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《蚕学通讯》1993,(1)
家蚕(Bombyx mori)滞育发生在一特定的胚胎时期,即在有头叶、尾节和中胚层分裂的胚带形成之后。当卵在25℃保育,则胚胎的细胞分裂和形态发生停滞。为查明在胚胎发生时期G_1、S和G_2期细胞的百分率变化,胚胎的核部分被分离出来并经乙酰碘(Propidium iodide)染色,经流式细胞仪分析。在头叶形成期,G_1、S、G_2期细胞的百分率分别为10,35和55％,而在滞育期G_2期细胞达98％。在经5℃冷藏或一个冷藏与盐酸相结合的复式处理作滞育解除,胚胎细胞分裂重新恢复,在此期,细胞从G_2期经G_1快速进入S期,意示着G_1期较短。滞育卵在产下后经25℃ 20小时用盐酸处理可防止滞育,胚胎可持续发育经25℃ 9.5天后孵化。在这一发育时期,G_1期细胞可增至90％。这些结果表明胚胎细胞在G_2期停滞,且意味着随着胚胎进一步发育,与G_1期细胞增加相应,细胞周期循环变慢。最后,大部分细胞可能停留在G_1而仅有相小部分细胞继续周期循环。 相似文献
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在生理温度下对正常幼年猪的肠系膜淋巴结进行了体外灌注。把无细胞灌注培养液,泵入动脉内,2.5小时后,淋巴细胞不断地释放到静脉流出液中。再循环的淋巴细胞是从淋巴结移出以后,直接进入血管系统的,而不是经过输出淋巴管进入血管的。用新的培养液灌注2小时后,在付皮质区的小静脉壁中出现淋巴细胞,故认为这些部位就是移出位点。从肠系膜淋巴结移出的淋巴细胞之比率为6×10~7/小 相似文献
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《中国兽医学报》2016,(10):1748-1752
选取28日龄、体质量(8.28±0.23)kg、PRRSV阴性的健康杜长大三元杂交仔猪40头,分为4组(Ⅰ组为健康对照组,Ⅱ组为感染对照组,Ⅲ、Ⅳ组为中药保健组),适应饲养至35日龄开始正式试验。36~39日龄,Ⅰ、Ⅱ组均饲喂基础日粮,Ⅲ、Ⅳ组在基础日粮中分别添加0.5%和1.0%的复方中药"猪康散";40日龄时除Ⅰ组外,其余各组猪均滴鼻接种PRRSV SCM株1.0mL/只。分别于50和60日龄时每组随机选取4头仔猪无菌取脾脏,进行脾脏淋巴细胞周期及凋亡率检验,观察复方中药"猪康散"对人工感染PRRSV猪脾脏淋巴细胞周期及凋亡率影响的动态变化。结果显示复方中药"猪康散"具有降低人工感染PRRSV猪G0/G1期脾脏淋巴细胞数量,提高S期、G2+M淋巴细胞数量及淋巴细胞PI值的作用(P0.05或0.01),以0.5%剂量组最佳;复方中药"猪康散"降低人工感染PRRSV猪脾脏淋巴细胞凋亡百分率的作用以1.0%剂量组最佳。由此表明复方中药"猪康散"保健用药具有提高人工感染PRRSV猪脾脏淋巴细胞增殖并降低脾脏淋巴细胞凋亡率的作用。 相似文献
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试验旨在研究不同浓度的天门冬多糖(ASP),在ConA或LPS的协同刺激下对猪脾淋巴细胞体外增殖的影响。猪脾淋巴细胞体外培养体系中加入不同浓度的天门冬多糖使其终浓度为400、200、100、50、25、12.5μg/ml,在ConA(5μg/ml)或者LPS(10μg/ml)的协同刺激作用下,细胞培养24、48、72 h时,观察猪脾淋巴细胞增殖情况。结果表明,天门冬多糖及其协同ConA或LPS能显著或极显著的促进猪脾淋巴细胞体外增殖(P<0.05或P<0.01)。 相似文献
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本试验分析研究了：（1）猪卵子体外成熟所需要的培养时间；（2）促性腺激素和猪卵泡液对猪卵子体外成熟的作用；（3）不同体外受精次数对猪卵子体受精率的影响；（4）不同精子获能辅助剂对猪精子体外获能的作用；（5）不同种类猪精液的体外受精能力。研究结果表明，猪卵子体外成熟所需培养时间是32－36小时，在体外成熟培养液中加入0.25IU/ml PMSG（或FSH）和10％猪卵泡液可以促进猪卵子体外成熟，在精子体外获能培养液中加入0.05mg/ml肝素，在体外受精培养液中加入2mg/ml咖啡因可以促进猪精子体外获能并可提高体外受精率，体外成熟后的猪卵子进行2次受精可以获得较高的体外受精率，本试验用新鲜射出精子，冷冻射出精子，新附睾精子，冷冻附睾精子对体外成熟猪卵子进行体外受精，受精后卵裂率（2－4细胞期）分别是24.26％、23.40%,22.65%和24.24%。 相似文献
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<正>超强猪周期结束,养猪行业再次陷入低迷期超强猪周期终于结束了,养猪行业再次陷入低迷期已成定局。从2015年3月以来,养猪行业进入新一轮猪周期,生猪的收购价格重新进入低迷期,这个时间有多长,目前尚无定论,有人说还得需要2年,也有人说持续到年底就结束了。来自农业部的监测数据显示,全国 相似文献
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为了解猪miR-1307序列和结构特征,阐明其在猪卵巢颗粒细胞周期中的作用,利用生物信息学方法分析猪miR-1307的序列特征、染色体定位和潜在的生物学功能;在体外培养的猪卵巢颗粒细胞中转染miR-1307模拟物(mimics)和抑制剂(inhibitor),利用流式细胞术检测细胞周期。结果显示:猪miR-1307前体序列长度为80 bp,其核苷酸序列(包括成熟序列和种子序列)和基因组定位等与哺乳动物其他物种高度一致;功能富集分析发现miR-1307靶基因富集在rRNA分解代谢进程和蛋白酪氨酸磷酸酶活性等多个重要的生物学进程和分子功能中;在猪卵巢颗粒细胞中,过表达miR-1307可使G0/G1期细胞比例增加,S期细胞比例显著降低(P<0.05);抑制miR-1307可使G0/G1期细胞比例降低,S期细胞比例显著增加(P<0.05)。结果表明:miR-1307是猪卵巢颗粒细胞周期的重要调节因子。 相似文献
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M Hayashi T Kuzumi S Arai T Okui 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(8):975-978
The effect of X-irradiation on the progression of the cell cycle in cell lines from LEC and WKAH rats was investigated by a flow cytometer. When the cells were exposed to 5 Gy of X-rays at S phase, the proportion of S-phase cells in both cell populations decreased with incubation time and that of G2/M-phase cells was approximately 80% at 6 hr post-irradiation. At 12 hr post-irradiation, approximately 45% of the WKAH rat cells appeared in the G1 phase. However, 80-90% of LEC rat cells remained in the G2/M phase and less than 5% in the G1 phase during 6-12 hr post-irradiation. Thus, the LEC rat cells irradiated at S phase remained in the G2/M phase for at least 6 hr longer than did the WKAH rat cells. 相似文献
