意大利蜜蜂蜂王与工蜂幼虫甲基供体S-腺苷甲硫氨酸合成与代谢的差异

【目的】研究意大利蜜蜂(Apis mellifera ligustica)蜂王与工蜂幼虫甲基供体S-腺苷甲硫氨酸(S-adenosylmethionine,SAM)合成与代谢的差异,为探索DNA甲基化与蜜蜂级型分化的关系提供理论依据。【方法】试验选用890只1日龄雌性蜂幼虫,分别来自5群姐妹蜂王群。其中445只进行人工育王(89只/群);剩余445只培育成工蜂(89只/群)。取3、4、5日龄蜂王和工蜂幼虫,测定其体内SAM合成与代谢关键酶基因表达和酶活性的差异。【结果】蜂王幼虫SAM含量随日龄的增加变化不显著(P0.05);工蜂幼虫SAM含量随日龄增加呈上升趋势(P0.05)。蜂王幼虫SAMS基因表达量随日龄增加呈梯度下降的趋势(P0.01),而工蜂幼虫SAMS表达随日龄变化不显著(P0.05);3日龄与4日龄时,蜂王幼虫SAMS表达量显著高于工蜂(P0.05),5日龄时,工蜂幼虫SAMS表达量显著高于蜂王(P0.05)。Dnmt1a与Dnmt3表达在两级型间差异不显著(P0.05),其中蜂王幼虫Dnmt1a表达随日龄增加无显著变化(P0.05),但其酶活性呈下降趋势(P0.05);工蜂幼虫Dnmt1a表达随日龄增加呈下降趋势(P0.05),其酶活性呈上升趋势(P0.01),其中3日龄与4日龄时,蜂王幼虫Dnmt1酶活性显著高于工蜂幼虫(P0.05),而5日龄时,工蜂幼虫Dnmt1酶活性显著高于蜂王幼虫(P0.05)。蜂王Dnmt3表达量随日龄增加呈下降趋势(P0.05),工蜂幼虫Dnmt3表达随日龄增加变化不显著(P0.05);蜂王幼虫Dnmt3酶活性随日龄变化不显著(P0.05),工蜂幼虫Dnmt3酶活性随日龄变化显著(P0.05),但蜂王幼虫Dnmt3酶活性在3、4、5日龄均显著高于工蜂幼虫(P0.01)。【结论】3—5日龄意大利蜜蜂蜂王幼虫与工蜂幼虫体内活性甲基供体SAM的合成与代谢存在差异。在4日龄之前,蜂王幼虫SAM的合成比工蜂活跃,4日龄之后,工蜂幼虫的SAM合成与蜂王幼虫相近;在4日龄之前,SAM参与DNA维持甲基化的代谢过程,蜂王幼虫比工蜂活跃,4日龄之后,工蜂幼虫比蜂王幼虫活跃;在3—5日龄,SAM参与DNA从头甲基化的代谢活性,蜂王幼虫始终不低于工蜂幼虫。     

RAPD分子标记在蜜蜂遗传育种中的应用

RAPD分子标记在蜜蜂遗传育种中得到较广泛应用 .利用 RAPD分子遗传标记 ,估测蜜蜂性别决定位点 (x)与低幼虫存活率位点的标记序列位置 (STS)之间的遗传距离为 1 .6c M;构建了蜜蜂 (Apismellifera)遗传连锁图 ,确定了蜜蜂性基因位点 (x)、黑色体色基因位点 (blk)、苹果酸脱氢酶 (Mdh-1 )位点分别位于第 3、6、1 8个连锁群 ;确定了影响蜜蜂采粉、报警信息素水平、螫刺行为和体长等数量性状的基因座位 ;筛选出 5种引物 ,这些引物所扩增的 RAPD标记可作为鉴别欧洲蜜蜂和非洲蜜蜂 (A. mellifera L.)的分子标记 .蜜蜂高产性状 RAPD标记的研究已取得一定进展     

