潘那利番茄叶片组织培养及植株再生研究

研究以潘那利番茄的叶片为外植体,研究不同激素及其不同浓度组合对潘那利番茄愈伤组织的诱导、不定芽分化及其生根的影响.结果表明.愈伤组织诱导和芽分化的最适培养基为MS+6-BA 3.0 mg·L-1+IAA0.2 mg·L-1,生根的最适培养基为MS+IAA 0.1 mg·L-1,试管苗移栽后成活率为87%.该研究结果为潘...     

九个粳稻品种未传粉子房的培养

9个粳稻品种未传粉子房的培养试验表明,品种间愈伤组织的诱导率、分化率均存在差异。早粳优于晚梗。抽穗期早的品种具有较高的成苗率。外源激素对诱导分化具有十分重要的作用。MCPA(2-甲基-4-氯苯氧乙酸)优于2.4-D。     

限位环境对妊娠母猪母性的影响

限位环境在带来生产便利的同时也限制了母猪的母性表达。从中枢控制、基因表达、激素调节等角度阐明母性行为的发生机制,分析限位环境应激对母猪行为、生理、心理等方面的影响导致的母性减弱,并总结限位母猪常见疾病对母性的影响;通过对限位环境中母性表达影响因素的分析,探究其在妊娠母猪中的作用机制,将有助于改进母猪的育种和管理。     

植物激素对坚龙胆种子萌发的影响

[目的]探讨植物激素对坚龙胆种子萌发的影响。[方法]以坚龙胆成熟种子为试验材料,采用正交试验设计研究赤霉素(GA3)、6-苄基腺嘌吟(6-BA)、吲哚乙酸(IAA)及浸种时间对坚龙胆种子发芽情况的影响。[结果]坚龙胆种子发芽过程中以200 mg/L GA3+5mg/L 6-BA+5 mg/L IAA配比并浸种48 h处理的效果最好,种子发芽率达93%以上,种子开始发芽时间和发芽持续时间短,发芽势和发芽指数最高。[结论]经过正交试验设计优选出影响坚龙胆种子发芽率的作用大小为IAAGA3浸种时间6-BA;经过植物激素处理可以提高坚龙胆种子的发芽率。     

Inhibition of juvenile hormone biosynthesis and methyl farnesoate epoxidase activity by 1,5-disubstituted imidazoles in the cockroach,Diploptera punctata

Seventeen substituted imidazoles were tested as inhibitors of juvenile hormone (JH) III synthesis by cockroach corpora allata in an in-vitro radio-chemical assay. Most of these 1,5-disubstituted imidazoles were highly potent, with IC₅₀ values of less than 100nM. The compounds differed in their ability to cause an accumulation of the precursor methyl farnesoate in the glands. Four of the imidazoles were tested by topical application to previtellogenic adult females, and all caused a significant inhibition of JH synthesis and an accumulation of intraglandular methyl farnesoate for at least three days after treatment. Methyl farnesoate epoxidase activity of homogenates of corpora allata was inhibited by the compounds TH -14 and TH -27. This P450-dependent epoxidase activity was inhibited at less than 10 nM. The results show that the 1,5-disubstituted imidazoles are powerful inhibitors of the last step of juvenile synthesis in this cockroach.     

Identification of novel juvenile-hormone signaling activators via high-throughput screening with a chemical library

Juvenile hormone (JH) is an insect-specific hormone that regulates molting and metamorphosis. Hence, JH signaling inhibitors (JHSIs) and activators (JHSAs) can be used as effective insect growth regulators (IGRs) for pest management. In our previous study, we established a high-throughput screening (HTS) system for exploration of novel JHSIs and JHSAs using a Bombyx mori cell line (BmN_JF&AR cells) and succeeded in identifying novel JHSIs from a chemical library. Here, we searched for novel JHSAs using this system. The four-step HTS yielded 10 compounds as candidate JHSAs; some of these compounds showed novel basic structures, whereas the others were composed of a 4-phenoxyphenoxymethyl skeleton, the basic structure of several existing JH analogs (pyriproxyfen and fenoxycarb). Topical application of seven compounds to B. mori larvae significantly prolonged the larval period, suggesting that the identified JHSAs may be promising IGRs targeting the JH signaling pathway.     

