Recruitment-dance signals draw larger audiences when honey bee colonies have multiple patrilines.

Honey bee queens (Apis mellifera) who mate with multiple males produce colonies that are filled with numerous genetically distinct patrilines of workers. A genetically diverse colony benefits from an enhanced foraging effort, fuelled in part by an increase in the number of recruitment signals that are produced by foragers. However, the influence of patriline diversity on the attention paid to these signals by audiences of potentially receptive workers remains unexplored. To determine whether recruitment dances performed by foragers in multiple-patriline colonies attract a greater number of dance followers than dances in colonies that lack patriline diversity, we trained workers from multiple- and single-patriline colonies to forage in a greenhouse and monitored their dance-following activity back in the hives. On average, more workers followed a dance if it was performed in a multiple-patriline colony rather than a single-patriline colony (33% increase), and for a greater number of dance circuits per follower. Furthermore, dance-following workers in multiple-patriline colonies were more likely to exit their hive after following a dance, although this did not translate to a difference in colony-level exit rates between treatment types. Recruiting nest mates to profitable food sources through dance communication is critical to a colony's foraging success and long-term fitness; polyandrous queens produce colonies that benefit not only from increased recruitment signalling, but also from the generation of larger and more attentive audiences of signal receivers. This study highlights the importance of integrating responses of both signal senders and receivers to understand more fully the success of animal-communication systems.

High-frequency transfection and cytopathology of the hepatitis B virus core antigen gene in human cells.

A protoplast fusion method was developed to stably transfect human cells with pSV2-derived plasmids at frequencies greater than 10(-3). This procedure made it possible to test the biological effect of a hepatitis B virus (HBV) gene independent of the viral structures required for infection. A pSV2gpt+ plasmid constructed to carry a subgenomic fragment of HBV that contained the core antigen gene (HBc gene) was transfected into human cells. A human epithelial cell line was stably transfected with the HBc+ gene by selecting recipient cells for expression of guanine phosphoribosyl transferase expression. With this gpt+/HBc+ cell line it was shown that growth in serum-free medium or treatment with 5'-azacytidine stimulates the production of the HBV core antigen. A hepatocellular carcinoma carrying the entire HBV genome was stimulated to produce the HBc gene product in response to the same factors that stimulated HBcAg production in the gpt+/HBc+ cell line constructed by transfection. The temporal relation between the cytopathologic response and HBc gene expression was similar for both cell types, indicating a primary role for HBc gene expression in the cytopathology of HBV-infected human liver.

Deciding on a new home: how do honeybees agree?

A swarm of honeybees (Apis mellifera) is capable of selecting one nest-site when faced with a choice of several. We adapt classical mathematical models of disease, information and competing beliefs to such decision-making processes. We show that the collective decision may be arrived at without the necessity for any bee to make any comparison between sites.

Do women taking hormone replacement therapy have a higher uptake of screening mammograms?

All British women in the 50-64 age group are now offered three yearly screening mammograms. A study was undertaken to compare the uptake of three yearly screening mammograms for women taking hormone replacement therapy with those not on treatment. Out of a list size of 15,000, there were 1309 women aged 50 to 64. Of these 265/286 (92.7%) of women taking hormone replacement therapy, and 877/1023 (85.7%) not taking treatment, attended for mammograms. Overall 286/1309 (21.8%), and in the 50-54 subgroup 193/524 (36.8%), were taking hormone replacement therapy. This study supports the idea that there is a selection bias with women taking hormone replacement therapy significantly more likely to attend for screening mammograms.

Oestrogen replacement therapy after hysterectomy.

