I Love Histology and Herpetology

Lizard tail regeneration, particularly the cartilage regeneration, is a compelling phenomenon to be studied as it has been widely known that the regenerative capacity of cartilage after injury/trauma is very limited (Tuan et al., 2013). Urodeles are capable to regenerate tissues similar to the originals (Lozito & Tuan, 2015) while the regenerated tail of lizard is considered as an imperfect replica due to the several anatomical differences (Fisher et al., 2012). One stand out structure of those imperfections is that the axial skeleton of regenerated tail is lack of bony structures, but instead, it is composed of cartilage (Alibardi & Meyer-Rochow, 1989). The caudal vertebrae of the original tail will be replaced by a continuous, unsegmented cartilage tube surrounding the growing ependymal canal. This cartilage tube only exists in the regenerated tail of lizard and is maintained throughout the life of the organism. An experiment conducted by Lozito & Tuan (2015) showed that ...

Lizard ability to regrow its tail following tail amputation is known as regeneration (Hutchins et al., 2016). Regeneration process is initiated by the formation of blastema from the dedifferentiated cells (Daniels et al., 2003; Alibardi & Lovicu, 2010). Later on, Alibardi (2015) stated that progenitor cells also play an important role in this process. These blastemal cells will proliferate and then differentiate to form new tissues to replace the lost/damaged tissue (Carlson, 2007; Narayanan, 2015). Regeneration process is divided into four stages: (1) wound healing stage, lasting up to 10 days post-autotomy (dpa); (2) blastema formation ranging from 10-15 dpa; (3) tail growth and differentiation ranging from 15-25 dpa; and (4) tail maturation when the tail becomes fully scaled (Alibardi, 2009) which is usually studied from 25-60 dpa (Fisher et al., 2012) with no currently known endpoint. Ependymal cells lining the central canal of the original spinal cord appear to be crucial for ...

McLean and Vickaryous (2011) studied epimorphic regeneration in Eublepharis macularius (Leopard Gecko) and the results showed that the transverse section of the tail is circular to ovoid and the skeletal system is located in the center. The histological observation also showed that the tail is separated into quadrants by the presence of connective tissue known as septa emerging from (1) the neural spine in the dorsal region, (2) chevron bone in the ventral region, and (3) transverse processes on both lateral sides. Both dorsal (epaxial) and ventral (hypaxial) quadrants consist of perivertebral adipose tissue, connective tissue and musculature. The outer part of the tail is well-protected by integument system modified into scales. Various tissues lie under the skin, from the outside in: segmented musculature, perivertebral adipose tissue surrounding the caudal vertebrae and the spinal cord located inside the vertebral canal. Peripheral nerve fibers can be found in the adipose and muscle...