Experimental evidence of masculinization by continuous illumination in a temperature sex determination teleost (Atherinopsidae) model: is oxidative stress involved?

The present study evaluates the influence of continuous light on phenotypic sex ratios in Chirostoma estor, a temperature sex determination animal model. Relative gene expression levels of 5 day old larvae were performed on two early gonad differentiation genes (sox9 and foxl2), two stress axis activation genes (gcr1 and crf) and four reactive oxygen species (ROS) antagonist effector genes (sod2, ucp2, gsr and cat). Two light treatments were applied from fertilization; control (12L:12D) simulated natural photoperiod and a continuous illumination photoperiod.

A complete chitinolytic system in the atherinopsid pike silverside Chirostoma estor: gene expression and activities.

The expression and digestive activity of pike silverside Chirostoma estor endogenous chitinases were analysed in samples from four life stages: whole eggs; larvae; juvenile intestine and hepatopancreas and adult intestine and hepatopancreas. A chitinase cDNA was cloned and partially sequenced (GenBank accession number: FJ785521). It was highly homologous to non-acidic chitinase sequences from other fish species, suggesting that it is a chitotriosidase.

NF-kappaB activation but not PI3K/Akt is required for dexamethasone dependent protection against TNF-alpha cytotoxicity in L929 cells.

Tumor necrosis factor alpha (TNF-alpha) is one of the best-described cell death promoters. In murine L929 fibroblasts, dexamethasone inhibits TNF-alpha-induced cytotoxicity. Since phosphatidyl inositol 3 kinase (PI3K) and nuclear factor kappa B (NF-kappaB) proteins regulate several survival pathways, we evaluated their participation in dexamethasone protection against TNF-alpha cell death.

[Respiratory oxidases: the enzymes which use most of the oxygen which living things breathe].

The respiratory oxidases are the last enzymes of the aerobic respiratory chain. They catalize the reduction of molecular oxygen to water, with generation of an electrochemical gradient useful for the energy demanding cellular processes. Most of the oxidases belong to the heme-copper superfamily.

[P53 protein and human papillomavirus oncogenes in carcinogenesis of the uterine cervix].

Human papillomavirus (HPV) DNA sequences are found in the majority (90%) of cervical tumors, and in cell lines derived from them. The products of the viral E6 and E7 oncogenes inactivate those from the p53 and Rb tumor suppressor genes. The p53 protein controls the entrance to the cell cycle.