OBJECTIVE: To identify those women who might benefit from oestrogen replacement after hysterectomy. DESIGN: Targeted health screening. SETTING: Large group practice. SUBJECTS: All women aged under 50 who had had a hysterectomy. MAIN OUTCOME MEASURES: Concentration of follicle stimulating hormone, symptom profile, uptake of oestrogen replacement therapy. RESULTS: 145 of 1953 women aged 32-49 had had a hysterectomy. 35 of the 41 with bilateral oophorectomy and 27 of 104 with one or more ovaries conserved were taking oestrogen replacement. 62 of the 68 who had ovaries conserved and were not taking oestrogen replacement attended for review, of whom 14 had a follicle stimulating hormone concentration > or = 20 IU/l. 16 of the 19 women identified as potentially able to benefit from oestrogen replacement started treatment and were still on treatment at six months of follow up. CONCLUSION: Systematic review of women who had had a hysterectomy identified an important group who would potentially benefit from oestrogen replacement therapy.

Honey bee colonies are group-level adaptive units.

It is not widely recognized that natural selection has produced adaptive units at the level of groups. Multilevel selection theory shows that groups can evolve a high level of functional organization when between-group selection predominates over within-group selection. Strong empirical evidence that natural selection has produced adaptive units at the group level comes from studies of social insects in which we find colonies in certain species functioning as highly integrated units. The functional organization of a social insect colony is best understood for honey bees. Recent experimental analyses of honey bee colonies have revealed striking group-level adaptations that improve the foraging efficiency of colonies, including special systems of communication and feedback control. These findings are reviewed with the aim of showing that evolution has produced adaptively organized entities at the group level.

Mutations in the Escherichia coli UvrB ATPase motif compromise excision repair capacity.

The Escherichia coli UvrB protein possesses an amino acid sequence motif common to many ATPases. The role of this motif in UvrB has been investigated by site-directed mutagenesis. Three UvrB mutants, with amino acid replacements at lysine-45, failed to confer UV resistance when tested in the UV-sensitive strain N364 (delta uvrB), while five other mutants constructed near this region of UvrB confer wild-type levels of UV resistance. Because even the conservative substitution of arginine for lysine-45 in UvrB results in failure to confer UV resistance, we believe we have identified an amino acid side chain in UvrB essential to nucleotide excision repair in E. coli. The properties of two purified mutant UvrB proteins, lysine-45 to alanine (K45A) and asparagine-51 to alanine (N51A), were analyzed in vitro. While the K45A mutant is fully defective in incision of UV-irradiated DNA, K45A is capable of interaction with UvrA in forming an ATP-dependent nucleoprotein complex. The K45A mutant, however, fails to activate the characteristic increase in ATPase activity observed with the wild-type UvrB in the presence of UvrA and DNA. From these results we conclude that there is a second nucleotide-dependent step in incision following initial complex formation, which is defective in the K45A mutant. This experimental approach may prove of general applicability in the study of function and mechanism of other ATPase motif proteins.

Purification and molecular properties of a Class II alcohol dehydrogenase (ADH-C2) from horse liver.

An alcohol dehydrogenase (ADH) from horse liver was purified by ion-exchange and affinity chromatography. The enzyme (designated ADH-C2), is a dimer with a similar subunit size (47,300 mol. wt), as determined by SDS-polyacrylamide gel electrophoresis, to other mammalian ADHs. Zinc analyses and 1,10 phenanthroline inhibition studies indicated that each subunit contained 2 g atoms of zinc, with at least one involved catalytically. The enzyme exhibited similar kinetic properties to human pi-ADH and mouse ADH-C2, previously classified as class II ADHs [Vallee and Bazzone (1983) Isozymes, Vol. 8, pp. 219-244; Algar et al. (1983) Eur. J. Biochem. 137, 139-147] but differed in most respects from the extensively investigated horse Class I ADHs; EE, ES and SS. Horse ADH-C2 exhibited a Km value for ethanol of 42 mM and a broad substrate specificity, with Km values decreasing dramatically with an increase in chain length. The enzyme was much less sensitive to pyrazole inhibition (by at least 3 orders of magnitude) as compared with the Class I ADHs.

Worker piping in honey bee swarms and its role in preparing for liftoff.

