Complex social behaviour derived from maternal reproductive traits

A fundamental goal of sociobiology is to explain how complex social behaviour evolves, especially in social insects, the exemplars of social living. Although still the subject of much controversy, recent theoretical explanations have focused on the evolutionary origins of worker behaviour (assistance from daughters that remain in the nest and help their mother to reproduce) through expression of maternal care behaviour towards siblings. A key prediction of this evolutionary model is that traits involved in maternal care have been co-opted through heterochronous expression of maternal genes to result in sib-care, the hallmark of highly evolved social life in insects. A coupling of maternal behaviour to reproductive status evolved in solitary insects, and was a ready substrate for the evolution of worker-containing societies. Here we show that division of foraging labour among worker honey bees (Apis mellifera) is linked to the reproductive status of facultatively sterile females. We thereby identify the evolutionary origin of a widely expressed social-insect behavioural syndrome, and provide a direct demonstration of how variation in maternal reproductive traits gives rise to complex social behaviour in non-reproductive helpers.     

4种昆虫基因组中的线粒体假基因

为了进一步了解昆虫核基因组中线粒体假基因(Numts)序列分布情况,避免Numts序列对基于线粒体DNA(mtDNA)进行系统发育关系研究结果的误导,利用Blast N对GenBank中已完成核基因组和mtDNA测序的4种昆虫核基因组中的Numts序列进行检索,结果表明:冈比亚按蚊Anopheles gambiae中没有Numts序列;黑腹果蝇Drosophila melanogaster中仅有少量Numts序列;赤拟谷盗Tribolium castaneum和意大利蜜蜂Apis melliera基因组中Numts序列超过100条,尤其是意大利蜜蜂中的Numts序列涵盖全部mtDNA.ND2,ND4,ND5,COⅠ与lrRNA向核内转移频率高于其他mtDNA基因片段,因此,在使用其进行系统发育关系研究时需加倍谨慎.     

Apis mellifera capensis蜜蜂失控自复制导致的正常群落破坏

提出对Apis mellifera capensis蜂造成Apis mellifera scutellata蜂群破坏的机制的一种新猜测，并根据logistic模型分别讨论这种猜测和已有的MARTIN猜测所导致的不同性质和规律，对2种猜测进行了比较．加强对社会成员之间信息网络的管理和监督，这也许是更加有效地防止破坏性子群体泛滥的途径．     

含毒死蜱有效成分的杀虫剂对意大利蜂(Apis mellifera L.)的经口毒性

采用摄入法在室内测定了7种含有毒死蜱有效成分的杀虫剂对成年意大利蜂的急性经口毒性.结果表明:所测定的7种杀虫剂对成年意大利的急性经口毒性均为高毒;毒力由高到低的顺序是:10％阿维·毒死蜱乳油＞12％高氯·毒死蜱乳油＞50％毒死蜱微乳剂＞30％甲维·毒死蜱乳油＞30％毒死蜱·三唑磷乳油＞20％毒死蜱·氟铃脲乳油＞22％吡虫·毒死蜱乳油.另外,22％吡虫·毒死蜱乳油对供试蜜蜂24h和48h的致死作用存在明显的差异,其24h LC50值约是48h LC50值的12.6倍.     

Parasitic Cape honeybee workers, Apis mellifera capensis, evade policing.

Relocation of the Cape honeybee, Apis mellifera capensis, by bee-keepers from southern to northern South Africa in 1990 has caused widespread death of managed African honeybee, A. m. scutellata, colonies. Apis mellifera capensis worker bees are able to lay diploid, female eggs without mating by means of automictic thelytoky (meiosis followed by fusion of two meiotic products to restore egg diploidy), whereas workers of other honeybee subspecies are able to lay only haploid, male eggs. The A. m. capensis workers, which are parasitizing and killing A. m. scutellata colonies in northern South Africa, are the asexual offspring of a single, original worker in which the small amount of genetic variation observed is due to crossing over during meiosis (P. Kryger, personal communication). Here we elucidate two principal mechanisms underlying this parasitism. Parasitic A. m. capensis workers activate their ovaries in host colonies that have a queen present (queenright colonies), and they lay eggs that evade being killed by other workers (worker policing)-the normal fate of worker-laid eggs in colonies with a queen. This unique parasitism by workers is an instance in which a society is unable to control the selfish actions of its members.     