蜂群中饲喂蜂王的工蜂亚家庭组成分析

蜜蜂是一种资源共享性强、社会分工精确度高且信息交流高度结构化的社会性群体。蜂群中,蜂王的交配方式是"一雌多雄",因此蜂群是由多个"同母异父"的亚家庭组成。研究表明,蜂群内这种"同母异父"的亚家庭结构,可以显著影响蜜蜂内在的部分社会分工。本研究以西方蜜蜂(Apis mellifera L.)为实验材料,从3群自然蜂群中各取样94只饲喂蜂王的工蜂和原蜂王,利用4对微卫星引物对样本进行个体基因型分析。分析得出了亚家庭总数分别为13、13和21的3群蜂群,结果表明:饲喂蜂王的工蜂的亚家庭组成并无亚家庭专属现象,即蜂王会接受各个亚家庭的适龄工蜂的饲喂。     

Methylation of tRNAAsp by the DNA methyltransferase homolog Dnmt2

The sequence and the structure of DNA methyltransferase-2 (Dnmt2) bear close affinities to authentic DNA cytosine methyltransferases. A combined genetic and biochemical approach revealed that human DNMT2 did not methylate DNA but instead methylated a small RNA; mass spectrometry showed that this RNA is aspartic acid transfer RNA (tRNA(Asp)) and that DNMT2 specifically methylated cytosine 38 in the anticodon loop. The function of DNMT2 is highly conserved, and human DNMT2 protein restored methylation in vitro to tRNA(Asp) from Dnmt2-deficient strains of mouse, Arabidopsis thaliana, and Drosophila melanogaster in a manner that was dependent on preexisting patterns of modified nucleosides. Indirect sequence recognition is also a feature of eukaryotic DNA methyltransferases, which may have arisen from a Dnmt2-like RNA methyltransferase.     

Epigenetic reprogramming in mammalian development

DNA methylation is a major epigenetic modification of the genome that regulates crucial aspects of its function. Genomic methylation patterns in somatic differentiated cells are generally stable and heritable. However, in mammals there are at least two developmental periods-in germ cells and in preimplantation embryos-in which methylation patterns are reprogrammed genome wide, generating cells with a broad developmental potential. Epigenetic reprogramming in germ cells is critical for imprinting; reprogramming in early embryos also affects imprinting. Reprogramming is likely to have a crucial role in establishing nuclear totipotency in normal development and in cloned animals, and in the erasure of acquired epigenetic information. A role of reprogramming in stem cell differentiation is also envisaged. DNA methylation is one of the best-studied epigenetic modifications of DNA in all unicellular and multicellular organisms. In mammals and other vertebrates, methylation occurs predominantly at the symmetrical dinucleotide CpG (1-4). Symmetrical methylation and the discovery of a DNA methyltransferase that prefers a hemimethylated substrate, Dnmt1 (4), suggested a mechanism by which specific patterns of methylation in the genome could be maintained. Patterns imposed on the genome at defined developmental time points in precursor cells could be maintained by Dnmt1, and would lead to predetermined programs of gene expression during development in descendants of the precursor cells (5, 6). This provided a means to explain how patterns of differentiation could be maintained by populations of cells. In addition, specific demethylation events in differentiated tissues could then lead to further changes in gene expression as needed. Neat and convincing as this model is, it is still largely unsubstantiated. While effects of methylation on expression of specific genes, particularly imprinted ones (7) and some retrotransposons (8), have been demonstrated in vivo, it is still unclear whether or not methylation is involved in the control of gene expression during normal development (9-13). Although enzymes have been identified that can methylate DNA de novo (Dnmt3a and Dnmt3b) (14), it is unknown how specific patterns of methylation are established in the genome. Mechanisms for active demethylation have been suggested, but no enzymes have been identified that carry out this function in vivo (15-17). Genomewide alterations in methylation-brought about, for example, by knockouts of the methylase genes-result in embryo lethality or developmental defects, but the basis for abnormal development still remains to be discovered (7, 14). What is clear, however, is that in mammals there are developmental periods of genomewide reprogramming of methylation patterns in vivo. Typically, a substantial part of the genome is demethylated, and after some time remethylated, in a cell- or tissue-specific pattern. The developmental dynamics of these reprogramming events, as well as some of the enzymatic mechanisms involved and the biological purposes, are beginning to be understood. Here we look at what is known about reprogramming in mammals and discuss how it might relate to developmental potency and imprinting.     

