• Reproductive and Developmental Biology
• /
• 제31권3호
• /
• pp.193-198
• /
• 2007

본 연구는 소의 초기 난할 단계인 2 또는 4세포기 수정란의 특정 분할구가 배반포 단계의 내부 세포괴(Inner Cell Mass)와 영양막 세포(Trophectoderm cells)로의 발달 운명이 미리 정해지는 지를 확인하기 위해 실시되었다. 먼저 생쥐의 체내수정란과 소의 체외 수정란에서 배반포의 영양막 세포에서만 특이적으로 발현하는 cdx2단백질의 발현 양상을 조사하였다. 또한, 소의 경우 2세포기와 4세포기가 내부 세포괴와 영양막 세포로 나눠지는 시점인지를 조사하기 위해 2 또는 4세포기의 특정 분할구에 Dextran의 주입 실험과 분할구 제거 실험을 통해 ICM과 TE 형성을 확인하였다. cdx2의 발현 경향은 생쥐와 소의 2세포기일 때 대칭과 비대칭적으로 발현되는 것을 확인하였다. 생쥐의 4, 8세포기 및 상실배기에서는 분할구 전체에서 발현되었으나, 소 수정란의 분할구에서는 전체 또는 부분적으로 발현되었다. 또한, 생쥐와 소의 배반포기에서는 영양막 세포에서만 발현이 되는 것을 확인하였다. 소 수정란의 2세포기와 4세포기 단계에서 특정 분할구에 주입된 De xtran은 배반포의 내부 세포괴와 영양막 세포의 양쪽에 분포된 것을 관찰할 수 있었다. 2세포기 단계에서 하나의 분할구가 제거된 수정란 역시 ICM 및 TE 세포를 지닌 정상 배반포로 발달함을 확인하였다. 따라서 본 연구 결과는 영양막 세포에서만 특이적으로 발현하는 cdx2의 발현이 2 또는 4세포기 단계 소 수정란에서는 특별한 차이를 보이지 않으며, 궁극적으로 난할 초기에는 ICM과 TE 세포로의 운명이 결정되지 않는다는 것을 보여준다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제16권1호
• /
• pp.15-22
• /
• 2003

Experiments were conducted to evaluate the effect of blastomere diameters and cell cycle stages on the subsequent development of nuclear transplant rabbit embryos (NT-embryos) using nuclei derived from the 16- or 32-cell stage embryos. All blastomeres and NT-embryos were cultured individually in modified Ham's F-10 medium supplemented with 10% rabbit serum (RS) at $38^{\circ}C$ and 5% $CO_2$ in air. The diameter of blastomeres from 16-cell stage embryos was found twice of those from 32-cell stage (51 vs 27 ${\mu}m$). Significant differences were observed in cleavage rates ($\geq$3 divisions) in the isolated single blastomeres (54 vs 48 for 16-cell; 28 vs 14 for 32-cell, p<0.05), but the fusion rates of oocytes with transferred nuclei were similar between small and large single blastomeres derived from either 16-cell or 32-cell stage embryos. When 16-cell stage blastomeres were used as nuclear donors, cleavage rates ($\geq$3 divisions) of the NT-embryos were greater in the small nuclear donors than in the large donors (73 vs 55%, p<0.05). On the contrary, significantly higher cleavage (43 vs 6%, p<0.05) and developmental rates (14 vs 0%, p<0.05) were observed in the large blastomere nuclear donor group of the 32-cell stage embryos. When the cell cycle stages were controlled by a microtubule polymerization inhibitor (Demicolcine, DEM) or the combined treatment of DEM and Aphidicolin (APH), a DNA polymerase inhibitor, fusion rates were 88-96% for the 16-cell donor group (without DEM treatment), which were greater than the 32-cell donor group (54-58%). Cleavage rates were also greater in the transplants derived from G1 nuclear donor group (93-95%) than those from the DEM and APH combined treatment (73%) for the 16-cell donor group (p<0.05). No significant difference was detected in the morula/blastocyst rates in either donor cell stage (p>0.05). In conclusion, it appeared that no difference in the developmental competence between large and small isolated blastomeres was observed. When smaller 16-cell stage blastomeres were used as nuclear donor, the cleavage rate or development of NT-embryos was improved and was compromised when 32-cell stage blastomeres were used. Therefore, control nuclear stage of the donor cell at $G_1$ phase in preactivated nuclear recipients seemed to be beneficial for the cleavage rate of the reconstructed embryo in the 16-cell transplant, but not for subsequent morula or blastocyst development.

