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1.
  总被引:1,自引:0,他引:1  
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2.
以南瓜品种‘蜜本’为试材,研究生理因素影响未授粉南瓜胚形成的结果表明:开花前1d的子房最适宜于胚的诱导;胚诱导前以35℃高温处理6d后胚形成能力显著提高;高浓度2,4-D促进胚的发生,抑制愈伤组织的形成;加有4.0mg··L^-1 2,4-D、0.5mg·L^-1 NAA和0.5mg·L^-1 6-BA的MS培养基上的出胚率最高(20.6±3.8)%,每个子房块的平均出胚数达11.3±3.2。  相似文献   

3.
    
Nitric oxide acts as an important intracellular messenger in a variety of systems, including reproduction. Previous studies have shown the importance of nitric oxide in embryo development. NO is produced from l-arginine by the enzyme, nitric oxide synthase (NOS), which has three isoforms: endothelial (NOS3), neural (NOS1), and inducible (NOS2). We hypothesize that, because of the importance of NOS in development, at least two NOS isoforms are required in order for normal embryo development to occur. Through the generation of NOS3/NOS2, NOS3/NOS1, and NOS2/NOS1 double knockout mice, we found that while litter size remains unchanged, the expected number of generated double knockout mice varies significantly from what would be predicted by Mendelian genetics. Estrous cycles were similar for both DKO and the wild-type mice, and both groups were deemed fertile by their ability to mate with wild-type (CD-1) mice. Together, these results lead us to conclude that the lack of two NOS isoforms leads to a decreased viability in mice because of a developmental problem in the double knockout embryo.  相似文献   

4.
    
In this study, we have measured uterine concentrations of interferon tau and intensity of embryonic interferon tau mRNA expression between day 14 and 18 in cows. While interferon tau concentrations rose dramatically (P < 0.001) from day 14 to 18, there was no significant increase in the intensity of expression of interferon tau mRNA by the trophoblast. When results were analyzed on the basis of embryo size, well elongated embryos (>10 cm) produced significantly (P < 0.001) more interferon tau than smaller embryos but showed similar levels of interferon tau mRNA expression. These results demonstrate that the increase in interferon tau concentrations responsible for the maternal recognition of pregnancy results from the increase in embryo size during elongation and not from any upregulation of mRNA expression.  相似文献   

5.
Present study aimed to demonstrate daily rhythm features of hepatic melatonin concentrations in relation to ovarian functions during four reproductive phases of an annual cycle by measuring the levels of melatonin, 17-β estradiol (E2), vitellogenin (Vg) and maturation inducing hormone (MIH) in the liver and/or serum of adult carp Catla catla. Melatonin titres in liver, irrespective of reproductive phase, underwent daily variations with a peak in early dark phase and nadir at midday. However, the acrophase (Ø) of serum melatonin varied from late night in preparatory phase to midnight in the remaining parts of annual cycle. Their amplitude was highest during post-spawning phase and lowest during spawning phase. Hepatic E2 levels showed daily peak at midday and seasonal peak during pre-spawning phase. Though levels of serum Vg proteins and MIH did not exhibit daily variations, underwent seasonal changes with the highest and lowest values during spawning and post-spawning phases respectively. Hepatic melatonin titres always displayed significant negative correlation with the levels of both E2 and Vg. In essence, our study presented the first data on the daily and seasonal rhythm features of hepatic melatonin in carp and underlined their temporal relationship with the functions of ovary in any fish species.  相似文献   

6.
多囊卵巢综合征是育龄妇女常见的慢性炎症代谢性疾病,70%以上患者出现高雄激素血症。下丘脑-垂体-性腺相关激素是月经周期和卵巢活动的调节器,脑神经元分泌的Kisspeptin、褪黑素通过下丘脑-垂体-卵巢轴调节Gn RH神经元AMH、Gn RH的表达,卵巢促性腺激素、雄激素水平增高,有利于慢性炎症的形成,促进多囊卵巢综合征的发生发展。本文综述了近几年多囊卵巢综合征中雄激素相关的慢性炎症研究,并根据相关研究提出了一些见解,希望能为多囊卵巢综合征的研究提供一些新的思路。  相似文献   

