排卵延迟奶牛发情后不同阶段B超黄体相关指标变化规律分析

为研究排卵延迟奶牛发情配种后黄体的变化规律及其差异性,本研究在临床症状观察、直肠检查和B超辅助检查诊断的基础上,选取8头排卵延迟奶牛(排卵延迟组)、5头健康正常发情奶牛(对照组),应用B超对黄体的相关指标(直径、面积、周长和体积)进行了测量及分析,对获得的不同阶段典型黄体声像图进行了描述。结果显示,与对照组相比,排卵延迟组与对照组奶牛黄体的直径、面积、周长和体积在发情配种后7~15 d差异均不显著(P>0.05)。在发情配种后第9和13天排卵延迟组奶牛黄体相关指标(直径、体积、面积和周长)大于对照组奶牛,而在第11天小于对照组奶牛。结果表明,排卵延迟奶牛发情后不同阶段B超黄体直径、面积、周长和体积与正常发情排卵后的相应指标没有显著差别。     

家兔超数排卵与早期胚胎发育研究

为了提高家兔繁殖力,使用不同剂量的FSH对家兔进行了超数排卵研究,结果表明：采用高剂量FSH处理母兔的平均排卵点数与平均卵泡发育数显著（P〈0.05）高于低剂量FSH组,两种处理方法的平均卵泡囊肿数与平均卵泡数则差异不显著（P〉0.05）。家兔早期胚胎发育观察结果表明：母兔交配后24h采胚所获取的胚胎大多处于1细胞期,交配后30h胚胎多处于2细胞期,交配后35h胚胎多处于4细胞期。采用52IU FSH进行超数排卵处理,对家兔的胚胎发育无影响。     

风信子不同外植体及其年龄对试管鳞茎诱导的影响

以风信子的叶片、花被片和鳞茎作为外植体，并将它们分为5个年龄级，研究风信子不同外植体及其年龄对试管鳞茎诱导的影响。结果表明：外植体年龄越小，鳞茎的诱导率越高，鳞茎的质量(平均鲜重)也越好，叶片外植体在年龄1和年龄2时均有较高的鳞茎诱导率，平均鲜重也较高；花被片外植体年龄1、2和年龄3之间诱导鳞茎的能力差异不大，而鳞茎外植体年龄1的鳞茎诱导率明显比年龄2的高，叶片外植体的鳞茎诱导能力要大于花被片和鳞茎。     

菊花辐射诱变育种研究进展

综述了辐射诱变的方法及变异机理,探讨了当今菊花产业中辐射诱变的发展方向,提出了以辐射诱变、组培和分子标记相结合的复合育种的思路。     

Enhancement of Phenylalanine Ammonia Lyase,Polyphenoloxidase, and Peroxidase in Cucumber Seedlings by Bemisia tabaci（Gennadius） （Hemiptera： Aleyrodidae） Infestation

In this study, the activities of phenylalanine ammonia lyase （PAL）, polyphenoloxidase （PPO）, and peroxidase （POD） were assayed in cucumber seedlings （Cucumis sativus L.） at 0, 6, 12, 24, 48, 72, and 96 h after they were infested by Bemisia tabaci （Gennadius） using spectrophotometric analysis. The results indicated that herbivore infestation increased the activities of PAL, PPO, and POD. The enzymes showed different activity levels at different times after the infestation. The PAL activity reached the first high peak by 23.1% at 6 h and the highest peak by 29.1% at 48 h compared to the control. The PPO activity reached the first high peak by 22.7% at 6 h and the highest peak by 52.6% at 24 h, and the POD activity reached the highest peak by 213.2% at 6 h and another higher peak value by 135.2% at 96 h. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of cucumber plants against B. tabaci infestation.     

哺乳动物精清诱导排卵活性蛋白质研究

在动物的精清里包含一些与动物生殖生理活动密切相关的活性蛋白和多肽.驼科动物的双峰驼、美洲驼、羊驼和澳洲考拉等哺乳动物精清中含有类似促性腺激素释放激素(GnRH)作用的活性蛋白质,诱导排卵因子(ovulation inducing factor,OIF),它能引发外周血液中促黄体素(LH)峰浓度的出现和诱发母畜排卵.OIF被认为是一种新的生物活性蛋白质或潜在的新型激素.甚至报道在牛等自发排卵动物以及人精清中也存在类似的活性蛋白.这类因子的发现对于哺乳动物生殖生理及繁殖的深入研究具有重要的意义,有助于动物克服繁殖障碍及繁殖疾病的治疗等.     

