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221.
Leclaire S Merkling T Raynaud C Giacinti G Bessière JM Hatch SA Danchin E 《Die Naturwissenschaften》2011,98(7):615-624
The importance of olfaction in birds’ social behavior has long been denied. Avian chemical signaling has thus been relatively
unexplored. The black-legged kittiwake provides a particularly appropriate model for investigating this topic. Kittiwakes
preferentially mate with genetically dissimilar individuals, but the cues used to assess genetic characteristics remain unknown.
As in other vertebrates, their body odors may carry individual and sexual signatures thus potentially reliably signaling individual
genetic makeup. Here, we test whether body odors in preen gland secretion and preen down feathers in kittiwakes may provide
a sex and an individual signature. Using gas chromatography and mass spectrometry, we found that male and female odors differ
quantitatively, suggesting that scent may be one of the multiple cues used by birds to discriminate between sexes. We further
detected an individual signature in the volatile and nonvolatile fractions of preen secretion and preen down feathers. These
results suggest that kittiwake body odor may function as a signal associated with mate recognition. It further suggests that
preen odor might broadcast the genetic makeup of individuals, and could be used in mate choice to assess the genetic compatibility
of potential mates. 相似文献
222.
Lu Y Beeman RW Campbell JF Park Y Aikins MJ Mori K Akasaka K Tamogami S Phillips TW 《Die Naturwissenschaften》2011,98(9):755-761
We report that the abdominal epidermis and associated tissues are the predominant sources of male-produced pheromones in the
red flour beetle, Tribolium castaneum and, for the first time, describe the stereoisomeric composition of the natural blend of isomers of the aggregation pheromone
4,8-dimethyldecanal (DMD) in this important pest species. Quantitative analyses via gas chromatography–mass spectrometry showed
that the average amount of DMD released daily by single feeding males of T. castaneum was 878 ± 72 ng (SE). Analysis of different body parts identified the abdominal epidermis as the major source of aggregation
pheromone; the thorax was a minor source, while no DMD was detectable in the head. No internal organs or obvious male-specific
glands were associated with pheromone deposition. Complete separation of all four stereoisomers of DMD was achieved following
oxidation to the corresponding acid, derivatization with (1R, 2R)- and (1S, 2S)-2-(anthracene-2,3-dicarboximido)cyclohexanol to diastereomeric esters, and their separation on reversed-phase high-performance
liquid chromatography at −54°C. Analysis of the hexane eluate from Porapak-Q-collected volatiles from feeding males revealed
the presence of all four isomers (4R,8R)/(4R,8S)/(4S,8R)/(4S,8S) at a ratio of approximately 4:4:1:1. A walking orientation bioassay in a wind tunnel with various blends of the four synthetic
isomers further indicated that the attractive potency of the reconstituted natural blend of 4:4:1:1 was equivalent to that
of the natural pheromone and greater than that of the 1:1 blend of (4R,8R)/(4R,8S) used in commercial lures. 相似文献
223.
The sympatric neotropical termites Nasutitermes corniger and Nasutitermes ephratae are clearly distinguishable based on morphology, nest architecture, defensive secretion composition, and molecular markers.
However, given the extensive ecological, geographical, and behavioral overlap of these closely related species, the potential
for interbreeding may exist. To explore this possibility, heterospecific pairs were formed experimentally to examine courtship
and colony-establishment behaviors, and reproductive potential. Courtship and nest construction behavior occurred in heterospecific
pairs in a similar manner to that of conspecific pairs. Survival of pairs depended upon the species of the female partner.
N. ephratae females paired with N. corniger males produced as many offspring as conspecific pairs. N. corniger females mated to N. ephratae males, however, produced significantly fewer offspring at 60 days post-establishment than the reciprocal cross or conspecific
N. ephratae or N. corniger pairs. This was also the only pairing in which any aggression was observed. Heterospecific pairs and groups formed in mate
choice mesocosms, suggesting that species recognition between these two termites is not an important aspect of mate choice.
Overall, species mismatch tolerance and hybrid offspring viability are high. The present data, together with previous evidence
from defensive secretions and isozyme analysis, suggest that hybridization may periodically occur in nature, and that reproductive
barriers between these two species may be incomplete. Hybridization could provide a rare but important source of genetic diversity
and may ensure mating opportunities for the more abundant sex of alates in each species. 相似文献
224.
