Antifreeze and ice nucleator proteins in terrestrial arthropods

Reviews the two opposed protein families in terrestrial arthropods — those that inhibit ice growth and those that promote it — and the conditions under which a species produces each.

Studied in

Insecta, Arachnida

Sample size

review across terrestrial arthropods

Antifreeze proteins act by binding to the surface of small ice crystals and preventing their growth, producing a gap between the freezing and melting points; ice-nucleating proteins do the reverse. Some species produce both, at different times of year.

• Arthropod-focused; fish antifreeze proteins are structurally different and covered separately.
• The seasonal regulation is described in a small number of well-studied species.

• Freeze tolerance

  Freeze-tolerant animals make themselves freeze on purpose, at the highest sub-zero temperature they can manage. A slow freeze starting at −1 °C is survivable; a sudden one at −8 °C is not.

• Antifreeze proteins

  Antifreeze proteins do not work like the antifreeze in a car. They bind to tiny ice crystals and stop them growing, which leaves a strange signature: the freezing point no longer matches the melting point.