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1.
一、引言 家禽胚胎死亡并不是在整个孵化过程中随机地死亡，一般而言，胚胎在孵化的早期及后期阶段的死亡率要高于中间阶段。根据观察统计发现，鸡胚在孵化过程中的第2至第4天死亡机率较高，而火鸡胚胎在第3天至第6天死亡机率较高。家禽胚胎在早期发育过程中在生理及遗传方面要发生许多变化。 相似文献
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一．引言家禽胚胎死亡并不是在整个孵化过程中随机地死亡，一般而言，胚胎在孵化的早期及后期阶段的死亡率要高于中间阶段。根据观察统计发现，鸡胚在孵化过程中的第２至第４天死亡机率较高，而火鸡胚胎在第３天至第６天死亡机率较高。家禽胚胎在早期发育过程中在生理及遗传方面要发生许多变化。二．胚胎早期发育１．排卵前发育自卵子在输卵管漏斗部开始受精就意味着胚胎开始发育，在卵排出以前，这枚胚胎将在体内４１．５℃的环境下发育２４－２６小时（禽卵经由输卵管排出所需的时间）。第一次卵裂大约在输卵管的峡部，也就是卵沿输卵管下… 相似文献
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为了研究鸡胚胎腺垂体促肾上腺皮质激素(ACTH)细胞的发生及其在发育过程中的变化，分别在鸡胚胎发育的第3．5～20．5d采集鸡胚胎垂体，利用免疫组织化学方法对鸡胚胎腺垂体ACTH细胞的发生、数量和形态分布变化规律进行了研究。结果，鸡胚胎发育早期(10．5d)可观察到少量明显的ACTH细胞分布于腺垂体前叶，随着胚胎的发育，ACTH细胞的数量明显增多，分布于整个腺垂体前叶。早期ACTH细胞体积小、细胞浆少、细胞核较大、细胞界限不清，随着胚龄的增加，ACTH细胞体积增大、细胞浆增多、细胞浆浓染。结果证明，鸡胚胎腺垂体ACTH细胞发生于胚胎发育的中期，细胞的增殖和分化过程发生在胚胎发育的中期至出壳前，而ACTH细胞的分泌功能在胚胎后期最活跃。 相似文献
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猪胚胎冷冻保存研究进展 总被引：2，自引：0，他引：2
胚胎冷冻保存技术在大多数哺乳动物上已获得成功，牛胚胎冷冻已经进入商业化应用阶段。猪胚胎由于其特殊的低温生物学特性，冷冻保存研究进展缓慢。本文综述了猪胚胎在冷冻过程中的细胞生物学变化，以及近几年猪胚胎冷冻保存研究所取得的显著进展。 相似文献
6.
郭均 《河南畜牧兽医(综合版)》1999,(2)
2．胚胎死亡的确定有时在卵黄上面看不到胚胎或胚盘，这时就得把蛋转动以下，倒出一些蛋白，以便胚盘受精或未受精暴露出来，如果仍看不到胚胎发育的迹象，那么就将卵黄倒人一空盘中做仔细的检查。在大多数情况，以胚胎死亡时的周龄和畸形进行分类，就可以得到足够的信息。孵化ZI天后打蛋看死胚不如看活胚观察得更清楚。然而，具有一定经验的质量控制人员，可以根据胚胎的大小和胚胎发育的明显变化做出精确的分析。对死胚不必以胚龄分类，因为以早期门一7天）、中期（8-14天）和晚期（15－ZI天）来分类，就可得到足够的信息。确定早、中、… 相似文献
7.
家蚕胚胎发育扫描电镜观察 总被引：1，自引：0，他引：1
用扫描电镜的方法,对家蚕胚胎发育的外部形态学变化,进行了比较描述,发现反转期后有脱皮现象,器官形成方面观察更为清晰.甲胚胎头褶清楚.丙_2胚胎头褶、尾褶继续增大.丁_1胚胎神经沟清晰可见.丁_2胚胎第2～7环节开始发生突起.戊_1胚胎上唇及触角原基明显,气门开始发生.己_1胚胎头、胸、腹区分节清楚.己_3胚胎体表有脱皮残片附着.转青期口器及蚁蚕整体清晰. 相似文献
8.
