The Environment Recording Unit in coral skeletons – a synthesis of structural and chemical evidences for a biochemically driven, stepping-growth process in fibres

By J. Cuif, Y. Dauphin. 2005

144 citations recorded by the source corpus.

Abstract. This paper gathers a series of structural and biochemical in situ characterizations carried out to improve our knowledge of the fine scale growth patterns of fibres in coral skeletons. The resulting data show a clear correspondence between the mineral subunits of fibres and the spatial distribution of organic macromolecules. New observations using atomic force microscope confirm the close relationship between mineral and organic phases at the nanometre scale. Synthesis of these data results in a significant change in our concept of the mineralization process in coral skeletons. In contrast to the usual view of an aggregate of purely mineral units independently growing by simple chemical precipitation, coral fibres appear to be fully controlled structures. Their growth process is based on cyclic secretion of mineralizing compounds by the polyp basal ectoderm. These biochemical components of the coral fibres, in which sulfated acidic proteoglycans probably play a major role, are repeatedly produced (proteoglycans are those glycoproteins whose carbohydrate moieties consist of long unbranched chains of sulfated amino sugars). This results in a stepping growth mode of fibres and a layered global organization of coral skeletons. Therefore, in contrast to the widely accepted geochemical interpretation, we propose a fibre growth model that places coral skeletons among the typical ''matrix mediated'' structures. The crystal-like fibres are built by superimposition of few micron-thick growth layers. A biomineralization cycle starts by the secretion of a mineralizing matrix and the final step is the crystallization phase, during which mineral material grows onto the organic framework. Thus, each growth layer is the actual Environment Recording Unit. From a practical standpoint, these results may contribute to develop a new high resolution approach of the environment recording by coral skeletons.

Subfields: Biomaterials, Ecology, Ecology, Evolution, Behavior and Systematics

View Paper: https://www.semanticscholar.org/paper/1dd4df6d7c50405df8efce1c3258c905a6fd03d8

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Biomaterials

1. Denis Allemand
2. J. Ries
3. Bruce W. Fouke
4. Peter J. Edmunds
5. P. Jokiel

In Ecology

1. Denis Allemand
2. C. Ferrier‐Pagès
3. F. Houlbrèque
4. É. Tambutté
5. R. Dunbar
6. F. Marubini
7. P. Furla
8. J. Ries

In Ecology, Evolution, Behavior and Systematics

1. Denis Allemand
2. J. Ries
3. Bruce W. Fouke

Citations in the corpus

• Coral calcification responds to seawater acidification: a working hypothesis towards a physiological mechanism (2008, background): “…of a super-saturated solution, rather it is regulated by a process that combines organic matrix and mineral depositions in seasonal to diurnal growth layers (Barnes and Lough 1993; Cuif et al. 1999; Cohen and McConnaughey 2003; Allemand et al. 2004; Cuif and Dauphin 2005; Tambutté et al. 2007).”
• A biological origin for climate signals in corals—Trace element “vital effects” are ubiquitous in Scleractinian coral skeletons (2006, background): “However, the largest estimates of organic material so far published are 8 vol % [Cuif and Dauphin, 2005]: too small to account for all of the observed Mg. Alternatively, calcite is characteristically enriched in Mg, and depleted in U [Veizer, 1983], but Raman spectroscopy has failed to identify…”
• Observations of the tissue-skeleton interface in the scleractinian coral Stylophora pistillata (2007, background): “Early mineralizing zones, which are often referred to as centers of calciWcation (COC), show very diVerent stable isotope (e.g., C, O and B) or trace element (e.g., B, Mg, Sr, Ba, N, S) composition compared with other parts of the skeleton, and large chemical and isotopic variations have been docume”
• Vital effects in coral skeletal composition display strict three‐dimensional control (2006, background): “The construction of new skeleton is a continuous process in which COC are formed and subsequently overgrown by fibrous aragonite [Clode and Marshall, 2003; Cuif and Dauphin, 1998; Cuif and Dauphin, 2005; Stolarski, 2003].”