Genetic mosaics in the massive persisting rhizosphere colony “shiro” of the ectomycorrhizal basidiomycete Tricholoma matsutake

The ectomycorrhizal basidiomycete Tricholoma matsutake produces commercially valuable fruit bodies matsutake on a massive persisting rhizosphere aggregate of mycelia and mycorrhizas called shiro. Using inter-retrotransposon amplified polymorphism analysis, we attempted to explore the potential diversity within the population of T. matsutake isolated from small Pinus densiflora woodlands located in various parts of Japan. In general, random phylogenetic relationship was noted among T. matsutake tested. The population from each limited sampling area was highly heterogeneous. Even some isolates from fruit bodies produced in the same shiro and those from spores in the same fruit bodies were found to be genetically diverse, indicating the occurrence of genetic mosaics in shiro. In a mosaic shiro, heterologous genets produced their fruit bodies concurrently. Data suggested that the dispersal of spores through sexual reproduction may have been more prevalent than generally accepted in T. matsutake to bring mosaicism and coordination of heterologous genets within the shiro. Implementation of management taking such diversity into consideration is urgently needed for the restoration of devastated matsutake fields in Japan. Exploration of individual clones in mosaic fungal resources that promote colonization and fruit body production is necessary for it.     

Does foraging efficiency vary with colony size in the fairy martin Petrochelidon ariel?

Colonial breeding occurs in a wide range of taxa, however the advantages promoting its evolution and maintenance remain poorly understood. In many avian species, breeding colonies vary by several orders of magnitude and one approach to investigating the evolution of coloniality has been to examine how potential costs and benefits vary with colony size. Several hypotheses predict that foraging efficiency may improve with colony size, through benefits associated with social foraging and information exchange. However, it is argued that competition for limited food resources will also increase with colony size, potentially reducing foraging success. Here we use a number of measures (brood feeding rates, chick condition and survival, and adult condition) to estimate foraging efficiency in the fairy martin Petrochelidon ariel, across a range of colony sizes in a single season (17 colonies, size range 28–139 pairs). Brood provisioning rates were collected from multiple colonies simultaneously using an electronic monitoring system, controlling for temporal variation in environmental conditions. Provisioning rate was correlated with nestling condition, though we found no clear relationship between provisioning rate and colony size for either male or female parents. However, chicks were generally in worse condition and broods more likely to fail or experience partial loss in larger colonies. Moreover, the average condition of adults declined with colony size. Overall, these findings suggest that foraging efficiency declines with colony size in fairy martins, supporting the increased competition hypothesis. However, other factors, such as an increased ectoparasitise load in large colonies or change in the composition of phenotypes with colony size may have also contributed to these patterns.     

Social wasps desert the colony and aggregate outside if parasitized: parasite manipulation?

Infection of the paper wasp, Polistes dominulus (Christ), bythe strepsipteran parasite Xenos vesparum Rossi results in adramatic behavioral change, which culminates in colony desertionand the formation of extranidal aggregations, in which up to98% of occupants are parasitized females. Aggregations formedon prominent vegetation, traditional lek-sites of Polistes males,and on buildings, which were later adopted as hibernating sitesby future queens. First discovered by W.D. Hamilton, these aberrantaggregations are an overlooked phenomenon of the behavioralecology of this intensively studied wasp. For 3 months in thesummer of 2000, during the peak of colony development, we sampled91 extranidal aggregations from seven areas, numbering 1322wasps. These wasps were parasitized by both sexes of X. vesparum,but males were more frequent from July until mid-August, duringthe mating season of the parasite. Aggregations were presentfor days at the same sites (in one case a leaf was occupiedfor 36 consecutive days) and were characterized by extreme inactivity.After artificial infection, parasitized "workers" deserted thenest 1 week after emergence from their cell and before the extrusionof the parasite through the host cuticle. Infected individualsdid not work, were more inactive, and did not receive more aggressionthan did controls. We suggest that early nest desertion andsubsequent aggregations by parasitized nominal workers and "futurequeens" is adaptive manipulation of host behavior by the parasiteto promote the completion of its life cycle.     

