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1.
To improve the reproductive performance of water buffalo to level can satisfy our needs, the mechanisms controlling ovarian follicular growth and development should be thoroughly investigated. Therefore, in this study, the expressions of growth differentiation factor‐9 (GDF‐9) in buffalo ovaries were examined by immunohistochemistry, and the effects of GDF‐9 treatment on follicle progression were investigated using a buffalo ovary organ culture system. Frozen–thawed buffalo ovarian follicles within slices of ovarian cortical tissue were cultured for 14 days in the presence or absence of GDF‐9. After culture, ovarian slices were fixed, sectioned and stained. The follicles were morphologically analysed and counted. Expression pattern of GDF‐9 was detected in oocytes from primordial follicles onwards, besides, also presented in granulosa cells. Moreover, GDF‐9 was detected in mural granulosa cells and theca cells of pre‐antral follicles. In antral follicles, cumulus cells and theca cells displayed positive expression of GDF‐9. In corpora lutea, GDF‐9 was expressed in both granulosa and theca lutein cells. After in vitro culture, there was no difference in the number of primordial follicles between cultured plus GDF‐9 and cultured control that indicated the GDF‐9 treatment has no effect on the primordial to primary follicle transition. GDF‐9 treatment caused a significant decrease in the number of primary and secondary follicles compared with controls accompanied with a significant increase in pre‐antral and antral follicles. These results suggest that a larger number of primary and secondary follicles were stimulated to progress to later developmental stages when treated with GDF‐9. Vitrification/warming of buffalo ovarian tissue had a little remarkable effect, in contrast to culturing for 14 days, on the expression of GDF‐9. In conclusion, treatment with GDF‐9 was found to promote progression of primary follicle that could provide an alternative approach to stimulate early follicle development and to improve therapies for the most common infertility problem in buffaloes (ovarian inactivity).  相似文献   

2.
The aims of this study were to characterize EGF protein expression in ovine ovaries and to verify the effect of EGF on the in vitro development of isolated pre‐antral follicles. After collection, ovarian tissue was fixed for immunohistochemical analysis. Additional pairs of ovaries were collected, and secondary follicles were cultured for 18 days in α‐MEM+ (control) alone or supplemented with EGF (1, 10 or 50 ng/ml). The immunostaining for EGF was observed in oocytes from pre‐antral and antral follicles, in granulosa cells of primary and secondary follicles, as well as in cumulus and mural cells of antral follicles. After 18 days, the results showed that treatment with 50 ng/ml EGF significantly increased the percentage of morphologically normal follicles compared with the control group (α‐MEM+) and significantly reduced the precocious extrusion of oocytes and increased the percentage of antral follicles compared with the control and 1 ng/ml EGF. All the treatments induced a progressive and significant increase of the follicular diameter throughout the period of culture. However, there were no significant differences in follicular diameter or in the daily growth rate among treatments. In conclusion, this study demonstrated the presence of EGF in ovine ovaries. Moreover, 50 ng/ml EGF increased the percentage of normal follicles and improved antrum formation in isolated ovine follicles after 18 days of in vitro culture.  相似文献   

3.
This is the first report to show morphological evidence of in vitro maturation of oocytes recovered from xenotransplanted antral follicles. To develop a suitable tool for studing the growth and maturation of follicles and oocytes, we xenotransplanted small pieces of ovarian cortical tissue from sows, which contained small preantral follicles (primordial, primary, and secondary follicles; less than 0.05, 0.1 and 0.3 mm in diameter, respectively), under the capsules of kidneys of adult female severe combined immunodeficient (SCID) mice for 2 and 8 weeks, and then recovered cumulus-oocyte complexes from the growing tertiary follicles in xenografted tissues. The distribution of processes from cumulus cells to oocytes and the follicular growth, development, and maturation during xenotransplantation were histochemically analyzed. Tertiary follicles, 0.5 to 3.0 mm in diameter, were obtained from grafted tissues 2 (85%: 52 follicles/61 grafted tissues) and 8 (50%: 15/30) weeks after xenotransplantation, and then oocytes, which were tightly attached to cumulus cells, were collected from each tertiary follicle and cultured to assess their quality. At 2 weeks after grafting, 17.6% of the oocytes had matured to the metaphase II stage, but no such maturation was observed 8 weeks after grafting. Thus, in the 2 weeks group, preantral follicles rapidly grew in xenotransplanted porcine ovarian tissues to the tertiary stage, and oocytes could be recovered and matured from them by in vitro culture.  相似文献   

