Cell cycle analysis of brain cells as a growth index in larval cod at different feeding conditions and temperatures

• Published in: Scientia Marina
• Main Authors: Rafael González-Quirós, Iyziar Munuera, Arild Folkvord
• Format: Article in Journal/Newspaper
• Language: English
• Published: Consejo Superior de Investigaciones Científicas 2007
• Subjects: brain; cell cycle; cod larvae; flow cytometry; food; growth index; temperature; Aquaculture. Fisheries. Angling; SH1-691; Gadus morhua
• Online Access: https://doi.org/10.3989/scimar.2007.71n3485; https://doaj.org/article/36d998cbf0ec4d93a46fbb0a86c55284

The percentage of cells dividing in a specific tissue of individual larvae can be estimated by analyzing DNA per cell by flow cytometry. An experimental test was carried out with cod (Gadus morhua) larvae, with brain as the target tissue, to validate this technique as an appropriate growth index for larval fish. Standard length (SL), myotome height, and %S-phase (% of cells in the S-phase of the cell-division cycle) variability were analyzed, with temperature (6 and 10°C), food level (high- and no-food) and larval developmental stage (first feeding, pre-metamorphosis and post-metamorphosis) as independent factors. Cod larvae grew faster (in SL) and presented a higher %S-phase under high-food conditions. Larval SL increased with temperature in rearing and experimental tanks. However, there was a significant interaction between temperature and food in the %S-phase. There were no significant differences in the %S-phase between 6 and 10°C at high-food levels. We suggest that this result is a consequence of temperature-dependency of the duration of the cell cycle. In the absence of food, larvae at 10ºC had a lower %S-phase than larvae at 6°C, which may be related to increased metabolic costs with increasing temperature. Considering the effect of temperature, the mean % S-phase explained 74% of the variability in the estimated standard growth rate.