Effects of food rewards offered by ant–plant Macaranga on the colony size of ants

Myrmecophytes (ant–plants) have special hollow structures (domatia) in which obligate ant partners nest. As the ants live only on the plants and feed exclusively on plant food bodies, sap-sucking homopterans in the domatia, and/or the homopterans honeydew, they are suitable for the study of colony size regulation by food. We examined factors regulating ant colony size in four myrmecophytic Macaranga species, which have strictly species-specific association with Crematogaster symbiont ants. Intra- and interspecific comparison of the plants showed that the ant biomass per unit food biomass was constant irrespective of plant developmental stage and plant species, suggesting that the ant colony size is limited by food supply. The primary food offered by the plants to the ants was different among Macaranga species. Ants in Macaranga beccariana and Macaranga bancana relied on homopterans rather than food bodies, and appeared to regulate the homopteran biomass and, as a consequence, regulate the ants own biomass. In contrast, ants in Macaranga winkleri and Macaranga trachyphylla relied primarily on food bodies rather than homopterans, and the plants appeared to manipulate the ant colony size. Per capita plant investment in ants (ant dry weight plant dry weight^–1) was different among the four Macaranga species. The homoptera-dependent M. beccariana and M. bancana harbored lower biomass of ants than the food-body dependent M. winkleri, suggesting that energy loss is involved in the homoptera-interposing symbiotic system which has one additional trophic level. The plants investment ratio to the ants generally decreased as plants grew. The evolution of the plant reward-offering system in ant–plant–homopteran symbioses is discussed with an emphasis on the role of homopterans.     

Polydomy and the organization of foraging in a colony of the Malaysian giant ant Camponotus gigas (Hym. / Form.)

In Kinabalu National Park, Borneo we observed four colonies of the Malaysian giant ant Camponotus gigas in a primary forest. These predominantly nocturnal ants have underground nests, but forage in huge three-dimensional territories in the rain forest canopies. The colony on which our study was mainly focused had 17 nests with about 7000 foragers and occupied a territory of 0.8 ha. To improve observation and manipulation possibilities, these nests were linked at ground level by 430 m of artificial bamboo trail. A group of specialist transport worker ants carried food from `source' nests at the periphery to the central `sink' nest of the queen. Transport of food between nests started immediately after the evening exodus of the foragers. Transporter ants formed a physical subcaste among the minors and behaved according to predictions of the central-place foraging theory. Their load size was about five times that of the average forager and grew proportionally with head width. Longer distances were run by ants with greater head width and larger gross weight. Transporter ants that ran more often took heavier loads. Experiments with extra-large baits revealed that C. gigas used long-range recruitment to bring foragers from different nests to “bonanzas” at far distant places. The foraging strategy of C. gigas is based on a polydomous colony structure in combination with efficient communication, ergonomic optimization, polyethism and an effective recruitment system. Received: 16 March 1998 / Accepted: 24 August 1998     

How many soldiers are optimal for an aphid colony?

A number of aphid species produce sterile soldiers that defend their colony-mates against predators. How many soldiers should a colony produce? Assuming logistic growth of the aphid colony, we can theoretically deduce that soldiers will be produced until the marginal defensive efficacy of a soldier diminishes to rm/K, a ratio of two exogenous variables of the logistic equation, which are the maximum intrinsic rate of increase and carrying capacity. This conclusion holds true irrespective of the number of founders. As the number of founders increases, the entire colony size becomes larger, thus decreasing the percentage of soldiers. In case of multiple founders, each clone will produce the same number of reproductives that remain on the hostplant.     

A comparison of mark–release–recapture methods for estimating colony size in the wood ant Formica lugubris

Colony size can be considered the analogue of the body size of a superorganism. Just as body size is important to the physiology of an individual animal, colony size correlates with the life-history and ecology of social insects. Although nest excavation and counting all individuals is the most accurate method for estimating colony size (or nest size), it has the major drawback of being destructive. Alternatively, mark–release–recapture (MRR) can be used repeatedly to measure the size of the same colony or nest. We compared the accuracy and feasibility of four MRR methods and a Mound-Volume method with complete counts from nest excavation for estimating the nest size of F. lugubris, a mound-building wood ant of the Formica rufa group, during the early spring in Scotland. We found that our After-Disturbing method, in which we performed marking and recapturing after gentle disturbance to the top of nest mound, has the best balance between accuracy, non-destructiveness, and time required. We also found that mound volume can be an index of ant nest size under certain conditions. Both non-destructive methods can be used on the same colony or nest repeatedly to monitor nest dynamics.     

