Use this URL to cite or link to this record in EThOS:
Title: Investigations into the anatomical structure and differentiation related gene expression in the dog claw
Author: Henderson, Haley
Awarding Body: De Montfort University
Current Institution: De Montfort University
Date of Award: 2007
Availability of Full Text:
Access from EThOS:
Access from Institution:
The canine claw is a complex structure consisting of several cell types that undergo tissue specific differentiation. The aim was to study the anatomy and keratin expression within the canine claw. These studies showed that proximal canine claw was comparable to human nail and hair follicle. The claw fold contained several layers similar to hair follicle: outer root sheath (termed outer claw sheath: OCS), inner root sheath (inner claw sheath: ICS) companion layer (CL) and inner root sheath cuticle (lCS cuticle: ICScu). A thin cellular layer comparable to the hair and nail cuticle coated the surface of the claw plate was termed stratum externum (SE). Immunohistochemistry studies using human and mouse antibodies (K5, K6, K14, Kl6 and Kl7) showed that the OCS was K5, K6, K14, K16 and K17 positive and K6, Kl6 and Kl7 defined the CL. The claw plate comprised two macroscopic layers: stratum medium (SM) and stratum internum (SI). The SM was sub-divided into four layers (SMl-4), each generated from a different germinative region (GR) protected within the bony ungual groove of the distal phalanx. SM2 contained epithelial tubules, generated from the apex of G R2 papillae and ran the entire length of SM2. Tubule cells were K6 and K 16 positive and provided the hard claw plate with plasticity. GR3 (expressing K5, K6, K14, K16 and K17 positive) and GR4 (K6 and Kl7 positive) lay over a thick mesenchyme (lunula) and produced SM3 and SM4 horn respectively. The SM4 produced a large K6 positive eosinophillic strip within the claw plate providing it with further flexibility which may allow independent movement between two ’hard’ claw plate layers. The bony ungual process and longitudinal ridge (LR) decreased in size and shape in a distal direction and two additional layers (SI 1 and SI2) were generated (GR5 and GR6 respectively) and filled the gap between claw plate and bone. GR5 cells were K6 positive but no keratin expression was found in GR6. Over the medial and lateral walls, the laminar GR9 produced a soft epithelium (termed sole 2: S2) to which the hard claw plate adhered. Three further sole layers (SI, S3 and S4) were identified and all expressed K5, K6, K14, K16 and K 17. SDS-P AGE analysis of the claw plate showed protein bands within the hair-specific keratin (HSK) molecular weight range but HSK antibodies did not cross-react with canine tissue so the presence of these keratins within SM 1-4 and SIl and SI2 could not be confirmed.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available