The cynomolgus and Chinese rhesus macaques are used as animal models in biomedical research. Yan et al. sequence their genomes and compare the sequences to that of the Indian rhesus macaque, providing a genetic foundation for interpreting research results. The nonhuman primates most commonly used in medical research are from the genus Macaca1. To better understand the genetic differences between these animal models, we present high-quality draft genome sequences from two macaque species, the cynomolgus/crab-eating macaque and the Chinese rhesus macaque. Comparison with the previously sequenced Indian rhesus macaque reveals that all three macaques maintain abundant genetic heterogeneity, including millions of single-nucleotide substitutions and many insertions, deletions and gross chromosomal rearrangements. By assessing genetic regions with reduced variability, we identify genes in each macaque species that may have experienced positive selection. Genetic divergence patterns suggest that the cynomolgus macaque genome has been shaped by introgression after hybridization with the Chinese rhesus macaque. Macaque genes display a high degree of sequence similarity with human disease gene orthologs and drug targets. However, we identify several putatively dysfunctional genetic differences between the three macaque species, which may explain functional differences between them previously observed in clinical studies.

Background: MajorClostridium difficilevirulence factors are the exotoxins TcdA and TcdB. Due to the large size and poor stability of the proteins, the active recombinant TcdA and TcdB have been difficult to produce.Results: The toxin genestcdAandtcdBwere amplified by PCR using chromosomal DNA from a toxigenic strain as a template, and cloned into a shuttle vector pHis1522. The sequences of bothtcdAandtcdBgenes in the vector have been verified by DNA sequencing. The constructs were transformed intoB. megateriumprotoplasts and the protein expression was controlled under a xylose promoter. The recombinant toxins (rTcdA and rTcdB) were purified from bacterial crude extracts. Approximately 5 – 10 mg of highly purified recombinant toxins were obtained from one liter of bacterial culture. The resulting rTcdA and rTcdB had similar molecular masses to the native toxins, and their biological activities were found to be similar to their native counterparts after an extensive examination.Conclusion: We have generated the full length and active recombinant TcdA and TcdB inBacillus megaterium.

Neoadjuvant chemotherapy (NAC) for rectal cancer (RC) shows promising clinical response. The modulation of the tumor microenvironment (TME) by NAC and its association with therapeutic response remain unclear. Here, we use single-cell RNA sequencing and spatial transcriptome sequencing to examine the cell dynamics in 29 patients with RC, who are sampled pairwise before and after treatment. We construct a high-resolution cellular dynamic landscape remodeled by NAC and their associations with therapeutic response. NAC markedly reshapes the populations of cancer-associated fibroblasts (CAFs), which is strongly associated with therapeutic response. The remodeled CAF subsets regulate the TME through spatial recruitment and crosstalk to activate immunity and suppress tumor progression through multiple cytokines, including CXCL12, SLIT2, and DCN. In contrast, the epithelial-mesenchymal transition of malignant cells is upregulated by CAF_FAP through MIR4435-2HG induction, resulting in worse outcomes. Our study demonstrates that NAC inhibits tumor progression and modulates the TME by remodeling CAFs.