Cephalopod remains from stomachs of sperm whales (Physeter macrocephalus) that mass‐stranded along the Oregon coast

On 16 June 1979, a herd of 41 sperm whales stranded near the mouth of the Siuslaw River in Florence, Oregon. The stomach contents from 32 whales were collected, identified to the lowest taxonomic level possible, enumerated, and measured. A total of 20,247 cephalopod lower beaks that represented 24 species from 14 different families were recovered. The most numerous species were Histioteuthis hoylei (25.9%), Taonius borealis (12.9%), Galiteuthis phyllura (11.2%), Gonatopsis/Berryteuthis type (10.9%), and Moroteuthis robusta (10.7%). Reconstructed estimates of mass indicated that M. robusta contributed almost 50% of the total mass of cephalopods consumed, followed by H. hoylei (19.3%), and T. borealis (7.0%). The most important species in the diet of stranded whales were M. robusta, H. hoylei, T. borealis, G. phyllura, Octopoteuthis deletron, and Gonatopsis/Berryteuthis type. There were significant differences in the diet of males and females, but no differences between sperm whales of different age groups. Overall, sperm whales primarily consumed small cephalopods that were likely eaten south of 45ºN in or near the California Current System. This study provides new estimates of the food habits of sperm whales in the northeast Pacific from one of the largest strandings of this species.     

Activation of antifreeze proteins from larvae of the beetle Dendroides canadensis

Summary Purified antifreeze proteins (AFPs) from the larvae of the beetle Dendroides canadensis do not produce the high levels of antifreeze activity seen in the hemolymph of overwintering larvae, even when the purified AFPs are assayed at very high concentrations. However, addition of certain proteins or agar (at concentrations sufficiently low that the gel state does not result) to the Dendroides AFP resulted in a 2–3-fold increase in activity. A 70-kDa protein with AFP-activating capabilities was purified from Dendroides larvae. Addition of this endogenous activator protein to a 4 mg·ml^-1 solution of AFP increased the activity of the AFPs to values comparable to those of the hemolymph of overwintering larvae. Data derived from a modified immunoblot technique demonstrate that the activators bind to the AFP, or vice versa. Formation of this association must allow the AFP to block ice crystal growth by binding to the surface of potential seed crystals in the normal fashion. However, because the AFP-activator complex is much larger than the AFP alone, the complex probably blocks a greater surface area of the crystal and is thus a more efficient antifreeze.Abbreviations AFP antifreeze protein - BSA bovine serum albumine - DEAE diethylaminoethyl - Ig immunoglubolin - LPIN lipoprotein ice nucleator - PIN protein ice nucleator - SDS sodium dodecyl sulfate - PAGE polyacrylamide gel electrophoresis - TH thermal hysteresis     

Evidence for the involvement of a SchistoFLRF-amide-like peptide in the neural control of locust oviduct

Summary The presence of a SchistoFLRFamide-like peptide associated with the oviducts of Locusta migratoria has been shown using sequential reversed-phase high performance liquid chromatography separation coupled with radioimmunoassay and bioassay. The peptide is present in areas of the oviduct which receive extensive innervation, with sixfold less peptide in areas that receive little innervation. Material with FMRFamide-like immunoreactivity (determined by radioimmunoassay) is also present in the oviducal nerve and VIIth abdominal ganglion.SchistoFLRFamide is a potent modulator of contraction of this visceral muscle, inhibiting or reducing the amplitude and frequency of spontaneous contractions, relaxing basal tonus, and reducing the amplitude of neurally-evoked, proctolin-induced, glutamate-induced and high potassium-induced contractions. The FMRFamide-like immunoreactivity within the oviducts which co-elutes with SchistoFLRFamide on two separations is also capable of reducing the amplitude of neurally-evoked and proctolin-induced contractions, and of inhibiting spontaneous contractions and relaxing basal tonus.The effects of SchistoFLRFamide upon this visceral muscle are not abolished by the -adrenergic receptor antagonist phentolamine and do not appear to be mediated by cyclic AMP. Thus the receptors for Schisto-FLRFamide are distinct from those of octopamine which mediate similar physiological effects but which are blocked by phentolamine and which are coupled to adenylate cyclase.The results indicate that SchistoFLRFamide, or a very similar peptide, which has previously been identified as a modulator of locust heart beat, is also associated with visceral muscle of the reproductive system, and may play a neural role in concert with octopamine, at modulating muscular activity.Abbreviations BPP Bovine pancreatic polypeptide - BSA Bovine serum albumin - EJP Excitatory junctional potential - FaRPs FMRFamide-related peptides - FLI FMRFamide-like immuno-reactivity - LMS Leucomyosuppressin - RIA Radioimmunoassay - RP-HPLC Reversed-phase high performance liquid chromatography - TFA Trifluoroacetic acid     

Wide-field motion-sensitive neurons tuned to horizontal movement in the honeybee,Apis mellifera

This paper describes the morphology and response characteristics of two types of paired descending neurons (DNs) (classified as DNVII₁ and DNIV₁) and two lobula neurons (HR1 and HP1) in the honeybee, Apis mellifera.