A postanal tail is a major synapomorphy of the phylum Chordata, which is composed of three subphyla: Vertebrata, Cephalochordata,
and Tunicata (Urochordata). Among tunicates, appendicularians are the only group that retains the tail in the adult, and the
adult tail functions in locomotion and feeding in combination with a cellulose-based house structure. Given the phylogenetic
position of tunicates, the appendicularian adult tail may possess ancestral features of the chordate tail. We assess the ultrastructural
development of the tail epidermis of the appendicularian Oikopleura dioica. The epidermis of the larval tail is enclosed by the larval envelope, which is a thin sheet similar to the outer tunic layer
of ascidian larvae. The epidermis of the adult tail seems to bear no tunic-like cellulosic integuments, and the tail fin is
a simple folding of the epidermis. Every epidermal cell, except for the triangular cells at the edge of the tail fin, has
a conspicuous matrix layer of fibrous content in the apical cytoplasm without enclosing membranes. The epidermis of the larval
tail does not have a fibrous matrix layer, suggesting the production of the layer during larval development and metamorphosis.
Zonulae adhaerentes firmly bind the epidermal cells of the adult tail to one another, and the dense microfilaments lining
the cell borders constitute a mechanical support for the cell membranes. The intracellular matrix, cell junctions, and cytoskeletons
probably make the tail epidermis a tough, flexible shell supporting the active beating of the oikopleuran adult tail. 相似文献
225.
Pigeons were released at two sites of equal distance from the loft, one within a magnetic anomaly, the other in magnetically
quiet terrain, and their tracks were recorded with the help of GPS receivers. A comparison of the beginning of the tracks
revealed striking differences: within the anomaly, the initial phase lasted longer, and the distance flown was longer, with
the pigeons' headings considerably farther from the home direction. During the following departure phase, the birds were well
homeward oriented at the magnetically quiet site, whereas they continued to be disoriented within the anomaly. Comparing the
tracks in the anomaly with the underlying magnetic contours shows considerable differences between individuals, without a
common pattern emerging. The differences in magnetic intensity along the pigeons' path do not differ from a random distribution
of intensity differences around the release site, indicating that the magnetic contours do not directly affect the pigeons'
routes. Within the anomaly, pigeons take longer until their flights are oriented, but 5 km from the release point, the birds,
still within the anomaly, are also significantly oriented in the home direction. These findings support the assumption that
magnetically anomalous conditions initially interfere with the pigeons' navigational processes, with birds showing rather
individual responses in their attempts to overcome these problems. 相似文献
226.
Bogers R De Vries-Buitenweg S Geuijen I van de Waart B Kuiper R Van Der Linden S Puijker L Murk A Van Der Burg B Legler J 《Environment international》2007,33(3):292-301
Adult male fathead minnow were exposed for 14 or 28-days under flow-through conditions to undiluted filtered water samples from the rivers Meuse and Rhine in the Netherlands. The experiment included two vessels per treatment each containing 10 fish and samples of five fish were taken after 14 and 28 days. Additional groups were exposed to 17alpha-ethinylestradiol (EE2) as a reference and untreated drinking water as a negative control. Major endpoints examined included induction of vitellogenin (VTG) synthesis, VTG mRNA activity, hepato- and gonadosomatic indices (HSI and GSI) and gonadal histology. No significant difference was recorded in body weight or mean GSI values between the various treatments. Only exposure to Meuse water resulted in significantly higher HSI means after 14 days. Histological examination showed no apparent effects on gonadal tissue except for eosinophilic blood plasma in fish exposed to Meuse water or EE2. After 14 and 28 days, elevated VTG and VTG mRNA levels were measured in most livers of the fish exposed to Meuse water, but not in the fish exposed to Rhine water. This was confirmed by measuring estrogenic responses in the in vitro ER CALUX assay. Induction of VTG synthesis proved to be the most sensitive endpoint in the Non Spawning Male Fish Assay for in vivo detection of bio-available estrogenic activity supplementary to a sensitive in vitro assay. The other endpoints examined varied too much and required a higher number of fish or replicates to achieve sufficient power for statistical testing making them less animal friendly. 相似文献
227.
