古脊椎动物学报2023，Vol.61Issue(2)：108-122,15.DOI:10.19615/j.cnki.2096-9899.230309
钙化软骨中的软骨细胞比骨细胞具有更高的保存潜力?埋藏学实验初探
Do chondrocytes within calcified cartilage have a higher preservation potential than osteocytes?A preliminary taphonomy experiment
摘要
Abstract
Chondrocytes with remnants of nuclei and biomolecules were recently reported in two Cretaceous dinosaurs from North America and China.For multiple reasons,it was hypothesized that calcified cartilage(CC)had a better potential than bone to preserve ancient cells.Here we provide the first experimental test to this hypothesis by focusing on the most important variable responsible for cellular preservation:the postmortem blockage of autolysis.We compare the timing of autolysis between chondrocytes and osteocytes in an avian model(Anas platyrhynchos domesticus)buried for up to 60 days under natural conditions that did not inhibit autolytic enzymes.Within 15 days post-burial,almost all osteocytes were already cytolyzed but chondrocytes in CC were virtually unaffected.All osteocytes were cytolyzed after 30 days,but some chondrocytes were still present 60 days post-burial.Therefore,even in harsh conditions some CC chondrocytes still survive for months postmortem on a time scale compatible with permineralization.This is consistent with other data from the forensic literature showing the extreme resistance of hyaline cartilage(HC)chondrocytes after death and does support the hypothesis that CC has a better potential than bone for cellular preservation,especially in fossils that were not permineralized rapidly.However,because the samples used were previously frozen,it is possible that the pattern of autolysis observed here is also a product of cell death due to ice crystal formation and not strictly autolysis,meaning a follow-up experiment on fresh(non-frozen samples)is necessary to be extremely accurate in our conclusions.Nevertheless,this study does show that CC chondrocytes are very resistant to freezing,suggesting that chondrocytes are likely better preserved than osteocytes in permafrost fossils and mummies that underwent a freezing-thawing cycle.It also suggests that cartilage(both hyaline and calcified)may be a better substrate for ancient DNA than bone.Moreover,even though we warrant follow-up taphonomy experiments with non-frozen samples paired with DNA sequencing,we already urge ancient DNA experts to test CC as a new substrate for ancient DNA analyses in fossils preserved in hot and temperate environments as well.关键词
实验埋藏学/软骨细胞/骨细胞/死后自溶/冷冻相关细胞死亡/细胞和生物分子石化/古DNA研究对象Key words
experimental taphonomy/chondrocytes/osteocytes/postmortem autolysis/freeze related cell-death/cellular and biomolecule fossilization/aDNA substrate分类
生物科学引用本文复制引用
艾莉达,吴倩,李东升,李志恒,周忠和..钙化软骨中的软骨细胞比骨细胞具有更高的保存潜力?埋藏学实验初探[J].古脊椎动物学报,2023,61(2):108-122,15.基金项目
国家自然科学基金(批准号:42288201,42172029)资助.We thank Wang Yan for providing the duck specimens and helping with their shipment to Beijing.For discussions we thank Pan Yanhong,Dana Rashid,Brian K.Hall,Magdalena Koziol.We also thank Pan Yanhong and one anonymous reviewer for reviewing this manuscript.This work was funded by grants NSFC 42288201,42172029. （批准号:42288201,42172029）