Evolution of genes and genomes on the Drosophila phylogeny

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.     

Complex evolutionary history of the vertebrate sweet/umami taste receptor genes

Adaptive evolution plays a role in the functional divergence and specialization of taste receptors and the sense of taste is thought to be closely related to feeding ecology.To examine whether feeding ecology has shaped the evolution of taste receptor genes in vertebrates,we here focus on Tas1r gene family that encodes umami(Tas1r1 and Tas1r3 heterodimer) and sweet(Tas1r2 and Tas1r3 heterodimer) taste receptors.By searching currently available genome sequences in 48 vertebrates that contain 38 mammals,1 reptile,3 birds,1 frog,and 5 fishes,we found all three members of Tas1rs are intact in most species,suggesting umami and sweet tastes are maintained in most vertebrates.Interestingly,the absence and pseudogenization of Tas1rs were also discovered in a number of species with diverse feeding preferences and distinct phylogenetic positions,indicating widespread losses of umami and/or sweet tastes in these animals,irrespective of their diet.Together with previous findings showing losses of tastes in other vertebrates,we failed to identify common dietary factors that could result in the taste losses.Our results report here suggest the evolution of Tas1rs is more complex than we previously appreciated and highlight the caveat of analyzing sequences predicted from draft genome sequences.Future work for a better understanding of taste receptor function would help uncover what ecological factors have driven the evolution history of Tas1rs in vertebrates.     

Entomology: Asian honeybees parasitize the future dead

The queen of a honeybee colony has a reproductive monopoly because her workers' ovaries are normally inactive and any eggs that they do lay are eaten by their fellow workers. But if a colony becomes queenless, the workers start to lay eggs, stop policing and rear a last batch of males before the colony finally dies out. Here we show that workers of the Asian dwarf red honeybee Apis florea from other colonies exploit this interval as an opportunity to move in and lay their own eggs while no policing is in force. Such parasitism of queenless colonies does not occur in the western honeybee A. mellifera and may be facilitated by the accessibility of A. florea nests, which are built out in the open.     

紫藤传粉昆虫与花粉多型性研究

定位观测了紫藤的访花昆虫种类及觅食行为,用扫描电镜观察了花粉形态。结果表明：紫藤的主要访花昆虫为膜翅目的黄胸木蜂和意大利蜂,两者都有传粉行为,属传粉者。意大利蜂除有传粉行为外还有偷蜜行为。花粉在形态上表现出多型性：长球形（赤道观长椭圆形,极面观近三裂圆形）,三孔沟;三菱锥形（赤道观近三角形,极面观近三角形）,六孔沟;赤道观近三角形,极面观近菱形,四孔沟。外壁纹饰均为橘皮状。     

The bonobo genome compared with the chimpanzee and human genomes

Two African apes are the closest living relatives of humans: the chimpanzee (Pan troglodytes) and the bonobo (Pan paniscus). Although they are similar in many respects, bonobos and chimpanzees differ strikingly in key social and sexual behaviours, and for some of these traits they show more similarity with humans than with each other. Here we report the sequencing and assembly of the bonobo genome to study its evolutionary relationship with the chimpanzee and human genomes. We find that more than three per cent of the human genome is more closely related to either the bonobo or the chimpanzee genome than these are to each other. These regions allow various aspects of the ancestry of the two ape species to be reconstructed. In addition, many of the regions that overlap genes may eventually help us understand the genetic basis of phenotypes that humans share with one of the two apes to the exclusion of the other.     

Enantioselectivity of the Musk Odor Sensation

1 Introduction Chiral recognition of substrates is one of the most characteristic phenomena of biological activity. And one of the most fundamental biological activities of chemical substances is their smell. In 1991, Linda Buck and Richard Axel~([1]) discovered a large multigene family that en codes odorant receptors, for which they were awarded the 2004 Nobel Prize in Medicine and Physiology. These odorant receptors are highly homologous, consist of ca. 320 amino acids, and show a heptah…     

The recent disciplinal progresses of agricultural entomology in China

In this paper, four recent advances and achievements of China in agricultural insect research, namely, on the genome of silkworm （Bombyx mori Linnaeus）, on the geographical differentiation and regional migration of cotton bollworm （Helicoverpa armigera （Hübner））, on the standardized monitoring techniques for safety of honey bee （Apis mellifera Linnaeus） products, and on the virus transmission property of small brown planthopper （Laodelphax striatellus （Fallén）） as well as the interactions between vector and rice stripe virus （RSV）, were reported. All of these researches are very important for controlling agricultural insect pests and the diseases they transmit, accelerating the molecular biological research of silkworm, and promoting the international trade of honey bee products. Most of these achievements mentioned above have got the national, provincial, ministerial or municipal awards on science and technology.     

