Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster V92
Höfundar / Authors: Gunnhildur Erla Árnadóttir
Starfsvettvangur / Affiliations: Háskóli Íslands, Benchmark Genetics
Kynnir / Presenter: Gunnhildur Erla Árnadóttir
Hypoxia is an important environmental stressor in aquaculture and natural ecosystems, with potential effects on embryonic development and reproductive success in Atlantic salmon (Salmo salar). Primordial germ cell (PGC) migration depends heavily on the chemokine axis CXCL12/CXCR4, and emerging evidence suggests oxygen status may affect it through hypoxia-inducible factor (HIF) signaling. This study examined embryonic tolerance to transient hypoxia to establish a baseline for understanding how oxygen availability shapes early development. Embryos were incubated under normoxia (≈97% DO) and reduced oxygen conditions (80%, 60% & 50% DO). Survival and developmental abnormalities were recorded across families. Mild to moderate hypoxia (80% & 60% DO) was generally well tolerated, while severe hypoxia (50% DO) increased mortality, particularly during gastrulation. Embryos at 80% DO showed the lowest incidence of abnormalities, suggesting a possible hormetic effect. Strong family-specific variation indicated a genetic basis for hypoxia resilience. Elevated, fluctuating temperatures (8-10°C) likely acted as an additional stressor and may have underestimated tolerance under more optimal conditions. These findings demonstrate that Atlantic salmon embryos can tolerate moderate hypoxia, while family-specific variation suggests genetic differences in resilience. Together, these results provide a baseline for future studies on how oxygen availability influences early development in salmon.