利用光镜，电镜及特殊染色方法，观察胚兔胚龄15－25d的发育阶段成釉器细胞形态学的变化及胚胎诱导的生物行为的改变，结果显示，成釉器在发育过程中具有细胞增殖，组织分化，形态分化，基质表成，矿物化，萌出，均有胚胎诱导，在成釉细胞发育过程中存在着程序性细胞死亡（programmed cell death,PCD)的现象，以维持牙全和牙髓组织的正常形态的稳定性，避免牙体畸形及肿瘤的发生。 相似文献
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《中国家禽》2015,(10)
研究旨在建立快速分离鸭早期胚胎的方法,并观察鸭早期胚胎体节、神经系统、心脏、肢芽与胚胎外部轮廓发育特点,为以鸭胚胎为模型开展相关生物学研究提供资料。通过分离鸭早期不同阶段的胚胎、制作石蜡切片和显微观察,了解鸭胚早期发育各阶段的不同形态学特点。结果表明:鸭的卵裂为盘状卵裂;体节形成开始于孵化后27h左右;心脏从原基经发育成外形呈"S"型,直至心脏随躯体翻转完全向左;胚胎外部轮廓的变化依次为:长条状、头颈部开始弯曲,整体呈"C"型,整体呈"O"型。研究初步整理了鸭早期胚胎发育形态特点,并建立了以滤纸为载体分离鸭早期胚胎的方法,该方法对胚胎的损伤小,更易清理胚胎上的残余物质。 相似文献
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实验旨在探究附植期热应激对小鼠胚胎发育和生殖嵴损伤的影响。将108只体重为（30±3）g的见栓0.5d(0.5dpc)孕鼠随机分配为对照组（24±1℃室温饲养）、38℃热应激组和40℃热应激组；热应激组于4.5dpc分别以38℃和40℃热应激2h/d，连续7d。记录孕鼠每日体重，于13.5dpc取小鼠胚胎，同时记录胚胎数量、胚胎重量和死亡胚胎数量，统计分析胚胎雌雄比率、含死亡胚胎的子宫比率、胚胎分布异常的子宫占比、胚胎子宫内异常分布比率；采用组织切片及透射电子显微镜观察生殖嵴组织细胞结构的变化。结果显示：与对照组相比，38℃和40℃热应激可降低孕鼠4.5～10.5 dpc和0.5～13.5 dpc体重增长率以及胚胎重量（P<0.05），同时增加胚胎子宫内分布异常比率（P<0.01）;40℃热应激可降低附植胚胎数量及增加胚胎分布异常的子宫占比（P<0.05）;38℃和40℃热应激导致生殖嵴组织细胞间隙明显增大，细胞连接方式多为桥粒连接，粗面内质网及部分线粒体肿胀，溶酶体与自噬泡增多。上述研究结果表明，附植期孕鼠遭受热应激导致胚胎发育迟缓及生殖嵴组织细胞超微结构损伤。 相似文献
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Growth and metabolism of murine and bovine embryos in bovine uterine flushing-supplemented culture media. 
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下载免费PDF全文 The aim of this study was to compare the development and metabolic activity of cultured murine and bovine embryos in 2 standard media (HAM F-10 and RPMI) in the presence or absence of bovine uterine flushings. Murine morulae (n = 653) and day 7 bovine embryos (n = 273) were cultured for 18 h or 36 h in either HAM F-10 or RPMI in the presence or absence of bovine uterine flushings. After culture, the development, quality, and metabolic activity (glucose utilization or methionine uptake and incorporation) of embryos was assessed. It was found that HAM F-10 (without uterine flushings) was a more suitable medium than RPMI for optimal development and metabolism of murine and bovine embryos. Poor quality and development, as well as decreased metabolism, were evident after culture of murine embryos in RPMI; in contrast, this medium had no adverse effects on bovine embryos in culture. Supplementation of HAM F-10 with bovine uterine flushings improved the growth of murine embryos and the protein synthesis (as measured by an increased methionine incorporation) for both murine and bovine embryos. However, supplementation with bovine uterine flushings could not overcome deficiencies of an inappropriate medium (RPMI) for murine embryos. Supplementation of a well-defined culture medium with uterine flushings increased metabolism of embryos in culture, and thus might help to increase pregnancy rates after transfer of such embryos to recipient cows. 相似文献
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Bovine viral diarrhea virus (BVDV) has been isolated from washed and sonicated, in vitro-produced embryos, but the infectivity of BVDV associated with intact, developing, embryos has not been demonstrated. The objective of this study was to determine if a dose of BVDV infective for co-culture cells was associated with individual, developing embryos, following artificial exposure to the virus and washing. In 5 replicates, zona pellucida-intact, in vitro-produced embryos were assigned to a negative control embryo group, or were incubated in 10(5)-10(6) cell culture infective doses (50%, CCID50) per milliliter of a type I, noncytopathic (strain SD-1) BVDV for 2 h. Unexposed negative control embryos and exposed positive control embryos were washed, sonicated and assayed for BVDV using virus isolation with immunoperoxidase monolayer assay. Immediately or following cryopreservation, remaining