7.
【目的】褪黑素作为光周期信号变化的重要生理信号物质;在生物体内普遍存在;对生物有机体的代谢活动、免疫活动、抗逆活动及繁殖活动起着重要的调节作用。本研究旨在明确不同浓度外源褪黑素处理对草地贪夜蛾Spodoptera frugiperda生长发育和繁殖的影响。【方法】在室内采用饲喂法;孵化2 h内的草地贪夜蛾幼虫取食含不同浓度(0, 0.02, 0.2, 2和20 μg/g)外源褪黑素的人工饲料后;观察了草地贪夜蛾的发育历期、体型和体重变化、卵巢发育进度、以及成虫寿命和繁殖力变化。【结果】草地贪夜蛾幼虫取食含0.2, 2和20 μg/g外源褪黑素的人工饲料后; 3-6龄幼虫历期和总幼虫历期较对照(取食正常人工饲料)显著延长;雌蛹历期较对照显著缩短。在20 μg/g外源褪黑素处理下;草地贪夜蛾总幼虫历期最长;比对照延长2.53 d;雌蛹历期最短;较对照缩短1.67 d;而所有浓度外源褪黑素处理对雄蛹历期无显著影响。与对照相比; 2和20 μg/g外源褪黑素处理后; 2-6龄幼虫头壳宽度显著减小;预蛹前幼虫体重明显下降;雌雄蛹重显著减轻;成虫寿命和产卵期显著缩短;单雌平均产卵量和单雌日均产卵量显著下降。在20 μg/g外源褪黑素处理下;草地贪夜蛾雌成虫单雌平均产卵量和单雌日均产卵量均最低;与对照相比分别下降45.12%和31.66%。生殖系统解剖观察表明:随着外源褪黑素浓度的增加;雌蛾卵巢的发育速度明显减缓。【结论】高浓度外源褪黑素对草地贪夜蛾生长发育和繁殖有着明显的抑制作用;导致其发育历期延长、体型减小、体重减轻、生殖力下降。本研究的结果为褪黑素在有害生物防控方面的潜在利用和草地贪夜蛾的综合防控提供了理论依据。  相似文献   

8.
A liquid culture medium in cluster culture dishes supported development of detached wheat spikelets from 7 days pre-anthesis to grain maturity. Development of florets in vitro closely resembled that in vivo as revealed by the growth of anthers, ovaries, and the viability of developing embryos. The number and viability of pollen produced and percentage seed set, however, were significantly lower in cultured spikelets. The developing grain was grown to maturity in vitro by transfering the spikelets into fresh liquid medium every two weeks. The culture of wheat spikelets represents a new experimental tool for studying developmental phenomena and host-pathogen interactions in wheat.The research was supported by the Agricultural Research Service, US Department of Agriculture, in cooperation with the Agricultural Experiment Station, Oregon State University; Technical Paper No 8638 of the latter. Mention of a commercial product does not represent an endorsement of the product by the USDA or imply approval to the exclusion of other comparable products.  相似文献   

9.
Our objective was to determine the growth of the embryo and surrounding structures during baboon (Papio anubis) gestation using transvaginal sonography (TVS). To this end, we evaluated 19 timed-mated baboons using TVS between 37 and 62 days of gestation. After visualization of the gestational sac, amniotic sac, and yolk sac, the three largest diameters of each of these extra embryonic structures were measured using longitudinal and transverse views. Embryonic crown–rump length (CRL) was also recorded. Embryonic heart rates were determined using the M-mode function of the ultrasound equipment. All 19 gestations developed without complications. No significant trend could be demonstrated for heart rate or yolk sac diameters over the 37–62 day gestational age period. Mean (SD) gestational age in days, heart rate, and yolk sac diameter, respectively, for the group were 48 (7.8) days (range: 37–61), 180 (15) beats per minute (range: 156–221) and 5 (0.1) mm (range: 3–8). Significant correlations (P < 0.0001) were determined between gestational age and CRL and gestational and amniotic sacs. We conclude that TVS allows a clear visualization of the embryo proper and all the cavities within the gestational sac of the baboon gestation. This study has determined the normal pattern of changes of these cavities from 37–62 days of gestation. Future applications of these findings may include sampling fluid from these cavities for biochemical, cytological, and metabolic studies. Am. J. Primatol. 43:323–328, 1997. © 1997 Wiley-Liss, Inc.  相似文献   