Ant–plant interaction in the Neotropical savanna: direct beneficial effects of extrafloral nectar on ant colony fitness

Current evidence suggests that ant–plant relationships may influence species composition, abundance, and interactions at the community scale. The main resource that plants offer to ants is extrafloral nectar (EFN) and the major part of published studies shown benefits from ants to plants possessing EFNs. However, the complementary question of whether and how ants benefit from EFNs is rarely addressed. Here, we present the results of a long-term study to demonstrate whether EFN has a positive effect on ant colony fitness. We quantified colony growth rate, survival and the final weight of individuals as measures of benefit derived from EFN. Our results provide clear evidence that EFN can have a significant positive impact on the survivorship, growth and reproduction of the Myrmicinae Cephalotes pusillus. In fact, a diet rich in EFN (providing at least 30 cal per day) resulted in five times more individuals per colony, greater body weights, and more eggs. These results have shed new light on the relationships between ants and EFN-bearing plants such as in tropical and temperate systems. The ant C. pusillus is the first case in which we have firm evidence that EFN improves colony growth and development, corroborating more than 100 years of experimental evidence of benefits to plants in these widespread relationships.     

Physiological changes during colony establishment in the termite Hodotermes mossambicus (Hagen): Energy reserves—neutral lipids and glycogen

At swarming approximately 60% of the dry mass of the termite Hodotermes mossambicus male and female alates consisted of lipids, the bulk of which was neutral lipids. During the period prior to the appearance of the first larvae (27–32 days after swarming) there was a significant decrease in total lipid content and a dramatic increase in glycogen level. The latter may have been triggered by intake of water. During the period between the appearance of the first larvae and the first workers (42–50 days after swarming) there was a further drop in the lipid content and decrease in the glycogen level. This indicates that lipids are the primary energy source and that they and/or glycogenic amino acids derived from flight muscle degradation could serve as glycogen precursors.     

Observations of the effect of a New Year’s fireworks display on the behavior of the South American sea lion (Otaria flavescens) in a colony of central-south Chile

The use of fireworks has increased worldwide in recent years. Despite this, their effects on sea lions and similar species are almost undocumented. In this study, we documented some effects of the 2015 New Year’s fireworks on the behavior of South American sea lions (Otaria flavescens), a marine mammal species that utilizes coastal rookeries for breeding, resting, and care and nursing of pups. An immediate cessation of vocalizations followed the start of the fireworks and a significant decrease in the number of sea lions in the colony was registered. This provided evidence that fireworks disrupted the ongoing behavior of the South American sea lion. Further studies will be necessary to determine whether this disruption has negative consequences for these animals or whether they have evolved behavioral mechanisms for dealing with these kinds of short-term disruptive events.     

An ant colony optimization approach to flexible protein–ligand docking

The prediction of the complex structure of a small ligand with a protein, the so-called protein–ligand docking problem, is a central part of the rational drug design process. For this purpose, we introduce the docking algorithm PLANTS (Protein–Ligand ANT System), which is based on ant colony optimization, one of the most successful swarm intelligence techniques. We study the effectiveness of PLANTS for several parameter settings and present a direct comparison of PLANTS’s performance to a state-of-the-art program called GOLD, which is based on a genetic algorithm and frequently used in the pharmaceutical industry for this task. Last but not least, we also show that PLANTS can make effective use of protein flexibility giving example results on cross-docking and virtual screening experiments for protein kinase A. This article is based on a paper that won the best paper award at ANTS 2006, the 5th International Workshop on Ant Colony Optimization and Swarm Intelligence held in Brussels, Belgium, 2006. This article includes new types of experiments and also the possibility of considering flexibility of protein side-chains.     

