Ecology and Evolution Group, Department of Biology, Middle Tennessee State University, Murfreesboro, Tennessee, USA.
J Eukaryot Microbiol. 2023 Jan;70(1):e12937. doi: 10.1111/jeu.12937. Epub 2022 Aug 9.
Prorocentrum texanum var. texanum and its morphologically distinct yet genetically identical (as based on the sequences of five genes) variety P. texanum var. cuspidatum represent a species of Prorocentrum recently isolated from the Gulf of Mexico. Together, these two varieties represent a sister species to Prorocentrum micans. P. micans has had its sterols, which are ringed lipids common to eukaryotic cell membranes, shown in some studies to be comprised of cholesterol (cholest-5-en-3β-ol), 23,24-dimethyl-cholesta-5,22-dien-3β-ol, 23,24-dimethyl-5α-cholest-22E-en-3β-ol, dinosterol, and 4α,23,24-trimethyl-5α-cholestan-3β-ol (dinostanol) as major sterols, thus placing it within a previously identified cluster of dinoflagellates characterized by the predominance of cholesterol and dinosterol. In this study we have determined the sterol compositions of these two varieties of P. texanum to be abundant in cholesterol, 23,24-dimethyl-cholesta-5,22-dien-3β-ol, 23,24-dimethyl-5α-cholest-22E-en-3β-ol, dinosterol, and dinostanol such that the varieties are virtually indistinguishable from each other, making them both in general agreement with the sterols of P. micans, its closest species relative. This expands our knowledge of the sterols of this environmentally important dinoflagellate genus.
塔玛亚历山大藻（Prorocentrum texanum var. texanum）及其形态上明显不同但基因完全相同（基于五个基因的序列）的变种塔玛亚历山大藻（P. texanum var. cuspidatum）代表了一种最近从墨西哥湾分离出来的亚历山大藻属物种。这两个变种共同代表了拟菱形藻（Prorocentrum micans）的姐妹种。一些研究表明，拟菱形藻的甾醇（真核细胞膜常见的环状脂质）由胆固醇（胆甾-5-烯-3β-醇）、23,24-二甲基-胆甾-5,22-二烯-3β-醇、23,24-二甲基-5α-胆甾-22E-烯-3β-醇、二甾醇和 4α,23,24-三甲基-5α-胆甾烷-3β-醇（二甾醇醇）等主要甾醇组成，因此将其归入先前确定的以胆固醇和二甾醇为主的甲藻类群。在这项研究中，我们确定了这两个塔玛亚历山大藻变种的甾醇组成，其中胆固醇、23,24-二甲基-胆甾-5,22-二烯-3β-醇、23,24-二甲基-5α-胆甾-22E-烯-3β-醇、二甾醇和二甾醇醇含量丰富，以至于这两个变种彼此之间几乎无法区分，这使它们与最接近的物种拟菱形藻的甾醇基本一致。这扩展了我们对这种具有重要环境意义的甲藻属的甾醇的认识。
