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Table 1 Biomineralization types and the presence of α-CA in various metazoan phyla

From: The evolution of metazoan α-carbonic anhydrases and their roles in calcium carbonate biomineralization

 

Envir.

CaCO3structure

Predominant form of mineral

Organic phase

Calcifying cells/tissue

α-CAs

Technique

Tissue localization

Ref.

PORIFERA (appearance in Ediacaran)

Hexactinellida

DS

Spicules

Silica, aragonite

nd

Sclerocytes

nd

-

-

 

Demospongia

M, FW

"Spongine", silicatein, silintaphin-1, chitin

✓

RT-PCR & EST lib.

Adult whole organism, embryos

[7]

Calcarea

M

Calcite, aragonite

nd

✓

EST lib.

Adult whole organism

[45]

CNIDARIA (appearance in Ediacaran)

Octocorallia

M

Sclerites, spicules, skeleton

High-Mg calcite

Glycoproteins, lipids, polysaccharides…

Calicoblastic cells

✓

biochemistry, RT-PCR, EST lib.

Spicules, tentacules, polyps, larva, embryos

[50]

Hexacorallia

Hard skeleton

Aragonite

Glycoproteins, lipids, polysaccharides…

✓

EST lib., RT-PCR, genome

Calicoblastic cells

[9],[14],[51]-[53]

Hydrozoa

M, FW

Granules, skeleton

Aragonite

nd

-

EST lib., genome

Polyps

[54]

BRACHIOPODA (appearance in Cambrian)

Craniiformea

M

Shell

Low-Mg calcite

nd

Mantle cells

nd

-

-

 

Linguliformea

Ca3(PO4)2

nd

nd

-

-

 

Rynchonelliformea

Low-Mg calcite

Glycoproteins + polysaccharides…

nd

-

-

 

MOLLUSCA (appearance in Cambrian)

Solenogastra & Caudofoveata

M

Spicules

Calcite, aragonite

nd

Mantle cells

nd

-

-

 

Polyplachophora

nd

-

-

 

Bivalvia

M, FW

Shell & granules

Periostracum/OM

✓

RT-PCR, EST lib.

Mantle, gills, adductor muscles, larva

[2],[11],[13],[15]

Gastropoda

M, FW, T

✓

RT-PCR, EST lib., genomes

Mantle, nervous system, whole body

[16],[21]

Cephalopoda

M

Internal shell

Nautilin 63

✓

-

-

[55],[56]

ANNELIDA (appearance in Cambrian)

Pogonophora

M

Tube & soft granules

Calcite, aragonite

Mucopoly-saccharides

Epidermal glands

✓

RT-PCR

Branchial plume

[57]

ARTHROPODA (appearance in Cambrian)

Hexapoda

A, T

Exoskeleton

Calcite

Chitin, proteinaceous organic matrix

Cuticle epidermis

✓

RT-PCR, EST lib., genomes

Whole organism

[54]

Pancrustacea

A, M, FW, T

Exoskeleton, gastrolithes, sternal plates, caecal concretions

Calcite, vaterite, amorphous CaCO3

Cuticle epidermis, stomacal disc

✓

RT-PCR, EST lib.

Larvae, oocytes, gills, epidotes, brain, antennal glands…

[47],[58]-[60]

ECHINODERMATA (appearance in Cambrian)

Echinoidea

M

Test, teeth, spicules, spines

High-Mg calcite

OM

Syncitium/ "fenestrated" mineral

✓

EST lib., genomes

Pluteus ams, calcifying organic matrix

[48],[61]

Crinoidea

Articulated ossicules

nd

nd

nd

nd

-

-

 

Ophiuroidea

nd

nd

nd

nd

-

-

 

Asteroidea

Spicules

nd

nd

nd

✓

Biochemistry

-

[62]

Holothuridea

Tiny spicules or ossicules

nd

nd

nd

nd

-

-

 

UROCHORDATA (appearance in Cambrian)

Ascidiacea

M

Spicules

Calcite

OM

Sclerocytes

✓

EST lib.

nd

[54]

Appendicularia

nd

nd

nd

nd

✓

Genome

nd

[63]

VERTEBRATA (appearance in Silurian)

Actinopterygii

M, FW

Otoliths

Aragonite, vaterite

Endolymphatic constituants

Sacculus

✓

RT-PCR

Retina, kidney, erythrocytes, gills…

[49],[64]

Aves

T

Eggshell

Calcite

Uterine fluid

Distal oviduct

✓

Genome

Testis, retina…

[54]

  1. For each taxon we collected several lines of information: the environment in which each taxon can be found (A: amphibious; DS: deep-sea; FW: freshwater; M: marine; T: terrestrial); the general calcium carbonate structure; the predominant form of the mineral; the general nature of the organic phase within the mineral (OM: organic matrix); the source of the calcifying tissue/cells; whether carbonic anhydrases have been specifically detected within these cells; the method of identification (EST lib.: EST library); tissues where CAs were detected; references to studies from which this information was collated. nd: not determined.
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Frontiers in Zoology

ISSN: 1742-9994