Rated somite showed no significant change comparing to the un-operated somites PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/20460822 (Additional file 4: Figure S2).Discussion In this study, we investigated the function of the dermomyotome ventrolateral lip (VLL) using surgical ablationPu et al. BMC Developmental Biology 2013, 13:37 http://www.biomedcentral.com/1471-213X/13/Page 4 ofFigure 1 Ablation of the dorsolateral quarter of epithelial somites (primordium of the ventrolateral dermomyotome lip) interrupted hypaxial myotome growth. A and B: Operation scheme. The dorsolateral quarter of 3 somites (somite III or IV) of a stage 16 chick embryo was ablated. C-F: in situ hybridisation with Pax3. G and H: Transverse section at the level (indicated by a line in D and F) of the embryo in D and F. In the operated side the Pax3 expression was detected only in the epaxial domain (ep), while it was expressed in both epaxial (ep) and hypaxial (hyp) domain of the dermomyotome in the control side. I-L: Immunohistochemistry with MF20. M and N: 2,2,3,3-Tetrafluoropropyl N,N'-diethylcarbamimidothioate trifluoromethanesulfonate Transverse section at the level (indicated by a line in J and L) of the embryo in J and L. In the operated side the myosin heavy chain was detected only in the epaxial myotome (ep), while it was expressed in both epaxial (ep) and hypaxial (hyp) domain of the myotome in the control side. C, D, G, I, J, M: Operated embryos after one day reincubation. E, F, H, K, L, N: Operated embryos after two day reincubation. Operated somites are indicated by arrows (one arrow = one segment) in the whole mount. Arrow heads indicate the ventrolateral end of the hypaxial domain of the dermomyotome and myotome. Arrows mark the border between the epaxial and hypaxial domain. Abbreviations: ep epaxial domain, fl PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/3081428 forelimb, hl hind limb, hyp hypaxial domain, lat lateral, med medial, nt neural tube.technique in the chick embryo. A complication of this procedure is that it is difficult to remove all VLL cells and the remaining cells can reconstitute the ablated tissue. Therefore when small regions are ablated, the phenotype is limited due to regeneration. This can be circumvented by ablating the VLL from consecutive somites. This is a possible explanation why others who have carried out limited ablation experiment have failed to induce changes in myotome growth.We never observed labelled intermediate dermomyotome moving to the position of the previously ablated VLL. Combined with the observation that the hypaxial myotome truncated after removal of the VLL of 3 somites, we can conclude that the function of the VLL can not be replaced by the intermediate dermomyotome. After removal of the intermediate part, the myotome formed almost normally. It is possible that the remaining cells of the intermediate part could compensate the lost cells, therebyPu et al. BMC Developmental Biology 2013, 13:37 http://www.biomedcentral.com/1471-213X/13/Page 5 ofFigure 2 Ablation of the lateral lip of the dermomyotome after GFP labelling. A and B are scheme of the operation. A: The lateral part of interlimb somites was electroporated with a GFP vector. N-BOC-3-Fluoro-D-phenylalanine B: After one day reincubation, a GFP marked lateral lip was removed. C-F are pictures of a same embryo. C: One day after the electroporation. The lateral parts ijms17122034 of 5 somites were labelled with GFP. D: Immediately after the removal of the most lateral part of a somite (arrow). E: One day after the ablation. GFP domain of the ablated dermomyotomal lip did not grow as far ventrally as the unoperated somites. F: The Pax3-expression was affected in the operated segme.