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First paragraph: Genotypic information is widely used in the conservation and management of wild fish (Schwartz, Luikart & Waples 2007) and is increasingly valuable in the management of captive populations (e.g. for verification of pedigree or for marker-assisted selection; Perez-Enriquez, Takagi & Taniguchi 1999; Sonesson 2007). Obtaining DNA most commonly involves taking tissue samples from live fish, such as blood or a fin biopsy (Campanella & Smalley 2006), or killing fish (particularly if too small to take biopsy samples: Mirimin, O'Keeffe, Ruggiero, Bolton-Warberg, Vartia & Fitzgerald 2011). Tissue biopsy may have negative impacts on fish, potentially including infection and effects on survival, growth or behaviour (Le Vin, Adam, Tedder, Arnold & Mable 2011); e.g. the adipose fin, commonly removed from salmonids for marking and DNA extraction, is now known to show sexual dimorphism (Hisar, Sönmez, Hisar, Budak & Gültepe 2013) and is thought to function as a flow sensor (Buckland-Nicks, Gillis & Reimchan 2011). In studies on wild fish populations, particularly rare or uncommon species with small body size, it is undesirable to kill large numbers, and this has led to recent publications investigating extraction of DNA from mucus taken from the skin or mouth cavity (Campanella & Smalley 2006; Livia, Antonella, Hovirag, Mauro & Panara 2006; Le Vin etal. 2011; Mirimin etal. 2011; Reid, Kidd & Wilson 2012; de Verdal, Vandeputte, Pepey, Vidal & Chatain 2014). Brush swabbing is one of the less invasive sampling strategies, which is used in a range of other groups of organisms, e.g. humans (Clarke, Prost, Stanton, White, Kaplan & Matisoo-Smith 2014), amphibia (Pidancier, Miquel & Miaud 2003) and molluscs (Henley, Grobler & Neves 2006). The reduced invasiveness of such sampling techniques, and reduced likelihood of impact on the welfare of the fish concerned, also makes them less likely to come under regulations on animal experimentation; swab samples can also be collected without the use of anaesthesia, required under UK regulations for tissue biopsy (Le Vin etal. 2011). Potential drawbacks of such methods may include sample contamination, low DNA quantity or poor quality DNA (Taberlet, Waits & Luikart 1999; Lieber, Berrow, Johnston, Hall, Hall, Gubili, Sims, Jones & Noble 2013).

Background Infectious Pancreatic Necrosis (IPN) is a highly contagious birnavirus disease of farmed salmonid fish, which often causes high levels of morbidity and mortality. A large host genetic component to resistance has been previously described for Atlantic salmon (Salmo salar L.), which mediates high mortality rates in some families and zero mortality in others. However, the molecular and immunological basis for this resistance is not yet fully known. This manuscript describes a global comparison of the gene expression profiles of resistant and susceptible Atlantic salmon fry following challenge with the IPN virus. Results Salmon fry from two IPNV-resistant and two IPNV-susceptible full sibling families were challenged with the virus and sampled at 1 day, 7 days and 20 days post-challenge. Significant viral titre was observed in both resistant and susceptible fish at all timepoints, although generally at higher levels in susceptible fish. Gene expression profiles combined with gene ontology and pathway analyses demonstrated that while a clear immune response was observed in both resistant and susceptible fish, there were striking differences between the two phenotypes. The susceptible fish showed marked up-regulation of genes related to cytokine activity and inflammatory response that evidently failed to protect against the virus. In contrast, the resistant fish demonstrated a less pronounced immune response including up-regulation of genes relating to the M2 macrophage system. Conclusions While only the susceptible phenotype shows appreciable mortality levels, both resistant and susceptible fish can become infected with IPNV. Susceptible fish are characterized by a much larger, yet ineffective, immune response, largely related to cytokine and inflammatory systems. Resistant fish demonstrate a more moderate, putative macrophage-mediated inflammatory response, which may contribute to their survival This research was supported by Biotechnology and Biological Sciences Research Council (BBSRC) grants (BB/H022007/1, BB/F002750/1, BB/F001959/1) awarded to The Roslin Institute and University of Stirling, and by a BBSRC Institute Strategic Funding Grant to The Roslin Institute. DR was funded by a postgraduate grant from Fundación Barrié. The authors also acknowledge the support of the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) in the completion of this study. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions SI