E-β-ocimene, a volatile brood pheromone involved in social regulation in the honey bee colony (Apis mellifera)

BACKGROUND: In honey bee colony, the brood is able to manipulate and chemically control the workers in order to sustain their own development. A brood ester pheromone produced primarily by old larvae (4 and 5 days old larvae) was first identified as acting as a contact pheromone with specific effects on nurses in the colony. More recently a new volatile brood pheromone has been identified: E-β-ocimene, which partially inhibits ovary development in workers. METHODOLOGY AND PRINCIPAL FINDING: Our analysis of E-β-ocimene production revealed that young brood (newly hatched to 3 days old) produce the highest quantity of E-β-ocimene relative to their body weight. By testing the potential action of this molecule as a non-specific larval signal, due to its high volatility in the colony, we demonstrated that in the presence of E-β-ocimene nest workers start to forage earlier in life, as seen in the presence of real brood. CONCLUSIONS/SIGNIFICANCE: In this way, young larvae are able to assign precedence to the task of foraging by workers in order to increase food stores for their own development. Thus, in the complexity of honey bee chemical communication, E-β-ocimene, a pheromone of young larvae, provides the brood with the means to express their nutritional needs to the workers.     

Flight and colony foundation in twoCubitermes species (Isoptera: Termitidæ)

Summary Information on flight periods and times of flight ofCubitermes ugandensis and ofC. testaceus in eastern Uganda is reviewed. All work was done in the laboratory with the exception of a few field observations on flight. Alates removed from the mound were negatively phototactic and gregarious. These characteristics were reversed by use of the wings. Alates would fly only if free of contact with other termites of the colony and in the presence of light. Observations were made on the flight activity ofC. ugandensis in connection with light intensity. Wing shedding in both species was stimulated by pairing or attempted pairing but, inC. ugandensis at least, was not dependent on such stimulation. Wing shedding was followed by indifference to light. Artificial wing removal demonstrated that inC. ugandensis the connection between loss of wings and loss of positive phototaxis was not a direct one. The method of wing shedding is discussed. Females of both spp. did not generally take up the calling attitude until they had paired with, and lost, a male. In the absence of males,C. ugandensis females would run actively for many minutes after wing shedding, after which the calling attitude was taken up between further periods of active running. An apparent defence mechanism against small predators, used byC. ugandensis females in the calling attitude, was noted. The presence of wings did not inhibit pairing in either species. Male tandems were frequent but nearly always very inconstant. Female tandems were not seen and no female was seen to follow a male. Tandems showed no positive geotaxis and remained indifferent to light.C. ugandensis females tended to climb up and down for some minutes after pairing. Thigmotaxis proved important in nest site selection by both species. Burrowing appeared to be dependent on external factors and not part of a behaviour pattern. Gregariousness returned with selection of the nest site but definite photonegative behaviour was not seen until the pairs were installed in cells. The plasticity of post-flight behaviour is discussed.

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Zusammenfassung Die Arbeit berichtet über jahreszeitliche und tägliche Flugperioden vonCubitermes ugandensis und vonC. testaceus in Ost-Uganda. Die Untersuchungen wurden fast vollständig im Laboratorium ausgeführt. Geflügelte aus dem Nest genommen waren negativ phototactisch und hielten sich zusammen. Diese Eigenschaften wurden durch den Gebrauch der Flügel ins Gegenteil umgewandelt. Geflügelte flogen nur wenn sie nicht in Gesellschaft mit anderen Termiten des Baues und dem Lichte ausgesetzt waren. Beobachtungen wurden angestellt über Lichtintensität und die Flugfähigkeit vonC. ugandensis. Abwerfen der Flügel wurde in beiden Arten durch Paarung oder Paarungsversuche gefördert, hing aber, zum mindesten inC. ugandensis nicht von solcher Förderung ab. Auf das Abwerfen der Flügel folgte Gleichgültigkeit gegenüber Licht. Künstliche Entfernung der Flügel zeigte, dass beiC. ugandensis der Zusammenhang zwischen Flügelverlust und Verlust positives Phototaxis nicht direkt ist. Der Vorgang des Abwerfens der Flugel wird erörtert. Weibchen beider Arten nehmen im allgemeinen keine Lockstellung ein, bevor sie sich mit einem Männchen gepaart und es verloren hatten. Wenn Männchen fehlen, laufen Weibchen vonC. ugandensis nach Abwerfen der Flügel viele Minuten lebhaft herum, woraufhim zwischen weiteren Perioden lebhaften Laufens die Lockstellung eingenommen wurde. Eine mutmassliche Verteidungsmethode wenn im Lockstellung von Weibchen desC. ugandensis gegen Raubinsekten wurde beobachtet. Das Vorhandensein der Flügel behinderte Paarung in beiden Arten nicht. Männliche Tandems waren häufig, dauerten aber fast nie länger. Weibliche Tandems waren nicht zur Beobachtung, und es wurde nie beobachtet, dass ein Weibchen einem Männchen nachlief. Tandems zeigten keine positives Geotaxis und blieben gleichgültig gegenüber dem Licht. Weibchen vonC. ugandensis pflegten einige Minuten nach der Paarung auf- und abzuklettern. Thigmotaxis, war ein wichtiger Faktor bei beiden Arten in der Wahl eines Platzes für das Nest. Graben scheint von äusseren Faktoren abzuhängen und nicht Teil des Trieblebens zu sein. Der Trieb zur Vergesellschaftung kam mit der Wahl eines Platzes für das Nest wieder, aber deutliche photonegativen Verhalten wurde erst beobachtet, wenn die Paare sich in Zellen eingelebt hatten. Die Plastizität des Verhaltens nach dem Flug wird erörtert.