virally-exposed, washed embryos were co-cultured individually with BVDV-negative cultures of bovine uterine tubal cells in a medium free of BVDV-neutralizing activity. After two days in culture, uterine tubal cells and embryos (including the zona pellucida) were separated and washed. The culture medium, uterine tubal cells and embryos were then assayed for BVDV. Bovine viral diarrhea virus was not isolated from any negative control embryo group, but was isolated from all positive control embryo groups. Although all uterine tubal cell populations were confirmed to be susceptible to BVDV, virus was never isolated from uterine tubal cells or embryos from post-exposure culture. In conclusion, although BVDV remains associated with washed in vitro-produced embryos, the virus associated with unsonicated embryos was not infective for uterine tubal cells in vitro. 相似文献
13.
Twelve horse mares were used to investigate the effect of phenylbutazone or progesterone administration on uterine tubal motility, as reflected by embryo recovery from the uterus on day 5 after ovulation. Four treatment groups were used: group A (controls), in which uterine flush was performed 7 to 11 days after ovulation; group B (5-day controls), in which uterine flush was performed 5 days after ovulation; group C, in which uterine flush was performed 5 days after ovulation following administration of phenylbutazone (2 g, IV) on day 3; and group D, in which uterine flush was performed 5 days after ovulation following administration of progesterone in oil (250 mg, IM) on days 0, 1, and 2. Each mare was randomly assigned to each group once. Embryo recovery for each group was: group A, 13 embryos from 12 mares; group B, 3 embryos from 12 mares; group C, 4 embryos from 11 mares; and group D, 1 embryo from 11 mares. Recovery of embryos on day 5 in 3 of 12 nontreated mares indicated that equine embryos may enter the uterus before day 6. Neither treatment increased embryo recovery from the uterus on day 5 over that from the uterus of the 5-day controls. 相似文献
14.
Transfer of pig embryos to different uterine sites. 总被引：3，自引：0，他引：3
Embryo transfer in pigs normally involves surgery. In connection with the development of nonsurgical or endoscopic transfer techniques, it is important to know whether the uterine site to which embryos are transferred has an effect on the success rate. In the present investigation, prepubertal donor gilts were treated with 1,500 IU of PMSG and, 72 h later, with 500 IU of hCG. Gilts were artificially inseminated 24 and 36 h after hCG injection. Embryos at the expanded blastocyst stage were collected from donor gilts. Recipient gilts were treated synchronous with the donors, using 1,000 IU of PMSG followed, 72 h later, with 500 IU of hCG. After a maximum of 3 h in vitro, embryos (n = 15 to 20, mean = 17.3) were transferred surgically to the middle of the uterine horn, to the caudal quarter of the uterine horn, or to the uterine body. Recipients were slaughtered between 28 and 34 d after transfer. The pregnancy rate of the recipients was low when the embryos were deposited in the uterine body (12%), compared with the middle (88%) or the caudal quarter of the uterine horn (81%) (P < .01). The corresponding average number of viable fetuses per pregnant recipient was 8.2 in the uterine body, 5.6 in the middle, and 4.5 in the caudal quarter. Average survival rate of embryos after transfer to the middle of the uterine horn was 41% vs 29 and 3% after transfer to the caudal quarter or the uterine body, respectively (P < .01). Hence, the uterine body seems to be an unsuitable site for embryo transfer in pigs. These results may explain the unsatisfactory results achieved with nonsurgical embryo transfer in the past. 相似文献
15.
