Accessory sex glands as a tool to measure the efficacy of immunocastration in male pigs

The use of an anti-gonadotropin-releasing hormone vaccine for immunocastration of male pigs has been recently approved in the European Union. This technique is potentially useful for avoiding both castration-associated pain for the animal and boar taint in pork. However, some animals may escape immunocastration and be slaughtered as entire males, potentially exhibiting boar taint. Therefore, it is important to check the efficacy of immunocastration on the slaughter line. To achieve that, the currently proposed method, based on testis weight, is not fully reliable because there is some overlap in the distributions of testis weight between immunocastrates and entire males. On the basis of literature data on the effect of immunocastration on the development of accessory sex glands, this paper provides evidence that the weight of seminal vesicles might be a much better criterion for checking the efficacy of immunocastration, because their size decreases more rapidly, and to a greater extent, than that of the testis.     

Shoot anatomy and secretory structures in Hypericum species (Hypericaceae)

The anatomy and ultrastructure of internodes, leaves and petals were compared in Hypericum elegans, H. inodorum, H. olympicum, H. forrestii and two genotypes of H. perforatum. Internode anatomy was variable between species with respect to the structure of the cortical and pith parenchyma, including the presence of secretory reservoirs. Also, the secondary growth was more extensive in shrubs, i.e. H. inodorum and H. forrestii. In leaves, phloem secretory reservoirs were formed in all species, mesophyll secretory reservoirs were absent only in H. elegans and internal nodules were present only in H. elegans and H. perforatum. The petals differed between species in the mesophyll structure and the occurrence and location of secretory structures. The phloem secretory reservoirs lacked sheaths, whereas these were distinct in the mesophyll reservoirs. Other ultrastructural traits of the reservoirs were similar in all the species studied, with the exception of the leucoplast ultrastructure. In internal nodules, the inner cells vs. sheath cells differed in the number of vesicles and other membranous structures and plastid ultrastructure. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163 , 70–86.     

Effects of the dioxin-like PCB 126 on larval summer flounder (Paralichthys dentatus)

Little is known about the sensitivity of teleost post-embryonic developmental stages (larval and metamorphic) to dioxin-like compounds. Larval and metamorphosing summer flounder (Paralichthys dentatus) were exposed to the dioxin-like polychlorinated biphenyl congener PCB 126, to compare their sensitivity to other fish species early life stages, and to document effects on metamorphic development, including degree of eye migration and gastric maturation. Median lethal doses (LD 50 s) ranged between 30 and 220 ng/g wet mass, indicating that pre- and early-metamorphic stages of summer flounder are equally sensitive to the embryos of some of the most vulnerable fish species tested. Consistent with the presence of a functional aryl hydrocarbon receptor pathway, dose-dependent induction of cytochrome P-4501A (CYP1A) at four days post-exposure was observed in liver, stomach, intestine, and kidney of metamorphosing larvae. Stage-dependent differences in the epithelial distribution of CYP1A immunoreactivity were observed in the developing stomach of fish exposed to relatively high PCB 126 doses. A single sublethal dose (15 ng/g) delayed metamorphic progress (determined by the degree of eye migration), and resulted in abnormally high levels of cell proliferation and abnormal gastric gland morphology in late metamorphic stages. These results suggest that the post-embryonic larval and metamorphic stages of summer flounder, and potentially other fish species with complex life histories, are vulnerable to the effects of dioxin-like compounds, including lethality, developmental delay, and malformations.     

Foreword

The morphology of abdominal and alar androconial organs of four species representing four genera of danaine butterflies is described in detail, based mainly on scanning electron microscopy. The findings are discussed with respect to functional significance and phyletic development of the organs.     

Androconial systems in Danainae (Lepidoptera): functional morphology of Amauris, Danaus, Tirumala and Euploea

The morphology of abdominal and alar androconial organs of four species representing four genera of danaine butterflies is described in detail, based mainly on scanning electron microscopy. The findings are discussed with respect to functional significance and phyletic development of the organs.     

Anti-predator defence mechanisms in sawfly larvae of Arge (Hymenoptera, Argidae)

Larvae of the sawfly Arge (Hymenoptera, Argidae) are exposed to predators such as ants. Their defence mechanisms, which have been almost unstudied, were investigated by behavioural observations coupled to a morphological approach and by testing the bioactivity of several body parts. Arge larvae raised their abdomen when contacted by Myrmica rubra workers. The ants rarely bit a larva and generally retreated immediately, sometimes without contacting it. Most of those few ants that bit a larva then showed an uncoordinated walk. Crude hemolymph from a common species, A. pagana, was a feeding deterrent towards ants. Hemolymph extracts remained active up to a concentration of 0.8 microg DW extract per microlitre solution, and were more active than integument and gut extracts. We also observed ants paralysed by extracts, especially from the gut. It is likely that this toxicity is due to a polypeptide, lophyrotomin, which is known to occur in A. pullata. Six or seven non-eversible ventro-abdominal glands occurred in all species studied (A. fuscipes, A. nigripes, A. ochropus, A. pagana, A. pullata, A. ustulata). These glands contain volatiles. We consider both types of chemicals to be important in defence, and we propose that the paralysing effect is a common feature among Arge species.     

Functional utrastructure of Genlisea (Lentibulariaceae) digestive hairs

BACKGROUND AND AIMS: Digestive structures of carnivorous plants produce external digestive enzymes, and play the main role in absorption. In Lentibulariaceae, the ultrastructure of digestive hairs has been examined in some detail in Pinguicula and Utricularia, but the sessile digestive hairs of Genlisea have received very little attention so far. The aim of this study was to fill this gap by expanding their morphological, anatomical and histochemical characterization. METHODS: Several imaging techniques were used, including light, confocal and electron microscopy, to reveal the structure and function of the secretory hairs of Genlisea traps. This report demonstrates the application of cryo-SEM for fast imaging of whole, physically fixed plant secretory structures. KEY RESULTS AND CONCLUSION: The concentration of digestive hairs along vascular bundles in subgenus Genlisea is a primitive feature, indicating its basal position within the genus. Digestive hairs of Genlisea consist of three compartments with different ultrastructure and function. In subgenus Tayloria the terminal hair cells are transfer cells, but not in species of subgenus Genlisea. A digestive pool of viscous fluid occurs in Genlisea traps. In spite of their similar architecture, the digestive-absorptive hairs of Lentibulariaceae feature differences in morphology and ultrastructure.