印迹基因Igf2r的甲基化进程与兔卵母细胞直径关系的研究

本研究以3～4月龄兔为研究对象,收集卵母细胞,按直径将其划分为75～95μm、95～105μm、105～115μm3个组,通过亚硫酸盐测序法检测了印迹基因Igf2r的甲基化程度,并运用RT-PCR对Dnmt1、Dnmt3a、Dnmt3b、Dnmt3l、Lsh的表达量进行检测。结果表明,在3组卵母细胞内,Igf2r的甲基化比率依次为15.7%、60%、91.5%,甲基化程度随卵母细胞直径的增加而不断提高。     

Nutritional control of reproductive status in honeybees via DNA methylation

Fertile queens and sterile workers are alternative forms of the adult female honeybee that develop from genetically identical larvae following differential feeding with royal jelly. We show that silencing the expression of DNA methyltransferase Dnmt3, a key driver of epigenetic global reprogramming, in newly hatched larvae led to a royal jelly-like effect on the larval developmental trajectory; the majority of Dnmt3 small interfering RNA-treated individuals emerged as queens with fully developed ovaries. Our results suggest that DNA methylation in Apis is used for storing epigenetic information, that the use of that information can be differentially altered by nutritional input, and that the flexibility of epigenetic modifications underpins, profound shifts in developmental fates, with massive implications for reproductive and behavioral status.     

我国蜂蜜生产现状及国内外市场形势分析

【目的】调查我国蜂蜜生产现状及国内外市场蜂蜜国内外市场形势,为我国蜂产业健康发展提供参考。【方法】依据FAO、国家统计局和中国海关相关蜂群和蜂蜜统计数据,整理分析了1978—2019年我国蜂群数量、蜂蜜产量和产区、蜂蜜进出口贸易和居民消费水平的发展趋势,掌握我国蜂蜜生产现状及进出口贸易等情况,并分析存在问题。【结果】1978—2019年我国蜂群数量、蜂蜜产量和蜂蜜平均每群产量总体均呈上升趋势,其年均增长率分别为1.85%、4.44%和2.54%。我国蜂蜜产量地区分布不平衡,主要分布在华东地区、华中地区和西南地区,其中,浙江、河南和四川的蜂蜜产量在全国处于领先地位,2019年这3个省份蜂蜜产量占全国蜂蜜产量的40.72%。1978—2019年,我国蜂蜜出口量及其占全球蜂蜜出口量比例波动较大,蜂蜜出口显示性比较优势指数总体呈显著下降趋势,国际竞争力逐渐降低,且出口市场太过依赖于欧盟和日本,其他国际市场有待开发。我国蜂蜜进口量在我国蜂蜜消费中所占比例较低,人均蜂蜜表观消费量相对较低,基本维持在240 g左右,与发达国家相比还存在很大差距。目前,我国蜂产业还存在以下问题行业不受重视,从业人员少且生产落后,蜜粉资源开发力度不够,养蜂生产形式单一;蜂蜜生产缺乏统一的行业标准,蜂蜜品质低;蜂蜜国内外市场开发力度不够,国际竞争力较低。【建议】呼吁政府加大对养蜂业的重视和建设力度,社会各界共同探索发展现代化养蜂的新模式;应加强蜂蜜市场监督力度,树立行业标准,提高产品质量,促进蜂蜜产业良性发展;改变固有经营模式,创新经营机制,拓展国际国内两个市场;转变我国传统的养蜂观念,促进蜂产业向多元化方向发展。     

营养因素影响蜜蜂级型分化的研究进展

从营养元素方面综述蜜蜂级型分化的研究进展,介绍蜂王浆中10-HDA、Royalactin,蜂粮中相关MicroRNA对蜜蜂级型分化的影响,并展望今后蜜蜂级型分化分子机制的研究方向。     

Competitive interactions between neotropical pollinators and africanized honey bees

The Africanized honey bee, a hybrid of European and African honey bees, is thought to displace native pollinators. After experimental introduction of Africanized honey bee hives near flowers, stingless bees became less abundant or harvested-less resource as visitation by Africanized honey bees increased. Shifts in resource use caused by colonizing Africanized honey bees may lead to population decline of Neotropical pollinators.     

