Molecular and morphological convergence to sulfide-tolerant fishes in a new species of Jenynsia (Cyprinodontiformes: Anablepidae), the first extremophile member of the family
Molecular and morphological convergence to sulfide-tolerant fishes in a new species of Jenynsia (Cyprinodontiformes: Anablepidae), the first extremophile member of the family
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DOI：
10.1371/journal.pone.0218810
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发表时间：
2019-07-10
期刊：
影响因子：
3.7
通讯作者：
Torres-Dowdall, Julian
中科院分区：
文献类型：
--
作者：
Aguilera, Gaston;Enrique Teran, Guillermo;Torres-Dowdall, Julian
淡水硫化物泉有极端的环境条件，只有少数脊椎动物物种可以忍受。这些物种通常会发展出一系列的形态和分子适应，以科普硫化物泉有毒和缺氧条件下的生活挑战。本文描述了采自阿根廷西北部硫化物泉的一种新的拟步甲属鱼类，拟步甲科，这是该科中首次发现的极端环境鱼类。硫磺杰宁氏菌n.根据腹鳍前区无鳞或从腹鳍峡部到腹鳍基部有一排连续或不连续的鳞，可诊断为。此外，它还呈现出一系列形态和分子特征，这些特征似乎与其他鱼类（例如，石蛾科）栖息于硫化物泉。最值得注意的是，与该属的其他鱼类相比，J. sulphurica有一个扩大的头部和眶后区，以及一个带有肥大嘴唇的下颌骨，被认为有助于在空气-水界面呼吸。cox 1序列的分析表明，J. sulfurica有两个独特的突变，导致氨基酸取代收敛到那些在Poeciliids从硫化物泉和已知提供一个生理机制有关的生活在硫化物环境中。系统发育分析（包括分子和形态特征）将J. sulphurica列为J. alternimaculata的姐妹分类群，J. alternimaculata是一种发现于附近与硫化物泉直接相连的非硫化物栖息地的物种。因此，可以推断，H2S的存在所施加的选择导致了这两个物种之间的分歧，并可能成为基因流动的障碍。
Freshwater sulfide springs have extreme environmental conditions that only few vertebrate species can tolerate. These species often develop a series of morphological and molecular adaptations to cope with the challenges of life under the toxic and hypoxic conditions of sulfide springs. In this paper, we described a new fish species of the genus Jenynsia, Anablepidae, from a sulfide spring in Northwestern Argentina, the first in the family known from such extreme environment. Jenynsia sulfurica n. sp. is diagnosable by the lack of scales on the pre-pelvic area or the presence of a single row of scales, continuous or not, from the isthmus to the bases of the pelvic fins. Additionally, it presents a series of morphological and molecular characteristics that appear convergent with those seen in other fish species (e.g., Poeciliids) inhabiting sulfide springs. Most notably, J. sulfurica has an enlarged head and postorbital area compared to other fish of the genus and a prognathous lower jaw with a hypertrophied lip, thought to facilitate respiration at the air-water interface. Analyses of cox1 sequence showed that J. sulfurica has two unique mutations resulting in amino acid substitutions convergent to those seen in Poeciliids from sulfide springs and known to provide a physiological mechanism related to living in sulfide environments. A phylogenetic analysis, including molecular and morphological characters, placed J. sulfurica as sister taxa to J. alternimaculata, a species found in nearby, non-sulfide habitats directly connected to the sulfide springs. Thus, it can be inferred that the selection imposed by the presence of H2S has resulted in the divergence between these two species and has potentially served as a barrier to gene flow.