In December 2014, NIST’s laser-based Traveling SIRCUS calibration system was installed at Raytheon SAS in El Segundo, CA for testing of the NOAA/NASA Joint Polar Satellite System-1 (JPSS-1) VIIRS sensor’s visible and near-infrared bands. The tunable laser sources were installed in the ante-room outside the Raytheon clean room where the VIIRS sensor was located. The output from the tunable lasers was fiber-coupled into a 1-m diameter Spectralon integrating sphere source positioned in front of the VIIRS sensor’s Earth-view port and VIIRS Absolute Spectral Responsivity (ASR) measurements were made. In a second configuration, a polarizer was placed between the source and the VIIRS entrance port and polarization sensitivity testing was done. In this work, we present details of the T-SIRCUS calibration system, including a new automated tunable Optical Parametric Oscillator (OPO) system, achievable radiances with the 1-m Spectralon integrating sphere, and an uncertainty budget for the integrating sphere radiance. An approach to extend the dynamic range of out-of-band measurements using a recently develop Flat Plate Illuminator will be introduced. Finally, VIIRS sensor ASR and polarization responsivity results and implications based on the measurements are discussed.

International audience

Le bar n’a pas de sexe génétique : la preuve par les QTLs. Journée du SFAM (Syndicat Français de l'Aquaculture Marine et Nouvelle)

International audience

International audience

In Scotland and elsewhere, there are concerns that escaped farmed Atlantic salmon (Salmo salar L.) may impact on wild salmon stocks. Potential detrimental effects could arise through disease spread, competition, or inter-breeding. We investigated whether there is evidence of a direct effect of recorded salmon escape events on wild stocks in Scotland using anglers' counts of caught salmon (classified as wild or farmed) and sea trout (Salmo trutta L.). This tests specifically whether documented escape events can be associated with reduced or elevated escapes detected in the catch over a five-year time window, after accounting for overall variation between areas and years. Alternate model frameworks were somewhat inconsistent, however no robust association was found between documented escape events and higher proportion of farm-origin salmon in anglers' catch, nor with overall catch size. A weak positive correlation was found between local escapes and subsequent sea trout catch. This is in the opposite direction to what would be expected if salmon escapes negatively affected wild fish numbers. Our approach specifically investigated documented escape events, contrasting with earlier studies examining potentially wider effects of salmon farming on wild catch size. This approach is more conservative, but alleviates some potential sources of confounding, which are always of concern in observational studies. Successful analysis of anglers' reports of escaped farmed salmon requires high data quality, particularly since reports of farmed salmon are a relatively rare event in the Scottish data. Therefore, as part of our analysis, we reviewed studies of potential sensitivity and specificity of determination of farmed origin. Specificity estimates are generally high in the literature, making an analysis of the form we have performed feasible.

To investigate alternative routes to develop YY males and to examine some of the factors responsible for departures from predicted sex ratios in the Nile tilapia (Oreochromis niloticus), YY males were produced (i) by androgenesis from XY male parents; and (ii) by mitotic gynogenesis from XY neofemale parents. Progeny testing of these androgenetic and gynogenetic males, and gynogenetic females, showed that most families (i.e. sibling groups of males and in some cases females) gave monosex progeny only, when individuals were crossed to XX fish (i.e. all-male progeny from tested androgenetic or gynogenetic males; all-female progeny from tested gynogenetic females). There were significant differences among androgenetic families in deviations from expected progeny sex ratios, while among the gynogenetic families, the largest sex ratio deviations occurred in the same family for both male and female gynogenetics. The factor(s) that cause departures from the sex ratios predicted by chromosomal sex determination appear to be autosomal, heritable, polymorphic and able to influence sex ratios in both directions. Furthermore, the results suggest that YY and XX lines could be developed in which such factors had been selected against, for example, by elimination of families showing departures from monosex progeny.