Global honey bee viral landscape altered by a parasitic mite

Emerging diseases are among the greatest threats to honey bees. Unfortunately, where and when an emerging disease will appear are almost impossible to predict. The arrival of the parasitic Varroa mite into the Hawaiian honey bee population allowed us to investigate changes in the prevalence, load, and strain diversity of honey bee viruses. The mite increased the prevalence of a single viral species, deformed wing virus (DWV), from ~10 to 100% within honey bee populations, which was accompanied by a millionfold increase in viral titer and a massive reduction in DWV diversity, leading to the predominance of a single DWV strain. Therefore, the global spread of Varroa has selected DWV variants that have emerged to allow it to become one of the most widely distributed and contagious insect viruses on the planet.     

蜂花粉、蜂胶、蜂王浆、蜂蜜抗氧化作用的研究

[目的]比较蜂蜜、蜂王浆、蜂胶、蜂花粉的抗氧化效果,为其今后在抗氧化方面的应用提供理论依据,并指导人们正确地选择具有抗氧化活性的蜂产品。[方法]以蜂花粉、蜂胶、蜂王浆和蜂蜜为材料,采用Schaa烘箱法和羟自由基清除法测定4种蜂产品的抗氧化活性。[结果]4种蜂产品均具有较强的抗氧化作用。随着时间的延长,它们的POV值升高,在36 h内表现出较好的抑制油脂氧化的效应,其中蜂胶、蜂王浆和蜂花粉的抗氧化效果优于蜂蜜。在一定时间内,蜂花粉、蜂胶、蜂王浆、蜂蜜均能抑制大豆油的氧化,对羟基自由基的清除率分别为:65.93%、82.08%2、6.95%、27.20%。[结论]蜂花粉、蜂胶、蜂王浆和蜂蜜能够清除体内过多的自由基,降低过氧化脂质的生成,是很好的抗氧化产品。     

Chinese Honey Positioning and Price Trend in Domestic Market

China's bee industry is a small proportion of domestic agriculture with fewer farmers, and the government didn't attach much attention to or give supports to it. Agricultural production sector does not fully recognize the economic value of honeybee pollination. Chinese beekeepers gain profits only from products such as honey, royal jelly and bee pollen. Because of the production mode that aims at gathering and producing more honey while neglecting the health care of bees and the quality of products; export enterprises lack guidance and knowledge in export inspection and quarantine and technical regulations, and thus, the average price of China's bee honey exports is much lower than that of other countries in the world. Meanwhile, in domestic market, given the sustained development of China's macro economy and increasing incomes of residents, people show increasing interests in the health care function of honey. Based on the survey data of honey market in Beijing, Hangzhou, Qingdao, Zhengzhou and Chengdu from 2012 to 2015, the paper analyzes the price feature of China's honey market and its formulation basis, and also compares prices of honey with the same quality in different markets. Moreover, the paper combines data from fixed observation places of honey products production, which is carried out by the economic research group of bee industry in 11 provinces, to discuss reasons for continuous honey price rising in domestic market. Lastly, the paper uses the honey as an example to analyze pricing strategy of agricultural products with health care functions. The paper hold the opinions that the keys to solve the problem that high quality agricultural material couldn't sell in high price and good and bad are mixed in the market, is to build up quality and price mechanism in the processing of raw material purchasing to the terminal market, publicize more products information and superior customer attractiveness on health care effect.     

