title: Profiling of the embryonic Atlantic halibut (Hippoglossus hippoglossus L.) transcriptome reveals maternal transcripts as potential markers of embryo quality.
abstract: BACKGROUND
  Commercial Atlantic halibut (Hippoglossus hippoglossus) farming is restricted by variable oocyte quality, slow growth, and early maturation of male fish. Maternally transferred components regulate early developmental processes; therefore, they have an effect on the future viability of the embryo. Using a newly developed Agilent 10 k custom-made oligonucleotide array, we profiled components of the transcriptome involved in immune defence as well as germline and muscle development during early developmental stages: 8-cell embryos (8CS), germ ring stage (GR), 10-somite stage (10SS), and hatched embryos (HT). In addition, we identified differentially expressed transcripts in low (≤9 ± 3% hatching) and high (≥86 ± 3°% hatching) quality eggs at 8CS to identify potential maternal markers for embryo quality.
  
  
  RESULTS
  Out of 2066 differentially expressed transcripts, 160 were identified as maternal transcripts being specifically expressed at 8CS only. Twenty transcripts were differentially expressed in 8-cell embryos between low and high quality egg groups. Several immune-related transcripts were identified as promising molecular markers of hatching success including interferon regulatory factor 7 and mhc class 2A chain. Differential expression was positively validated with quantitative real-time PCR.
  
  
  CONCLUSIONS
  We have demonstrated maternal transfer of innate and adaptive immune system transcripts into Atlantic halibut embryos and their relation with future embryo developmental potential. We identified several transcripts as potential molecular markers of embryo quality. The developed microarray represents a useful resource for improving the commercial production of Atlantic halibut.
authors.forename: Maren
authors.initials: M
authors.lastname: Mommens
authors.forename: Jorge M O
authors.initials: JM
authors.lastname: Fernandes
authors.forename: Knut Erik
authors.initials: KE
authors.lastname: Tollefsen
authors.forename: Ian A
authors.initials: IA
authors.lastname: Johnston
authors.affiliation: Faculty of Biosciences and Aquaculture, University of Nordland, N-8049 Bodø, Norway. igor.babiak@uin.no.
authors.forename: Igor
authors.initials: I
authors.lastname: Babiak
mesh_terms: D056704:Adaptive Immunity; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D016000:Cluster Analysis; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D047108:Embryonic Development / Q000235:genetics; D005432:Flounder / Q000235:genetics / Q000254:growth & development; D020869:Gene Expression Profiling; D005854:Germ Cells / Q000378:metabolism; D007113:Immunity, Innate / Q000235:genetics; D050839:Interferon Regulatory Factor-7 / Q000235:genetics / Q000378:metabolism; D024510:Muscle Development / Q000235:genetics; D009132:Muscles / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010063:Ovum / Q000378:metabolism; D059467:Transcriptome
chemical_list: D015415:Biomarkers; D050839:Interferon Regulatory Factor-7