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Opsins are a class of transmembrane proteins encoded by opsin genes, and they play a variety of functional roles. Short wavelength-sensitive opsin 2 (sws2), one of the five classes of visual opsin genes, mainly senses blue light. Previous research has indicated that sws2 is essential for melanocyte formation in fish; however, its specific role in skin color differentiation remains to be elucidated. Here, we identified the sws2 gene in a prized reef-dwelling fish, Plectropomus leopardus. The full-length P. leopardus sws2 gene encodes a protein consisting of 351 amino acids, and exhibits substantial homology with other fish species. The expression of the sws2 gene was widespread across P. leopardus tissues, with high expression in eye and skin tissues. Through immunohistochemistry and in situ hybridization analyses, we discovered that the sws2 gene was primarily localized in the rod and cone cells of the retina, and epidermal cells of the skin. Furthermore, dsRNA interference was used for sws2 gene knockdown in living P. leopardus to elucidate its function in skin color differentiation. Black-color-related genes, melanin contents, and tyrosinase activity in the skin significantly decreased after sws2 knockdown (p < 0.05), but red-color-related genes and carotenoid and lutein contents significantly increased (p < 0.05). Retinoic acid injection produced the opposite results. Our results suggested that the sws2 gene influences P. leopardus skin color regulation by affecting vitamin synthesis and melanin-related gene expression levels. This study establishes a foundation for elucidating the molecular mechanisms by which sws2 regulates melanocyte formation in fish skin. [ABSTRACT FROM AUTHOR]

A significant shift in the mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902) range has been attributed to long-distance dispersal from the observed spatiotemporal patterns of beetle infestations in the recent outbreak in western Canada. However, long-distance dispersal is still the least understood aspect of mountain pine beetle ecology. In particular, the mechanisms responsible for the three major phases of long-distance dispersal, the ascent, transport, and descent, are poorly known. In this study, we used the North American Regional Reanalysis meteorological data (1999-2010) to determine climate conditions under and above the forest canopy during mountain pine beetle emergence and flight at the landscape scale. We found that climate conditions are distinct during emergence and flight. They provide an ideal underlying environment to facilitate the potential long-distance dispersal. Climate conditions are unstable under the forest canopy during emergence, which would help loft beetles above the forest canopy to initiate long-distance dispersal. The first direct evidence from wind directions above the forest canopy suggests that atmospheric transportation of mountain pine beetle in the planetary boundary layer is aided by wind. Key words: climate conditions, emergence, long-distance dispersal, mountain pine beetle, outbreak, planetary boundary layer. Un changement important dans l'aire de repartition du dendroctone du pin ponderosa (Dendroctonus ponderosae Hopkins, 1902) a ete attribue a la dispersion a longue distance sur la base des observations du comportement spatiotemporel des infestations du dendroctone lors de l'epidemie recente dans l'ouest du Canada. Cependant, la dispersion a longue distance est toujours l'aspect le moins bien compris de l'ecologie du dendroctone. En particulier, les trois phases de la dispersion a longue distance : l'ascension, le transport et la descente, sont peu connues. Dans cette etude, nous utilisons les donnees meteorologiques (1999-2010) de la reanalyse regionale nord-americaine pour determiner les conditions climatiques au-dessous et au-dessus du couvert forestier lors de l'emergence et de l'envol du dendroctone a l'echelle du paysage. Nous avons decouvert que les conditions climatiques sont differentes lors de l'emergence et de l'envol. Elles procurent un environnement sous-jacent ideal pour faciliter la dispersion potentielle a longue distance. Les conditions climatiques sont instables sous le couvert forestier durant l'emergence, ce qui pourrait aider les insectes presents au-dessus du couvert forestier a initier la dispersion a longue distance. Le premier indice direct provenant de la direction des vents au-dessus du couvert forestier indique que le transport atmospherique du dendroctone dans la couche limite planetaire est assiste par le vent. [Traduit par la Redaction] Mots-cles : conditions climatiques, emergence, dispersion a longue distance, dendroctone du pin ponderosa, epidemie, couche limite planetaire., Introduction Mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902) is a native disturbance agent in the pine forests of western North America (Safranyik and Carroll 2006; Negron and Fettig 2014). The [...]