Worker piping, previously reported only in hives, was observed in swarms as they prepared to liftoff to fly to a new home. Pipers are excited bees which scramble through the swarm cluster, pausing every second or so to emit a pipe. Each pipe consists of a sound pulse which lasts 0.82 +/- 0.43 s and rises in fundamental frequency from 100-200 Hz to 200-250 Hz. Many. if not all, of the pipers are nest-site scouts. The scouts pipe when it is time to stimulate the non-scouts to warm themselves to a flight-ready temperature (35 degrees C) in preparation for liftoff. The time-course of worker piping matches that of swarm warming, both start at a low level, about an hour before liftoff, and both build to a climax at liftoff. When we excluded pipers from bees hanging in the cool, outermost layer of a swarm cluster, we found that these bees did not warm up. The form of worker piping that we have studied in swarms differs from the form of worker piping that others have studied in hives. We call the two forms "wings-together piping" (in swarms) and "wings-apart piping" (in hives).

The role of Escherichia coli UvrB in nucleotide excision repair.

The role of UvrB in determining the nucleotide dependence of Escherichia coli excision repair has been investigated. The mutation of lysine 45 in the ATPase motif of UvrB to alanine leads to an acute defect in ATP hydrolysis and failure to support incision of UV-damaged DNA. This ATP hydrolysis activity is not required for interaction of UvrB with UvrA in solution, or for formation of a damage-independent nucleoprotein complex in the presence of UvrA and nucleotide. This UvrB mutant fails, however, to support damage-specific nucleoprotein complex formation, and does not participate in a UvrA-UvrB-dependent helicase-like activity. We conclude from these results that mutation at lysine 45 in the ATPase motif of UvrB specifically inhibits a key step in nucleotide excision repair involving the UvrB ATPase-dependent translocation of nucleoprotein complexes from undamaged to damaged DNA sites.

Genetics and ontogeny of butyryl CoA dehydrogenase in the mouse and linkage of Bcd-1 with Dao-1.

A zymogram method has been developed for fatty acyl CoA dehydrogenase and used to examine the electrophoretic properties of butyryl CoA dehydrogenase (BCD) from mouse tissues. A single form of BCD is present in extracts of liver, kidney, heart, and intestine. Ontogenetic, tissue distribution, and subcellular fractionation results are consistent with the mitochondrial origin previously reported for this enzyme. A genetic variant for BCD-1 was used to provide evidence for a locus determining the electrophoretic properties of this enzyme (designated Bcd-1), which is linked to Dao-1 (encoding D-amino acid oxidase).

Electrophoretic analyses of alcohol dehydrogenase, aldehyde dehydrogenase, aldehyde reductase, aldehyde oxidase and xanthine oxidase from horse tissues.

Cellulose acetate zymograms of alcohol dehydrogenase (ADH), aldehyde dehydrogenase (AHD), aldehyde reductase (AHR), aldehyde oxidase (AOX) and xanthine oxidase (XOX) extracted from horse tissues were examined. Five ADH isozymes were resolved: three corresponded to the previously reported class I ADHs (EE, ES and SS) (Theorell, 1969); a single form of class II ADH (designated ADH-C2) and of class III ADH (designated ADH-B2) were also observed. The latter isozyme was widely distributed in horse tissues whereas the other enzymes were found predominantly in liver. Four AHD isozymes were differentially distributed in subcellular preparations of horse liver: AHD-1 (large granules); AHD-3 (small granules); and AHD-2, AHD-4 (cytoplasm). AHD-1 was more widely distributed among the horse tissues examined. Liver represented the major source of activity for most AHDs. A single additional form of NADPH-dependent AHR activity (identified as hexonate dehydrogenase), other than the ADHs previously described, was observed in horse liver. Single forms of AOX and XOX were observed in horse tissue extracts, with highest activities in liver.

An early chapter in behavioral physiology and sociobiology: the science of Martin Lindauer.

The fields of behavioral physiology and sociobiology enjoyed spectacular success in post World War II Germany. One of the major contributors to this blossoming in behavioral science was Martin Lindauer, who furthered the research approach of his mentor (Karl von Frisch), made numerous seminal discoveries, and nurtured a strong next generation in the area of neurobiology and behavior. We review the scientific development of Martin Lindauer within the German academic system in the years surrounding World War II, examine his research approach and achievements, and discuss his unusually successful methods of scientific pedagogy.

