动物生物钟基因研究进展

昼夜节律生物钟是一种以近似24小时为周期的自主维持的振荡器,由输人通路、中央振荡器和输出通路三部分组成的。生物钟机制的研究已深入到分子水平。生物钟相关基因相继被分离鉴定,它们及其编码的蛋白质产物构成的自主调节的转录和翻译反馈环是生物钟运转的分子机制。本文介绍了果蝇和小鼠主要生物钟基因的发现以及其突变体对生物昼夜节律的影响,展望了揭示生物钟调节机制在遗传学上的重要意义。     

植物开花光周期反应的分子调控机制

植物开花时间受到日照长短季节性变化的调节,拟南芥和水稻中与光周期反应相关基因的分离,使人们得以认识植物开花光周期反应的分子调控机制。植物感知日照长短的变化主要由CONSTANS(CO)基因的表达所控制。CO能够将光信号与生物钟信号整合,调节开花基因FLOWERING LOCUS T(FT)的表达,并最终控制植物的开花时间。本文对这一研究的最新进展进行了综述。     

投喂节律对异育银鲫氮收支的影响

在水温(28±1)℃、自然光照条件下,以4种投喂节律饲养异育银鲫(Carassius auratus gibelio)60d,并测定异育银鲫氮的收支。其中对照组为每天投喂,3个试验组分别为投喂1d后饥饿1d、投喂2d后饥饿1d、投喂4d后饥饿1d。结果显示,3个试验组的摄食氮(mg/(g.d))显著高于对照组;以占摄食氮比例来观察,试验组的氮收支模式与对照组差异显著(P<0.05);以占吸收氮比例来观察,4组模式无显著差异。     

新生犊牛某些营养代谢成分和激素水平昼夜动态变化规律的研究

研究６头健康新生犊牛３日龄和１０日龄时血液营养代谢成分和激素水平的昼夜动态变化结果表明：血糖（Ｇｌｕ）的平均水平夜间较昼间高．进食后血糖明显升高，１０日龄较３日龄时进食反应显著；α－氨基氮（α－ＮＨ２．Ｎ）昼夜间差别不大，进食后．先稍降．而后升高；胰岛素（Ｉｎｓ）夜间高于昼间．进食可引起Ｉｎｓ升高，其升高程度随日龄增长明显加强；胰高血糖素（ＧＣ）清晨至中午分泌水平较低．至夜晚２０：００－２２：００时出现分泌高峰；皮质醇（Ｃｏｒｔ）分泌峰值出现在午夜至凌晨，随年龄增长．有后移的趋势；生长激素（ＧＨ）夜间较昼间高，在凌晨０２：００－０６：００时出现连续性分泌高峰。说明犊牛在生后３日龄时某些生理节律性已建立，而且呈现一定的年龄性变化规律。     

乌桕1年生播种苗生长规律

播种试验,对乌桕1年生播种苗的苗高、地径和生物量生长规律进行了研究。结果表明,乌桕1年生幼苗苗高与地径生长均符合S形生长曲线,可用Logistic方程来拟合;采用有序样本聚类分析法把乌桕幼苗生长期划分为4个阶段,即出苗期(4月20日以前)、生长初期(4月21日—6月15日)、生长盛期(6月16日—8月15日)和生长后期(8月16日—10月30日),其中,生长盛期的高生长量占全年高生长量的57.76%;单株生物量动态分析表明,7—8月份是乌桕个体生物量增加的关键期,且生长停止后,1年生幼苗茎的生物量在单株总生物量中所占的比例最大。     

北京地区泌乳牛夏季鼓膜温度昼夜节律及影响因素研究

【目的】 试验旨在揭示北京地区荷斯坦泌乳牛鼓膜温度的群体特征及其随昼夜和环境温湿度指数（temperature-humidity index,THI）的变化规律,探究中度热应激下泌乳牛鼓膜温度的影响因素及其与直肠温度的关系。【方法】 2021年8月对北京地区某规模化牧场638头荷斯坦泌乳牛的鼓膜温度、直肠温度及环境温湿度进行测定,并对其进行描述性统计;对161头荷斯坦泌乳牛6 h鼓膜温度和直肠温度进行相关性分析;利用混合线性模型分析THI、测定时间、胎次、泌乳阶段和繁殖状态等因素对鼓膜温度和直肠温度的影响。【结果】 北京地区荷斯坦泌乳牛夏季鼓膜平均温度为（39.01±0.40）℃;测定时间内THI为76.11~83.18,此时泌乳牛处于中度热应激。泌乳牛鼓膜温度昼夜变化较大,昼夜节律表现为上午低、下午和傍晚均较高且在早晨和下午出现不正常峰值,鼓膜温度的变化滞后于THI变化。鼓膜温度与直肠温度呈显著正相关关系（P<0.05,r＝0.35）,且两种体温均随着THI的升高而升高,回归系数分别为0.09（P<0.05,R²=0.09）和0.10（P<0.05,R²=0.08）。测定时间和胎次对泌乳牛鼓膜温度有显著影响（P<0.05）,胎次和泌乳阶段对泌乳牛直肠温度有显著影响（P<0.05）,且THI对两部位温度的回归均显著（P<0.05）。【结论】 本研究揭示了奶牛体温的节律变化和影响因素,鼓膜温度可有效反映奶牛实时体温,可为精细化管理牛群提供理论依据。     