4.
Growing porcine oocytes from early antral follicles can acquire meiotic and developmental competence under suitable culture conditions, but at lower rates compared to full‐grown oocytes. We postulated that estradiol‐17β (E2) supported the acquisition of meiotic and developmental competence as well as cumulus‐expansion ability during growth culture. Growing oocytes from early antral follicles (1.2 to 1.5 mm in diameter) were grown in vitro for 5 days in a medium containing 0, 10?7, 10?6, 10?5 or 10?4 mol/L E2; after in vitro maturation, 35, 58, 47, 74 and 49% of oocytes matured to metaphase II, 25, 79, 77, 90 and 97% acquired cumulus‐expansion ability, and 23, 54, 63, 89 and 64% were fully surrounded by cumulus cells, respectively. Following maturation, electro‐stimulation was applied to the oocytes grown with 10?5 mol/L E2. After 6 days of culture, in vitro‐grown oocytes developed to the blastocyst stage at a rate similar to that for full‐grown oocytes (31% and 40%, respectively). Therefore, we suggest that the use of E2 during growth culture improves the meiotic and developmental competence of oocytes, cumulus‐expansion ability, and cumulus cell attachment to the oocytes.  相似文献   

5.
The aim of the present study was to evaluate the effects of different medium replacement intervals on the viability, antral cavity formation, growth and in vitro maturation (IVM) of oocytes from caprine and ovine pre‐antral follicles. Pre‐antral ovarian follicles (≥150 μm) were isolated from the ovarian cortex of goats and sheep and were individually cultured for 24 days using two different medium replacement intervals [2 days (T1) or 6 days (T2)]. Follicle development was evaluated on the basis of antral cavity formation, increases in follicular diameter and the presence of healthy cumulus oocyte complexes and fully grown oocytes. For caprine species, results showed a higher percentage (p < 0.05) of viable follicles in T1 than T2 from day 6 until the end of the culture. In addition, when comparing both treatments after the same culture duration, the rate of antrum formation was significantly higher in T1 than in T2 from day 12 onwards. Yet, in ovines, when both treatments were compared on day 24 of the culture, there were more viable follicles in T2 than in T1 (p < 0.05). In the caprine species, percentages of fully grown oocytes (≥110 μm) acceptable for IVM after 24 days of culture were significantly higher in normal follicles cultured in T1 (30.0%) than in T2 (6.7%; p < 0.05). On the other hand, in ovines, at the end of the culture, the percentage of oocytes destined for IVM was higher in T2 than in T1 (23.5% vs 2.9%; p < 0.05). In conclusion, under the same conditions, the frequency of medium replacement significantly affected the in vitro development of caprine and ovine pre‐antral follicles. To improve the efficiency of the culture system, the medium must be replaced every 2 and 6 days for goat and sheep pre‐antral follicles, respectively.  相似文献   

6.
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7.
The present study was designed to determine the localization of nitric oxide synthase-3 (NOS-3) in porcine follicles during follicular development. A 130-kDa NOS-3 protein was found with greater frequency much in the oocytes than in the cumulus cells, as revealed by Western blotting analysis. The content of NOS-3 in the oocyte was higher in large follicles (> 7-mm diameter) than in small follicles (< 2-mm). The data by Western blotting showed the same pattern as the observations obtained from the immunohistochemical studies, in which the periphery of the oocyte stained strong positive. The inner surface cell layer of granulosa cells and cumulus cells were positive staining, especially in large antral follicles. In the primordial follicles, NOS-3 was restricted to the cytoplasm of oocytes, and no stained product was observed in the nucleus of oocytes or granulosa cells. A significant synthesis of NO by oocytes was observed in the presence of ionomycin, but not in the absence of ionomycin, indicating that oocyte NOS-3 functions in response to transient elevations in the intracellular calcium level. We concluded that NOS-3 is expressed in the oocyte from the primordial follicular stage to antral follicular stage, and that it is functional at least in the antral follicles.  相似文献   

