Size regulation of dorsal root ganglia (DRG) in developing axolotls with a deficiency or oversupply of neural crest material

神经嵴（NC）是脊椎动物胚胎中的关键结构，其产生各种重要的衍生物，如色素细胞、内脏颅骨架或周围神经系统的神经节和神经胶质。我们调查的NC衍生背根神经节（DRG）在两个不同的时间点在发展过程中的蝾螈（Ambystoma mexicanum）以下的实验下和过度供应NC材料的大小调节。美西螈以其再生能力而闻名。它可以再生缺失的结构，如肢体，尾巴或脊髓，因此注定要用于组织修复的研究。在我们的主要实验中，我们去除了白色（d/d）宿主神经胚的两个神经折叠，并且a）用一个含有NC细胞的GFP+标记的折叠替换其右侧神经折叠，或者B）植入四个GFP+神经折叠，每个去除的折叠两个。在这两种情况下（a+B），我们通过早期组（发育中的幼虫，10 mm）和晚期组（青少年，4-8 cm）中的三个限定的前躯干节段在冷冻切片上确定GFP+ DRG的大小，所述冷冻切片用抗GFAP和Dapi染色。我们的目的是找出是否DRGs的大小可以上调或下调到正常大小的幼虫或青少年时，一个或四个GFP+折叠，分别存在。

The neural crest (NC) is a key structure in vertebrate embryos that gives rise to various important derivatives such as pigment cells, the viscerocranial skeleton, or ganglia and glia of the peripheral nervous system. We investigate the size regulation of NC-derived dorsal root ganglia (DRG) at two different timepoints during the development of the axolotl (Ambystoma mexicanum) following an experimental under- and oversupply with NC material. The axolotl is known for its regenerative capacity. It can regenerate missing structures such as limb, tail or the spinal cord and is therefore predestined for studies on tissue repair. In our main experiments we remove both neural folds of a white (d/d) host neurula and a) replace its right neural fold with one GFP+ labeled fold containing NC cells or b) implant four GFP+ neural folds, two for each extirpated fold. In both cases (a+b) we determine the size of GFP+ DRGs on cryosections through three defined anterior trunk segments in an early time group (developing larvae, 10 mm) and a later timegroup (juveniles, 4-8 cm) which are stained with anti-GFAP and Dapi. Our aim is to find out whether the size of DRGs can be up- or downregulated to normal size in larvae or juveniles when one orfourGFP+folds are present, respectively.