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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Chelsea K. Fujimoto</dc:contributor>
  <dc:contributor>Silas K. Phipps-Costin</dc:contributor>
  <dc:contributor>Ingibjorg E. Einarsdottir</dc:contributor>
  <dc:contributor>Bjorn Thrandur Bjornsson</dc:contributor>
  <dc:contributor>Stephen D. McCormick</dc:contributor>
  <dc:creator>Jason P. Breves</dc:creator>
  <dc:date>2017</dc:date>
  <dc:description>&lt;div id="ASec1" class="AbstractSection"&gt;&lt;h3 class="Heading"&gt;Background&lt;/h3&gt;&lt;p id="Par1" class="Para"&gt;In preparation for migration from freshwater to marine habitats, Atlantic salmon (&lt;i class="EmphasisTypeItalic"&gt;Salmo salar&lt;/i&gt; L.) undergo smoltification, a transformation that includes the acquisition of hyposmoregulatory capacity. The growth hormone (Gh)/insulin-like growth-factor (Igf) axis promotes the development of branchial ionoregulatory functions that underlie ion secretion. Igfs interact with a suite of Igf binding proteins (Igfbps) that modulate hormone activity. In Atlantic salmon smolts, &lt;i class="EmphasisTypeItalic"&gt;igfbp4&lt;/i&gt;,−&lt;i class="EmphasisTypeItalic"&gt;5a&lt;/i&gt;,−&lt;i class="EmphasisTypeItalic"&gt;5b1&lt;/i&gt;,−&lt;i class="EmphasisTypeItalic"&gt;5b2&lt;/i&gt;,−&lt;i class="EmphasisTypeItalic"&gt;6b1&lt;/i&gt; and&lt;i class="EmphasisTypeItalic"&gt;−6b2&lt;/i&gt; transcripts are highly expressed in gill. We measured mRNA levels of branchial and hepatic &lt;i class="EmphasisTypeItalic"&gt;igfbps&lt;/i&gt; during smoltification (March, April, and May), desmoltification (July) and following seawater (SW) exposure in March and May. We also characterized parallel changes in a broad suite of osmoregulatory (branchial Na&lt;sup&gt;+&lt;/sup&gt;/K&lt;sup&gt;+&lt;/sup&gt;-ATPase (Nka) activity, &lt;i class="EmphasisTypeItalic"&gt;Na&lt;/i&gt;&lt;sup&gt;&lt;i class="EmphasisTypeItalic"&gt;+&lt;/i&gt; &lt;/sup&gt;&lt;i class="EmphasisTypeItalic"&gt;/K&lt;/i&gt; &lt;sup&gt;&lt;i class="EmphasisTypeItalic"&gt;+&lt;/i&gt; &lt;/sup&gt;&lt;i class="EmphasisTypeItalic"&gt;/2Cl&lt;/i&gt; &lt;sup&gt;&lt;i class="EmphasisTypeItalic"&gt;−&lt;/i&gt; &lt;/sup&gt;&lt;i class="EmphasisTypeItalic"&gt;cotransporter 1&lt;/i&gt; (&lt;i class="EmphasisTypeItalic"&gt;nkcc1&lt;/i&gt;) and &lt;i class="EmphasisTypeItalic"&gt;cystic fibrosis transmembrane regulator 1&lt;/i&gt; (&lt;i class="EmphasisTypeItalic"&gt;cftr1&lt;/i&gt;) transcription) and endocrine (plasma Gh and Igf1) parameters.&lt;/p&gt;&lt;/div&gt;&lt;div id="ASec2" class="AbstractSection"&gt;&lt;h3 class="Heading"&gt;Results&lt;/h3&gt;&lt;p id="Par2" class="Para"&gt;Indicative of smoltification, we observed increased branchial Nka activity, &lt;i class="EmphasisTypeItalic"&gt;nkcc1&lt;/i&gt; and &lt;i class="EmphasisTypeItalic"&gt;cftr1&lt;/i&gt; transcription in May. Branchial &lt;i class="EmphasisTypeItalic"&gt;igfbp6b1&lt;/i&gt; and &lt;i class="EmphasisTypeItalic"&gt;-6b2&lt;/i&gt; expression increased coincidentally with smoltification. Following a SW challenge in March, &lt;i class="EmphasisTypeItalic"&gt;igfbp6b1&lt;/i&gt; showed increased expression while &lt;i class="EmphasisTypeItalic"&gt;igfbp6b2&lt;/i&gt; exhibited diminished expression. &lt;i class="EmphasisTypeItalic"&gt;igfbp5a,−5b1&lt;/i&gt; and&lt;i class="EmphasisTypeItalic"&gt;−5b2&lt;/i&gt; mRNA levels did not change during smolting, but each had lower levels following a SW exposure in March.&lt;/p&gt;&lt;/div&gt;&lt;div id="ASec3" class="AbstractSection"&gt;&lt;h3 class="Heading"&gt;Conclusions&lt;/h3&gt;&lt;p id="Par3" class="Para"&gt;Salmonids express an especially large suite of &lt;i class="EmphasisTypeItalic"&gt;igfbps&lt;/i&gt;. Our data suggest that dynamic expression of particular &lt;i class="EmphasisTypeItalic"&gt;igfbps&lt;/i&gt; accompanies smoltification and SW challenges; thus, transcriptional control of &lt;i class="EmphasisTypeItalic"&gt;igfbps&lt;/i&gt; may provide a mechanism for the local modulation of Igf activity in salmon gill.&lt;/p&gt;&lt;/div&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1186/s12899-017-0028-5</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>BioMed Central</dc:publisher>
  <dc:title>Variation in branchial expression among &lt;i&gt;insulin-like growth-factor binding proteins (igfbps)&lt;/i&gt; during Atlantic salmon smoltification and seawater exposure</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>