8.
Gap junctions have been implicated in the regulation of cellular metabolism and the coordination of cellular functions during growth and differentiation of organs and tissues, and gap junctions play a major role in direct cell-cell communication. Gap junctional channels and connexin (Cx) proteins have been detected in adult ovaries in several species. Furthermore, it has been shown that several environmental factors, including maternal diet, may affect fetal organ growth and function. To determine whether maternal diet affects expression of Cx26, Cx32, Cx37, and Cx43 in fetal ovaries, sheep were fed a maintenance (M) diet with adequate (A) selenium (Se) or high (H) Se levels from 21 d before breeding to day 132 of pregnancy. From day 50 to 132 of pregnancy (tissue collection day), a portion of the ewes from the ASe and HSe groups was fed a restricted (R; 60% of M) diet. Sections of fetal ovaries were immunostained for the presence of Cxs followed by image analysis. All four Cxs were detected, but the distribution pattern differed. Cx26 was immunolocalized in the oocytes from primordial, primary, secondary, and antral follicles; in granulosa and theca layers of secondary and antral follicles; stroma; and blood vessels. Cx32 was in oocytes, granulosa, and theca cells in a portion of antral follicles; Cx37 was on the borders between oocyte and granulosa/cumulus cells of primordial to antral follicles and in endothelium; and Cx43 was on cellular borders in granulosa and theca layers and between oocyte and granulosa/cumulus cells of primordial to antral follicles. Maternal diet affected Cx26 and Cx43 expression, Cx26 in granulosa layer of antral follicles was decreased (P < 0.01) by HSe in the M and R diets, and Cx43 in granulosa layer of primary and granulosa and theca of antral follicles was increased (P < 0.05) by the M diet with HSe. Thus, Cxs may be differentially involved in regulation of fetal ovarian function in sheep. These data emphasize the importance of maternal diet in fetal growth and development.  相似文献   

9.
Transplantation of ovarian tissue has high potential for female gamete conservation. However, optimal timing of oocyte recovery for in vitro maturation and fertilization is still critical. Therefore the aim of the present study was to use high-resolution transcutaneous ultrasonography to monitor follicular development within xenografted ovarian tissue. Ovarian cortex fragments (n=44) from domestic cats were transplanted into athymic nude rats (n=12). Graft development in the animals was assessed weekly by high frequency ultrasound (10-22 MHz) under two different FSH regimes. Blood collection for serum estradiol determination and vaginal smears were performed simultaneously. The xenografts were removed at different time points according to the ultrasound findings. The survival rate of the transplants 4 weeks after surgery was 54.5% and antral follicular growth was observed within 10 grafts from 5 different hosts (8.6 +/- 6.43 follicles per graft). Early follicle antrums could be detected from 0.4 mm onwards. The growth rate of the antral cavity was calculated from weekly measurements (0.56 +/- 0.44 mm per week). Although vaginal cells and estradiol levels followed a cyclic pattern, no correlation was found between follicular diameter, estradiol and keratinized vaginal cells. We recovered 5, 1 and 4 cumulus oocyte complexes from three different individuals during weeks 19, 21, and 23 respectively. Extrusion of a polar body (1 oocyte) and germinal vesicle break down (7 oocytes) indicated progression of maturation after in vitro culture. We conclude that ultrasonography und provided a reliable method to examine xenograft survival and follicular development within the grafts. Furthermore, this technique is suitable for assessment of the efficiency of hormonal treatment and narrowing of the optimal time frame for oocyte retrieval. To our knowledge, this is the first report of the in vivo development of early antral follicles in mammalian species.  相似文献   

10.
This study was conducted to describe in detail the ultrastructural features and morphological characteristics of camel oocytes from preantral follicles in relation to the sequential stages of follicular development and also for oocytes from antral follicles in relation to their diameter. Camel oocytes from primordial, primary, secondary and also early to late antral follicles were processed and examined by light and transmission electron microscopy. Primordial follicular oocytes were characterized by a layer of flattened granulosa cells around and also eccentric nucleus and few cytoplasmic organelles in the peripheral region. Up to the secondary follicle stage, flat cells were replaced by cuboidal granulosa cells and their number increased and also an increase in the number of organelles such as vesicles, mitochondria and endoplasmic reticulum was observed. In the early antral stage, the formation of zona pellucida, appearance of microvilli and pleomorphic mitochondria was seen and the nucleus was dislocated to the peripheral region. During final growth phase, the extent of endoplasmic reticulum, vesicles and mitochondria increased, the number of lipid droplets decreased and cumulus cell process endings (CCPE) were observed. In conclusion, the growth of camel oocyte is associated with progressive increase in the number of mitochondria, endoplasmic reticulum, Golgi complexes and cytoplasmic vesicles as well as decrease in the number of lipid droplets and the nucleus migration from an eccentric in preantral to a peripheral location in antral follicles.  相似文献   