奶牛乳腺上皮细胞的不同培养方法比较及激素和细胞因子对β-酪蛋白mRNA表达的诱导

本试验旨在建立一种高效的奶牛乳腺上皮细胞培养方法,并研究不同激素和细胞因子对其表达β-酪蛋白mRNA的诱导作用.分别采用组织块培养法和机械破碎法培养奶牛乳腺上皮细胞,利用成纤维细胞和乳腺上皮细胞对胰酶的敏感性不同,对获得的细胞进行纯化.通过细胞计数法测定纯化细胞的生长曲线,通过免疫荧光组织化学染色法检测角蛋白18的表达,通过实时定量PCR法检测8种不同激素和细胞因子组合培养液诱导细胞表达β-酪蛋白mRNA的效果.结果表明:通过机械破碎法可以分离得到增殖旺盛的奶牛乳腺上皮细胞,与组织块培养法相比,具有细胞迁出速度快等优点.细胞生长曲线呈典型的“S”型.在纯化的乳腺上皮细胞及第20代乳腺上皮细胞中都检测到角蛋白18的表达.100 ng/mL类胰岛素生长因子Ⅰ(IGF-Ⅰ)显著提高了乳腺上皮细胞中β-酪蛋白mRNA的表达(P＜0.05).由结果可知,本试验采用的机械破碎法是一种高效的奶牛乳腺上皮细胞培养方法,100 ng/mL IGF-Ⅰ对细胞中β-酪蛋白mRNA表达的诱导效果最好.     

Seasonal changes in circulating growth hormone (GH), hepatic GH-binding and plasma insulin-like growth factor-I immunoreactivity in a marine fish,gilthead sea bream,Sparus aurata

We have studied the seasonal relationship between growth and circulating growth hormone (GH), hepatic GH-binding and plasma insulin-like growth factor-I immunoreactivity in gilthead sea bream,Sparus aurata. The seasonal increase in plasma GH levels preceded by several weeks the summer increase in growth rates. In contrast, a marked increase in hepatic GH-binding with a high degree of endogenous GH occupancy was found during the period of maximum growth which suggests an enhanced sensitivity of liver to GH action. Thus, circulating levels of immunoreactive IGF-I, probably derived from the liver in response to GH action, were positively correlated with growth throughout the experimental period although a consistent relationship between growth and circulating GH was not found. In spite of this, we consider that, in gilthead sea bream, as in several other teleosts, the availability of endogenous GH can limit growth. Thus, under environmental conditions of suboptimal growth, a single intraperitoneal injection of recombinant rainbow trout GH (rtGH) induced over the dose range tested (0.75, 1.5, 3 μg g BW⁻¹) an increase in plasma IGF-I-like immunoreactivity comparable to that seen during the period of maximum growth.     

Effects of Estradiol and Testosterone on the Expression of Growth‐related Genes in Female and Male Nile Tilapia,Oreochromis niloticus

Nile tilapia exhibits strong sexual growth dimorphism. The potential role of sex steroid hormones in sexual growth dimorphism is not fully understood. We investigated the effects of estradiol (E₂) and testosterone (T) on growth rate, plasma sex hormones, and expression of growth hormone (GH)‐insulin‐like growth factor (IGF) axis genes and muscle regulatory factor (MRF) genes in female and male Nile tilapia. The results revealed that serum concentrations of E₂ and T were significantly higher after correlative injection (P < 0.05). Compared to male fish, female fish had lower growth rates. E₂ increased growth performance in females with no significant effects on males, whereas T significantly increased growth performance in males, with no significant effects on females. In females, E₂ significantly increased expression of ghr1, ghr2, igf1, and igf2, while T decreased igf2 and increased ghr1 and ghr2 expression. In males, T increased expression of igf1, igf2, ghr1, and ghr2, and E₂ decreased expression of igf1, ghr1, and ghr2. Additionally, E₂ and T enhanced the expression of MRF genes (myod1, myod2, myog, and myf5) in female and male fish, respectively. The results suggest that sex steroid hormones play a role in sexual growth dimorphism by regulating the expression of GH‐IGF axis and MRF genes.     

应用于鱼道设计的新疆木扎提河斑重唇鱼的游泳能力测试

为了探究斑重唇鱼的游泳能力,给过鱼设施设计和鱼类游泳行为学研究提供基础参数,本研究以木扎提河野生斑重唇鱼(全长TL=12～16 cm)为研究对象,测定了其在(16.6±1.6)℃水温下的感应流速、临界游泳速度、爆发游泳速度及持续与耐久游泳能力。结果显示,斑重唇鱼感应流速为(0.18±0.02)m/s,相对感应流速为(1.40±0.23) BL/s (BL为体长);临界游泳速度为(1.02±0.15) m/s,相对临界游泳速度为(8.58±1.65) BL/s;爆发游泳速度为(1.39±0.17) m/s,相对爆发游泳速度为(10.92±1.86) BL/s;最大持续游泳速度为0.87 m/s,最大耐久游泳速度为1.37 m/s,与平均爆发游泳速度相近。其持续游泳时间与流速呈负相关(l g T=?5:136X+8:504)。当以斑重唇鱼为主要过鱼对象时,建议为吸引鱼类进入鱼道,进口流速设计为1.02～1.39 m/s,休息池主流设计为0.20～1.02 m/s,鱼道竖缝处流速宜低于0.85 m/s。鱼道长度为1 000 m时,鱼道内平均水流速度应低于0.78m/s。本研究结果可为新疆木扎...