Several species of the genus Tetraselmis (Chlorodendrophyceae, Chlorophyta) were recently discovered to possess unsuspected biomineralization capacities: they produce multiple intracellular inclusions of amorphous calcium carbonate (ACC), called micropearls. Early light-microscopists had spotted rows of refractive granules in some species, although without identifying their mineral nature. Scanning electron microscope (SEM) observations showed that the distribution of the micropearls in the cell forms a pattern, which appears to be characteristic for a given species. The present study shows that this pattern correlates with the shape of the chloroplast, which differs between Tetraselmis species, because micropearls align themselves along the incisions between chloroplast lobes. This was observed both by SEM and in live cells by light microscopy (LM) using Nomarski differential interference contrast. Additionally, molecular phylogenetic analyses, of rbcL and ITS2 gene sequences from diverse strains of Chlorodendrophyceae, corroborated the morphological observations by identifying two groups among nominal Tetraselmis spp. that differ in chloroplast morphology, micropearl arrangement, and ITS2 RNA secondary structure.

最近发现了几种特拉瑟米属（Chlorodendrophyceae，Chlorophyta）具有不可怀疑的生物矿化能力：它们产生多种细胞内的无定形碳酸钙（ACC）内含物，称为微珍珠。早期的光学显微镜专家在某些物种中发现了成排的折射颗粒，尽管没有确定其矿物性质。扫描电子显微镜（SEM）观察表明，微珍珠在细胞中的分布形成了一种模式，这似乎是给定物种的特征。本研究表明，这种模式与叶绿体的形状相关，在四叶形之间不同种，因为微珍珠沿着叶绿体裂片之间的切口对齐。这是通过SEM和使用Nomarski微分干涉对比的光学显微镜（LM）在活细胞中观察到的。此外，对来自不同绿藻科的菌株的rbcL和ITS2基因序列进行分子系统发育分析，通过在标称四合木属中鉴定出两组来证实了形态学观察。在叶绿体形态，微珍珠排列和ITS2 RNA二级结构方面存在差异。