11.
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12.
试验根据直径将猪卵泡分为2组:G1组(4~7 mm)和G2组(2~4 mm),对2组卵泡内获取的卵母细胞体外成熟率和发育潜能进行了比较,利用相对定量PCR检测了卵丘细胞中卵丘扩展相关基因Has2、Ptgs2、Ptx31及Pgr的表达水平,应用绝对定量PCR检测了成熟培养前后卵母细胞线粒体拷贝数,并利用5,5'-二巯基-2-硝基苯酸(DTNB)酶循环法检测了体外成熟培养过程中卵母细胞谷胱甘肽(GSH)的含量。结果显示,G1组和G2组卵母细胞体外成熟率分别为95.06%和68.19%,G1和G2组排出第一极体的成熟卵母细胞孤雌激活后的囊胚率分别为51.47%和29.44%,2组卵母细胞在体外成熟率和孤雌发育率上均差异显著(P<0.05)。G1组卵丘细胞在体外成熟培养过程中的扩展程度明显高于G2组,G1组卵母细胞对应的卵丘细胞扩展相关基因Has2、Ptgs2、Ptx31、Pgr的表达水平高于G2组(Has2基因在卵母细胞成熟培养0、24 h除外);G1组卵母细胞线粒体数、谷胱甘肽含量均高于G2组。以上结果表明,大卵泡来源的卵母细胞体外成熟能力和发育潜力优于小卵泡来源的卵母细胞,这可能与卵母细胞成熟过程中卵丘扩展程度、卵丘扩展相关基因表达激活情况、卵胞质内谷胱甘肽含量和线粒体拷贝数有关。  相似文献   

13.
This study quantified Fibroblast growth factor 2 (FGF-2) mRNA and localized FGF-2 protein in different categories of follicles isolated from goat ovaries. In addition, we verified the effects of this factor on the in vitro culture of preantral follicles isolated from goats. For mRNA quantification, we performed real-time PCR using primordial, primary and secondary follicles, as well as cumulus-oocyte complexes (COCs) and mural granulosa and theca cells of small and large antral follicles. For FGF-2 protein localization, the ovaries were subjected to conventional immunohistochemical procedures. Preantral follicles were isolated and cultured in vitro for 12 days in either control (basic) or supplemented with FGF-2 medium. The expression of FGF-2 mRNA was detected in all categories of follicles and there was no difference in preantral follicles and COCs or granulosa/theca cells from small and large antral follicles. However, in large antral follicles, COCs showed expression levels significantly lower than in granulosa/theca cells (p < 0.05). We observed moderate expression of FGF-2 protein in preantral follicles but not in granulosa cells of primordial follicles and theca cells of secondary follicles. In both small and large antral follicles, strong, moderate and weak staining was observed in oocytes, granulosa and theca cells, respectively. The addition of FGF-2 caused a significant increase in the daily follicular growth rate compared to the control group. We conclude that FGF-2 mRNA is expressed throughout follicular development and that its protein can be found in different patterns in preantral and antral follicles. Furthermore, FGF-2 increases the follicular growth rate in vitro.  相似文献   

14.
The effect of co‐culture of buffalo preantral follicles (PFs) with different somatic cells, i.e, cumulus, granulosa, ovarian mesenchymal and oviductal epithelial cells was studied. Large PFs (250–450 μm) were isolated by microdissecting the trypsin (1%) digested ovarian cortical slices. Cumulus cells were isolated by repeated pipetting of oocytes, granulosa cells were isolated by aspirating from punctured PFs and ovarian mesenchymal cells were isolated from ovarian cortex by scraping the cortical slices and passing through 20 μm filter. Preantral follicles were cultured in standard culture medium without somatic cells or co‐cultured with cumulus cells, granulosa cells, ovarian mesenchymal cells and oviductal epithelial cells for 80 days. The growth rate (μm/day) of the PFs was monitored by measuring follicular diameter on day 0, 30, 60 and 80 days of culture. The viability of PFs was evaluated by trypan blue staining. The results indicated that PFs co‐cultured with cumulus, granulosa and ovarian mesenchymal cells had a better development and survivality compared with control and those co‐culture with oviductal epithelial cells. Maximum growth and survivality of PFs were achieved when cultured with cumulus cells. It is concluded that inclusion of somatic cells in PF culture media had beneficial effect on the growth of PFs and cumulus cells supported maximum growth and survivality of PFs in vitro of all somatic cells tested.  相似文献   

