Saprolegnia diclina IIIA and S. parasitica employ different infection strategies when colonizing eggs of Atlantic salmon, Salmo salar L.

Acknowledgements The work has been funded by the European Commission through the EU Marie Curie ITN project SAPRO (238550) (MMS, AW). We would also like to acknowledge support from the BBSRC and the University of Aberdeen (PvW) and Landcatch and AquaGen for providing salmon eggs. Elin Rolen's assistance with sequencing of the strains is highly appreciated.Peer reviewedPublisher PD

Studies of the reproductive biology and of the structure, composition and physiology of the egg of Graphognathus leocoloma Boheman (Coleoptera : Curculionidae): a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Zoology at Massey University

The published information regarding the biology and pest status of Graphognathus leucoloma Boheman is summarized. A study was made of egg development at temperatures ranging from 4 to 37.8°C and relative humidities ranging from 40 to 100%. Egg hatch was frequently very low and showed considerable variability. Median duration of development ranged from about 14 days at 31.5°C to 95-97 days at 15°C, with the developmental-hatching threshold between 12.1 and 13.5°C. Sub-threshold temperatures were lethal. Virtually no hatching occurred below 100% RH but the eggs could withstand considerable dessication and would hatch when moistened. Possible effects of humidity on the duration of development and of parental age on egg viability are also discussed. Some reasons for the very low egg viability are suggested, along with modifications to the experimental design to eliminate them. Studies were made of adult and pupal size, and of longevity, pre-oviposition period and reproductive output. Some reasons for unexpectedly low fecundity and long pre-oviposition period are discussed. The structure of the egg envelopes and the cement in which the eggs are laid was studied, using scanning and transmission electron microscopy, and Nomarski differential interference microscopy. A histo-chemical study of these structures, supplemented by some simple chemical tests, was also made, to elucidate in part their composition. The chorion is thick and composed entirely of protein; some 250,000 aeropyles are scattered over the surface, and its structure is such that it could probably act as a plastron when the egg is submerged. There is no micropyle. Disulphide linkages are probably important in the structure of the chorion, as in many other species, but unlike other beetles so far studied, no crystalline proteins were found. The vitelline membrane was found to be a three-layered structure 0.3-O.5μm thick composed of protein and acid mucopolysaccharides, and to be highly resistant to chemical attack. Waterproofing is probably provided by a layer of lipid on the outer surface of the vitelline membrane. The cement was found to be a complex, variable and heterogeneous mixture of protein and up to five acid mucopolysaccharides, which is unlike that of any other species reported. Some possible functions of the cement and the significance of its composition are suggested. A note on the citation of publications, and the referral to species and their systematic status. Any publication by three joint authors is cited in full the first time it is referred to and thereafter is abbreviated to the form: senior author et al. Publications with more than three joint authors are cited in the form: senior author et al. each time they are cited, including the first. The specific name of any organism is given in full only on the first time it is referred to, and the names of insect species and genera and their taxonomic status are listed in Appendix Five

Patterns of gene expression in schistosomes: localization by whole mount in situ hybridization

rom the identification of genes to the characterization of their functions and interactions. Developmental biologists have long used whole mount in situ hybridization (WISH) to determine gene expression patterns, as a vital tool for formulating and testing hypotheses about function. This paper describes the application of WISH to the study of gene expression in larval and adult schistosomes. Fixed worms were permeablized by proteinase K treatment for hybridization with digoxygenin-labelled RNA probes, with binding being detected by alkaline phosphatase-coupled anti-digoxygenin antibodies, and BM Purple substrate. Discrete staining patterns for the transcripts of the molecules Sm29, cathepsin L, antigen 10.3 and chorion were observed in the tegument cell bodies, gut epithelium, oesophageal gland and vitelline lobules, respectively, of adult worms. Transcripts of the molecules SGTP4, GP18-22 and cathepsin L were localized to tegument cell bodies and embryonic gut, respectively, of lung schistosomula. We also showed that Fast Red TR fluorescent substrate can refine the pattern of localization permitting use of confocal microscopy. We believe that method of WISH will find broad application, in synergy with other emerging post-genomic techniques, such as RNA interference, to studies focused at increasing our molecular understanding of schistosomes

A method for isolating and culturing placental cells from failed early equine pregnancies

Early pregnancy loss occurs in 6–10% of equine pregnancies making it the main cause of reproductive wastage. Despite this, reasons for the losses are known in only 16% of cases. Lack of viable conceptus material has inhibited investigations of many potential genetic and pathological causes. We present a method for isolating and culturing placental cells from failed early equine pregnancies. Trophoblast cells from 18/30 (60%) failed equine pregnancies of gestational ages 14–65 days were successfully cultured in three different media, with the greatest growth achieved for cells cultured in AmnioChrome™ Plus. Genomic DNA of a suitable quality for molecular assays was also isolated from 29/30 of these cases. This method will enable future investigations determining pathologies causing EPL

