to a mat-uration time curve determined before the beginning of the present study. Usingimmunostaining and fluorescence microscopy, we imaged spindle and chromo-somal distribution of oocytes that extruded the first polar body after IVM.

RESULTS: IVM rates were similar for both groups (53.1% and 50%, re-spectively, for the PCOS and control groups). Spindle and chromosome orga-nization were observed in 35 and 17 oocytes from the endometriosis andPCOS groups, respectively. In the endometriosis group, 13 were normalMII oocytes (37.2%), 9 abnormal MII (25.7%), 11 normal telophase I(31.4%), and 2 normal telophase II (5.7%). In the PCOS group, 6 oocyteswere normal MII (35.3%), 8 abnormal MII (47.1%), and 3 normal telophaseI (17.6%). The proportions of normal MII oocytes were similar for the twogroups (37.2% and 35.3% in endometriosis and PCOS groups, respectively).

CONCLUSIONS: Our preliminary data demonstrate that in vitro matura-tion rates of immature oocytes obtained from stimulated cycles are similar innon-obese infertile women with endometriosis and with PCOS. In vitro ma-tured oocytes from endometriotic patients have a higher percentage of TIwhen compared to PCOS patients. Our preliminary results also suggestthat the incidence of meiotic anomalies, characterized by spindle ruptureand/or chromosome misalignment, is similar in in vitro matured oocytesfrom non-obese PCOS and endometriotic patients. Both results will be betterevaluated by increasing the present patient series.

Supported by: CAPES, CNPq, and FAEPA/HC-FMRP/USP, Brazil.

OVARIAN RESERVEA-313

WHICH PATIENT DO YOU PREFER IN THE OFFICE? YOUNGERWITH ELEVATED FSH OR ELDERLY WITH NORMAL FSH.E. Young, Jr, L. Sabatini, M. I. Viola, F. Lorenzo, L. M. Auge, H. Beraja. Gy-necology, IFER, Buenos Aires, Capital Federal, Argentina.

OBJECTIVE: Analyze which factor has more impact as a predictor of re-sponse in IVF outcomes: age or basal FSH.

DESIGN: Retrospective cohort study.MATERIALS AND METHODS: Of the 268 patients who carried out an

IVF treatment with antagonist GnRh cycles from February to August2005, 128 met the inclusion criteria (% 35 years and FSH R 7.71 and >35 years and FSH < 7.71).Main outcome measure were: Cause of infertility,

Vol. 90, Suppl 1, September 2008