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Résumé Des renseignements sont présentés sur les périodes et les heures de vol deCubitermes ugandensis etC. testaceus en Ouganda oriental. Presque tout le travail s'est effectué au laboratoire. Les ailés retirés du monticule étaient grégaires et négativement phototactiques. L'emploi des ailes renversa ces caractères. Les ailés nevolaient que s'ils étaient hors de contact avec d'autres termites de la colonie et dans la lumière. Des observations ont été faites sur l'intensité de la lumière et l'activité de vol chezC. ugandensis. La pariade ou un essai de pariade stimula l'amputation des ailes chez les deux espèces, mais, du moins chezC. ugandensis, cette stimulation n'était pas obligatoire. Après l'amputation des ailes, les adultes se montraient indifférents à la lumière. Par l'enlèvement artificiel des ailes, on a démontré que le rapport entre la perte des ailes et la perte de la phototaxie positive chezC. ugandensis n'est pas direct. Il y a une discussion des moyens utilisé par les, adultes pour perdre leurs ailes. En général, chez les deux espèces, les femelles n'adoptaient la posture d'appel que lorsqu'elles s'étaient accouplées avec un mâle et l'avaient perdu. En l'absence des mâles, les femelles deC. ugandensis couraient activement pendant plusieurs minutes après l'amputation de leurs ailes, puis prenaient la posture d'appel entre d'autres périodes de déplacement rapide. On nota l'emploi par les femelles deC. ugandensis dans la posture d'appel de ce qui paraissait être un mécanisme défensif contre les petits prédateurs. La présence des ailes n'empêcha pas la pariade chez l'une ou l'autre espèce. Des tandems mâles se voyaient souvent, mais ils étaient presque toujours instables. On n'a vu ni de tandems femelles ni une femelle derrière un mâle. Les tandems ne montraient aucune géotaxie positive et restaient indifférents à la lumière. Les femelles deC. ugandensis tendaient à grimper et redescendre pendant quelques minutes après la pariade. La thigmotaxie était importante dans le choix de l'emplacement du nid chez les deux espèces. Le creusement paraissait dépendre de facteurs extérieurs et ne pas faire partie d'un schéma de comportement. Une fois l'emplacement du nid choisi, les couples redevenaient grégaires, mais ils ne se montraient absolument photonégatifs que lorsqu'ils s'étaient installés dans des cellules. Il y a une discussion sur la plasticité du comportement après le vol.

     

Trichophyton simii in a "Caí" monkey (Cebus apella) colony in the province of Corrientes, Argentina.

The objective is to describe an outbreak of Trichophyton simii in a Cebus apella monkey colony in Argentine. During summer, alopecic zones appeared on dorsal regions from head to base of the tail of the animals. The hair and skin of nine animals were streaked onto Sabouraud dextrose with cloramphenicol and incubated at 25 degrees C. By the 10th day, white, filamentous colonies, which turned pale pink, developed from simples of four animals. Microscopical examinations were carried out and, because of colony and macroconidia morphology, were classified as Trichopyton simii. Although infection with T. simii is considered a zoonosis, we did not find human cases.     