Martín-Díaz ML Kalman J Riba I de la Reguera DF Blasco J DelValls A 《Environment international》2007,33(4):463-468
Ecotoxicological effects associated with contaminants present in dredged material from Spain were determined using a marine biotest based on the determination of metallothionein-like-protein concentrations (MTLPs) in the shore crab Carcinus maenas. Intermoult female C. maenas were exposed in the laboratory to sediments from three Spanish ports, Ría de Huelva (SW, Spain), La Coru?a (NW, Spain) and Bahía de Cádiz (SW, Spain) per replicate during 21 days. Hepatopancreas samples from crabs were taken for metallothioneins analysis on days 0, 7 and 21. Furthermore, chemical analysis was performed in the stations to determine the degree and nature of sediment contamination (Cr, Ni, Cu, Zn, Cd, Pb, Hg, As, PAHs and PCBs). A significant increase (p<0.05) in metallothionein concentration was observed over time in individuals exposed to sediment from the port Ría de Huelva characterized by high concentrations of metals. A toxicokinetic approach is proposed in this study related to the use of this biomarker in C. maenas to evaluate bioavailability associated with metals present in dredged material. As a first step, this toxicokinetic approach might reveal as a sensitive tool for evaluating bioavailability of contaminants present in dredged material. 相似文献
228.
In beaver ponds, the species diversity, abundance, biomass, and production of cladocerans and the amount of food consumed by them have increased and the composition of dominant species has changed as compared to those in the stretches of small rivers with running water or dammed by man. The stimulating effect of water from a beaver pond has been confirmed in laboratory experiments. The average number of juvenile Ceriodaphnia affinis produced by one female was considerably greater in this water than in the water from flowing and dammed (by man) river stretches. 相似文献
229.
D. M. S. Esquivel A. A. C. Corrêa O. S. Vaillant V. Bandeira de Melo G. S. Gouvêa C. G. Ferreira T. A. Ferreira E. Wajnberg 《Die Naturwissenschaften》2014,101(3):245-249
Insects have been used as models for understanding animal orientation. It is well accepted that social insects such as honeybees and ants use different natural cues in their orientation mechanism. A magnetic sensitivity was suggested for the stingless bee Schwarziana quadripunctata, based on the observation of a surprising effect of a geomagnetic storm on the nest-exiting flight angles. Stimulated by this result, in this paper, the effects of a time-compressed simulated geomagnetic storm (TC-SGS) on the nest-exiting flight angles of another stingless bee, Tetragonisca angustula, are presented. Under an applied SGS, either on the horizontal or vertical component of the geomagnetic field, both nest-exiting flight angles, dip and azimuth, are statistically different from those under geomagnetic conditions. The angular dependence of ferromagnetic resonance (FMR) spectra of whole stingless bees shows the presence of organized magnetic nanoparticles in their bodies, which indicates this material as a possible magnetic detector. 相似文献
230.
Samira Veiga Ravaiano Ríudo de Paiva Ferreira Lucio Antonio de Oliveira Campos Gustavo Ferreira Martins 《Die Naturwissenschaften》2014,101(8):603-611
The sensilla of insects are integumental units that play a role as sensory structures and are crucial for the perception of stimuli and for communication. In this study, we compared the antennal sensilla of females (workers and queens), males (haploid (n) and diploid (2n)), and queen-like males (QLMs, resulting from 2n males after juvenile hormone (JH) treatment) in the stingless bee Melipona quadrifasciata. Images of the dorsal antenna surfaces were acquired using a scanning electron microscope. As reported for other hymenopterans, this species exhibits a heterogeneous sensillar distribution along the antennae. Thirteen different types of sensilla were found in the antennae of M. quadrifasciata: trichodea (subtypes I to VI), chaetica (subtypes I and II), placodea, basiconica, ampullacea, coeloconica, and coelocapitula. Sensilla trichodea I were the most abundant, followed by sensilla placodea, which might function in olfactory perception. Sensilla basiconica, sensilla chaetica I, sensilla coeloconica, and sensilla ampullacea were found exclusively in females. In terms of the composition and size of the sensilla, the antennae of QLMs most closely resemble those of the 2n male, although QLMs exhibit a queen phenotype. This study represents the first comparative analysis of the antennal sensilla of M. quadrifasciata. The differences found in the type and amount of sensilla between the castes and sexes are discussed based on the presumed sensillary functions. 相似文献