15.
本实验旨在研究甘氨酸对卵丘细胞及卵母细胞体外成熟质量的影响,优化猪卵母细胞体外成熟(IVM)培养体系。在猪卵母细胞体外成熟培养液中添加6 mmol/L甘氨酸,体外培养至44 h后,通过倒置显微镜测量卵丘细胞扩散直径,结合流式细胞术与qPCR检测卵丘细胞凋亡情况;进一步检测成熟卵母细胞中谷胱甘肽(GSH)、细胞成熟促进因子(MPF)和丝裂原活化蛋白激酶(MAPK)水平及细胞成熟相关基因表达。结果表明:甘氨酸能显著提高卵丘细胞扩散直径,减少卵丘细胞的总凋亡率,并能显著提高卵丘细胞中Bcl-2的mRNA表达;甘氨酸能显著增加成熟卵母细胞中的GSH、MPF和MAPK水平以及成熟相关基因BMP15、GDF9、CyclinB1、CDK1、C-MOS的mRNA表达。综上可知,甘氨酸可提高猪卵母细胞体外成熟质量,降低卵丘细胞凋亡率。  相似文献   

16.
为了明确Ghrelin在绵羊卵巢有腔卵泡上是否存在表达,本研究利用实时定量RT-PCR技术检测了绵羊卵巢有腔卵泡内的卵母细胞、卵丘细胞和壁层颗粒细胞的Ghrelin蛋白的表达量情况。结果揭示绵羊卵巢有腔卵泡内各类型细胞Ghrelin mRNA的相对表达量大致相同。绵羊卵巢有腔卵泡内各类型细胞Ghrelin蛋白的表达及Ghrelin mRNA的表达模式,尤其是卵母细胞中的表达,揭示这一新型分子在绵羊卵巢上具有潜在的调控作用。  相似文献   

17.
The aim of this investigation was to examine the chromatin configuration of the nucleus, pattern of mitochondrial aggregation and mitochondrial activity in parallel studies in the same horse oocytes. Horse oocytes recovered by ultrasound-guided follicle aspiration in vivo were classified according to two main initial cumulus morphologies as having compact or expanded cumulus. The percentage of oocytes with a diplotene meiotic configuration at the time of recovery from the follicles was highest in compact oocytes. Oocytes with expanded cumulus layers at the time of recovery matured more rapidly in vitro and reached a proportion >50% at the metaphase II stage (M 2) sooner during in vitro maturation (IVM), than did compact oocytes. The mitochondrial aggregation pattern changed from finely distributed (Type 1) through crystalline (Type 2) to an aggregated, granulated appearance (Type 3) during IVM. The pattern of mitochondrial aggregation at the time of recovery was associated with the initial cumulus morphology of the oocyte, in that compact oocytes had a higher proportion of Type 1 aggregation, whereas expanded oocytes had a higher proportion of Type 3. The fluorescence intensity of metabolic active mitochondria, measured by fluorescence intensity (Em 570) per oocyte after MitoTracker CMTM Ros orange labelling, increased in the oocytes during IVM and depended on initial cumulus investment. Oocytes with the granulated type of aggregated mitochondria Type 3 had the highest level of metabolic activity and were in more progressed stages of meiosis (A 1-M 2). Oocytes initially having expanded layers of cumulus reached significantly higher levels of mitochondrial activity after IVM than did oocytes initially having compact cumuli. During resumption of meiosis the mitochondrial activity of oocytes with initially expanded cumulus increased continuously up to M 2, whereas in oocytes from compact cumulus-oocyte complex (COC), the activity declined after A 1/T 1 stages of meiosis.  相似文献   