10.
Real-time B-mode ultrasonography was used to evaluate uterine changes associated with the estrous cycle in 22 ovulatory periods in 12 nulliparous heifers. Irregular, nonechogenic (black) areas were seen on the images of uterine horns during the periovulatory period. These nonechogenic areas were presumably due to intraluminal fluids since they coincided with the discharge of clear, viscous mucus preceding ovulation and blood-tinged mucus after ovulation. Eight heifers were bred until five pregnant heifers were obtained for study of the ultrasonic morphology of the conceptus. Ultrasound examinations were done daily to day 50 of pregnancy. Discrete, nonechogenic areas were first visible within the uterus between days 12 and 14, when they were approximately 2 mm in diameter. These discrete nonechogenic structures were identified as the embryonic vesicle, since they were observed only in heifers later confirmed to be pregnant and were always in the uterine horn ipsilateral to the corpus luteum. The presence of an embryo within the embryonic vesicle was confirmed by observing an echogenic (white) area with rhythmic pulsations (heartbeat). The embryonic vesicle gradually increased in length from the day of first observation until day 26 when it extended past the curvature of the horn and began to encroach into the contralateral horn. In all heifers, by day 32 the vesicle extended to the tip of the contralateral horn. The embryo was first visible between days 26 and 29 when the mean length was 10 mm. The embryo increased in length an average of 1.1 mm per day. A heartbeat was detectable in the embryo on the first day observed. In one superovulated heifer, five vesicles were visible in the uterine horns by day 14 and by day 33 seven embryos were observed; two of the seven embryos apparently resorbed by day 43.  相似文献   

11.
    
The present study aims at quantification of gonadotropin releasing hormone (GnRH) by radioimmunoassay, relative expression of its mRNA by real-time PCR accompanied by its cellular localization in the rat ovary by immunonohistochemistry (IHC) during different time points of pregnancy. To determine the involvement of endogenous ovarian GnRH in receptor mediated local autocrine/paracrine functions within the ovary, the cell specific localization of the classical receptor for GnRH (GnRHR) in the ovary by IHC and expression pattern of its mRNA were studied during pregnancy. Receptor expression during each time point within the ovary was reconfirmed by Western blot analysis accompanied by densitometric analysis of the signal intensity. Results reveal that the content of ovarian GnRH reaches its maximum on Day 20. The densitometric analysis of GnRHR receptor expression from Western blot study exhibits a decreasing trend by Day 20. Presence of GnRH and GnRHR mRNA in the ovary indicates the local synthesis of both ligand and receptor in the rat ovary. Differential expression of GnRH/GnRHR in the corpus luteum throughout pregnancy strengthens the hypothesis of the involvement of ovarian GnRH in local ovarian functions by receptor-mediated mechanisms. The expression of GnRH and GnRHR in the atretic antral follicles is indicative of the possible involvement of this decapeptide in processes like follicular atresia. The expression of GnRH/GnRHR in the nonatretic antral follicles and their oocytes requires further in-depth investigation. Collectively, this study for the first time reveals the presence of endogenous ovarian GnRH/GnRHR supporting their possible involvement in local autocrine/paracrine functions during pregnancy.  相似文献   

12.
    