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M Hayashi T Kawamura H Akaike S Arai T Okui 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(4):389-394
DNA synthesis was effectively inhibited by antisense oligonucleotide A1 complementary to the BamHI-H gene family in Marek's disease virus (MDV)-derived lymphoblastoid MDCC-MSB1 cells. When a cell cycle distribution of a total cell population was analyzed by flow cytometry, the proportion of S-phase cells increased in the cell populations by treatment with oligonucleotide A1. Approximately 60-70% of the cells appeared in the S phase for 24 and 36 hr of incubation in the presence of oligonucleotide A1 (20-30% in the untreated control cells). The inhibition of cell cycle progression by treatment with oligonucleotide A1 was reversible. When the cells were treated with 5 microM aphidicolin for 12 hr, a similar pattern of cell cycle distribution was observed to that obtained after treatment with oligonucleotide A1. Aphidicolin is an inhibitor of cellular DNA polymerase alpha, and it halts progression of the cell cycle at the G1/S border or early S phase. When the cells were treated with aphidicolin for 12 hr and subsequently incubated with oligonucleotide A1, no significant difference was observed in the cycle phase distribution of cells in the presence and absence of oligonucleotide A1. In contrast, when the cells were treated with oligonucleotide A1 for 12 hr and subsequently incubated with aphidicolin, the cell cycle did not progress from the G1/S border or early S phase to the next phase. 相似文献
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Observations in early equine pregnancy clearly reveal maternal immune recognition of and response to the presence of the conceptus. Nevertheless, both maternal cellular and humoral responses appear ineffective in destroying the developing placenta and fetus in early pregnancy. Our previous studies had shown that the pre-conditioned medium generated from the culture of equine invasive trophoblast inhibited mitogen-induced lymphocyte proliferation and the expression of cytokine messenger RNA in vitro. Those findings also suggested that lymphocytes might have been halted in the G0/G1 phase of the cell cycle. To characterize the cell cycle and the intracellular mechanisms involved in the inhibition of lymphocyte proliferation, equine peripheral blood lymphocytes were cultured in the presence or absence of pokeweed mitogen (PWM) in fresh medium, or in medium pre-conditioned through cell culture of invasive trophoblast cells or fetal fibroblasts. Two-color flow cytometric analysis for bromodeoxyuridine (BrdU) incorporation by stimulated lymphocytes, and concomitant DNA staining with 7-amino-actinomycin D (7-AAD), indicated that a greater proportion of lymphocytes were found in the G0/G1 phase of the cell cycle when cultured in the invasive trophoblast cell pre-conditioned medium compared to controls. Analysis using carboxyfluorescein diacetate succinimidyl ester (CFSE) fluorescence intensity demonstrated that lymphocytes cultured in the presence of invasive trophoblast cell pre-conditioned medium had fewer cells going through