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

神经脊(NC)是脊椎动物胚胎中的一个关键结构，它产生各种重要的衍生物，如色素细胞、内脏颅骨骨架或周围神经系统的神经节和神经胶质细胞。我们研究了在两个不同的时间点，NC来源的背根神经节(DRG)的大小调节在两个不同的时间点。Axolotl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研究。在我们的主要实验中，我们移除了白色(d/d)宿主神经元的两个神经折叠，并且a)用一个包含NC细胞的GFP+标记的折叠来替换它的右侧神经折叠，或者b)植入四个GFP+神经折叠，每个切除的折叠两个。在这两种情况下(a+b)，我们通过三个明确的前干节段(早期组(发育中的幼虫，10 mm)和晚期组(幼虫，4-8 cm))在冰冻切片上测定GFP+DRGs的大小，并对其进行抗GFAP和DAPI染色。我们的目的是找出当分别存在一个或四个GFP+折叠时，幼体或幼体的DRGs大小是否可以上调或下调至正常大小。

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.