Rhabdom Size and Chromophore Contents under the Daily Light Cycle in the Blowfly, Lucilia cuprina

The eyes of the fly have been employed in an extensive range of studies, but the existence of diurnal rhythmicity, which is involved in the adaptation to different light environments between the day and night is still unclear. The rhythmicity of the photoreceptor cells of the blowfly Lucilia cuprina was observed over a precise time schedule under a daily light cycle. Both the morphology of the photoreceptive structure called rhabdom and the amount of the visual pigment chromophore were mostly constant. Each photoreceptor area measured from the cross sections and each amount of chromophore was ca. 22.5±1.85 μm2 and ca. 1.4 pmol, respectively. The number of the multivesicular bodies, assuming the indicator of the photoreceptive membrane turnover, was small compared with other reports of arthropods. We confirmed that there is no diurnal rhythmicity either in the morphology of rhabdom or in the visual pigment contents under the daily light cycles

Sky radiance and spectral gradient are orienting cues for the sandhopper Talitrus saltator (Crustacea, Amphipoda).

The sandhopper Talitrus saltator relies on both the sun and the moon compasses to return to the belt of damp sand of the beach in which it lives buried during the day. In addition to the sun, the gradient of radiance and the spectral distribution across the sky could provide directional information that T. saltator can potentially use to orient itself during the day even when the sun is not visible (e.g. cloudy sky). The scope of this work was 1) to determine the intensity levels of sky radiance that the sandhoppers use in their zonal recovery and 2) to investigate whether this species relies on the celestial spectral gradient in its zonal recovery. Sandhoppers were tested in the laboratory under artificial radiance or spectral gradients.Our results show that under an artificial sky, simulating the natural radiance gradient on a cloudless day, sandhoppers orientated toward the correct seaward direction of their home beach, however, individuals lost their ability to use the intensity gradient as an orientation cue when the radiance was attenuated by at least 40%. Sandhoppers were also able to head in the correct seaward direction of their home beach at any time of the day by using the spectral gradient as their only source of visual orientation reference

Sampling, identification and sensory evaluation of odors of a newborn baby’s head and amniotic fluid

For baby odor analyses, noninvasive, stress-free sample collection is important. Using a simple method, we succeeded in obtaining fresh odors from the head of five newborn babies. These odors were chemically analyzed by two-dimensional gas chromatography coupled with mass spectrometry (GC x GC-MS), and compared with each other or with the odor of amniotic fluid from the baby\u27s mother. We identified 31 chemical components of the volatile odors from neonate heads and 21 from amniotic fluid. Although 15 of these components were common to both sources, there was an apparent difference in the GC x GC patterns between the head and amniotic fluid odors, so the neonate head odor might be individually distinct immediately after birth. Therefore, we made artificial mixtures of the major odor components of the neonate head and maternal amniotic fluid, and used psychological tests to examine whether or not these odors could be distinguished from each other. Our data show that the artificial odor of a neonate head could be distinguished from that of amniotic fluid, and that the odors of artificial head odor mixtures could be correctly discriminated for neonates within an hour after birth and at 2 or 3 days of age

A Putative Sugar-binding Protein in the Chemosensory Organ of the Fruit Fly, Drosophila melanogaster

A single chemosensillum usually includes five sensory cells, and one of them is traditionally called as the sugar receptor cell. We have collected the legs and wings of the fruit fly, Drosophila melanogaster, using several grades of sieve and here demonstrate the presence of the putative pyranose-site protein by a two-dimensional affinity electrophoresis method