division, but that those fewer cells sustained similar numbers of cell divisions as in control cultures. Hypophosphorylated retinoblastoma (Rb) protein expression was increased and p27Kip1 expression was maintained at higher levels in lymphocytes cultured in invasive trophoblast pre-conditioned medium compared to fresh medium. In agreement with these data, flow cytometric measurement of the Ki-67 protein expression in lymphocytes cultured in invasive trophoblast pre-conditioned medium was lower in comparison to controls. These findings suggest that the equine lymphocyte proliferation is at least partially regulated by the expression of proliferation inhibitory proteins such as p27Kip1 and hypophosphorylated Rb. These proteins seem to be important regulators of cell cycle transition between G1 and S phase in equine lymphocytes. 相似文献
14.
试验旨在探索使较高比例的淋巴细胞富集在有丝分裂G2/M期的最佳条件。运用植物血凝素(PHA)和刀豆蛋白A(ConA)对淋巴细胞进行刺激使其增殖,培养一定时间后加秋水仙素对淋巴细胞进行同步化处理,用流式细胞仪检测G2/M期的细胞数量进行比对,观察试剂的最佳作用浓度和加秋水仙素的最佳时间。结果表明,采用PHA和ConA刺激淋巴细胞增殖的最佳作用浓度是60和5 μg/mL,且淋巴细胞经ConA刺激培养45 h再加秋水仙素处理5 h G2期的比例最高为58.38%。结果提示,就绒山羊的淋巴细胞来说,ConA刺激绒山羊淋巴细胞增殖的效果比PHA好,且摸索出细胞G2/M期的时间点至关重要。 相似文献
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Cheong HT Park TM Ikeda K Takahashi Y 《The Japanese journal of veterinary research》2003,51(2):95-103
This study was undertaken to examine the cell cycle characteristics of bovine fetal and adult somatic cells (fetal fibroblasts, adult skin and muscle cells, and cumulus cells) after culture under a variety of conditions; 1) growth to 60-70% confluency (cycling), 2) serum starvation, 3) culture to confluency. Cell -cycle phases were determined by flow cytometry with propidium iodide staining enabling the calculation of percentages of cells in G0 /G1, S and G2 /M. The majority was in G0/G1 regardless of cell type and treatment. Serum-starved or confluent cultures contained higher percentages of cells in G0/G1 (89.5-95.4%; P < 0.05). Percentages of cells in G0/G1 increased as cell size decreased regardless of the cell type and treatment. In the serum-starved and confluent cultures, about 98% of small cells were in G0/G1 . Serum-starved cultures contained higher percentages of small cells (38.5-66.9%) than cycling and confluent cultures regardless of cell type (P < 0.05) . After trypsinization of fetal fibroblasts and adult skin cells that were serum-starved and cultured to confluency, the percentages of cells in G0/G1 increased (P < 0.05) on incubation for 1.5 (95.7-99.5%) or 3 hr (95.9-98.6%). These results verify that serum starvation and culture to confluency are efficient means of synchronizing bovine somatic cells in G0/G1, and indicate that a more efficient synchronization of the cells in G0/G1 can be established by incubation for a limited time period after trypsinization of serum-starved or confluent cells. 相似文献
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Y Taura Y Mullen T Papoian T Tsunoda T Shiogama 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(3):365-369
