Increasing cell mobility is the basis of tumor invasion and metastasis, and is therefore a therapeutic target for preventing the spread of many types of cancer. Septins are a family of cytoskeletal proteins with GTPase activity, and play a role in many important cellular functions, including cell migration. SEPT9 isoform 1 protein (SEPT9_i1) has been associated with breast tumor development and the enhancement of cell migration; however, the exact mechanism of how SEPT9_i1 might affect breast cancer progression remains to be elucidated. Here, we report that the expression of SEPT9_i1 positively correlated with paxillin, and both were significantly upregulated in invasive breast cancer tissues of patients with lymph node metastases. Lentivirus-mediated shRNA knockdown of SEPT9 in MCF-7 cells diminished tumor cell migration, focal adhesion (FA) maturation and the expression of β-actin, β-tubulin, Cdc42, RhoA, and Rac, whereas overexpression of SEPT9_i1 in SEPT9-knockdown MCF-7 cells promoted cell migration, FA maturation and relevant protein expression. Furthermore, overexpression of SEPT9_i1 in MCF-7 cells markedly increased FAK/Src/paxillin signaling, at least in part through RhoA/ROCK1 upstream activation. Transcriptome profiling suggested that SEPT9_i1 may directly affect “Focal adhesion” and “Regulation of actin cytoskeleton” signaling mechanisms. Finally, overexpression of SEPT9_i1 markedly enhanced lung metastases in vivo 6 weeks after tumor inoculation. These findings suggest that a mechanism of Septin-9-induced aberrant cancer cell migration is through cytoskeletal regulation and FA modulation, and encourages the use of SEPT9 as novel therapeutic target in the prevention of tumor metastasis.

Genetic divergences of mitochondrial cytochrome c oxidase subunit I genes, known as DNA barcodes, have been used in species identification in the animal kingdom. Barcodes can assist field workers and taxonomists to determine groups in need of taxa analysis, and facilitate the recognition of appropriate populations and scales for conservation planning. In this study, 18 species of Bovidae were selected to evaluate the effectiveness of DNA barcoding for species differentiation. The results showed that all but 2 species had unique DNA barcodes. The mean intraspecific variation was 0.63%, yielding a threshold of 6.3% for flagging putative species. The results supported the inference that barcode variation within species of mammals is somewhat higher than within other animal groups. The present study validated the effectiveness of barcoding for the identification of bovid species.

Results showed that all 66 species investigated had unique COI sequences and no sequences were shared between the species. Our results were congruent with previous studies suggesting that the COI barcode permits distinguishing most of the closely related species. Furthermore, by using geographically distinct clusters, diagnostic characters, and threshold levels, deep genetic splits (>1.5%) were observed in three species, and we therefore suggest treating them as evolutionary significant units.