Germplasm rescue of post-mortem critically endangered Yangtze Sturgeon by cell cryopreservation

Abstract With the growing sophistication of cloning technology, rescuing cell resources is of great significance for the protection of endangered animals. The Yangtze sturgeon (Acipenser dabryanus), one of the three Acipenseriformes species in the Yangtze River, is critically endangered. Natural reproduction of the Yangtze sturgeon has not been detected since 2000. Less than 20 wild individuals are kept in husbandry and all are too old to breed. Therefore, it is urgently to rescue the genetic resources of every wild Yangtze sturgeon. Here, we isolated and preserved viable cells from the post-mortem critically endangered Yangtze Sturgeon for the first time. Attempt of rescuing and preserving cell resources were carried out from 8 tissues, brain, kidney, heart, fin, liver, skin, spleen and muscle of over-35-years-old female wild Yangtze sturgeon between 11 and 14 hours after death at 19.8℃ in outdoor concrete pond, and only muscle tissue cells could be successfully sub-cultured and preserved. Furthermore, the cultured cells were assessed by population doubling time, immunofluorescence analysis, microorganism detection, karyotyping and origin identification, and no abnormality was observed in the morphology, structure, growth and ploidy. These results suggest that viable cells could also be successfully isolated and cryopreserved from the wild Yangtze sturgeon in a short time after death, and muscle tissues had more potential to separate living cells than other tissues. This report is not only of great significance to the germplasm rescue of critically endangered Yangtze sturgeon, but also provides some scientific reference for the germplasm preservation of other endangered fish.