아프리카산 발톱개구리 치아의 백악질에 관한 형태학적 연구
Morphological study on the cementum in the tooth of Xenopus laevis
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초록
치아는 백악질과 치아주위인대, 이틀뼈로 구성된 치아주위조직에 의해서 지지된다. 백악질은 조직학적특성에 따라 무세포성시멘트질과 세포성시멘트질로 구분된다. 아프리카산 발톱개구리의 치아는 일생동안탈락과 대체되는 과정을 반복하는 다생치아이고, 치아판와 모자시기, 종시기, 기능단계치아와 같은 여러 시기의 치아와 치배로 이루어져 있다. 또한, 치아주위조직중 백악질도 주기적으로 흡수와 재형성 과정을 반복한다. 그러나 아프리카산 발톱개구리 치아의 백악질에 관한 형태학적 특성은 잘 알려져 있지 않다. 실험동물은 변태 후 3개월 된 어린 개구리와 3년 이상 된 성숙한 개구리를 사용하였다. 각 실험동물의 위턱을 채취하여 4% 파라포름알데하이드 용액으로 4℃에서 14~16시간 동안 고정하였다. 고정된 조직을 10% EDTA/1x PBS 용액으로 탈회하였고, 파라핀에 포매한 후 5 μm 연속절편을 제작하여H-E, picrosirius red (PR), Masson’s trichrome (MT) 염색, Integrin binding sialoprotein (IBSP) in situ hybridization을 실시하였다. 뿌리집(HERS)은 분절화되지 않고 이어져 치아뿌리 전체면을 덮고 있다. 기능단계 치아는 위턱뼈에 유착되어 있고, PR 염색과 MT 염색을 실시한 결과 아교섬유는 뿌리집과 치아가 맞닿는 부위와 뿌리집으로 덮여 있지 않는 치아뿌리의 유착부위에서 관찰되었으나, IBSP 는 뿌리집으로 덮여 있지 않는 치아뿌리의 유착부위에서만 발현되었다. 아프리카산 발톱개구리의 치아에서 아교섬유의 분포와 IBSP 의 발현을 결과로 치아는 기저부에서 위턱뼈와 유착되는 치아주위조직중 일부에서 세포성시멘트질을 포함하는 것으로 추측된다. 이러한 결과는 향후아프리카산 발톱개구리의 치아에서 백악질의 미세구조와 분자유전학적 연구에 활용될 수 있을 것이다.
Abstract
Teeth are supported by the periodontium, which is composed of cementum, periodontal ligaments, and alveolar bone. The cementum consists of acellular and cellular cementum according to the histological features. The functional tooth of Xenopus laevis is shed and formed repeatedly during its lifetime, which is called polyphyodont. Xenopus laevis has various stages of tooth germ or tooth, i.e., lamina, cap and bell stages, and functional tooth. The cementum is also resorbed and formed, reiteratedly. However, little is known about the morphological data on the cementum in the teeth of Xenopus laevis. Juvenile and adult frogs were collected at the age of three month and three years or older. Upper jaws were fixed in a 4% paraformaldehyde solution at 4℃ overnight. The samples were treated with 10% EDTA and 1x PBS solution for decalcification and then embedded with paraffin via dehydration with graded ethanol and cleared using xylene. Five μm tissue sections were stained with hematoxylin-eosin (HE), picrosirius red (PR), Masson’s trichrome (MT) staining, and IBSP in situ hybridization. Hertwig’s epithelial root sheath (HERS) was continuous without fragments and covered with root dentin. A functional tooth was attached to the (pre)maxilla. The distribution of collagen fibers is shown in 1) a layer between HERS and tooth, and 2) the ankylosis area of the apical portion of the root lacking HERS. IBSP is only expressed in the latter. We suggest that the cellular cementum might be formed in the ankylosis area of the apical portion of the tooth root by the localization of collagen fibers and IBSP RNA in Xenopus laevis. Therefore, these results could be useful for molecular genetics and ultrastructural research of the cementum in the teeth of Xenopus laevis.
참고문헌 (19)
- 김민석, "치아형태학", pp.54~67 (2016), 대한나래출판사
- Thomas J. C. Bertin, "Current Perspectives on Tooth Implantation, Attachment, and Replacement in Amniota", Frontiers in Physiology, 9, pp.1630~ (2018), Frontiers Media SA[DOI]
- Luan X, "Evolution and development of Hertwig’s epithelial root sheath", Dev Dyn, 235, pp.1167~1180 (2006)[DOI]
- Tsuneyuki Yamamoto, "Histology of human cementum: Its structure, function, and development", Japanese Dental Science Review, 52(3), pp.63~74 (2016), Elsevier BV[DOI]
- Nanci A, "Ten Cate’s Oral Histology: Development, Structure, and Function", pp.205~218 (2013), Mosby Elsevier
- McIntosh JE, "Caiman periodontium as an intermediate between basal vertebrate ankylosis-type attachment and mammalian “true”periodontium", Microsc Res Tech, 59, pp.449~459 (2002)[DOI]
- Tiphaine Davit-Béal, "Amphibian teeth: current knowledge, unanswered questions, and some directions for future research", Biological Reviews, 82(1), pp.49~81 (2007), Wiley[DOI]
- Sasagawa I, "The structure and development of the collar enameloid in two teleost fishes, Halichoeres poecilopterus and Pagrus major", Anat Embryol (Berl), 178, pp.499~511 (1988)[DOI]
- Zaher H, "Tooth implantation and replacement in squamates, with special reference to mosasaur lizards and snakes", Am Mus, 3271, pp.1~19 (1999)
- Lee MSY, "On snake-like dentition in mosasaurian lizards", J Nat Hist, 31, pp.303~314 (1997)
- Caldwell MW, "Histology of tooth attachment tissues in the Late Cretaceous mosasaurid Platecarpus", J Vertebr Paleontol, 23, pp.622~630 (2003)
- Aaron R. H. LeBlanc, "Tooth attachment and pleurodont implantation in lizards: Histology, development, and evolution", Journal of Anatomy, 238(5), pp.1156~1178 (2021), Wiley[DOI]
- Mestriner G, "Histological analysis of ankylothecodonty in Silesauridae (Archosauria: Dinosauriformes) and its implications for the evolution of dinosaur tooth attachment", Anat Rec (Hoboken) (2021)[DOI]
- Foster BL, "Methods for studying tooth root cementum by light microscopy", Int J Oral Sci, 4, pp.119~128 (2012)[DOI]
- Ganss B, "Bone Sialoprotein", Crit Rev Oral Biol Med, 10, pp.79~98 (1999)[DOI]
- Lemaire P, "A role for cytoplasmic determinants in mesoderm patterning: cell-autonomous activation of the goosecoid and Xwnt-8 genes along the dorsoventral axis of early Xenopus embryos", Development, 120, pp.1191~1199 (1994)
- LeBlanc ARH, "Dental ontogeny in extinct synapsids reveals a complex evolutionary history of the mammalian tooth attachment system", Proc Biol Sci, 285 (2018)[DOI]
- Luan X, "The mosasaur tooth attachment apparatus as paradigm for the evolution of the gnathostome periodontium", Evol Dev, 11, pp.247~259 (2009)[DOI]
- Erin E. Maxwell, "Histology of tooth attachment tissues and plicidentine in Varanus (Reptilia: Squamata), and a discussion of the evolution of amniote tooth attachment", Journal of Morphology, 272(10), pp.1170~1181 (2011), Wiley[DOI]