Saliva chromogranin A in growing pigs: A study of circadian patterns during daytime and stability under different storage conditions

Salivary chromogranin A (CgA) is considered to be a biomarker of activation of the sympatho-adrenomedullary system, and has recently been proposed as a useful indicator of the acute stress response in pigs. The aim of the present study was to determinate whether salivary CgA concentrations in healthy growing pigs exhibits any circadian pattern during the daytime, and to evaluate its stability under different storage conditions. A total of 80 pigs (40 in spring and another 40 in autumn) of two different ages and genders were used. To establish the circadian pattern, saliva samples were collected at 07.00, 11.00, 15.00 and 19.00 h on two consecutive days. Pooled samples were used for the stability study and were measured on the day of sampling and periodically for up to 360 days later. Samples were stored at 4 °C, ?20 °C or ?80 °C and the effect of repeated freezing and thawing was also evaluated.No circadian pattern was detected for salivary CgA in either season and there were no significant effects of gender or age. However, mean salivary CgA concentrations were significantly higher (P < 0.0001) in the pigs sampled in autumn, compared to those sampled in the spring. Short term storage at 4 °C is recommended for up to 2 days, whereas frozen samples can be stored for 1 year at ?20 °C or ?80 °C, without substantial reduction in CgA values. In addition, samples can be frozen and thawed up to seven times without significant loss of the biomarker.     

枣粘虫性行为时辰节律的研究

本文利用腺体提取、瓶内收集、触角电位和田间试验等方法对枣粘虫产生和释放性信息素时辰节律进行了研究。其中瓶内收集性信息素的方法,在研究昆虫释放性信息素时辰节律方面报道很少,更重要的是,此法在我们的实验中取得了比较满意的效果。研究结果表明:(1)羽化后1—6天的提取物产生的触角电位无明显差异,说明性信息素在此期间的产生与日龄无关(2)腺体中性信息素的含量高峰在凌晨4点,而从体内往体外释放的高峰在早晨7点。(3)利用处女雌蛾不同时辰的诱蛾量的田间试验也进一步证明了枣粘虫产生和释放性信息素与交配行为在时辰节律上的同步性。     

Internal regulation of reproduction seasonality in earthworm Dendrobaena octaedra (Savigny, 1826) (Lumbricidae, Oligochaeta)

The study was conducted on Dendrobaena octaedra—a small epigeic earthworm species common in different forest types. In the laboratory the P (parent animals collected in forest) and F1 generations were cultured separately in containers filled with 50 g artificial soil. The containers were kept at 15±0.5 °C, 80% humidity and constant artificial light of low intensity. Every month during the 47 months of culture, the animals and cocoons were removed from the soil by washing on a sieve, weighed, and replaced into new soil. Individuals of the F1 generation did not reproduce continuously. Cocoon production was seasonal, despite culture in constant conditions throughout the whole experiment. Reproduction was highest in spring and summer, and dropped in the winter months. Seasonality characterized the fraction of animals reproducing as well as the number of cocoons produced. The observed seasonal changes in the cocoon production of the F1 generation cultured in constant conditions suggest that internal regulation of reproduction may exist in the earthworm D. octaedra. External factors like temperature, moisture, photoperiod or food supply, which could be responsible for seasonality of reproduction were missing.     

Circadian protein Cry2 is a prognostic factor of colorectal cancer and a predictor of chemotherapy

AIM:To assess the association between the expression of Cry2 and the prognosis of colorectal cancer for determining the role of Cry2 in predicting the outcome of chemotherapy. METHODS:Sixteen primary colorectal cancer patients who consecutively underwent neoadjuvant chemotherapy with 5-fluorouracil were enrolled in the present study. The tumor specimens were obtained by colonscopy prior to treatment. The tumor response was evaluated by the response evaluation criteria in solid tumors(RECIST). Accordingly, the patients were divided into 2 groups:complete response(CR)/partial response(PR) and stable disease(SD)/progress disease(PD). Two-tail ² test was applied to analyze the data. In parallel, we assessed 307 patients, who underwent tumor resection between 2001 and 2005. Survival time was calculated from the date of surgery to the date of death or the last follow-up date. Survival curves were obtained by Kaplan-Meier method. Log-rank test was applied for univariate analysis. The Cox proportional hazards regression model was used to identify the independent prognostic factors. RESULTS:The expression of Cry2 was high in CR/PR patients and was low in SD/PD patients, with significant difference(P<0.05). The average survival time of the 84 patients with high expression of Cry2 was 83.458 months, while the average survival time of 223 patients with low expression of Cry2 was 100.10 months, also with significant difference(P<0.05). The patients with low expression of Cry2 lived longer. The multivariate Cox regression analysis indicated that the expression of Cry2 was an independent prognostic factor for colorectal cancer patients(HR was 1.70, 95% CI was 1.09 to 2.66, P<0.05). Multivariate Cox regression showed that high Cry2 expression predicted a worse prognosis(HR was 2.88, 95%CI was 1.03 to 8.06, P<0.05) in colorectal cancer patients with neoadjuvant chemotherapy. CONCLUSION:Expression of Cry2 is an independent prognostic factor for colorectal cancer patients. Lower expression of Cry2 indicates good response to neoadjuvant chemotherapy.