A genetic switch determines whether the indifferent gonad develops into an ovary or a testis. In adult females of many avian species, the left ovary is functional while the right one regresses. In the embryo, bone morphogenetic proteins (BMP) mediate biological effects in many organ developments but their roles in avian sex determination and gonadal differentiation remains largely unknown. Here, we report the sex-specific and left-right (L-R) asymmetric expression pattern of Bmp7 in the chicken gonadogenesis. Bmp7 was L-R asymmetrically expressed at the beginning of genital ridge formation. After sexual differentiation occurred, sex-specific expression pattern of Bmp7 was observed in the ovary mesenchyme. In addition, ovary-specific Bmp7 expression was reduced in experimentally induced female-to-male reversal using the aromatase inhibitor (AI). These dynamic changes of expression pattern of Bmp7 in the gonad with or without AI treatment suggest that BMP may play roles in determination of L-R asymmetric development and sex-dependent differentiation in the avian gonadogenesis.  相似文献   

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Embryos were collected from two-year-old donor mares and transferred surgically during 1983 and 1984. The overall embryo recovery rate from two-year-old donors was 36.3%. Over both years, 71.4% of the donors (3042) provided at least one embryo. There was a trend both years for slightly higher embryo recovery rates prior to August 1 (47.7%), as compared to after August 1 (31.1%). Pregnancy rates in recipient mares after surgical embryo transfer were not affected by month of the breeding season. However, there was a trend for improved pregnancy rates when embryos were transferred after August 1 (87.5%), as compared to before August 1 (70.0%). There was a 8.3% incidence of fetal loss between Days 15 and 35 of gestation in recipients. The incidence of fetal loss between Days 35 and 60 of gestation was 2.7%. Based on these data, the chance of obtaining a pregnancy from a two-year-old mare is 28.2% (36.3% recovery × 77.7% pregnancy rate). Thus embryo transfer may prove to be a beneficial tool for obtaining foals from two-year-old donor mares.  相似文献   

15.
IVF cycles utilizing the ICSI technique for fertilization have been rising over the 25 years since its introduction, with indications now extending beyond male factor infertility. We have performed ICSI for 87% of cases compared with the ANZARD average of 67%. This retrospective study reports on the outcomes of 1547 autologous ART treatments undertaken over a recent 3-year period. Based on various indications, cases were managed within 3 groupings - IVF Only, ICSI Only or IVF-ICSI Split insemination where oocytes were randomly allocated. Overall 567 pregnancies arose from mostly single embryo transfer procedures up to December 2016, with 402 live births, comprising 415 infants and a low fetal abnormality rate (1.9%) was recorded. When the data was adjusted for confounders such as maternal age, measures of ovarian reserve and sperm quality, it appeared that IVF-generated and ICSI-generated embryos had a similar chance of both pregnancy and live birth. In the IVF-ICSI Split model, significantly more ICSI-generated embryos were utilised (2.5 vs 1.8; p?<?0.003) with productivity rates of 67.8% for pregnancy and 43.4% for livebirths per OPU for this group. We conclude that ART clinics should apply the insemination method which will maximize embryo numbers and the first treatment for unexplained infertility should be undertaken within the IVF-ICSI Split model. Whilst ICSI-generated pregnancies are reported to have a higher rate of fetal abnormalities, our data is consistent with the view that the finding is not due to the ICSI technique per se.  相似文献   

16.
    