1. Early uterine embryos were obtained from hens by induced oviposition 7.5-8.0 h after the preceding egg was laid. They were cultured in vitro and then in recipient shells to hatch. As controls, embryos from freshly laid eggs were cultured in recipient shells to hatch. 2. For embryos cultured from uterine eggs, the hatch rate was 22.5%, and for embryos cultured from laid eggs, the hatch rate was 62.5%. 3. The weight of the chicks hatched from culture was about 60% of the weight of the preceding egg, or donor egg. Male and female chicks reached maturity and have produced viable offsprings. 4. The results show that it is possible to grow chick embryos in culture from the early cleavage stage (stage II) to hatch. They extend earlier findings on the culture of embryos from the blastoderm stage (Stage X) to hatch. The technique provides a basis for investigations on chick embryo cryopreservation. 相似文献
16.
The aim of this study was to investigate whether uterine capacity (UC) in rabbits was related to uterine horn length and weight and whether these uterine traits and vascular supply were related to fetal development and survival. Data from 48 unilaterally ovariectomized (ULO) does of the High and 52 ULO does of the Low UC lines of a divergent selection experiment on UC were used. Does were slaughtered on d 25 of fifth gestation. The High line showed higher ovarian weight (0.08 g, P < 0.05) linked to a higher ovulation rate (1 ovum, P < 0.05) and greater length of the empty uterine horn. There were no differences between lines in the remaining doe traits. The number of implanted embryos and live fetuses, fetal survival, and uterine weight and length were positively associated and explained most of the observed variation. Average weights of the live fetuses and their fetal and maternal placentae were not related to uterine weight and length. The linear regression coefficient of full uterine horn length on the number of live fetuses was 2.43 +/- 0.21. The weight of the full uterine horn showed a small quadratic relationship (P < 0.05) with the number of live fetuses. Full uterine horn length, after adjusting for the number of embryos, was negatively associated (P < 0.001) with the number of dead fetuses. The linear regression coefficient of average fetal placental weight of the live fetuses on number of implanted embryos was higher (P < 0.10) in the Low line (-0.23 +/- 0.04 vs. -0.12 +/- 0.04). The linear regression coefficient of average weight of the live fetuses on the average weight of their fetal placentae was higher (P < 0.10) in the High line (2.56 +/- 0.47 vs. 1.27 +/- 0.57). The High line was more efficient, most likely because an increase in intrauterine crowding has a lesser effect on the development of fetal placentae and fetuses. The fetal position within the uterus did not affect the proportion of dead embryos. Fetuses with placentae receiving a single blood vessel had a higher probability of death (P < 0.001) and the lowest weight. There was no difference between lines for individual weight of the live fetuses, but the High line showed higher individual weights of fetal (P < 0.01) and maternal placentae (P < 0.10). Live fetuses in the midportion of the uterus were lighter in weight (P < 0.05) than in the oviductal and cervical regions (20.3 vs. 21.6 and 21.7g). Increasing uterine capacity increases uterine length and decreases weights of fetus and fetal placenta in rabbits. 相似文献
17.
The effect of homogenized embryos on IUD-induced luteal regression in the ewe was studied. Plastic spiral IUDs were inserted in an uterine horn adjacent to an ovary containing a corpus luteum during various times of the estrous cycle. The ewes were sacrificed on Day 6 for examination of the corpus luteum. Estrous Cycle Day 3 was the last day in which the IUD insertion induced luteal regression. Corpus luteum was maintained in ewes when the IUD was inserted on Day 4, 5, or 6. Corpus luteum regression was not prevented when homogenized 14- or 15-day-old embryos were injected into the uterus at the time of IUD insertion. Ewes which received an IUD, a cannula, and an infusion of saline or homogenized embryos on Days 3, 4, and 5 maintained corpora lutea in 4 of 7 embryo-infused ewes and in none of 7 saline-infused ewes (p less than .05). It was determined that the IUD must remain in the uterine horn for longer than 1 day to induce corpus luteum regression and that embryos can sometimes prevent the IUD-induced regression. 相似文献
18.
