The South China tigers (Panthera tigris amoyensis) are extinct in the wild, but viable populations remain in breeding centers and zoos after 60 years of effective conservation efforts. At present, however, the existing genetic variation of these tigers remains unknown. In this study, we assembled a high-quality chromosome-level genome using long-read sequences and re-sequenced 29 high-depth genomes of the South China tigers. We identified two significantly differentiated genomic ancestries in the extant populations, which also harbored some rare genetic variants introgressed from other subspecies, suggesting limited but essential genetic diversity to sustain the South China tigers. The unique pattern of dual ancestry and the genomic resources generated in our study pay the way for a genomics-informed conservation, following the real-time monitoring and controlled exchange of all reproductive South China tigers.

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Background: Most patients with thyroid carcinoma have a good prognosis, but some thyroid carcinomas are aggressive and prone to recurrence and metastasis. Further, concomitant overdiagnosis and overtreatment are important issues. This study aimed to investigate the relationship between mutations and copy number variations in m6A regulatory genes and the clinicopathological features of thyroid carcinoma.Results: Advanced pathological stage and T stage were significantly correlated with changes in m6A regulatory genes (p<0.05). Patients with abnormal copy numbers of m6A regulatory genes had a significantly shorter progression-free interval than patients with normal copy numbers. Mutations and copy number variations in m6A regulatory genes were significantly correlated with advanced pathological stage and T stage. Conclusions: Copy number variations were a poor prognostic factor for thyroid carcinoma as evidenced by the significantly short progression-free interval in patients with copy number variations in m6A regulatory genes. Further, the ZC3H13 gene may be involved in the occurrence and development of thyroid carcinoma by regulating cancer-associated signaling pathways and biological processes. These findings may help distinguish patients with poor prognoses who may need more aggressive treatment from patients who have better prognoses.