Dancing bees tune both duration and rate of waggle-run production in relation to nectar-source profitability.

For more than 50 years, investigators of the honey bee's waggle dance have reported that richer food sources seem to elicit longer-lasting and livelier dances than do poorer sources. However, no one had measured both dance duration and liveliness as a function of food-source profitability. Using video analysis, we found that nectar foragers adjust both the duration (D) and the rate (R) of waggle-run production, thereby tuning the number of waggle runs produced per foraging trip (W, where W= DR) as a function of food-source profitability. Both duration and rate of waggle-run production increase with rising food-source profitability. Moreover, we found that a dancing bee adjusts the rate of waggle-run production (R) in relation to food-source profitability by adjusting the mean duration of the return-phase portion of her dance circuits. This finding raises the possibility that bees can use return-phase duration as an index of food-source profitability. Finally, dances having different levels of liveliness have different mean durations of the return phase, indicating that dance liveliness can be quantified in terms of the time interval between consecutive waggle runs.

Fever in honeybee colonies.

Honeybees, Apis spp., maintain elevated temperatures inside their nests to accelerate brood development and to facilitate defense against predators. We present an additional defensive function of elevating nest temperature: honeybees generate a brood-comb fever in response to colonial infection by the heat-sensitive pathogen Ascosphaera apis. This response occurs before larvae are killed, suggesting that either honeybee workers detect the infection before symptoms are visible, or that larvae communicate the ingestion of the pathogen. This response is a striking example of convergent evolution between this "superorganism" and other fever-producing animals.

Purification and molecular properties of mouse alcohol dehydrogenase isozymes.

Alcohol dehydrogenase isozymes from mouse liver (A2 and B2) and stomach (C2) tissues have been purified to homogeneity using triazine-dye affinity chromatography. The enzymes are dimers with similar but distinct subunit sizes, as determined by SDS/polyacrylamide gel electrophoresis: A, 43000; B, 39000, and C, 47000. Zinc analyses and 1,10-phenanthroline inhibition studies indicated that the A and C subunits each contained two atoms of zinc, with at least one being involved catalytically, whereas the B subunit probably contained a single non-catalytic zinc atom. The isozymes exhibited widely divergent kinetic characteristics. A2 exhibited a Km value for ethanol of 0.15 mM and a broad substrate specificity, with Km values decreasing dramatically with an increase in chain length; C2 also exhibited this broad specificity for alcohols but showed a Km value of 232 mM for ethanol. These isozymes also showed broad substrate specificities as aldehyde reductases. In contrast, B2 showed no detectable activity as an aldehyde reductase for the aldehydes examined, and used ethanol as substrate only at very high concentrations (greater than 0.5 M). The isozyme exhibited low Km and high Vmax values, however, with medium-chain alcohols. Immunological studies showed that A2 was immunologically distinct from the B2 and C2 isozymes. In vitro molecular hybridization studies gave no evidence for association between the alcohol dehydrogenase subunits. The results confirm genetic analyses [Holmes, Albanese, Whitehead and Duley (1981) J. Exp. Zool. 215, 151-157] which are consistent with at least three structural genes encoding alcohol dehydrogenase in the mouse and confirm the role of the major liver isozyme (A2) in ethanol metabolism.

Phosphorylation of human MAD1 by the BUB1 kinase in vitro.

The BUB/MAD signaling pathway monitors attachment of chromosomes to spindle poles in mitotic cells. Mutations of the human BUB1 locus were identified in cancer cells exhibiting an unstable chromosomal complement. We report that the human BUB3 gene maps to a site on chromosome 10 subject to frequent modification in cancers. Thus, defects in BUB/MAD signaling may contribute to genetic instability and to cancer progression. In vitro, BUB1 and BUB3 proteins form a complex of monomers of each protein. These proteins interact with the human MAD1 gene product, a target of the HTLV-1 tax oncogene. This multiprotein complex exhibits a kinase activity with a requirement for lysine 821 in the BUB1 kinase motif, resulting in BUB1 autophosphorylation and phosphorylation of associated MAD1.