• Clinical and Experimental Reproductive Medicine
• /
• 제31권1호
• /
• pp.29-39
• /
• 2004

Objectives: This study was performed to evaluate the laboratory system for successful PGD using fluorescence in situ hybridization (FISH) and the clinical outcome of PGD cycles in five years experiences. Methods: A total of 181 PGD-FISH cycles of 106 couples were performed, and diagnosed chromosome normality in the preimplantation embryos. The laboratory and clinical data were classified by the following optimization steps, and statistically analyzed. Phase I: Blastomere biopsy with two kinds of pipettes, removal of cytoplasmic proteins without treatment of pepsin and culture of biopsied embryos with single medium; Phase II: Blatomere biopsy with single pipette, removal of cytoplasmic proteins with pepsin and culture of biopsied embryos with single medium; Phase III: Blastomere biopsy with single pipette, removal of cytoplasmic proteins with pepsin and culture of biopsied embryos with sequential media. Results: A total of 3, 209 oocytes were collected, and 83.8% (2, 212/2, 640) of fertilization rate was obtained by ICSI procedure. The successful blastomere biopsies were accomplished in 98.6% (2, 043/2, 071) of embryos, and the successful diagnosis rate of FISH was 94.7% (1, 935/ 2, 043) of blastomeres from overall data. Embryo transfers with normal embryos were conducted in 93.9% (170/181) of started cycles. There was no difference in the successful rate of biopsy and diagnosis among Phase I, II and III. However, the pregnancy rate per embryo transfer of Phase III (38.8%, 26/67) was significantly (p<0.05) higher than those of Phase I (13.9%, 5/36) and Phase II (14.9%, 10/67). Conclusions: The laboratory optimization and experience for the PGD with FISH procedure can increase the pregnancy rate to 38.8% in the human IVF-ET program. Our facility of PGD with FISH provides the great possibility to get a normal pregnancy for the concerned couples by chromosomal aberrations.

• 한국가축번식학회지
• /
• 제7권1호
• /
• pp.24-29
• /
• 1983

These experiments were carried out to obtain basic information necessary of the success of in vitro culture of blastomeres separated from mouse embryo. Total 446 single blastomeres separated from 2-, 4- and 8-cell mouse embryos by protease treatment (0.5% in Whittingham's medium), were cultured under the gas phase of 5% CO2 in air at 37$^{\circ}C$. whittingham's medium was used for culture of blastomeres. The results obtained in these experiments were summerized as follows: 1. Of total 446 blastomeres cultured, 127(87.0%), 134(73.2%) and 77(65.8%) blastomeres separated repectively from 2-, 4- and 8-cell embryos were developed to morula or blastular stages. 2. The numbers of blastomeres, being separated from 2-. 4- and 8-cell embryos and developing to blastocysts containing inner cell mass, were 97(76.4%), 86(64.2%) and 33(42.9%) respectively. 3. After in vitro culture of the blastomeres, the incidence of trophoblastic vesicles increased with the development of the cell stage of embryo. In case of blastomeres separated from 8-cell embryos, 50.6% of blastomeres that developed to blastular stage was trophoblastic vesicles.

