The first report of liver coccidian Goussia cruciata in jack mackerel, Trachurus murphyi, from the South Pacific and its relationship with host variables.

The liver coccidian Goussia cruciata is considered as a specific parasite of the genus Trachurus, but to date, this parasite has only been reported for Atlantic species (Trachurus picturatus, Trachurus lathami, Trachurus trachurus and Trachurus mediterraneus). Therefore, this is the first report of this parasite in a species of Trachurus from the South Pacific. The prevalence and abundance of this coccidian in jack mackerel, T. murphyi, was determined, and its relationships with host variables such as total body length, condition factor and hepatosomatic index were evaluated. A total of 49 individuals were sampled from a commercial vessel of the central Chilean coast (36° 41' S, 73° 06' W) in November 2013 and February and May 2014. The parasite was identified by means of liver smears using light microscopy. The relationship between the abundance of the parasites and the host total length, condition factor and hepatosomatic index was analysed with Spearman's correlations. The sporogonic stages exhibited sporocysts that were morphologically concordant with coccidian G. cruciata. All hosts were parasitised with this coccidian, and the abundance varied between 2 and 224 oocytes per host. The parasite abundance was negatively correlated with the host total length. Infection levels of G. cruciata in T. murphyi apparently do not produce negative effects on fish condition.

Association of SND1 protein to low density lipid droplets in liver steatosis.

Although the human homologue of SND p102, p100 coactivator, was initially described as a nuclear protein, the p100 coactivator protein family members have non-nuclear localization in mammalian cells with active lipid handling, storage, and secretion. However, their role in lipid homeostasis remains unresolved. Here, we investigate the distribution of the rat homologue SND p102 (also called SND1) and its association with newly formed lipid droplets in the liver parenchyma and cultured hepatocytes. Sucrose gradient fractionation showed that SND p102 cofractionated with endoplasmic reticulum and Golgi markers. Such cofractionation was not altered in regenerating steatotic rat liver. However, SND p102 was also detected in lipid droplets from regenerating liver, showing a specific directionalization to the least dense ones. Confocal microscopy of cultured hepatocytes confirmed the findings of gradient fractionation. In addition, p100 coactivator was consistently encountered in microsomes and lipid droplets in control and oleate-treated HepG2 cells. The total amount of SND p102 in hepatocytes was similar in both conditions, suggesting a specific translocation of the protein. Our findings indicate that SND p102 and the human p100 coactivator have a ubiquitous cytoplasmic distribution in hepatocytes and that steatogenic conditions promote the targeting of SND p102 from other cell compartments to specific low density lipid droplets.

Association of SND1 protein to low density lipid droplets in liver steatosis

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Although the human homologue of SND p102, p100 coactivator, was initially described as a nuclear protein, the p100 coactivator protein family members have non-nuclear localization in mammalian cells with active lipid handling, storage, and secretion. However, their role in lipid homeostasis remains unresolved. Here, we investigate the distribution of the rat homologue SND p102 (also called SND1) and its association with newly formed lipid droplets in the liver parenchyma and cultured hepatocytes. Sucrose gradient fractionation showed that SND p102 cofractionated with endoplasmic reticulum and Golgi markers. Such cofractionation was not altered in regenerating steatotic rat liver. However, SND p102 was also detected in lipid droplets from regenerating liver, showing a specific directionalization to the least dense ones. Confocal microscopy of cultured hepatocytes confirmed the findings of gradient fractionation. In addition, p100 coactivator was consistently encountered in microsomes and lipid droplets in control and oleate-treated HepG2 cells. The total amount of SND p102 in hepatocytes was similar in both conditions, suggesting a specific translocation of the protein. Our findings indicate that SND p102 and the human p100 coactivator have a ubiquitous cytoplasmic distribution in hepatocytes and that steatogenic conditions promote the targeting of SND p102 from other cell compartments to specific low density lipid droplets (AU)