The influence of direct and indirect fibroblast cell contact on human myogenic cell behavior and gene expression in vitro

Underpinning skeletal muscle plasticity is the interplay between many cell types, of which fibroblasts are emerging as potent players, both negatively in the development of fibrosis but also positively in stimulating muscle repair through enhancing myogenesis. The mechanisms behind this interaction however remain unknown. To investigate this, waste hamstring muscle tissue was obtained from eight healthy young men undergoing reconstructive anterior cruciate ligament surgery and primary myoblasts and fibroblasts were isolated. Myoblasts were cultured alone or with fibroblasts, either in direct or indirect contact (separated by an insert with a permeable membrane). The myogenesis parameters proliferation, differentiation, and fusion were determined from immunostained cells, while, in replicate samples, gene expression levels of GAPDH, Ki67, Pax7, MyoD, myogenin, myomaker, MHC-Iβ, TCF7L2, COL1A1, and p16 were determined by RT-PCR. We found only trends for an influence of skeletal muscle fibroblasts on myogenic cell proliferation and differentiation. While greater mRNA levels of GAPDH, Pax7, MyoD, myogenin, and MHC-Iβ were observed in myogenic cells in indirect contact with fibroblasts (insert) when compared with cells cultured alone, a similar effect of an empty insert was also observed. In conclusion we find very little influence of skeletal muscle fibroblasts on myoblasts derived from the same tissue, although it cannot be excluded that a different outcome would be seen under less optimal myogenic growth conditions.NEW & NOTEWORTHY Using passage one primary myoblasts and fibroblasts isolated from human skeletal muscle, we found only a trend for an effect of skeletal muscle fibroblasts on myogenic cell proliferation and differentiation. This is contrary to previous reports and raises the possibility that fibroblasts of different tissue origins exert distinct roles.

Identifying artificial selection signals in the chicken genome

Identifying the signals of artificial selection can contribute to further shaping economically important traits. Here, a chicken 600k SNP-array was employed to detect the signals of artificial selection using 331 individuals from 9 breeds, including Jingfen (JF), Jinghong (JH), Araucanas (AR), White Leghorn (WL), Pekin-Bantam (PB), Shamo (SH), Gallus-Gallus-Spadiceus (GA), Rheinlander (RH) and Vorwerkhuhn (VO). Per the population genetic structure, 9 breeds were combined into 5 breed-pools, and a 'two-step' strategy was used to reveal the signals of artificial selection. GA, which has little artificial selection, was defined as the reference population, and a total of 204, 155, 305 and 323 potential artificial selection signals were identified in AR_VO, PB, RH_WL and JH_JF, respectively. We also found signals derived from standing and de-novo genetic variations have contributed to adaptive evolution during artificial selection. Further enrichment analysis suggests that the genomic regions of artificial selection signals harbour genes, including THSR, PTHLH and PMCH, responsible for economic traits, such as fertility, growth and immunization. Overall, this study found a series of genes that contribute to the improvement of chicken breeds and revealed the genetic mechanisms of adaptive evolution, which can be used as fundamental information in future chicken functional genomics study.

A novel approach for in vitro meat production

The present review describes the possibility of in vitro meat production with the help of advanced co-culturing methods. In vitro meat production method could be a possible alternative for the conventional meat production. Originally, the research on in vitro meat production was initiated by the National Aeronautics and Space Administration (NASA) for space voyages. The required key qualities for accepting in vitro meat for consumption would be good efficiency ratio, increased protein synthesis rate in skeletal muscles, and mimicking the conventional meat qualities. In vitro culturing of meat is possible with the use of skeletal muscle tissue engineering, stem cell, cell co-culture, and tissue culture methods. Co-culture of myoblast and fibroblast is believed as one of the major techniques for in vitro meat production. In our lab, we have co-cultured myoblast and fibroblast. We believe that a billion pounds of in vitro meat could be produced from one animal for consumption. However, we require a great deal of research on in vitro meat production.