西藏八角莲种胚愈伤诱导的初探

以西藏八角莲成熟种子为材料,研究了外植体的不同处理方法、激素浓度及光照条件对愈伤诱导的影响。结果表明,在暗培养条件下,以带种胚的种子段为外植体,在MS＋6-BA 2.0 mg/L＋NAA 0.2 mg/L培养基上可以获得诱导率较高的愈伤组织,诱导率为66.7%。     

香蕉ACC氧化酶基因(MAO3)的克隆及其表达特性分析

 根据同源扩增得到香蕉(Musa acuminata) ACC氧化酶基因(MAO3) 的核心部分, 再通过3'和5'RACE扩增上、下游序列以及Genome-Walker的方法得到启动子部分, 共获得3 718 bp长度的序列。将所得结果进行聚类分析, 发现香蕉中ACC氧化酶的氨基酸序列非常保守, 各序列间的同一性高达99% ,与单子叶植物和双子叶植物中ACC氧化酶的氨基酸序列的同源性在66.7%～71.8%之间。组织原位杂交试验表明MAO3基因的表达具有组织特异性, 初步认为是在韧皮部筛管组织中特异表达。运用实时荧光定量PCR技术, 实时监测到了MAO3基因和香蕉乙烯受体基因ERS2受机械伤诱导的定量变化。     

Steroidogenesis during induced oocyte maturation and ovulation in the African catfish,Clarias gariepinus

Changes in ovarian steroidogenesis accompanying oocyte maturation and ovulation were studied in the African catfish,Clarias gariepinus. Laboratory-reared females with postvitellogenic ovaries were treated with pimozide and LHRH-analogue. The plasma gonadotropin levels were determined by means of a homologous radioimmunoassay, the condition of the ovaries was studied by histological examination of the follicles, and the steroidogenetic capacity of the ovaries was analyzed byin vitro incubation of tissue fragments for 3 h with [³H]-pregnenolone and [³H]androstenedione as precursors. Data were collected at regular intervals between 0 and 16 h after pimozide-LHRH analogue administration.Until 4 h after the beginning of the experiments the plasma gonadotropin levels did not rise above 25 ng/ml, the ovaries remained in the stage of postvitellogenesis, and testosterone was the main end product of steroidogenesis. Four hours later the gonadotropin concentration in the blood had risen to more than 150 ng/ml, and the ovaries had entered the stage of germinal vesicle migration. At the same time steroidogenesis shifted towards the production of 17,20-dihydroxy-4-pregnen-3-one, 5-pregnane-3, 17-diol-20-one, 5-pregnane-3,6,17-triol-20-one, 5-pregnane-3,17,20-triol and 5-pregnane-3,6,17,20-tetrol. During the subsequent stage of germinal vesicle breakdown the plasma gonadotropin level remained high, and the synthesis of the C₂₁-steroids showed a further increase. Simultaneously, the production of some C₁₉-steroid glucuronides was enhanced. The preovulation and especially the postovulation stages were accompanied by a gradual decrease in steroidogenic capacity of the ovaries, even though the plasma gonadotropin level remained high. It is concluded that the prematuration surge of gonadotropin influences the activity of enzymes involved in steroidogenesis, leading to a reduced C_17,20-lyase and to an augmented activity of the enzymes 20-hydroxysteroid dehydrogenase (HSD), 5-reductase, 3-HSD, 6-hydroxylase and UDP-glucuronosyltransferase. During ovulation the activity of all steroidogenic enzymes, including such key enzymes as 3-HSD and 17-hydroxylase, gradually decreases.Not only 17,20-dihydroxy-4-pregnen-3-one, but also the 5-reduced pregnanes may be involved in inducing oocyte maturation and/or ovulation. The very polar triol and tetrol products may function, together with the steroid glucuronides as sex pheromones.A preliminary account of these results was presented at the XIII Conference of European Comparative Endocrinologists, Belgrade, September 7–12, 1986     

Cervix–rectum temperature differential at the time of insemination is correlated with the potential for pregnancy in dairy cows

This study sought to establish whether temperature gradients between the cervix, vagina, and rectum at and 7 days post-artificial insemination (AI) were associated with the incidence of pregnancy in lactating dairy cows (Experiment I; n = 90 ovulating cows) and to evaluate temperature gradient dynamics from the time of insemination to 7 days post-AI under heat stress conditions (Experiment II; n = 16 ovulating and 4 non-ovulating cows). In Experiment I, 39 cows (43.3%) became pregnant. The odds ratio for pregnancy was 2.5 for each one-tenth of a degree drop in cervical temperature with reference to the control rectal temperature at the time of AI (P = 0.01), whereas the same decrease in the cervix–rectum temperature differential 7 days post-AI resulted in an odds ratio of 0.44 (P = 0.02). In Experiment II, 5 of the ovulating cows (31.3%) became pregnant. The mean values of the vagina–rectum, vagina–cervix, and cervix–rectum temperature differentials at AI (day 0), 8 h, 24 h, and 7 days post-AI changed significantly from day 0 to day 7 (within-subject effect; P < 0.02) in ovulating cows but not in non-ovulating cows. Temperature differentials on days 0 and 7 were similar between ovulating cows and cows of Experiment I. Overall, our findings support the notion that a temperature differential between the caudal cervical canal and rectum at AI may be an indicator of the likelihood of pregnancy. Possible prospects of confirming estrus at the herd-level are also suggested.