Windsor Amanda M, Moore M Katherine, Warner Kimberly A, Stadig Sarah R, Deeds Jonathan R
Office of Regulatory Science, United States Food and Drug Administration, College Park, MD, USA.
Conservation Biology Division, Forensic Laboratory, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Charleston, SC, USA.
PeerJ. 2019 Nov 5;7:e7827. doi: 10.7717/peerj.7827. eCollection 2019.
Rathbun, 1896 is a western Atlantic species with a disjointed natural geographic range from Massachusetts, USA to Venezuela (distribution area 1) and from Alagoas, Brazil to northern Argentina (distribution area 2). It is the only species of portunid crab commercially harvested in the continental United States but is also imported into the US from several Latin American countries, Venezuela and Mexico in particular. In the United States, crab products labeled as "blue crab" and "Product of the USA" may not legally contain other species of crab or not harvested in the United States. The present study documents nucleotide variation within the barcode region of cytochrome oxidase I (COI) in 417 reference specimens of collected from throughout its natural range. The goal of this study is to determine if this variation can be utilized to detect mislabeled products sold in interstate commerce by comparing genetic signatures in reference specimens to those observed in commercial crabmeat labeled as "Product of the USA" and "Product of Venezuela." In reference specimens, we observed high levels of genetic variation in the barcode region. However, three lineages were consistently observed with significant pairwise F values between the lineages. Lineage 1 was observed throughout the natural geographic range but predominated in the continental US and was the only lineage observed in the major crabmeat-producing states (MD, LA, VA, NC). Lineage 2 primarily occurred in the Caribbean region of distribution area 1 but was also infrequently encountered in the South Atlantic Bight region of the US coast. Finally, Lineage 3 was only observed in Brazilian waters and had the lowest haplotype and nucleotide diversity values. Lineages 1 and 2 were separated by a mean pairwise distance (-distance) of 3.15%, whereas Lineage 3 had a mean -distance of 2.55% and 1.35% to Lineages 1 and 2, respectively. Within lineage mean -distances were 0.45%, 0.19%, and 0.07% for Lineages 1, 2, and 3, respectively. Among all vouchered reference specimens collected from the continental United States, Mexico, Puerto Rico, and Venezuela, we identified 22 phylogenetically informative sites that drive observed lineage divergences. Haplotypes identified from barcode COI sequences from commercial products labeled as originating from the US all aligned with haplotypes from Lineage 1 reference specimens and haplotypes from commercial products labeled as originating from Venezuela all aligned with Lineage 2, suggesting that these lineages may be useful for indicating whether products originate from the continental US or are imported when package labeling is in question.
拉特本蟹（Rathbun, 1896）是一种西大西洋物种，其自然地理分布范围不连续，从美国马萨诸塞州到委内瑞拉（分布区域1），以及从巴西阿拉戈斯到阿根廷北部（分布区域2）。它是美国大陆唯一一种有商业捕捞价值的梭子蟹科螃蟹，但也从几个拉丁美洲国家，特别是委内瑞拉和墨西哥进口到美国。在美国，标有“蓝蟹”和“美国产品”的蟹类产品在法律上不得包含其他蟹种，也不得包含非美国捕捞的蟹。本研究记录了从其整个自然分布范围内收集的417个参考样本中细胞色素氧化酶I（COI）条形码区域内的核苷酸变异。本研究的目的是通过比较参考样本中的基因特征与标有“美国产品”和“委内瑞拉产品”的商业蟹肉中观察到的基因特征，来确定这种变异是否可用于检测在州际贸易中销售的贴错标签的产品。在参考样本中，我们观察到条形码区域存在高水平的基因变异。然而，始终观察到三个谱系，谱系之间的成对F值显著。谱系1在整个自然地理范围内都有观察到，但在美国大陆占主导地位，并且是主要蟹肉生产州（马里兰州、路易斯安那州、弗吉尼亚州、北卡罗来纳州）中唯一观察到的谱系。谱系2主要出现在分布区域1的加勒比地区，但在美国海岸的南大西洋湾地区也很少见。最后，谱系3仅在巴西水域观察到，其单倍型和核苷酸多样性值最低。谱系1和2之间的平均成对距离（-距离）为3.15%，而谱系3与谱系1和2的平均-距离分别为2.55%和1.35%。在谱系1、2和3中，谱系内平均-距离分别为0.45%、0.19%和0.07%。在从美国大陆、墨西哥、波多黎各和委内瑞拉收集的所有有凭证的参考样本中，我们确定了22个系统发育信息位点，这些位点推动了观察到的谱系分化。从标有原产于美国的商业产品的条形码COI序列中鉴定出的单倍型与谱系1参考样本中的单倍型全部匹配，而从标有原产于委内瑞拉的商业产品中鉴定出的单倍型与谱系2全部匹配，这表明当包装标签存在疑问时，这些谱系可能有助于指示产品是原产于美国大陆还是进口的。
