Here we report the genome sequence of the honeybee Apis mellifera, a key model for social behaviour and essential to global ecology through pollination. Compared with other sequenced insect genomes, the A. mellifera genome has high A+T and CpG contents, lacks major transposon families, evolves more slowly, and is more similar to vertebrates for circadian rhythm, RNA interference and DNA methylation genes, among others. Furthermore, A. mellifera has fewer genes for innate immunity, detoxification enzymes, cuticle-forming proteins and gustatory receptors, more genes for odorant receptors, and novel genes for nectar and pollen utilization, consistent with its ecology and social organization. Compared to Drosophila, genes in early developmental pathways differ in Apis, whereas similarities exist for functions that differ markedly, such as sex determination, brain function and behaviour. Population genetics suggests a novel African origin for the species A. mellifera and insights into whether Africanized bees spread throughout the New World via hybridization or displacement.

Transmission mechanisms of six honeybee viruses, including acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Kashmir bee virus (KBV), and sacbrood bee virus (SBV), in honey bee colonies were investigated by reverse transcription-PCR (RT-PCR) methods. The virus status of individual queens was evaluated by examining the presence of viruses in the queens' feces and tissues, including hemolymph, gut, ovaries, spermatheca, head, and eviscerated body. Except for head tissue, all five tissues as well as queen feces were found to be positive for virus infections. When queens in bee colonies were identified as positive for BQCV, DWV, CBPV, KBV, and SBV, the same viruses were detected in their offspring, including eggs, larvae, and adult workers. On the other hand, when queens were found positive for only two viruses, BQCV and DWV, only these two viruses were detected in their offspring. The presence of viruses in the tissue of ovaries and the detection of the same viruses in queens' eggs and young larvae suggest vertical transmission of viruses from queens to offspring. To our knowledge, this is the first evidence of vertical transmission of viruses in honeybee colonies.The honeybee, Apis mellifera L., plays a vital role in agriculture by assisting in the pollination of a wide variety of crops, with an annual added market value exceeding 15 billion dollars (13). However, the health and vigor of honeybee colonies are threatened by numerous parasites and pathogens, including viruses, bacteria, protozoa, and mites. Among pathogens attacking honeybees, viruses are probably the least understood because of the lack of information about the dynamics underlying viral disease outbreaks.A most crucial stage in the dynamics of virus infections is the mode of virus transmission. In general, transmission of viruses can occur through two pathways: horizontal and vertical transmission. In horizontal transmission, viruses are transmitted among individuals of the same generation, while vertical transmission occurs from adults to their offspring. Transmission can occur through multiple routes in social organisms. Over the past several years, horizontal transmission of honeybee viruses has been documented in bee colonies. experimentally demonstrated that the parasitic mite Varroa destructor obtained deformed wing virus (DWV) from infected bees and acted as a vector to transmit the virus to uninfected bees, which developed morphological deformities or died after mites fed on them for certain periods of time. Our recent study with Kashmir bee virus (KBV) established the role of V. destructor in virus transmission and provided evidence of miteto-brood transmission and mite-to-mite acquisition of viruses in bee colonies (5). Although these results demonstrated horizontal transmission of viruses, virus transmission in honeybees is still not completely understood. For instance, in our subsequent studies with DWV (4, 6), we detected virus in honeybee eggs and young lar...

Honey bee (Apis mellifera) sperm remains viable in the spermatheca of mated female honey bees for several years. During this time, the sperm retains respiratory activity, placing it at risk of the damaging effects of reactive oxygen species common to many biological processes. Antioxidative enzymes might help reduce this damage. Here we use quantitative real-time RT-PCR to establish gene-expression profiles in male and female honey bee reproductive tissues for three antioxidative enzymes: catalase, glutathione-S-transferase (GST) and superoxide dismutase (SOD1, cytosolic). Catalase and GST showed ten- to twenty-fold transcript increases in the sperm storage organs of mated queens vs. unmated queens, whereas SOD1 levels are high in both mated and unmated queens. Male reproductive and somatic tissues showed relatively high levels of all three antioxidant-encoding transcripts. All three enzymes screened were higher in mature males vs. young males, although this effect did not appear to be confined to reproductive tissues and, hence, need not reflect a role in sperm longevity. Furthermore, antioxidative enzyme transcripts remained present, and apparently increased, in male tissues long after sperm had matured and seminal fluid was produced. We also found measurable levels of catalase transcripts in honey bee semen. The presence of catalase transcripts in both reproductive tissues and semen in bees suggests that this enzyme might play a key role in antioxidative protection.

Honey bee ( Apis mellifera L.) queens mate early in life and store sperm for years. Male bees likely contribute significantly to sperm survival. Proteins were extracted from seminal vesicles and semen of mature drones, separated by electrophoresis, and analysed by peptide mass fingerprinting. Computer searches against three databases, general species, honey bees and fruit flies, were performed. Spectra were used to query the recently generated honey bee genome protein list as well as general species and fruit fly databases. Of the 69 unique honey bee proteins found, 66 are also in Drosophila melanogaster . Two proteins only matched honey bee genes and one is a widespread protein lost from the fly genome. There is over-representation of genes implicated in the glycolysis pathway. Metabolismassociated proteins were found primarily in the seminal vesicle. Male accessory gland proteins as identified in Drosophila rarely had orthologs among proteins found in the honey bee. A complete listing of gel spots chosen including honey bee genome matches and Mascot searches of MALDI-TOF results with statistics is in the Supplementary table. MALDI-TOF spectra and more complete Mascot peptide mass fingerprinting data are available on request. Supplementary figs 1 -3 show the stained protein gels.

-Catalase (CAT), glutathione S-transferase (GST) and superoxide dismutase (SOD) activities were determined in postmitochondrial fractions of tissue homogenates (spermathecae, muscle and ventriculi), in hemolymph plasma, and in semen of honey bees. The highest CAT activity was found in semen (4.8 mU/µg fresh weight), and the enzyme was confined to the spermatozoa. CAT and GST activities of ventriculi exceeded those of other tissues and hemolymph, CAT being highest in mated queen ventriculi (2.7 mU/µg) and GST highest in worker ventriculi (10 mU/mg). Spermathecae of mated queens had higher CAT and GST activities (0.84 mU/µg, and 2.4 mU/mg, respectively) than virgin spermathecae (0.15 mU/µg, and 1.6 mU/mg). SOD activities (15-59 mU/µg) varied less than activities of CAT or GST between tissues. Seminal plasma contained two thirds of the total SOD activity of semen and one third was in the spermatozoa. The substantial activities of all three enzymes in spermathecae of mated queens suggest their involvement in the long-term protection of the spermatozoa from oxidative stress.Apis mellifera / catalase / glutathione S-transferase / superoxide dismutase