The Functions of the Multiproduct and Rapidly Evolving \u3cem\u3edec-1\u3c/em\u3e Eggshell Gene Are Conserved Between Evolutionarily Distant Species of Drosophila

The Drosophila dec-1 gene encodes multiple proteins that are required for female fertility and proper eggshell morphogenesis. Genetic and immunolocalization data suggest that the different DEC-1 proteins are functionally distinct. To identify regions within the proteins with potential biological significance, we cloned and sequenced the D. yakuba and D. virilis dec-1 homologs. Interspecies comparisons of the predicted translation products revealed rapidly evolving sequences punctuated by blocks of conserved amino acids. Despite extensive amino acid variability, the proteins produced by the different dec-1 homologs were functionally interchangeable. The introduction of transgenes containing either the D. yakuba or the D. virilis dec-1 open reading frames into a D. melanogaster DEC-1 protein null mutant was sufficient to restore female fertility and wild-type eggshell morphology. Normal expression and extracellular processing of the DEC-1 proteins was correlated with the phenotypic rescue. The nature of the conserved features highlighted by the evolutionary comparison and the molecular resemblance of some of these features to those found in other extracellular proteins suggests functional correlates for some of the multiple DEC-1 derivatives

Development of extra-embryonic membranes and fluid compartments

An account of the development of extra-embryonic membranes in the embryo of poultry. The roles of these membranes in the transfer of water from albumen to yolk and to embryonic tissue is reviewed

Light sheet microscopy with acoustic sample confinement

Contactless sample confinement would enable a whole host of new studies in developmental biology and neuroscience, in particular, when combined with long-term, wide-field optical imaging. To achieve this goal, we demonstrate a contactless acoustic gradient force trap for sample confinement in light sheet microscopy. Our approach allows the integration of real-time environmentally controlled experiments with wide-field low photo-toxic imaging, which we demonstrate on a variety of marine animal embryos and larvae. To illustrate the key advantages of our approach, we provide quantitative data for the dynamic response of the heartbeat of zebrafish larvae to verapamil and norepinephrine, which are known to affect cardiovascular function. Optical flow analysis allows us to explore the cardiac cycle of the zebrafish and determine the changes in contractile volume within the heart. Overcoming the restrictions of sample immobilisation and mounting can open up a broad range of studies, with real-time drug-based assays and biomechanical analyses.</p

Intra-uterine fetal demise caused by amniotic band syndrome after standard amniocentesis

The amniotic band syndrome represents a prime example of exogenous disruption of an otherwise normal feta I development. It may be a sequel of invasive diagnostic procedures such as amniocentesis or fetal blood sampling. A 38-year-old gravida II, para II delivered a morphologically normal male stillborn at term. The pregnancy history had been unremarkable but for an early 2nd-trimester amniocentesis. Cause of the intra-uterine fetal demise was noted to be an amniotic band constricting the umbilical cord, An amniotic band is a rare but potentially fatal condition which may be induced by, e.g., invasive prenatal procedures. Such bands are not usually diagnosed prenatally; however, selected patients with augmented risk may profit from intensive ultrasound evaluation including Doppler studies. Copyright (C) 2000 S. Karger AG, Basel

Egg Production in the Boxelder Bug \u3ci\u3eBoisea Trivittata\u3c/i\u3e (Hemiptera: Rhopalidae)

Boxelder bug females emerged from overwintering sites in the spring and rapidly provisioned eggs with yolk materials. Five discrete egg stages were identified based on egg size, protein content, and degree of chorion sclerotization. Females did not accumulate yolk materials into the egg until after melanization was completed, as unmelanized animals rarely possessed even stage 2 eggs. All adult females entering overwintering sites possessed only immature stage eggs (stage 1 and 2). The rate of egg vitellogenesis in the spring was rapid; a major change in numbers of more mature stage eggs (stage 3 and above) in the ovary occurred within approximately 6 days. Most mating pairs recovered in the field (92%, 12/13) possessed ovaries full of eggs in stages 3, 4 or 5. The remaining female contained only immature eggs of stage 1 and 2. This finding indicates that fully provisioned ovaries are not an absolute requirement for mating to occur. The signals that initiate vitellogenesis and control the movement of materials from fat body into eggs are unknown for the boxelder bug

A Life History Study of Caecilius Aurantiacus (Hagen) (Psocoptera: Caeciliidae)

Caecilius aurantiacus is a common, widely distributed psocid in well established forested areas of North America. Published information on this species is fragmentary and limited primarily to taxonomy. This paper is a description of the habits and biology of this small, little-known, but common insect. Of the 212 named species in the genus Caecilius (Smithers, 1967), the bionomics of only Caecilius manteri have been published