Research on the cryobiology of the plain frog (Pelophlax Ridibunda)

This study examined the strategies that ensured the survival of Pelophylax Ridibunda during winter periods when exposed to sub-zero temperatures. In this regard, when a frog is subjected to freezing, anoxia and dehydration. Glucose levels in blood, skeletal muscle and liver tissue, amount of water in muscle and liver tissue, changes in body weight, and expression level of transcripts of amphibian antifreeze proteins (AFP; Fr10, Li16 and Fr47) were examined. During freezing, a 2.54-fold increase in blood glucose level (from 1.96 to 4.98 μmol mL-1) was recorded in P. Ridibunda. In the freezing, anoxia and dehydration groups, glucose levels in liver tissue were 6.5 times (mean 18.4 µmol g-1 ), 4.63 times (mean 12.9µmol g-1 ) and 2.8 times (mean 7.84 µmol), respectively. g-1 ) increase was detected. Significant changes in gene expression levels of some AFPs were noted under stress and normalization conditions. The fr47 gene was increased in all stress and normalization groups in liver tissue in P. ridibunda. Exposure to cold increased 1.430 times, cold exposure normalization increased 1.618 times in the dissolution group, 0.862 times in anoxia stress, 0.47 times increased anoxia normalization in the reoxya group, 1.480 times in dehydration exposure, and 1.218 times in the rehydration group with dehydration normalization. As a result of our study, it has been proven that the Anatolian mountain frog P. ridibunda species collected from Afyonkarahisar can survive below the freezing point and the presence of cryoprotectant glucose and frog-specific AFPs are the biggest factors that ensure its survival. Concentrating on the bioinformatics of genomic, transcriptomic and proteomic research of AFPs and elucidating the mechanisms of binding and testing of AFPs to ice crystals will provide beneficial developments in the field of biotechnology.