Transcriptomic insights into the loss of vision in Molnár János Cave’s crustaceans
Transcriptomic insights into the loss of vision in Molnár János Cave’s crustaceans
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对莫纳尔亚诺斯洞穴甲壳类动物视力丧失的转录组学见解
DOI：
10.1093/icb/icy071
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发表时间：
2018
影响因子：
2.6
通讯作者：
Bracken-Grissom, Heather D
中科院分区：
文献类型：
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作者：
Pérez-Moreno, Jorge L;Balázs, Gergely;Bracken-Grissom, Heather D
栖息在地下环境中的动物在过渡到永久黑暗中生活时，经常经历各种不同的表型修饰（称为“troglomorphy”）。然而，troglomorphy背后的分子基础仍然知之甚少，特别是在转录组水平上减少和/或丧失性状的机制。在这项研究中，我们调查了洞穴甲壳动物种群视力丧失背后的转录基础。我们采用系统发育和转录组学的方法，表面和洞穴适应人口的一个新兴的模式物种，isopodAsellus aquaticus（林奈，1758年），和端足类Niphargus hrabeS。卡拉曼，1932年。这两个物种在地表-洞穴过渡中显示出对比鲜明的方向性，这使它们成为理想的研究对象。Asellus aquaticus常见于地表沃茨，仅偶尔在洞穴中发现，其种群呈现不同程度的眼睛缩小和色素沉着。另一方面，eyelessN. hrabei尽管属于几乎完全居住在洞穴中的属，但成功地在地表环境中定居。通过测序和组装robustde novotranscriptomes，我们的特点是上述物种的表面和洞穴种群之间的视觉基因和途径的差异。我们的研究结果表明，尽管眼睛缩小，最近的洞穴殖民者A。水生动物仍然能够在洞穴中表达功能性的视觉视蛋白和光传导途径的主要成分。来自古老洞穴的物种-然而，推定的功能性视蛋白和其他光转导基因的表达得以维持，这表明这种无眼物种可能具有眼外光感受能力。通过本研究，我们的目标是提出Molnár János洞穴系统作为一个有前途的研究途径，以提高我们对洞穴和其他无光环境中视力下降和丧失模式的理解。
Animals that inhabit subterranean environments often undergo various distinct phenotypic modifications (referred to as “troglomorphy”) as they transition to life in perpetual darkness. However, the molecular basis behind troglomorphy remains poorly understood, particularly in regards to the mechanisms involved in the reduction and/or loss of traits at the transcriptomic level. In this study, we investigate the transcriptional basis behind vision loss in populations of cave-dwelling crustaceans. We employ phylogenetic and transcriptomic methods on surface and cave-adapted populations of an emerging model species for biospeleology, the isopodAsellus aquaticus(Linnaeus, 1758), and the amphipodNiphargus hrabeiS. Karaman, 1932. These two species show contrasting directionality in the surface-cave transition, which positions them as ideal study subjects.Asellus aquaticusis common in surface waters and is only occasionally found in caves, where its populations present different degrees of eye reduction and pigmentation. On the other hand, the eyelessN. hrabeihas successfully colonized surface environments despite belonging to an almost exclusively cave-dwelling genus. By sequencing and assembling robustde novotranscriptomes we characterized differences in visual genes and pathways among surface and cave populations of the aforementioned species. Our results indicate that despite having reduced eyes, recent cave colonizerA. aquaticusis still capable of expressing functional visual opsins and major components of the phototransduction pathway within the cave.Niphargus hrabei, a species with an ancient cave origin, shows no clear indication of being capable of sight. However, the expression of putative functional visual opsins and other phototransduction genes was maintained, which suggests that this eyeless species might be capable of extraocular photoreception. With the present study, we aim to bring forth the Molnár János Cave system as a promising research avenue to improve our understanding of patterns of reduction and loss of vision in caves and other aphotic environments.