• 한국가축번식학회지
• /
• 제16권4호
• /
• pp.341-346
• /
• 1993

The development of isolated blastomeres from mammalian preimplantation embryos has been basically studied for the multiplication of embryos from superior animals. Therefore, this study was investigated the effect of co-culture with mouse fetal fibroblast cells(MFFC) on in vitro development of blastomeres from mouse preimplantation embryos. Mature female ICR mice were treated with hormone to induce superovulation and embryos were collected at each 2, 4, and 8-cell stage. Then, after removing zona pellucida with protease, blastomeres were isolated by micropipetting, or reconstituted with different stage blastomere, and incubated for 72 hrs either in T6 or TCM199 or on the monolayer of MFFC, which was prepared with fibroblast cells from 14∼14 day mouse fetus. After incubation, we examined their development rates every day and the nuclei numbers of each blastocyst by Hoechst-33342 staining. In the development rates of blastomeres, there were no significant differences between media but the higher rateswere found in the monolayer of MFFC, regardless of reconsititution. In addition, blastomeres cultured with MFFC had slightly greater number of nuclei than those cultured in single media. Generally, the higher development rates of blastomeres were found from earlier stage embryos than the later ones, regardless of culture conditions. Reconsitituted blastomeres had more nuclei but did not show the higher development rates, compared to the single blastomeres. Taken together, our results suggest that co-culture with MFFC have a beneficial effect on the in vitro development of blastomeres from mouse embryos.

• Clinical and Experimental Reproductive Medicine
• /
• 제24권1호
• /
• pp.51-56
• /
• 1997

Recently, through the development of the primer extension preamplification(PEP) method which amplifies the whole genome, simultaneous multiple DNA analysis has become possible. Whole genome from each single cell can be amplified using 15 base oligonucleotide random primer. The greatest advantage of PEP-PCR is the ability to investigate several loci simultaneously and confirm results by analysing multiple aliquots for each locus. This technique led to the development of preimplantation genetic disease diagnosis using blastomere from early embryo, sperm, polar body and oocyte. In this study, we applied PEP-PCR in 20 cases of single amniocyte and 20 cases of single chorionic villus cell for the clinical application of the prenatal and preimplantational genetic diagnosis. We analysed 7 gene loci simultaneously which are 46, 47 exons related to dystrophin gene, two VNTR (variable number tandem repeat) markers using 5'dysIII, 3'CA related to dystrophin gene and DYZ1, DYZ3, DYS14 regions on chromosome Y. In all the tests, 97.5% of PEP-PCR amplifications with single cells were successful. We obtained 38/40 (95%) accuracy in gender determination through chromosome analysis comparison. Therefore, these results have significant implications for a sperm or oocyte analysis and prenatal or preimplantational genetic diagnosis.

• Clinical and Experimental Reproductive Medicine
• /
• 제45권1호
• /
• pp.52-55
• /
• 2018

This study retrospectively assessed whether time-lapse data relating to developmental timing and morphology were associated with clinical outcomes, with the eventual goal of using morphokinetic variables to select embryos prospectively for cryopreservation. In this study, we examined the clinical outcomes of single vitrified-warmed blastocyst transfer cycles that were cultured in a time-lapse incubation system. The morphokinetic variables included uneven pronuclei, an uneven blastomere, multinucleation, and direct, rapid, and irregular division. A total of 164 single vitrified-warmed blastocyst transfer cycles were analyzed (102 cycles of regularly developed blastocysts and 62 cycles of blastocysts with morphokinetic variables). No significant differences in the age of females or the standard blastocyst morphology were found between these two groups. The regularly developed blastocysts showed significantly higher implantation and clinical pregnancy rates than the blastocysts exhibiting morphokinetic variables (30.4% vs. 9.7% and 37.3% vs. 14.5%, respectively; p< 0.01). The blastocysts that exhibited morphokinetic variables showed different mean development times compared with the regularly developed blastocysts. Although morphokinetic variables are known to have fatal impacts on embryonic development, a considerable number of embryos developed to the blastocyst stage. Morphokinetic variables had negative effects on the implantation and clinical pregnancy rates in vitrified-warmed blastocyst transfer cycles. These findings suggest that blastocysts cultured in a time-lapse incubation system should be considered for selective cryopreservation according to morphokinetic variables.