In order to determine the means of monitoring the immunological status of allograft recipients in miniature swine, an assay was developed to measure interleukin (IL)-2 production in vitro by pretreatment of donor peripheral blood lymphocytes (PBL). Miniature swine were given 0 to 4 weekly intravenous transfusions of 5-10 X 10(7) donor PBL incompatible at major histocompatibility complex (MHC) and assayed in vitro for donor specific immune IL-2-like activities. The results are summarized as follows: (1) IL-2-like activity in 24 hr and 48 hr supernatants from mixed lymphocyte cultures (MLC) with MHC-incompatible PBL was detected without pretreatment. The 48 hr MLC supernatant exhibited a high IL-2-like activity compared with the 24 hr; (2) IL-2-like activity after only one transfusion with MHC-incompatible PBL was higher than that without pretreatment; (3) IL-2-like activity in 4 weekly transfusions was detectable slightly earlier than that without pretreatment or three transfusions with MHC-incompatible PBL. 相似文献
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将5种不同浓度复方中药多糖(CPPS)加入到小鼠脾淋巴细胞中培养48 h,观察CPPS对小鼠脾淋巴细胞增殖、对体外培养的脾淋巴细胞中NO的生成和蛋白激酶G(PKG)活性的影响。结果显示,CPPS能显著提高淋巴细胞增殖,显著升高细胞培养液中NO的生成,细胞内PKG活性明显提高,且CPPS、NO和PKG与淋巴细胞增殖有一定相关性。CPPS可能通过NO介导信号通路,引起第二信使环化鸟苷酸(cGMP)生成,从而提高PKG活性促进淋巴细胞的增殖,发挥其免疫调节作用。 相似文献
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Synchronization of the cell cycle stages in G0/G1 phase is one of the key factors determining the success of nuclear transplantation. Serum deprivation, contact inhibition and chemical inhibitors are widely used methods for this purpose. In this study, cell cycle stages of foetal fibroblasts and cumulus cells were determined using flow cytometry [fluorescence-activated cell scan (FACS)]. Foetal fibroblasts (in vitro cultured for 72-120 h) and fresh cumulus cells were analysed in Experiment 1. Fifty to 55% proliferating fibroblasts remained in G0/G1 phase compared with 78% in confluent culture (p <0.05). In contrast to foetal fibroblasts, fresh cumulus cells maintained 90% of the population in the G0/G1 stage. When serum was retrieved from the proliferating fibroblasts from day 1 to day 5 (Experiment 2), proportions of G0/G1 cells increased from the initial ratio of 53 to 87% at day 4 of starvation, which was significantly higher than the non-starved proliferating cells (p <0.05). In Experiment 3, fibroblasts were treated with aphidicolin (0.1 microg/ml, 6 h), demicolcine (0.5 microg/ml, 10 h), or a combination of these two chemicals to synchronize the cell cycle stages. Surprisingly, no differences or significantly lower in the proportions of G0/G1)phase cells were detected (25-50%) compared with the uncontrolled growing cells (53%). These results suggested that fresh cumulus cells rest their cell cycle in G0/G1 stage. Serum deprivation became effective in the first 24 h and reached the highest proportions during days 4-5 after deprivation. Chemical synchronization of the cell cycle stage of rabbit foetal fibroblasts to G0/G1 phase appeared less effective compared to serum deprivation. 相似文献
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Baris Guner Melih Erturk Gulnaz Yilmazbas-Mecitoglu Abdulkadir Keskin Ebru Karakaya-Bilen Rabia Cakircali Enes Serim Abdulkadir Orman Ahmet Gumen 《Reproduction in domestic animals》2020,55(10):1411-1417