Sooty Shearwater (<Emphasis Type="Italic">Puffinus griseus</Emphasis>) on Guafo Island: the largest seabird colony in the world?

Sooty Shearwater (Puffinus griseus) is the most common Procellariiform seabird along the south-eastern South American coast. In recent years the wintering population off California has declined noticeably. This decline has been confirmed on the breeding grounds in New Zealand. In Chile, knowledge of the population is limited. Investigations on Isla Guafo were carried out during two seasons (03/04 and 04/05), beginning an ongoing monitoring and evaluation of the breeding population of this species in southern South America. On Isla Guafo we estimate a population of about 4 million birds that nest above 150 m above sea level (m.a.s.l.) under a forest without understory. Sooty Shearwaters on Isla Guafo prefer north and western slopes that we hypothesise protect them from the predominantly southerly winds. Population of the species from New Zealand and Australia are compared with the Isla Guafo population and the state of its conservation is discussed.     

Does granulocyte colony stimulating factor have protective effects against carbon monoxide-induced apoptosis?

Carbon monoxide (CO) produced by incomplete combustion of hydrocarbons, has many toxic effects on different organs, especially the heart and brain that have greater demands for oxygen. The present study aimed to evaluate the protective effects of granulocyte colony stimulating factor (G-CSF) on apoptosis after CO poisoning in rats. Male Wistar rats were exposed to CO 1500 or 3000 ppm for 60 min. Single and multiple doses of G-CSF (10, 50, and 100 μg/kg) were administered to animals. After CO poisoning, carboxyhemoglobin concentration was measured, apoptotic cells were evaluated by TUNEL assay and caspase 3 activity was determined by immunofluorescence. Blood levels of carboxyhemoglobin significantly increased following exposure to both 1500 and 3000 ppm concentrations of CO. However, carboxyhemoglobin levels were significantly higher following exposure to CO 3000 ppm compared to CO 1500 ppm (p?<?0.05). Differences in caspase 3 activity between G-CSF and control groups were significant and G-CSF could decrease apoptosis following CO 3000 ppm poisoning (p?<?0.001). TUNEL assay showed that in rats treat with 5 doses of G-CSF 100 μg/kg, apoptosis was significantly ameliorated compared to control rats and sham (rats that were not exposed to CO) group (p?<?0.05). Concerning caspase 3 activity and apoptosis rate, the best results were found in rats exposed to 3000 ppm and treated with G-CSF 100 μg/kg. In this study, we confirmed that CO poisoning leads to cardiomyocytes apoptosis which could be significantly reduced by G-CSF treatment.     

Expression of the human granulocyte–macrophage colony stimulating factor (hGM-CSF) gene under control of the 5′-regulatory sequence of the goat alpha-S1-casein gene with and without a MAR element in transgenic mice

Expression of the human granulocyte–macrophage colony-stimulating factor (hGM-CSF) gene under the control of the 5′-regulatory sequence of the goat alpha-S1-casein gene with and without a matrix attachment region (MAR) element from the Drosophila histone 1 gene was studied in four and eight transgenic mouse lines, respectively. Of the four transgenic lines carrying the transgene without MAR, three had correct tissues-specific expression of the hGM-CSF gene in the mammary gland only and no signs of cell mosaicism. The concentration of hGM-CSF in the milk of transgenic females varied from 1.9 to 14 μg/ml. One line presented hGM-CSF in the blood serum, indicating ectopic expression. The values of secretion of hGM-CSF in milk of 6 transgenic lines carrying the transgene with MAR varied from 0.05 to 0.7 μg/ml, and two of these did not express hGM-CSF. Three of the four examined animals from lines of this group showed ectopic expression of the hGM-CSF gene, as determined by RT-PCR and immunofluorescence analyses, as well as the presence of hGM-CSF in the blood serum. Mosaic expression of the hGM-CSF gene in mammary epithelial cells was specific to all examined transgenic mice carrying the transgene with MAR but was never observed in the transgenic mice without MAR. The mosaic expression was not dependent on transgene copy number. Thus, the expected “protective or enhancer effect” from the MAR element on the hGM-CSF gene expression was not observed.