ALBERT

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Xiaorui Song, Ying Song, Miren Dong, Zhaoqun Liu, Weilin Wang, Lingling Wang, Linsheng Song〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Runx family is a kind of heteromeric transcription factors, which is defined by the presence of a runt domain. As transcriptional regulator during development and cell fate specification, Runx is best known for its critical roles in hematopoiesis. In the present study, a Runx transcription factor (designed as 〈em〉Cg〈/em〉Runx) was identified and characterized from the oyster 〈em〉Crassostrea gigas〈/em〉. The complete coding sequence of 〈em〉Cg〈/em〉Runx was of 1638 bp encoding a predicted polypeptide of 545 amino acids with one conserved runt domain, which shared high similarity with other reported Runx proteins. 〈em〉Cg〈/em〉Runx was highly expressed in hemocytes, gill and mantle both at the protein and nucleic acid levels. 〈em〉Cg〈/em〉Runx protein was localized specifically in the cell nuclei of hemocytes, and distributed at the tubule lumen of gill filament. During the larval developmental stages, the mRNA transcripts of 〈em〉Cg〈/em〉Runx gradually increased after fertilization, reached to a relative high level at the 8 cell embryos and the blastula stage of 2–4 hpf (hours post fertilization) (about 40-fold), and peaked at early trochophore larvae (10 hpf) (about 60-fold). Whole-mount immunofluorescence assay further revealed that the abundant immunofluorescence signals of 〈em〉Cg〈/em〉Runx distributed through the whole embryo at blastula stage (5 hpf), and progressively reduced with the development to a ring structure around the dorsal region in trochophore larvae (10 hpf). Scattered positive immunoreactivity signals finally appeared in the velum region of D-veliger larvae. After LPS and 〈em〉Vibrio splendidus〈/em〉 stimulations, the expression levels of 〈em〉CgRunx〈/em〉 mRNA in hemocytes were up-regulated significantly compared with that in the control (0 h), which were 2.98- and 2.46-fold (〈em〉p〈/em〉 〈 0.05), 2.67- and 1.5-fold (〈em〉p〈/em〉 〈 0.05), 2.36- and 1.38-fold (〈em〉p〈/em〉 〈 0.05) at 3 h, 6 h and 12 h, respectively. These results collectively suggested that 〈em〉Cg〈/em〉Runx involved in immune response and might participate in larvae hematopoiesis in oyster.〈/p〉〈/div〉 〈/div〉