Interspecific variation in the defence secretions of Nasutitermes soldiers

Termite soldiers of the genus Nasutitermes (Isoptera, Termitidae, Nasutitermitinae) eject a viscous, sticky defense secretion composed of non-polar monoterpene hydrocarbons and polyoxygenated diterpenes from the frontal gland. Chemical compositions are described in detail for the East African species, N. kempae and N. infuscatus, and for the Neotropical species N. ephratae. Additional comparisons with the new world species N. costalis, N. rippertii and N. octopilis are presented. The structure of a new monohydroxykempene from N. ephratae is described, and a physicochemical model for the stickiness of the glue is presented. Although the structures of the individual secretion components vary within the genus, the glue-like nature of the secretion remains essentially unchanged. Chemical analysis of soldier defense secretions may be useful in studying the systematic biology of termites.     

Intraspecific variation in soldier defense secretions of Longipeditermes longipes (Isoptera,Nasutitermitinae)

The chemical defense secretions of major and minor soldiers of 46 colonies of the free-ranging termite Longipeditermes longipes (Isoptera, Termitidae, Nasutitermitinae) were isolated and analyzed by chromatography and spectroscopy. The colonies, collected from rainforest sites in Malaysia, showed monoterpene patterns rich in pinenes and limonene but with few qualitative differences among colonies. In marked contrast, the diterpene chemistry is highly variable that includes bicyclic (secotrinervitane), tricyclic (trinervitane), tetracyclic (rippertane), and a spirotetracyclic (longipane) skeleton. This paper presents the compositional and structural diversity, and calculates genetic distances among sympatric and allopatric colonies from a single species.     

Study of the dynamics of sertoli cell secretions in a new superfusion,two-compartment culture system

Summary A new superfusion, two-compaatment culture system recently developed in our laboratory was used to investigate the dynamic changes in bidirectional secretion of transferrin, (Trf) and androgen binding protein (ABP) by rat Sertoli cells (Sc) cultured for up to 12 d under various experimental conditions. The system is unique in that the cells are grown on porous substrate and can be superfused independently at the apical (A) and basal (B) surfaces. The Sc formed confluent monolayers with tight junctions and were highly polarized, morphologically resembling their normal appearance in vivo. The bidirectional secretion patterns (total amount and A:B ratio) of both Trf and ABP were affected by the addition of hormones (testosterone, 10⁻⁶ M; follicle stimulating hormone, 0.1 μg/ml; and fetal bovine serum 2%), but not by changes in the medium flow rate (0.8 to 3.2 ml/h). The superfusion, two-compartment culture system provides a very useful model for culture of polarized cell monolayers and for the study of bidirectional secretions under more “physiologic” conditions than those provided by static cultures. This work was supported in part by grant HD 17802 (AS) from the National Institutes of Health, Bethesda, MD.     

Ability of bed bug (Hemiptera: Cimicidae) defensive secretions (E)‐2‐hexenal and (E)‐2‐octenal to attract adults of the common bed bug Cimex lectularius

Accurate and timely surveillance of bed bug infestations is critical for the development of effective control strategies. Although the bed bug‐produced volatiles (E)‐2‐hexenal and (E)‐2‐octenal are considered as defensive secretions, the present study demonstrates, using ethovision® video‐tracking software (Noldus Information Technology Inc., Leesburg, Virginia), that low amounts of these commercially‐obtained aldehydes function as attractants, and high amounts function as local repellents, against the common bed bug Cimex lectularius L. In behavioural assays, both males and female C. lectularius are attracted to 0.04 µg of an aldehyde blend (1 : 1) for up to 1 h after initial treatment of filter paper disks. Males differ from females in their response to higher amounts of aldehydes, with females and males exhibiting maximum local repellency at 40 µg and 400 µg, respectively. The results suggest that these bed bug secretions may be candidates for lures and monitors.     

A possible phylogenetic signal in milliped chemical defenses: The polydesmidan milliped Leonardesmus injucundus Shelley & Shear secretes p-cresol and lacks a cyanogenic defense (Diplopoda, Polydesmida, Nearctodesmidae)

The nearctodesmid polydesmidan milliped Leonardesmus injucundus Shelley and Shear was found to secrete p-cresol as a defensive fluid, and to lack mandelonitrile, benzaldehyde and hydrogen cyanide, heretofore found to be characteristic of most polydesmidan millipeds. The sympatric nearctodesmid Kepolydesmus anderisus Chamberlin does not secrete p-cresol, but utilizes the usual cyanogenic pathway. These are only the second reports on defensive secretions in the milliped family Nearctodesmidae. p-Cresol may be the characteristic secretion of members of the nematophoran order Callipodida (p-cresol is reported here from Delophon georgianum Chamberlin [Callipodida, Abacionidae] for the first time) and thus its presence in a polydesmidan may be indicative of a relationship between Callipodida and Polydesmida, which orders share other synapomorphies. Examples of two species of Glomeridesmus (Glomeridesmida, Glomeridesmidae) were examined and found to lack any sign of repugnatorial pores.     