球状轮藻叶绿体全基因组的组装与特征分析

为揭示球状轮藻叶绿体全基因组的特征以及探究其在轮藻科内的系统发育关系,本研究基于高通量测序技术对其叶绿体全基因组进行组装和序列分析.结果表明:球状轮藻叶绿体基因组全长180 652 bp, GC含量26.6%,具有典型的四分体环状结构,与普生轮藻十分类似;球状轮藻叶绿体基因组共注释出137个基因,其中包括94个蛋白质编码基因、37个tRNA基因和6个rRNA基因,比无色丽藻多2个蛋白质编码基因和3个tRNA基因,与高等植物相比具有rpl12、trnL(gag)、rpl19、ycf20四个特殊基因;球状轮藻叶绿体全基因组共检测出87个SSR位点且绝大部分由A和T构成;此外,球状轮藻共包含24 989个密码子且密码子使用更偏好A和T,亮氨酸(Leu)是编码氨基酸最多的密码子;通过邻近法(NJ)对包括球状轮藻在内的5个种的叶绿体全基因组构建系统发育树显示,球状轮藻的亲缘关系与普生轮藻更为接近.本研究对球状轮藻叶绿体全基因组进行了解析,利用现有数据确立其系统发育学地位.     

Butterfly genome reveals promiscuous exchange of mimicry adaptations among species

The evolutionary importance of hybridization and introgression has long been debated. Hybrids are usually rare and unfit, but even infrequent hybridization can aid adaptation by transferring beneficial traits between species. Here we use genomic tools to investigate introgression in Heliconius, a rapidly radiating genus of neotropical butterflies widely used in studies of ecology, behaviour, mimicry and speciation. We sequenced the genome of Heliconius melpomene and compared it with other taxa to investigate chromosomal evolution in Lepidoptera and gene flow among multiple Heliconius species and races. Among 12,669 predicted genes, biologically important expansions of families of chemosensory and Hox genes are particularly noteworthy. Chromosomal organization has remained broadly conserved since the Cretaceous period, when butterflies split from the Bombyx (silkmoth) lineage. Using genomic resequencing, we show hybrid exchange of genes between three co-mimics, Heliconius melpomene, Heliconius timareta and Heliconius elevatus, especially at two genomic regions that control mimicry pattern. We infer that closely related Heliconius species exchange protective colour-pattern genes promiscuously, implying that hybridization has an important role in adaptive radiation.     

Genome sequence of the human malaria parasite Plasmodium falciparum

The parasite Plasmodium falciparum is responsible for hundreds of millions of cases of malaria, and kills more than one million African children annually. Here we report an analysis of the genome sequence of P. falciparum clone 3D7. The 23-megabase nuclear genome consists of 14 chromosomes, encodes about 5,300 genes, and is the most (A + T)-rich genome sequenced to date. Genes involved in antigenic variation are concentrated in the subtelomeric regions of the chromosomes. Compared to the genomes of free-living eukaryotic microbes, the genome of this intracellular parasite encodes fewer enzymes and transporters, but a large proportion of genes are devoted to immune evasion and host-parasite interactions. Many nuclear-encoded proteins are targeted to the apicoplast, an organelle involved in fatty-acid and isoprenoid metabolism. The genome sequence provides the foundation for future studies of this organism, and is being exploited in the search for new drugs and vaccines to fight malaria.     

