No abstract

Sexual attraction and perception, governed by separate genetic circuits in different organs, are crucial for mating and reproductive success, yet the mechanisms of how these two aspects are integrated remain unclear. In Drosophila, the male-specific isoform of Fruitless (Fru), FruM, is known as a master neuro-regulator of innate courtship behavior to control perception of sex pheromones in sensory neurons. Here we show that the non-sex specific Fru isoform (FruCOM) is necessary for pheromone biosynthesis in hepatocyte-like oenocytes for sexual attraction. Loss of FruCOM in oenocytes resulted in adults with reduced levels of the cuticular hydrocarbons (CHCs), including sex pheromones, and show altered sexual attraction and reduced cuticular hydrophobicity. We further identify Hepatocyte nuclear factor 4 (Hnf4) as a key target of FruCOM in directing fatty acid conversion to hydrocarbons in adult oenocytes. fru- and Hnf4-depletion disrupts lipid homeostasis, resulting in a novel sex-dimorphic CHC profile, which differs from doublesex- and transformer-dependent sexual dimorphism of the CHC profile. Thus, Fru couples pheromone perception and production in separate organs for precise coordination of chemosensory communication that ensures efficient mating behavior.

A 6-week 5×2 factorial study was conducted to examine the effects of stocking density and feeding frequency on growth performance, body composition, digestive enzyme activity, and tissue histology of juvenile hybrid groupers raised in an indoor circulating water system. Triplicate groups of fish were reared in tanks following a factorial design consisting of ten treatments including 5 stocking densities (SD) [1.1 kg m−3(0.55 kg fish per tank, SD1.1), 2.2 kg m-3(1.1 kg fish per tank, SD2.2), 3.3 kg m−3(1.65 kg fish per tank, SD3.3), 4.4 kg m−3(2.2 kg fish per tank, SD4.4) and 5.5 kg m−3(2.75 kg fish per tank, SD 5.5)] and 2 feeding frequencies (FF) [3 meals a day (FF3) and 2 meals a day (FF2)]. The resulting 10 treatments were G1(SD1.1,FF3), G2(SD2.2,FF3), G3(SD3.3,FF3), G4(SD4.4,FF3), G5(SD5.5,FF3), G6(SD1.1,FF2), G7(SD2.2, FF2), G8(SD3.3, FF2), G9(SD4.4, FF2) andG10 (SD5.5, FF2). Feed consumption and temperature were recorded throughout the experiment. After 6 weeks, the results indicated that the weight gain rate (WGR) and specific growth rate (SGR) of fish in the G7 group were significantly higher than those of other groups (P< 0.05), followed by G1, with G3 being the lowest. Weight gain and specific growth rates were generally higher in fish fed twice a day than those fed three times a day. The variations in protein content between groups were consistent with the muscle protein content trends. Feeding frequency and stocking density had significant effects on serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglycerides (TGs), and cholesterol (CHO) (P < 0.05). Regarding immune function, grouper albumin (ALB), serum lysozyme (LZY), superoxide dismutase (SOD), and alkaline phosphatase (AKP) were significantly affected by stocking density and feeding frequency (P< 0.05). Pepsin and lipase activities in the stomach, intestine, and liver were also affected. The histological structure of the stomach, liver, and intestine in G1, G2, G7, and G8 fish was relatively normal, whereas those of the remaining groups exhibited varying degrees of damage. Overall, the optimum stocking densities were 1.343 kg/m3 (approximately 10 fish) and 2.004 kg/m3 (approximately 20-30 fish) when the fish were fed 3 and 2 times per day, respectively.

Sexual attraction and perception are crucial for mating and reproductive success. In Drosophila melanogaster , the male-specific isoform of Fruitless (Fru), Fru M , is a known master neuro-regulator of innate courtship behavior to control the perception of sex pheromones in sensory neurons. Here, we show that the non–sex-specific Fru isoform (Fru COM ) is necessary for pheromone biosynthesis in hepatocyte-like oenocytes for sexual attraction. Loss of Fru COM in oenocytes resulted in adults with reduced levels of cuticular hydrocarbons (CHCs), including sex pheromones, and show altered sexual attraction and reduced cuticular hydrophobicity. We further identify Hepatocyte nuclear factor 4 ( Hnf4 ) as a key target of Fru COM in directing fatty acid conversion to hydrocarbons. Fru or Hnf4 depletion in oenocytes disrupts lipid homeostasis, resulting in a sex-dimorphic CHC profile that differs from doublesex- and transformer- dependent CHC dimorphism. Thus, Fru couples pheromone perception and production in separate organs to regulate chemosensory communications and ensure efficient mating behavior.