IFT52 plays an essential role in sensory cilia formation and neuronal sensory function in Drosophila

Cilia are microtubule-based, hair-like organelles involved in sensory function or motility, playing critical roles in many physiological processes such as reproduction, organ development, and sensory perception. In insects, cilia are restricted to certain sensory neurons and sperms, being important for chemical and mechanical sensing, and fertility. Although great progress has been made regarding the mechanism of cilia assembly, the formation of insect cilia remains poorly understand, even in the insect model organism Drosophila. Intraflagellar transport (IFT) is a cilia-specific complex that traffics protein cargos bidirectionally along the ciliary axoneme and is essential for most cilia. Here we investigated the role of IFT52, a core component of IFT-B, in cilia/flagellar formation in Drosophila. We show that Drosophila IFT52 is distributed along the sensory neuronal cilia, and is essential for sensory cilia formation. Deletion of Ift52 results in severe defects in cilia-related sensory behaviors. It should be noted that IFT52 is not detected in spermatocyte cilia or sperm flagella of Drosophila. Accordingly, ift52 mutants can produce sperms with normal motility, supporting a dispensable role of IFT in Drosophila sperm flagella formation. Altogether, IFT52 is a conserved protein essential for sensory cilia formation and sensory neuronal function in insects.     

The relationship of hemolymph osmotic pressure to spermatogenesis in the tobacco budworm,Heliothis virescens

The hemolymph osmotic pressure of male Heliothis virescens last instar larvae and pupae can be correlated with the state of spermatogenesis: intermediate (approx. 325 mOsm/kg) osmotic pressures are found in pre-meiotic animals, low (approx. 300 mOsm/kg) osmotic pressures characterize meiosis and elongation, and high (approx. 370 mOsm/kg) osmotic pressures, characterize the tests of diapausing pupae, where mature sperm have disappeared and only pre-meiotic sperm are found. In vitro studies show that, as the osmotic pressure of the medium is increased, spermatogenesis is inhibited and the survival of pre-meiotic cysts is enhanced. It is proposed that the osmotic pressure of the hemolymph plays a role in spermatogenesis and in the preservation of immature cysts during diapause.     

The effect of Agonoscena targionii (Licht.) (Homoptera: Psylloidea) on seed production by Pistacia terebinthus L.

This study investigated the potential negative effect that psyllids may have on the production of viable seeds in Pistacia terebinthus, a wild plant species with a circummediterranean distribution. Manipulative experiments, involving the application of insecticide, showed that the reduction in fruit maturation is rather low, not exceeding 10%. This is mainly due to other factors that determine seed inviability. Such factors include those intrinsic to the plant, such as parthenocarpy and seed abortion, and extrinsic to it, such as seed predation by chalcidoid wasps. There is much variation in the frequency of psyllids per plant; such variation appears uncorrelated with variables decribing plant size, fecundity, and distance to fruiting conspecifics. No consistency in the incidence of psyllids on a given individual plant was found between years.     

Expression of the human antigen SPAG2 in the testis and localization to the outer dense fibers in spermatozoa

Antisperm antibodies (ASAs) have been implicated in some instances of infertility. To characterize sperm antigens relevant to immunologic and immunocontraceptive development, SPAG2 (sperm-associated antigen 2) was identified by screening a human testis cDNA library with human sera positive for ASAs. Subsequently, two isoforms, SPAG2–1 and SPAG2–2, were identified in testis and placenta libraries, respectively. In the current study, Southern analysis of human genomic DNA with a probe common to the two SPAG2 isoforms indicated a single SPAG2 gene; therefore, alternative splicing is a likely mechanism for production of variant mRNAs. In situ hybridization of human testis sections demonstrated the expression of SPAG2 in primary spermatocytes, with decreased or arrested expression in postmeiotic cells. Immunofluorescence of Triton X-100–extracted spermatozoa with an anti-SPAG2 peptide antiserum indicate that SPAG2 is an intracellular component of the sperm flagellum. Electron microscopy refined this localization to the outer dense fibers (ODFs), structural filaments associated with the mammalian sperm axoneme. The ODFs have been reported to be composed of keratinlike intermediate filament proteins. However, SPAG2 does not exhibit the molecular characteristics of such proteins, nor does SPAG2 demonstrate sequence homology with previously characterized ODF proteins. Therefore, SPAG2 represents a novel protein of human sperm ODFs. Characterization of SPAG2 will further our understanding of ODF function in normal sperm motility and of flagellar abnormalities that lead to male infertility. Mol. Reprod. Dev. 50:284–293, 1998. © 1998 Wiley-Liss, Inc.     

Directional control by male gypsy moths of upwind flight along a pheromone plume in three wind speeds

By attaching a reflective strip to the thorax, we documented with video recordings in a wind tunnel the spatial orientation of male gypsy moths, Lymantria dispar, as they flew along a plume of sex pheromone. In wind speeds of 61, 122, and 183 cm s⁻¹, moths flew very similar tracks along a pheromone plume. Moths aimed their thrust closer to upwind in increasing wind speeds using a roll maneuver. As a result, the orientation of their visual flow field, represented by the slip angle (the angular distance between the direction of flight and the longitudinal body axis), remained relatively constant. We propose that directional control during self-steered zigzagging is achieved by rolling, thereby maintaining a set slip angle. Following a roll at the apex of a turn that aligns the moth with its preferred slip angle, a moth banks toward a cross wind leg. By banking moths may maintain a stable image flow at oblique angles to their longitudinal body axis. Accepted: 16 July 1998