Defensive Secretions in Callipodella fasciata (Latzel, 1882; Diplopoda,Callipodida, Schizopetalidae)

The small millipede Callipodella fasciata secretes an earthy smell when disturbed. This secretion was obtained by CH₂Cl₂ extraction from specimens of both sexes and was identified by GC/MS analyses to be composed of p‐cresol (96.5%), phenol (3.5%), and p‐ethylphenol (traces). This is the first identification of these compounds in an epigean European callipodidan species and the first report of intergeneric differences in the chemical composition of defensive secretions in callipodidans. These compounds have repellent, antimicrobial, and antifungal properties.     

Induction of the acrosome reaction in the spermatozoa of the goat by secretions of the male accessory glands and milk

The balancing effects of bulbourethral gland secretion (BUS) and of seminal vesicle secretion (SVS) on goat semen quality were previously demonstrated. In the present study, electron microscope observations revealed a high frequency of spermatozoa with a reacted acrosome among spermatozoa from cauda epididymis exposed to BUS in the presence of milk. This frequency was significantly reduced when SVS had been added either before or after BUS. No reacted acrosome was observed in the absence of milk. All mount spermatozoa were incubated with milk or SVS or BUS or combinations of the three materials labeled with colloidal gold. SVS attached specifically on the plasma membrane covering the anterior part of the acrosome, whereas BUS spread all over the sperm head. Milk attached on the anterior half of the sperm head only when BUS was present in the sperm environment. It is concluded that BUS plays an active role in the induction of the acrosome reaction in the presence of milk and that SVS counteracts this role.     

The role of Dufour's gland secretions in bees

ABSTRACT. Dufour's gland of bees is often hypertrophied and an extremely rich source of diverse natural products. In the ground-dwelling bees the secretion is mostly used for lining the brood cell with a hydrophobic lining. Whereas in several species the secretion is smeared on the cell walls without any modification, in others the hydrophobic lining is formed only after a chemical transformation of the secretion. The diversity of the chemical means by which hydrophobicity of the brood cells is achieved suggests that it has evolved repeatedly in the bees. In addition to lining their brood cells, several species use Dufour's gland secretion to mark their nest entrance. Analyses of single glands from various species reveal that each bee possesses its own individual composition, expressed in specific relative amounts of each component. Interestingly in the social halictid Evylaeus malachurum , nestmates (considered as sisters) are more similar to each other than non-related bees. The possible functional evolution of the glandular exudate from structural functions to communication and its implications for our understanding of eusociality in bees, is discussed.     

Gastric emptying during walking and running: effects of varied exercise intensity

Gastric emptying is increased during running (50%-70% maximal aerobic uptake, VO2max) as compared to rest. Whether this increase varies as a function of mode (i.e. walking vs running) and intensity of treadmill exercise is unknown. To examine the gastric emptying characteristics of water during treadmill exercise performed over a wide range of intensities relative to resting conditions, 10 men ingested 400 ml of water prior to each of six 15 min exercise bouts or 15 min of seated rest. Three bouts of walking exercise (1.57 m.s-1) were performed at increasing grades eliciting approximately 28%, 41% or 56% of VO2max. On a separate day, three bouts of running (2.68 ms-1) exercise were performed at grades eliciting approximately 57%, 65% or 75% of VO2max. Gastric emptying was increased during treadmill exercise at all intensities excluding 75% VO2max as compared to rest. Gastric emptying was similar for all intensities during walking and at 57% and 65% VO2max during running. However, running at 74% VO2max decreased the volume of original drink emptied as compared to all lower exercise intensities. Stomach secretions were markedly less during running as compared to walking and rest. These data demonstrate that gastric emptying is similarly increased during both moderate intensity (approximately 28%-65% VO2max) walking or running exercise as compared to resting conditions. However, gastric emptying decreases during high intensity exercise. Increases in gastric emptying during moderate intensity treadmill exercise may be related to increases in intragastric pressure brought about by contractile activity of the abdominal muscles.     

Structural differences in the vicinity of the waxy locus among the Oryza species with the AA-genome: identification of variable regions

We constructed a fine physical map for a 260-kb rice BAC contig surrounding the waxy locus. In order to identify variable regions within this 260-kb as to the restriction fragments length polymorphisms and copy numbers, sixty overlapping fragments derived from the 260-kb contig were used as probes to compare their corresponding structures among the Oryza species with AA-genome. According to the hybridization patterns, each fragment was classified into four types; true single copy (class 1), single copy with a smear background (class 2), multiple copy without a smear background (class 3), and only a smear background (class 4). Out of 16 single copy (class 1 and class 2) regions obtained in this map, the one site corresponding to wx gave rise to remarkable polymorphisms among AA-genome species in Oryza. In most of the fragments observed as repetitive segments (class 4), we could not find obvious differences in the hybridization pattern. However, interestingly, one site sorted into class-3 showed copy numbers varying among the lines. The lines belonging to O. sativa O. rufipogon, O. meridionalis,and O. longistaminata possessed high-copy numbers of this fragment, whereas only a few bands were detected in the lines from O. glaberrima, O. barthii, and O. glumaepatula. The two variable regions found within the AA-genome species represented genomic dynamisms. Received: 3 February 1999 / Accepted: 22 June 1999