Effect of balance taping on trunk stabilizer muscles for back extensor muscle endurance: A randomized controlled study

Objective:The purpose of this study was to investigate the difference in back extensor muscle endurance before and after kinesiology tape application to all back stabilizer muscles and to the erector spinae alone.Methods:We assessed 32 adults (16 men and 16 women), randomly divided into two groups. In the erector spinae taping (EST) group, kinesiology tape was applied only to the erector spinae, and in the total muscle taping (TMT) group, kinesiology tape was applied to the erector spinae, latissimus dorsi, lower trapezius, internal oblique abdominis, and external oblique abdominis.Results:Both groups showed significant difference in terms of back extensor muscle endurance after kinesiology tape application (p<0.05). Between-group comparison revealed that the TMT group had more back extensor muscle endurance than the EST group (p<0.05) after kinesiology tape application.Conclusions:These findings indicate that, to improve back extensor muscle endurance, kinesiology tape should be applied to all back stabilizer muscles, rather than to the erector spinae muscles alone.     

RS‐1 enhances CRISPR‐mediated targeted knock‐in in bovine embryos

Targeted knock‐in (KI) can be achieved in embryos by clustered regularly interspaced short palindromic repeats (CRISPR)‐assisted homology directed repair (HDR). However, HDR efficiency is constrained by the competition of nonhomologous end joining. The objective of this study was to explore whether CRISPR‐assisted targeted KI rates can be improved in bovine embryos by exposure to the HDR enhancer RS‐1. In vitro produced zygotes were injected with CRISPR components (300 ng/µl Cas9 messenger RNA and 100 ng/µl single guide RNA against a noncoding region) and a single‐stranded DNA (ssDNA) repair template (100 ng/µl). ssDNA template contained a 6 bp XbaI site insert, allowing targeted KI detection by restriction analysis, flanked by 50 bp homology arms. Following microinjection, zygotes were exposed to 0, 3.75, or 7.5 µM RS‐1 for 24 hr. No differences were noted between groups in terms of development or genome edition rates. However, targeted KI rates were doubled in the group exposed to 7.5 µM RS‐1 compared to the others (52.8% vs. 25% and 23.1%, for 7.5, 0, and 3.75 µM, respectively). In conclusion, transient exposure to 7.5 µM RS‐1 enhances targeted KI rates resulting in approximately half of the embryos containing the intended mutation, hence allowing direct KI generation in embryos.     

An exploration of the role of Sertoli cells on fetal testis development using cell ablation strategy

Sertoli cells (SCs) are presumed to be the center of testis differentiation because they provide both structural support and biological regulation for spermatogenesis. Previous studies suggest that SCs control germ cell (GC) count and Leydig cell (LC) development in mouse testes. However, the regulatory role of SCs on peritubular myoid (PTM) cell fate in fetal testis has not been clearly reported. Here, we employed Amh‐Cre; diphtheria toxin fragment A (DTA) mouse model to selectively ablate SCs from embryonic day (E) 14.5. Results found that SC ablation in the fetal stage caused the disruption of testis cords and the massive loss of GCs. Furthermore, the number of α‐smooth muscle actin‐labeled PTM cells was gradually decreased from E14.5 and almost lost at E18.5 in SC ablation testis. Interestingly, some Ki67 and 3β‐HSD double‐positive fetal LCs could be observed in Amh‐Cre; DTA testes at E16.5 and E18.5. Consistent with this phenomenon, the messenger RNA levels of Hsd3b1, Cyp11a1, Lhr, Star and the protein levels of 3β‐HSD and P450Scc were significantly elevated by SC ablation. SC ablation appears to induce ectopic proliferation of fetal LCs although the total LC number appeared reduced. Together, these findings bring us a better understanding of SCs’ central role in fetal testis development.