18.
Epidermal growth factor (EGF) is one of the important regulatory factors of EGF family. EGF has been indicated to effectively inhibit the apoptosis of follicular cells, to promote the proliferation of granulosa cells and the maturation of oocytes, and to induce ovulation process via binding to epidermal growth factor receptor (EGFR). However, little is known about the distribution and expression of EGF and EGFR in cattle ovary especially during oestrous cycle. In this study, the localization and expression rule of EGF and EGFR in cattle ovaries of follicular phase and luteal phase at different time points in oestrous cycle were investigated by using IHC and real-time qPCR. The results showed that EGF and EGFR in cattle ovary were mainly expressed in granulosa cells, cumulus cells, oocytes, zona pellucida, follicular fluid and theca folliculi externa of follicles. The protein and mRNA expression of EGF/EGFR in follicles changed regularly with the follicular growth wave both in follicular and in luteal phase ovaries. In follicular phase ovaries, the protein expression of EGF and EGFR was higher in antral follicles than that of those in other follicles during follicular growth stage, and the mRNA expression of EGFR was also increased in stage of dominant follicle selection. However, in luteal phase ovaries, the growth of follicles was impeded during corpus luteum development under the action of progesterone secreted by granular lutein cell. The mRNA and protein expressions of EGF and EGFR in ovarian follicles during oestrous cycle indicate that they play a role in promoting follicular development in follicular growth waves and mediating the selection process of dominant follicles.  相似文献   

19.
During oocyte growth and follicle development, oocytes closely communicate with cumulus cells. We examined the effects of oocyte-derived growth factors, growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), on the growth and acquisition of meiotic competence of porcine oocytes collected from early antral follicles (1.2–1.5 mm). First, we confirmed that GDF9 and BMP15 mRNAs were expressed almost exclusively in the oocytes. Oocyte–cumulus cell complexes (OCCs) collected from early antral follicles were cultured in growth medium supplemented with 0–100 ng/ml of GDF9 or BMP15 for 5 days. GDF9 dose-dependently increased the OCC diameter, while BMP15 did not. GDF9 and BMP15 had no significant effects on oocyte growth (P > 0.05). When OCCs that had been cultured with 50 and 100 ng/ml BMP15 were subjected to a subsequent maturation culture, they expanded fully by gonadotropic stimulation and 49% and 61% of oocytes matured to metaphase II (MII), respectively. In contrast, GDF9 did not promote cumulus expansion, and < 10% of oocytes matured to MII. Based on the difference in cumulus expansion, we compared the expression of luteinizing hormone/choriogonadotropin receptor (LHCGR) and follicle stimulating hormone receptor (FSHR) mRNAs in cumulus cells. The level of LHCGR mRNA was increased in cumulus cells of the BMP15 group, although there were no significant differences in FSHR mRNA levels among the groups. These results suggest that GDF9 promotes the growth of OCCs and that BMP15 promotes LHCGR mRNA expression in cumulus cells during oocyte growth culture, which may contribute to cumulus expansion and oocyte maturation.  相似文献   

20.
Incomplete cytoplasmic maturation of in vitro matured (IVM) oocytes has been known to cause microtubule and microfilament alterations, which may result in abnormal pronuclear formation and failed embryonic development. We examined the influences of maturation conditions on meiotic spindle morphology at metaphase of meiosis II (MII) in porcine oocytes. Porcine oocytes were matured under various conditions, i.e., in vitro or in vivo, with different amounts of cumulus cells, with or without hormonal supplements, and with various exposure durations to the hormones, to examine the effects on spindle morphology in MII oocytes by immunofluorescence under confocal laser microscopy. Interpolar spindle length (microm) and spindle area (microm2) were compared among these maturation conditions. The spindle length was significantly shorter in IVM oocytes compared to those matured in vivo. Oocytes collected from cumulus oocyte complexes (COCs), which were poor in cumulus cells, showed smaller spindle areas than those from cumulus-rich COCs. The spindle length and area were both significantly reduced in oocytes grown without hormonal supplements. When oocytes were grown with hormonal supplements for either 6 or 22 hours for the first half of culture, there was no difference in the spindle morphology between these oocytes. These results suggested that maturation conditions significantly influence morphogenesis of MII spindles in porcine oocytes. Oocytes matured in poor conditions were more likely to have a shorter spindle length (long axis) and smaller spindle areas.  相似文献   

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