SO2对大鼠肺基因组表达谱的影响——环境表达不稳定基因组存在的证据

采用A ffym etrix的基因芯片(RAE 230A)研究了SO2短期(56 m g/m3,6 h/day,for 7 days)及长期(14 m g/m3,1 h/day,for 30 days)吸入后对大鼠肺基因表达谱改变的影响.结果表明,与其相应的对照组相比,SO2短期吸入后表达上调的基因有31个,其中包括18个已知基因和13个新基因,而表达下调的基因有30个,其中包括19个已知基因和11个新基因;SO2长期吸入后表达上调的基因有173个,其中包括79个已知基因和94个新基因,而表达下调的基因有85个,其中包括46个已知基因和39个新基因.由此结论:1)高剂量短期吸入与低剂量长期吸入SO2在体内的作用机理不同;2)短期吸入SO2的大鼠肺基因表达谱与其对照组相比,氧化磷酸化相关的一些基因发生了变化,这表明高剂量短期吸入SO2可能导致线粒体功能的恶化;3)长期吸入SO2的大鼠肺基因表达谱与其对照组相比,表达有差异的基因涉及到脂肪酸代谢、免疫、炎症、氧化应激、原癌基因、肿瘤抑制基因和细胞外基质等,表明低剂量长期吸入SO2在体内的机理要更为复杂.本研究证明,在基因组中存在一些基因,它们的表达对环境污染物很敏感,可被称为环境表达不稳定基因组.     

大学毕业生就业生态问题及对策

就业生态指大学毕业生的就业期待、高等教育的培养预期与社会对人才的需求程度所构成的相互矛盾或协调的生态系统。这一生态系统中存在着三个层次的生态圈，即观念生态圈、行为生态圈、社会生态圈。观念生态圈的失衡、行为生态圈的错位、社会生态圈的失范是造成大学生就业难的生态原因。解决的办法，就是不断优化就业生态，改变观念生态圈的失衡；实行政策倾向，修正行为生态圈的错位；加快文化制度建设，扭转社会生态圈的失范。     

Learning about addiction from the genome

Drug addiction can be defined as the compulsive seeking and taking of a drug despite adverse consequences. Although addiction involves many psychological and social factors, it also represents a biological process: the effects of repeated drug exposure on a vulnerable brain. The sequencing of the human and other mammalian genomes will help us to understand the biology of addiction by enabling us to identify both genes that contribute to individual risk for addiction and those through which drugs cause addiction. We illustrate this potential impact by searching a draft sequence of the human genome for genes related to desensitization of receptors that mediate the actions of drugs of abuse on the nervous system.     

Distinct physiological and behavioural functions for parental alleles of imprinted Grb10

Imprinted genes, defined by their preferential expression of a single parental allele, represent a subset of the mammalian genome and often have key roles in embryonic development, but also postnatal functions including energy homeostasis and behaviour. When the two parental alleles are unequally represented within a social group (when there is sex bias in dispersal and/or variance in reproductive success), imprinted genes may evolve to modulate social behaviour, although so far no such instance is known. Predominantly expressed from the maternal allele during embryogenesis, Grb10 encodes an intracellular adaptor protein that can interact with several receptor tyrosine kinases and downstream signalling molecules. Here we demonstrate that within the brain Grb10 is expressed from the paternal allele from fetal life into adulthood and that ablation of this expression engenders increased social dominance specifically among other aspects of social behaviour, a finding supported by the observed increase in allogrooming by paternal Grb10-deficient animals. Grb10 is, therefore, the first example of an imprinted gene that regulates social behaviour. It is also currently alone in exhibiting imprinted expression from each of the parental alleles in a tissue-specific manner, as loss of the peripherally expressed maternal allele leads to significant fetal and placental overgrowth. Thus Grb10 is, so far, a unique imprinted gene, able to influence distinct physiological processes, fetal growth and adult behaviour, owing to actions of the two parental alleles in different tissues.     

The genome of the social amoeba Dictyostelium discoideum

The social amoebae are exceptional in their ability to alternate between unicellular and multicellular forms. Here we describe the genome of the best-studied member of this group, Dictyostelium discoideum. The gene-dense chromosomes of this organism encode approximately 12,500 predicted proteins, a high proportion of which have long, repetitive amino acid tracts. There are many genes for polyketide synthases and ABC transporters, suggesting an extensive secondary metabolism for producing and exporting small molecules. The genome is rich in complex repeats, one class of which is clustered and may serve as centromeres. Partial copies of the extrachromosomal ribosomal DNA (rDNA) element are found at the ends of each chromosome, suggesting a novel telomere structure and the use of a common mechanism to maintain both the rDNA and chromosomal termini. A proteome-based phylogeny shows that the amoebozoa diverged from the animal-fungal lineage after the plant-animal split, but Dictyostelium seems to have retained more of the diversity of the ancestral genome than have plants, animals or fungi.