蜂产业主要害螨种类及贵州蜜蜂资源保护探讨

狄斯瓦螨Varroa destructor是蜂蜜生产重要的害螨,其防治一直是无公害蜂蜜产业的难题。贵州省蜂蜜产业规模大,意大利蜜蜂饲养占一定比例,而其害螨研究报道较少。论文总结了蜜蜂主要相关螨类的种类主要研究现状,总结出防治害螨是蜜蜂驯化种群科学管理和蜜蜂野生种群保护的关键因素,以期为贵州省蜂蜜产业和蜜蜂保护提供资料。     

Wasp gene expression supports an evolutionary link between maternal behavior and eusociality

The presence of workers that forgo reproduction and care for their siblings is a defining feature of eusociality and a major challenge for evolutionary theory. It has been proposed that worker behavior evolved from maternal care behavior. We explored this idea by studying gene expression in the primitively eusocial wasp Polistes metricus. Because little genomic information existed for this species, we used 454 sequencing to generate 391,157 brain complementary DNA reads, resulting in robust hits to 3017 genes from the honey bee genome, from which we identified and assayed orthologs of 32 honey bee behaviorally related genes. Wasp brain gene expression in workers was more similar to that in foundresses, which show maternal care, than to that in queens and gynes, which do not. Insulin-related genes were among the differentially regulated genes, suggesting that the evolution of eusociality involved major nutritional and reproductive pathways.     

贵州仁怀斯氏蜜蜂茧蜂研究

调查发现,在贵州仁怀野外常有斯氏蜜蜂茧蜂快速攻击野生和家养中蜂,并在中蜂体内产卵,中蜂返巢后,体内已有斯氏蜜蜂茧蜂的卵.观察发现,斯氏蜜蜂茧蜂可在野生和家养中蜂巢内完成世代发育.对贵州仁怀斯氏蜜蜂茧蜂(标本)与印度产斯氏蜜蜂茧蜂(电镜照片)形态进行比较,发现并无形态上的差异.由于中蜂起源于中国西南地区,估计印度北部的斯...     

吡虫啉不同剂型对蜜蜂的急性毒性

以成年意大利工蜂(Apis mellifera L.)为受试生物,研究了吡虫啉原药及其不同制剂对蜜蜂的急性经口和接触性毒性。结果表明:在急性经口试验中,48 h的LD50值在1.60×10~(-2)到0.805μg a.i./蜂之间,以20%吡虫啉微乳剂的毒性最强,600 g/L吡虫啉悬浮种衣剂的毒性最弱,最强毒性是最弱毒性的50.31倍;在急性接触试验中,48 h的LD_(50)值在2.10×10~(-2)到0.225μg a.i./蜂之间,以2.15%吡虫啉饵剂的毒性最强,600 g/L吡虫啉悬浮种衣剂的毒性最弱,最强毒性是最弱毒性的10.71倍。吡虫啉各剂型间毒性差异不显著,对蜜蜂均表现为高毒。     

甘肃河西蜜蜂就地室外越冬的研究

连续四年蜜蜂就地室外越冬的试验研究表明:只要王好、群强、蜜足、安静,适时喂越冬饲料,适时适当的内外包装,蜜蜂就地室外越冬是成功的。损失率和下降率可以分别控制在10％和30％左右。3月下旬开始繁蜂,能达到及时授粉的要求。每群收蜜35—40公斤,繁蜂1:10—15倍(以脾计)。同时获得了投资少,成本低,方法简便易行,经济效益显著的效果。     

蜂蜜孢粉学的研究与应用

 蜂蜜孢粉学是研究蜂蜜中花粉的科学，研究方法从整体封片法、醋酸酐分解法发展到追踪孢子法。花粉是天然蜂蜜的重要标志，蜂蜜中的花粉主要来自于蜜蜂采集花蜜时吸入的花粉。因为蜜蜂的前胃能快速有效地过滤掉花蜜中的花粉，蜂蜜中花粉的比例并不总代表其中的花蜜比例。为了测定蜜蜂采集的花蜜中的原始的花粉比例，发展了相应的花粉系数。蜂蜜孢粉学主要应用于鉴定蜂蜜的植物来源和地域来源，也有助于有毒蜜的鉴别和蜜蜂种间竞争的研究。