Experiments were conducted in 1985 and 1986 at the Eastern Ohio Resource Development Center, Belle Valley, to examine the feasibility of using embryo transfer to induce twinning and to examine the influence of twinning on traits of the cow and calf. Embryos were collected from a total of 14 superovulated Angus donors on two dates each in 1985 and 1986 and were transferred to Angus recipients. A total of 124 embryos were transferred to 79 recipients, with 43 (34.7%) calves born alive. Seven of 45 (15.6%) recipients implanted with two embryos produced twins. In no case did both halves of the 15 embryos that were split to produce identical twins and implanted in the same recipient survive to birth. Proportion of calves born alive did not differ among transfer codes 3 (nonsplit embryos from two different donors implanted in separate uterine horns of the same recipient), 6 (nonsplit embryos from one embryo flush implanted in separate uterine horns of the same recipient) and 7 (nonsplit embryos from two different donors implanted in the same uterine horn of one recipient). Surgical transfers tended to result in a higher proportion of embryos surviving to birth (.43 vs .21; P = .16) and a higher twinning rate (.29 vs .04; P = .36) than did nonsurgical transfers. Age of recipient did not influence embryo survival (P = .98) or twinning rate (P = .99). Gestation length was 5 d shorter (P less than .01) for twin calves than for singles. Singles were 9 kg heavier (P less than .01) at birth and 32 kg heavier (P less than .01) at weaning than twins. However, cows raising twins produced 108 kg (51%) more total weaning weight than did cows raising singles. 相似文献
19.
A series of three experiments was conducted to test the functional status of the uterus and embryos in prepubertal gilts. In Exp. 1, gilts were induced to ovulate by treating with gonadotropins followed by hCG 72 or 96 h later, and were artificially inseminated 24 h after hCG. Five of the 10 gilts treated at 120 d of age, but none of the gilts treated at 100 of age, maintained pregnancies. We next tested the function of the uterine environment by transferring embryos from postpubertal females into gilts of various ages that had been induced to ovulate but not inseminated (Exp. 2). Pregnancy rate at d 50 of gestation was 44% (4/9) for 100-d-old recipients, 67% (2/3) for 140-d-old recipients, and 60% (3/5) for postpubertal recipients (P > 0.20). Therefore, uteri of 100-d-old gilts are able to maintain pregnancies with conceptuses from postpubertal gilts. In Exp. 3, embryos from 100-d-old and postpubertal gilts were transferred into postpubertal recipients. Uterine horns of recipients were surgically separated before transfer, and embryos from 100-d-old and post-pubertal females were transferred to opposite horns of some recipients (experimental). Other recipients received embryos from postpubertal females in both uterine horns (control). When examined on d 50 to 60 of gestation, three of five control gilts were pregnant and three of seven experimental gilts were pregnant (P > 0.50). In experimental recipients, the survival of embryos from 100-d-old gilts was 38% (8/21) compared to 57% (15/26) for embryos from postpubertal gilts (P > 0.30). Because all uterine horns of pregnant recipients contained fetuses, these results support the hypothesis that embryos from 100-d-old gilts are able to initiate and maintain pregnancies in the uteri of postpubertal gilts. Therefore, the uterine environment of 100-d-old gilts provides an environment that supports development of embryos produced by postpubertal gilts, and the embryos produced by 100-d-old gilts can survive and develop in the uteri of postpubertal gilts. It was only the combination of embryos and uteri of 100-d-old gilts that did not permit pregnancy to be maintained. 相似文献
20.
Hasina Santatriniaina Rasolomboahanginjatovo Younès Chorfi Raynald Dupras Louis Mills Réjean Lefebvre 《Journal of veterinary science (Suw?n-si, Korea)》2014,15(2):273-281
The objective of this study was to determine the effects of superovulation (SOV) on serum and uterine biochemical parameters, uterine bacteriology and cytology and number of transferable embryos (TE). Dairy cows were placed on a Presynch/CIDR Synch protocol. The SOV group was superovulated, induced in estrus, and inseminated, whereas the control group was induced in estrus and inseminated without SOV. Uterine bacteriology and cytology and uterine and serum biochemical parameters were measured at day 7 of the estrous cycle to start the SOV protocol, as well as on the day of embryo recovery (DER). The SOV group produced 7.5 ± 6.7 oocytes/embryos, of which 3.4 ± 4.7 were TE. Serum urea and E2 and uterine Glu, CK, LDH, TP, P4 and PGFM in the control group and serum P4 and PGFM and uterine LDH and PGFM in the SOV group were significantly higher (p < 0.01) at DER than day 7. At DER, uterine urea, LDH, PGFM and TP and serum urea, LDH, PGFM, and P4 concentrations were higher (p < 0.01) in the SOV group than the control. There was no significant variation in uterine bacteriology or cytology. Overall, these results infer that SOV affects both serum profile and uterine secretions, and that these changes may influence the number of TE. 相似文献