• Clinical and Experimental Reproductive Medicine
• /
• 제35권3호
• /
• pp.213-221
• /
• 2008

목 적: 난소기능이 저하된 저반응군 불임 여성에서 한 개의 배아를 이식할 때 임신율에 영향을 주는 요인에 대해 알아보고자 한다. 연구방법: 본원에서 1996년 6월부터 2006년 4월까지 시험관 시술을 받은 환자 중, basal FSH가 12 mIU/mL 이상, 획득된 난자가 4개 이하, hCG 투여일에 혈청 $E_2$가 500 pg/ml 미만인 저반응군 총 919주기에서 한 개의 배아만을 이식한 235주기를 대상으로 하였다. 여성의 연령, hCG 투여일에 혈청 $E_2$, basal FSH, 3일째 배아 이식 시 할구수, 과배란 유도 방법, 이식 횟수에 따른 임신율과 생존아 출생률을 비교하였으며, 통계학적인 방법은 Chi-square를 이용하여 p-value 0.05 이하인 경우를 유의하게 평가하였다. 결 과: 총 919주기 중 난자채취 취소율은 25.6% (235주기), 난자채취 실패율은 18.5% (170주기), 배아 이식 취소율은 14.0% (129주기)였다. 한 개의 배아를 이식한 군의 전체 임신율은 8.1% (19주기), 생존아 출생률은 4.7% (11주기)였고, 35세 미만의 여성에서 35세 이상의 여성보다 임신율과 생존아 출생률이 통계적으로 유의하게 높았다 (20% vs. 3.5% p<0.0001, 12.3% vs. 1.8%, p=0.002). hCG 투여일에 혈청 $E_2$, basal FSH, 3일째 배아 이식 시 할구수, 과배란 유도 방법에 따른 임신율과 생존아 출생률은 차이가 없었다. 이식 횟수에 따른 누적 임신율은 1회에 8.1%, 2회에 9.2%, 3회에 9.7%, 4회에 9.0%, 5회에 9.5%였다. 결 론: 저반응군의 체외수정에서 한 개의 배아를 이식할 때, 불임 여성의 연령이 35세 미만에서 임신율과 생존아출생률이 유의하게 증가함을 확인하였고, 이식 횟수에 따른 누적 임신율은 차이가 없었다. 이는 체외수정을 시도하려고 하는 난소기능 저하의 불임 여성에서 구체적인 상담 자료로 사용할 수 있겠다.

• 한국가축번식학회지
• /
• 제18권2호
• /
• pp.121-126
• /
• 1994

This study was conducted to examine the condition of activation of the nuclear transplant bovine embryos. In vitro fertilized(IVF) and nuclear transplant embryos(NTs) were co-cultured with bovine oviduct epithelial tissue(BOET). NTs were treated with cycloheximide(CHXM) for 0 to 6 h after electrofusion to investigate the activation conditin of recipient ooplast. Then, the infljence of the CHXM treatment timing on the cleavage and development of NTs were investigated in relation to the nuclear transplant time. The cleavage rates of NTs were increased with the increasing time of the CHXM treatment from 0 to 6 h (54.7 to 91.3%, P<0.01). Similar trend was shown in the development into the morula or blastocyst stage, but very limitted. Activation of enucleated oocytes prior to fusion enhanced development of NTs compared with that post fustion. This result suggests that the frequency of activation of NTs can be greatly enhanced by treating with CHXM for 6 h. The result also suggests that if blastomeres of unknown cell cycle stage are used, activation of enucleated oocytes prior to fusion enhances development of NTs.

• Clinical and Experimental Reproductive Medicine
• /
• 제46권4호
• /
• pp.206-210
• /
• 2019

Mucopolysaccharidosis type II (MPS II) is a rare X-linked recessive lysosomal storage disease caused by mutation of the iduronate-2-sulfatase gene. The mutation results in iduronate-2-sulfatase deficiency, which causes the progressive accumulation of heparan sulfate and dermatan sulfate in cellular lysosomes. The phenotype, age of onset, and symptoms of MPS II vary; accordingly, the disease can be classified into either the early-onset type or the late-onset type, depending on the age of onset and the severity of the symptoms. In patients with severe MPS II, symptoms typically first appear between 2 and 5 years of age. Patients with severe MPS II usually die in the second decade of life although some patients with less severe disease have survived into their fifth or sixth decade. Here, we report the establishment of a preimplantation genetic diagnosis (PGD) strategy using multiplex nested polymerase chain reaction, direct sequencing, and linkage analysis. Unaffected embryos were selected via the diagnosis of a single blastomere, and a healthy boy was delivered by a female carrier of MPS II. This is the first successful application of PGD in a patient with MPS II in Korea.