Coexistence of Three Divergent mtDNA Lineages in Northeast Asia Provides New Insights into Phylogeography of Goldfish (Carssius auratus).

Lei Cheng,Chao Li,Le Wang,Cuiyun Lu,Xiaoli Yu

doi:10.3390/ani10101785

Lei Cheng, Chao Li + Show 3 more

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https://doi.org/10.3390/ani10101785

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Abstract

Simple SummaryGoldfish (Carassius auratus) is a well-known fish as food and as a pet, which is also frequently used as experimental animal. A unique mtDNA sequence was detected in a sample from our experimental station, which motivated us to study genetic constitution of goldfish in Northeast Asia. Three divergent mtDNA lineages were confirmed to coexist in this region. Two of which corresponded to the known lineages (C2 and C6), which was consistent with the zoogeographical records that there were two sympatric subspecies in Amur river basin. However, the third one (lineage C7) was largely neglected in the previous studies. Our results suggested lineage C7 had a wide distribution from Central Asia to Northeast Asia.Goldfish (Carassius aurautus), which is a middle size cyprinid, widely distribute throughout Eurasia. Phylogeographic studies using mtDNA markers have revealed several divergent lineages within goldfish. In this study, mtDNA variations were determined to elucidate the phylogeographical pattern and genetic structure of goldfish in Northeast Asia. A total of 1054 individuals from Amur river basin were analyzed, which including five newly collected populations and four previously reported populations. Three distinct mtDNA lineages were identified in those samples, two of which corresponded to two known lineages C2 and C6, respectively. The third lineage referred to as C7, following six known lineages of goldfish in mainland Eurasia. AMOVA results suggested that most of the genetic variations were among lineages, rather than among populations or twice samplings. We noted that the control region (CR) and cytochrome b (cytb) sequences of lineage C7 have been reported in previous studies, respectively. However, the evolutionary position and distribution pattern of this lineage was not discussed in the context of the species. Our results showed that “odd” CR and “hidden” cytb sequences from Central Asia represent the same mtDNA lineage of goldfish. The known samples of C7 lineage were collected from Central Asia (Eastern Kazakhstan and Western Mongolia) to East Asia (Northeast China and Far East Russia), which suggested that it had a wider distribution, rather than limit in Central Asia.

Highlights

Fishes of genus Carassius populate a wide variety of habitats throughout Eurasia, especially in EastAsia
Three species are generally considered to be valid in this genus: C. carassius, C. auratus and C. cuvieri [1,2,3,4]
In NJ tree based on cytb sequences (Figure S1), C. cuvieri is closer to the Japanese clade than the continent clade

Summary

Introduction

Fishes of genus Carassius populate a wide variety of habitats throughout Eurasia, especially in EastAsia. Fishes of genus Carassius populate a wide variety of habitats throughout Eurasia, especially in East. Three species are generally considered to be valid in this genus: C. carassius, C. auratus and C. cuvieri [1,2,3,4]. Crucian carp (C. carassius), which is native to parts of Europe and Central Asia, can be diagnosed from its congeners with the free edge of the dorsal and tail fins were convex [1,3]. Goldfish (C. auratus) could be found from Asia to Europe, which usually further deiminated into a few Animals 2020, 10, 1785; doi:10.3390/ani10101785 www.mdpi.com/journal/animals. Japanese white crucian carp (C. cuvieri) was previously regarded as a subspecies of C. aurautus [8]. A growing number of literatures treated it as a valid species, due to its genetic independence and limited distribution [9,10,11]

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