The objective of the study was to evaluate the interval from onset of oestrus to time of artificial insemination (AI) to obtain the optimum pregnancy rate with sex-sorted semen in Holstein heifers. Heifers in oestrus were detected and inseminated only by using heat–rumination neck collar comprised electronic identification tag at the age of 13–14 months. Heifers (n = 283) were randomly assigned to one of three groups according to the timing of insemination at 12–16 hr (G1, n = 97), at 16.1–20 hr (G2, n = 94) and at 20.1–24 hr (G3, n = 92) after reaching the activity threshold. The mean duration of oestrus was 18.6 ± 0.1 hr, and mean peak activity was found at 7.5 ± 0.1 hr after activity threshold. The mean interval from activity threshold to ovulation was 29.4 ± 0.4 hr. The overall pregnancy per AI (P/AI) was 53.0% at 29–35 days and 50.9% at 60–66 days after AI. There was a significant reduction between G1 (13.8 ± 1.4 hr) and G3 (7.9 ± 1.4 hr) related to the intervals from AI to ovulation time. Sex-sorted semen resulted in significantly higher P/AI at 29–35 days when heifers inseminated in G3 (60.9%) after oestrus than those inseminated in G1 (49.5%) and G2 (48.9%). In terms of fertility, when the temperature–humidity index (THI) was below the threshold value (THI ≤65) at the time of AI, there was a tendency (≤65; 57.2% vs. > 65; 47.1%) for high pregnancy rate. There was no effect of sire on P/AI. In addition, the interaction of the technician with the time of AI was found significant, and three-way interaction of technician, sire and time of AI was tended to be significant on pregnancy rate. Thus, in addition to delaying the time of insemination (between 20.1 and 24 hr) after oestrous detection, THI and experienced technician were also found to be critical factors in increasing fertility with the use of sex-sorted semen in Holstein heifers. 相似文献
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Hosoya K Murahari S Laio A London CA Couto CG Kisseberth WC 《American journal of veterinary research》2008,69(4):519-526
OBJECTIVE: To evaluate the biological activity of dihydroartemisinin on canine osteosarcoma cell lines in vitro. SAMPLE POPULATION: 4 canine osteosarcoma cell lines. PROCEDURES: Cell viability assays were performed on canine osteosarcoma cell lines OSCA2, OSCA16, OSCA50, and D17 after 24, 48, and 72 hours of treatment with dihydroartemisinin at concentrations of 0.1 to 100 microM. Apoptosis was assessed by use of an ELISA for free nuclosomal DNA fragmentation and by western blot analysis for cleavage of caspase 3. Cell cycle analysis was performed by use of staining with propidium iodide and flow cytometry. Detection of reactive oxygen species (ROS) was conducted in the D17 cell line by use of 6-carboxy-2',7'-dihydrofluorescein diacetate and flow cytometry. RESULTS: The concentration of dihydroartemisinin required for 50% inhibition of cell viability (IC50) was achieved in all 4 canine osteosarcoma cell lines and ranged from 8.7 to 43.6 microM. Induction of apoptosis was evident as an increase in nucleosomal DNA fragmentation, cleavage of caspase 3, and an increase in the population in the sub G0/G1 phase of the cell cycle detected by flow cytometry. Exposure to dihydroartemisinin also resulted in a decrease in the G0/G1 population. Iron-dependent generation of ROS was detected in dihydroartemisinin-treated D17 cells; ROS generation increased in a dose-dependent manner. CONCLUSIONS AND CLINICAL RELEVANCE: Incubation with dihydroartemisinin resulted in biological activity against canine osteosarcoma cell lines, which included induction of apoptosis and arrest of the cell cycle. Clinical trials of dihydroartemisinin in dogs with osteosarcoma should be conducted. 相似文献