Dietary melatonin supplementation during mid- to late-gestation increased umbilical artery blood flow and caused disproportionate fetal growth. This melatonin-induced increase in umbilical artery blood flow may alter nutrient availability to the fetus, which may lead to alterations in fetal size. The objectives of the current experiment were to determine amino acid (AA) and glucose concentrations as well as AA and glucose flux across the uteroplacenta using a mid- to late-gestation model of intrauterine growth restriction supplemented with dietary melatonin as a 2 × 2 factorial design. At day 50 of gestation, 32 ewes were supplemented with 5 mg of melatonin (MEL) or no melatonin (CON) and were allocated to receive 100% (adequate; ADQ) or 60% (restricted; RES) of nutrient requirements. On day 130 of gestation, uterine and umbilical blood flows were determined via Doppler ultrasonography during a non-survival surgery. Blood samples were collected under general anesthesia from the maternal saphenous artery, gravid uterine vein, umbilical artery, and umbilical vein for AA analysis and glucose. Total α-AA concentrations in maternal artery and gravid uterine vein were decreased (P < 0.05) in RES v. ADQ fed ewes. Maternal arterial − venous difference in total α-AA was increased (P ⩽ 0.01) in RES v. ADQ fed ewes, while total uterine α-AA flux was not different (P > 0.40) across all treatment groups. Fetal venous − arterial difference in total α-AA as well as uteroplacental flux of total α-AA were decreased (P < 0.05) in CON-RES v. CON-ADQ, and similar (P > 0.20) in MEL-RES v. CON-ADQ. Maternal concentrations and uterine flux of branched-chain AA (BCAA) were not different across all treatment groups; however, fetal uptake of BCAA was decreased (P < 0.05) in CON-RES v. CON-ADQ, and similar (P > 0.20) in MEL-RES v. CON-ADQ. Uterine uptake of glucose was not different (P ⩾ 0.08) across all treatment groups, while uteroplacental uptake of glucose was increased (P ⩽ 0.05) in RES v. ADQ ewes. In conclusion, maternal nutrient restriction increased maternal arterial − venous difference in total α-AA, while total uterine α-AA flux was unaffected by maternal nutrient restriction. Melatonin supplementation did not impact maternal serum concentrations or uterine flux of glucose or AA; however, melatonin did improve fetal BCAA uptake during maternal nutrient restriction.  相似文献   

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目的:通过检测IVF-ET患者取卵后血清雌激素水平的变化模式,探讨其在预测妊娠中的意义。方法:纳入因榆卵管因素或男性因素行IVF-ET的患者62例(75个周期)。对行IVF-ET的患者,在取卵后隔日监测血清雌二醇(E_2)水平,并比较其在妊娠组与未孕组的差异。结果:取卵后,血E_2水平在妊娠组与未孕组均迅速降低,在取卵后2,4,6,8 d,两组间无统计学差异。在妊娠周期,血E_2平均水平在取卵后10d降至最低,之后逐渐上升。妊娠组与未孕组之间E_2水平的差异从取卵后10d开始可以检测出(分别为816.4±537.6pg/ml和189.5±69.3pg/ml)(P<0.05)。在未孕周期,10d的E_2水平(189.5±69.3pg/ml)显著低于8d(989.2±581.5pg/ml)(P<0.05)。结论:在取卵后8d和10d连续测2次血E_2水平,有助于早期发现妊娠:妊娠患者的E_2水平在10d出现上升预示妊娠,而10d出现剧陡降时,往往预示妊娠失败。  相似文献   

19.
    
Yao K  Yu Y  Wang K  Ye J  Lu D  Jiang H 《Bioelectromagnetics》2007,28(8):628-635
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Maternal thromboembolism and a spectrum of placenta‐mediated complications including the pre‐eclampsia syndromes, fetal growth restriction, fetal loss, and abruption manifest a shared etiopathogenesis and predisposing risk factors. Furthermore, these maternal and fetal complications are often linked to subsequent maternal health consequences that comprise the metabolic syndrome, namely, thromboembolism, chronic hypertension, and type II diabetes. Traditionally, several lines of evidence have linked vasoconstriction, excessive thrombosis and inflammation, and impaired trophoblast invasion at the uteroplacental interface as hallmark features of the placental complications. “Omic” technologies and biomarker development have been largely based upon advances in vascular biology, improved understanding of the molecular basis and biochemical pathways responsible for the clinically relevant diseases, and increasingly robust large cohort and/or registry based studies. Advances in understanding of innate and adaptive immunity appear to play an important role in several pregnancy complications. Strategies aimed at improving prediction of these pregnancy complications are often incorporating hemodynamic blood flow data using non‐invasive imaging technologies of the utero‐placental and maternal circulations early in pregnancy. Some evidence suggests that a multiple marker approach will yield the best performing prediction tools, which may then in turn offer the possibility of early intervention to prevent or ameliorate these pregnancy complications. Prediction of maternal cardiovascular and non‐cardiovascular consequences following pregnancy represents an important area of future research, which may have significant public health consequences not only for cardiovascular disease, but also for a variety of other disorders, such as autoimmune and neurodegenerative diseases. Birth Defects Research (Part C) 105:209–225, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   

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