Decomposition is a complex process involving the interaction of both biotic and abiotic factors. Microbes play a critical role in the process of carrion decomposition. In this study, we analysed bacterial communities from live rats and rat remains decomposed under natural conditions, or excluding sarcosaphagous insect interference, in China using Illumina MiSeq sequencing of 16S rRNA gene amplicons. A total of 1,394,842 high-quality sequences and 1,938 singleton operational taxonomic units were obtained. Bacterial communities showed notable variation in relative abundance and became more similar to each other across body sites during the decomposition process. As decomposition progressed, Proteobacteria (mostly Gammaproteobacteria) became the predominant phylum in both the buccal cavity and rectum, while Firmicutes and Bacteroidetes in the mouth and rectum, respectively, gradually decreased. In particular, the arrival and oviposition of sarcosaphagous insects had no obvious influence on bacterial taxa composition, but accelerated the loss of biomass. In contrast to the rectum, the microbial community structure in the buccal cavity of live rats differed considerably from that of rats immediately after death. Although this research indicates that bacterial communities can be used as a “microbial clock” for the estimation of post-mortem interval, further work is required to better understand this concept.

Background The epithelial-mesenchymal transition (EMT) is crucial for metastasis and positively regulated by calcium-related signaling. The melastatin-related transient receptor potential 7 (TRPM7) regulates a non-selective cation channel and promotes cancer metastasis. However, the mechanisms underlying the action of TRPM7 in ovarian cancer are unclear. Methods The expression of TRPM7 and EMT markers (Vimentin, N-cadherin, Twist and E-cadherin) in ovarian cancer samples was detected. TRPM7was knockdown by shRNA in Ovarian cancer cell lines to examine calcium [Ca2+]i, EMT markers and PI3K/AKT markers. Various cellular assays, such as invasion and migration, were performed in vitro, and further confirmed in vivo. Results TRPM7 expression is negatively correlated with E-cadherin, but positively with N-cadherin, Vimentin and Twist expression in ovarian cancer samples. TRPM7 depletion inhibited the migration and invasion in SKOV3 and OVCAR3 cells. In addition, TRPM7 silencing decreased the lung metastasis of SKOV3 tumors and prolonged the survival of tumor-bearing mice. Similar to that of TRPM7 silencing, treatment with MK886, a potent 5-lipoxygenase inhibitor to reduce TRPM7 expression, and/or BAPTA-AM, an intracellular calcium chelator, significantly mitigated the Epidermal growth factor (EGF) or Insulin-like growth factors (IGF)-stimulated migration, invasion, and the EMT in ovarian cancer cells by decreasing the levels of intracellular calcium [Ca2+]i. Furthermore, treatment with LY2904002, a PI3K inhibitor, also inhibited the migration, invasion, and treatment with both LY2904002 and BAPTA-AM further enhanced their inhibition in ovarian cancer cells. Moreover, treatment with BAPTA-AM mitigated the IGF-stimulated migration, invasion, particularly in TRPM7-silenced ovarian cancer cells. Finally, TRPM7 silencing attenuated the PI3K/AKT activation, which was enhanced by BAPTA-AM, MK886 or LY2904002 treatment in ovarian cancer cells. Conclusions TRPM7 silencing inhibited the EMT and metastasis of ovarian cancer by attenuating the calcium-related PI3k/AKT activation. Our findings suggest that TRPM7 may be a therapeutic target for intervention of ovarian cancer. Electronic supplementary material The online version of this article (10.1186/s13046-019-1061-y) contains supplementary material, which is available to authorized users.

Forensic entomology could provide valuable data for the minimum postmortem interval (PMImin) estimation and other relevant information, such as causes and circumstances of death. Some representatives of flesh flies are one of the dominant necrophagous insects during early stages of decomposition, demonstrating unique biological characteristics compared with other necrophagous flies. Moreover, they lead to global health concerns as carriers of various pathogenic micro-organisms, and dominantly result in the traumatic myiasis. Thus, sarcophagid flies are considered important in decomposition processes for PMImin estimation. However, the utility of sarcophagid flies has been seriously hampered by limited ecological, biological and taxonomic knowledge of them. The aim of this paper is to provide a brief review on the species, distribution and biological habit of forensically important sarcophagid flies. In addition, the relation between traumatic myiasis and flesh flies, molecular identification methods and developmental pattern of flesh flies are summarized.

Insects attracted to cadavers may provide important indications of the postmortem interval (PMI). However, use of the flesh flies (Diptera: Sarcophagidae) for PMI estimation is limited as the species are often not morphologically distinct, especially as immatures. In this study, 23 forensically important flesh flies were collected from 13 locations in 10 Chinese provinces. Then, a 278-bp segment of the cytochrome oxidase subunits one (COI) gene and a 289-bp segment of the 16S rDNA gene of all specimens were successfully sequenced. Phylogenetic analysis of the sequenced segments showed that all sarcophagid specimens were properly assigned into four species (Boerttcherisca peregrina [Robineau-Desvoidy, 1830], Helicophagella melanura [Meigen, 1826], Parasarcophaga albiceps [Meigen, 1826], and Parasarcophaga dux [Thompson, 1869]) with relatively strong supporting values, thus indicating that the COI and 16S rDNA regions are suitable for identification of sarcophagid species. The difference between intraspecific threshold and interspecific divergence confirmed the potential of the two regions for sarcophagid species identification.