Panthera tigris is a top predator that maintains the integrity of forest ecosystems and is an integral part of biodiversity. No more than 400 Amur tigers (P. t. altaica) are left in the wild, whereas the South China tiger (P. t. amoyensis) is thought to be extinct in the wild, and molecular biology has been widely used in conservation and management. In this study, the genetic information of Amur tigers and South China tigers was studied by whole-genome sequencing (WGS). A total of 647 Gb of high-quality clean data was obtained. There were 6.3 million high-quality single-nucleotide polymorphisms (SNPs), among which most (66.3%) were located in intergenic regions, with an average of 31.72% located in coding sequences. There were 1.73 million insertion-deletions (InDels), among which there were 2438 InDels (0.10%) in the coding region, and 270 thousand copy number variations (CNVs). Significant genetic differences were found between the Amur tiger and the South China tiger based on a principal component analysis and phylogenetic tree. The linkage disequilibrium analysis showed that the linkage disequilibrium attenuation distance of the South China tiger and the Amur tiger was almost the same, whereas the r² of the South China tiger was 0.6, and the r² of the Amur tiger was 0.4. We identified functional genes and regulatory pathways related to reproduction, disease, predation, and metabolism and characterized functional genes related to survival in the wild, such as smell, vision, muscle, and predatory ability. The data also provide new evidence for the adaptation of Amur tigers to cold environments. PRKG1 is involved in temperature regulation in a cold climate. FOXO1 and TPM4 regulate body temperature to keep it constant. Our results can provide genetic support for precise interspecies conservation and management planning in the future.

In this study, different growth characteristics of hematopoietic stem cells and bone marrow mesenchymal stem cells were used to isolate and culture BMSCs by whole bone marrow adhesion method, and RT-PCR was used to detect cell surface markers CD29, CD31, CD34, CD44, CD71, CD73, CD90. The differentiation of osteocytes into adipocytes and osteoblasts was induced in vitro, and the differentiation ability was observed by staining with oil red O and rubinin. To investigate the isolation and culture methods of BMSCs from Guizhou miniature pigs (Sussa lvanius) in vitro, and to study their biological characteristics and potential for multi-differentiation. The results showed that a small number of adherent cells could be seen in the primary BMSCs cultured in vitro within 48 hours, and the confluent cells reached 90% in 5~6 days. The cell growth state was good, and the shape was spindle and polygonal. RT-PCR was used to detect the positive expression of CD29, CD44, CD71, CD73 and CD90 on the cell surface, and the negative expression of CD31 and CD34. Oil red O staining showed the formation of lipid droplets in the cells, and alizarine red staining showed calcium nodules in the cells, indicating that the cells isolated and cultured in this experiment had the ability of multidirection differentiation. It is consistent with the characteristics of BMSCs. The growth of BMSCs cultured in vitro was stable, and the expanded BMSCs had multidirectional differentiation potential, which was an ideal seed cell for tissue engineering.