{"id":438599,"date":"2022-05-30T14:13:34","date_gmt":"2022-05-30T17:13:34","guid":{"rendered":"https:\/\/revistapesquisa.fapesp.br\/?p=438599"},"modified":"2022-05-30T16:58:31","modified_gmt":"2022-05-30T19:58:31","slug":"transgenic-zebrafish-found-in-streams-in-the-paraiba-do-sul-basin-minas-gerais","status":"publish","type":"post","link":"https:\/\/revistapesquisa.fapesp.br\/en\/transgenic-zebrafish-found-in-streams-in-the-paraiba-do-sul-basin-minas-gerais\/","title":{"rendered":"Transgenic zebrafish found in streams in the Para\u00edba do Sul basin, Minas Gerais"},"content":{"rendered":"

The zebrafish (Danio rerio<\/em>), a species popular among aquarium lovers and widely used as a model for scientific research, is native to freshwater habitats in Asia. In Brazil it is named after the state of S\u00e3o Paulo (paulistinha<\/em>) due to its dark-blue and silver stripes, which resemble the state flag (see<\/em> Pesquisa FAPESP n\u00ba. 209<\/em><\/a>). Several overseas companies now sell a genetically modified variant of the species with genes from fluorescent jellyfish and coral that make it glow green, red, orange, and blue\u2014the modified variant has been a big hit with fish collectors. Although imports into Brazil have been banned since 2008, the transgenic zebrafish species can be found in private aquariums and, according to a recent study, even in the wild.<\/p>\n

A paper in the February issue of Studies on Neotropical Fauna and Environment<\/em> reports that over 100 individuals have been found in two headwater creeks in Brazil\u2019s Para\u00edba do Sul River Basin. Researchers at the Federal University of S\u00e3o Jo\u00e3o del-Rei (UFSJ), in Minas Gerais, and the Federal University of Sergipe (UFS) sampled five creeks in the municipalities of Vieiras and Muria\u00e9, in 2015, 2017, and 2018. Glow-in-the-dark zebrafish variants were spotted swimming in two creeks\u2014Lopes and Queiroga\u2014near the municipalities of Vieiras and Gl\u00f3ria.<\/p>\n

\u201cThis is a concerning discovery,\u201d says Andr\u00e9 Magalh\u00e3es, an ecologist at UFSJ and the lead author of the study. \u201cThere\u2019s no telling what effects the proliferation and dietary habits of this transgenic species might have on native fauna.\u201d In Minas Gerais, zebrafish have no natural predators in the locations where they were found, and the insects and zooplankton they feed on are abundant. Water temperatures in these creeks are relatively constant all year round at between 24 \u00b0C and 30 \u00b0C, allowing the species to reproduce during all seasons.<\/p>\n

Magalh\u00e3es and his colleagues worry that native fish, such as minnows (Deuterodon janeiroensis<\/em>), which have similar dietary habits, could be at a disadvantage if they have to compete for food with genetically modified zebrafish. \u201cIf minnows or any other local species become extinct, this would remove a link in the food chain that could potentially upset the balance of stream ecosystems,\u201d says Magalh\u00e3es. Although the genetically modified zebrafish are not yet considered an invasive species in the basin, this may soon be the case if nothing is done about them. The fluorescent variant appears to have adapted well to its new habitat.<\/p>\n

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L\u00e9o Ramos Chaves\u2002<\/span>Wilde-type zebrafish are recognizable by their dark blue and silver stripesL\u00e9o Ramos Chaves\u2002<\/span><\/p><\/div>\n

Near the creeks where the zebrafish were captured is a large ornamental aquaculture center in Muria\u00e9, where wild-type zebrafish\u2014which can be legally imported\u2014are grown in ponds that are often connected to the nearby streams. The common and wild-type zebrafish species are very similar in appearance, especially the greenish variety. The glowing colors of the genetically modified version become more visible when the fish is exposed to ultraviolet light. This has led the researchers to hypothesize that the emerald-colored variant may have been imported and subsequently bred in captivity among wild-type species.<\/p>\n

Fish breeders may have been unaware that they were interbreeding in their aquaculture ponds. According to the study, it is likely that some genetically modified individuals may have escaped from these fish farms and found their way to nearby creeks, where they began to multiply. Their escape might have occurred, for example, when emptying fishponds without containment netting. \u201cWe recommend using nylon netting on the pipes used to discharge pond water into the river,\u201d says Magalh\u00e3es.<\/p>\n

Carla Pavanelli, a zoologist at the State University of Maring\u00e1 (UEM) in Paran\u00e1, who was not part of the research, says the article addresses an important yet little-studied problem which can have significant adverse impacts on native species that are fished by local communities, such as minnows. \u201cThe paper also highlights Brazil\u2019s legislation on exotic species and good practices in breeding them,\u201d says Pavanelli, who specializes in neotropical fish.<\/p>\n

Hernandes Carvalho, a biologist at the University of Campinas (UNICAMP), who was not involved in the UFSJ study, notes that genetically modified zebrafish are used in research but under tightly controlled conditions. \u201cAt research laboratories, these fish are contained within safe barriers,\u201d says Carvalho. His research group, for example, uses genetically modified specimens to study the role of genes and proteins in heart development. Zebrafish are used before testing with rodents and later trials in humans.<\/p>\n

Introducing genetically modified or exotic species in the wild, whatever their origin, will not necessarily have a negative impact, says Carvalho. He believes issues can arise when an invasive species escapes its safety zone and enters an unintended habitat. \u201cThe tilapia is an exotic species native to Africa, but is widely cultivated all around the world. Exotic species are introduced fairly frequently,\u201d says Carvalho. \u201cBut genetically modified fish escaping to the wild could have negative environmental impacts. This, however, needs to be dealt with case by case\u2014for instance, we wouldn\u2019t want to ban imports of animals, such as zebrafish, that are needed for research.\u201d<\/p>\n

Scientific article<\/strong>
\nMAGALH\u00c3ES, A. L. B. et al<\/em>. The fluorescent introduction has begun in the southern hemisphere: Presence and life-history strategies of the transgenic zebrafish Danio rerio (Cypriniformes: Danionidae) in Brazil<\/a>. Studies on Neotropical Fauna and Environment<\/strong>. Online. Feb. 3, 2022.<\/p>\n","protected":false},"excerpt":{"rendered":"More than a hundred specimens of the fluorescent zebrafish were captured by researchers","protected":false},"author":702,"featured_media":438604,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[159],"tags":[211,209,224,266],"coauthors":[3889],"class_list":["post-438599","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science","tag-biochemistry","tag-biology","tag-ecology","tag-zoology"],"acf":[],"_links":{"self":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/438599","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/users\/702"}],"replies":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/comments?post=438599"}],"version-history":[{"count":2,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/438599\/revisions"}],"predecessor-version":[{"id":439225,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/438599\/revisions\/439225"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media\/438604"}],"wp:attachment":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media?parent=438599"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/categories?post=438599"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/tags?post=438599"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/coauthors?post=438599"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}