title: Not all the number of skeletal muscle fibers is determined prenatally.
abstract: BACKGROUND
  The investigation of skeletal muscle development is of importance in stock farming and biomedicine. It is still ambiguous that whether animals are born with the full set of skeletal muscle fibers or if the number of myofibers continues to increase postnatally.
  
  
  RESULTS
  Here, an inducible lineage-tracing system was employed to monitor the changes of myofiber number in various skeletal muscles during development. We confirm that the total myofiber number of longissimus dorsi, gastrocnemius and rectus femoris is determined prenatally. However, tibialis anterior and extensor digitorum longus have a different development pattern, and their myofiber number still increases in the first postnatal week and then remains stable afterwards.
  
  
  CONCLUSIONS
  Our results highlight different development time frames of anatomically distinct skeletal muscles.
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Beisan Road, Guangzhou, 510006, China. mingsensys@163.com.
authors.forename: Mingsen
authors.initials: M
authors.lastname: Li
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Beisan Road, Guangzhou, 510006, China. etetjoe@qq.com.
authors.forename: Xingyu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Beisan Road, Guangzhou, 510006, China. chyaosh@mail.sysu.edu.cn.
authors.forename: Yaosheng
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Beisan Road, Guangzhou, 510006, China. nypnguh@gmail.com.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Nie
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Beisan Road, Guangzhou, 510006, China. 362181547@qq.com.
authors.forename: Huaxing
authors.initials: H
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Beisan Road, Guangzhou, 510006, China. chenhu126@126.com.
authors.forename: Hu
authors.initials: H
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Beisan Road, Guangzhou, 510006, China. modelin@mail.sysu.edu.cn.
authors.forename: Delin
authors.initials: D
authors.lastname: Mo
mesh_terms: D000818:Animals; D004318:Doxycycline; D051379:Mice; D008822:Mice, Transgenic; D024510:Muscle Development / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000166:cytology*; D011401:Promoter Regions, Genetic / Q000235:genetics; D052097:Quadriceps Muscle / Q000254:growth & development; D013194:Staining and Labeling; D001616:beta-Galactosidase / Q000235:genetics
chemical_list: D001616:beta-Galactosidase; D004318:Doxycycline