Distinct patterns of notochord mineralization in zebrafish coincide with the localization of Osteocalcin isoform 1 during early vertebral centra formation

Bensimon-Brito, A.; Cardeira Da Silva, João; Cancela, Leonor; Huysseune, Ann; Witten, Paul

Publication

Distinct patterns of notochord mineralization in zebrafish coincide with the localization of Osteocalcin isoform 1 during early vertebral centra formation

2012-10-09Journal article

dc.contributor.author	Bensimon-Brito, A.
dc.contributor.author	Cardeira Da Silva, João
dc.contributor.author	Cancela, Leonor
dc.contributor.author	Huysseune, Ann
dc.contributor.author	Witten, Paul
dc.date.accessioned	2012-12-10T10:46:04Z
dc.date.available	2012-12-10T10:46:04Z
dc.date.issued	2012-10-09
dc.date.updated	2012-12-08T06:48:53Z
dc.description.abstract	In chondrichthyans, basal osteichthyans and tetrapods, vertebral bodies have cartilaginous anlagen that subsequently mineralize (chondrichthyans) or ossify (osteichthyans). Chondrocytes that form the vertebral centra derive from somites. In teleost fish, vertebral centrum formation starts in the absence of cartilage, through direct mineralization of the notochord sheath. In a second step, the notochord is surrounded by somite-derived intramembranous bone. In several small teleost species, including zebrafish (Danio rerio), even haemal and neural arches form directly as intramembranous bone and only modified caudalmost arches remain cartilaginous. This study compares initial patterns of mineralization in different regions of the vertebral column in zebrafish. We ask if the absence or presence of cartilaginous arches influences the pattern of notochord sheath mineralization. Results - To reveal which cells are involved in mineralization of the notochord sheath we identify proliferating cells, we trace mineralization on the histological level and we analyze cell ultrastructure by TEM. Moreover, we localize proteins and genes that are typically expressed by skeletogenic cells such as Collagen type II, Alkaline phosphatase (ALP) and Osteocalcin (Oc). Mineralization of abdominal and caudal vertebrae starts with a complete ring within the notochord sheath and prior to the formation of the bony arches. In contrast, notochord mineralization of caudal fin centra starts with a broad ventral mineral deposition, associated with the bases of the modified cartilaginous arches. Similar, arch-related, patterns of mineralization occur in teleosts that maintain cartilaginous arches throughout the spine.Throughout the entire vertebral column, we were able to co-localize ALP-positive signal with chordacentrum mineralization sites, as well as Collagen II and Oc protein accumulation in the mineralizing notochord sheath. In the caudal fin region, ALP and Oc signals were clearly produced both by the notochord epithelium and cells outside the notochord, the cartilaginous arches. Based on immunostaining, real time PCR and oc2:gfp transgenic fish, we identify Oc in the mineralizing notochord sheath as osteocalcin isoform 1 (Oc1). Conclusions - If notochord mineralization occurs prior to arch formation, mineralization of the notochord sheath is ring-shaped. If notochord mineralization occurs after cartilaginous arch formation, mineralization of the notochord sheath starts at the insertion point of the arches, with a basiventral origin. The presence of ALP and Oc1, not only in cells outside the notochord, but also in the notochord epithelium, suggests an active role of the notochord in the mineralization process. The same may apply to Col II-positive chondrocytes of the caudalmost haemal arches that show ALP activity and Oc1 accumulation, since these chondrocytes do not mineralize their own cartilage matrix. Even without cartilaginous preformed vertebral centra, the cartilaginous arches may have an inductive role in vertebral centrum formation, possibly contributing to the distinct mineralization patterns of zebrafish vertebral column and caudal fin vertebral fusion.	por
dc.identifier.citation	BMC Developmental Biology. 2012 Oct 09;12(1):28	por
dc.identifier.doi	10.1186/1471-213X-12-28
dc.identifier.uri	http://hdl.handle.net/10400.1/1941
dc.language.iso	eng	por
dc.peerreviewed	yes	por
dc.publisher	BioMed Central	por
dc.rights.uri	http://creativecommons.org/licenses/by/2.0
dc.title	Distinct patterns of notochord mineralization in zebrafish coincide with the localization of Osteocalcin isoform 1 during early vertebral centra formation	por
dc.type	journal article
dspace.entity.type	Publication
oaire.citation.issue	28	por
oaire.citation.volume	12	por
person.familyName	Bensimon-Brito
person.familyName	Cardeira da Silva
person.familyName	Cancela
person.givenName	Anabela
person.givenName	João
person.givenName	M. Leonor
person.identifier	1460592
person.identifier.ciencia-id	8419-63A7-D0E5
person.identifier.ciencia-id	DC15-86F7-3AAC
person.identifier.orcid	0000-0003-1663-2232
person.identifier.orcid	0000-0003-3722-8810
person.identifier.orcid	0000-0003-3114-6662
person.identifier.rid	N-7291-2014
person.identifier.scopus-author-id	36154529200
person.identifier.scopus-author-id	55224020100
rcaap.rights	openAccess	por
rcaap.type	article	por
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