title: Identification of genes regulating growth and fatness traits in pig through hypothalamic transcriptome analysis.
abstract: Previous studies on Iberian × Landrace (IBMAP) pig intercrosses have enabled the identification of several quantitative trait locus (QTL) regions related to growth and fatness traits; however, the genetic variation underlying those QTLs are still unknown. These traits are not only relevant because of their impact on economically important production traits, but also because pig constitutes a widely studied animal model for human obesity and obesity-related diseases. The hypothalamus is the main gland regulating growth, food intake, and fat accumulation. Therefore, the aim of this work was to identify genes and/or gene transcripts involved in the determination of growth and fatness in pig by a comparison of the whole hypothalamic transcriptome (RNA-Seq) in two groups of phenotypically divergent IBMAP pigs. Around 16,000 of the ∼25.010 annotated genes were expressed in these hypothalamic samples, with most of them showing intermediate expression levels. Functional analyses supported the key role of the hypothalamus in the regulation of growth, fat accumulation, and energy expenditure. Moreover, 58,927 potentially new isoforms were detected. More than 250 differentially expressed genes and novel transcript isoforms were identified between the two groups of pigs. Twenty-one DE genes/transcripts that colocalized in previously identified QTL regions and/or whose biological functions are related to the traits of interest were explored in more detail. Additionally, the transcription factors potentially regulating these genes and the subjacent networks and pathways were also analyzed. This study allows us to propose strong candidate genes for growth and fatness based on expression patterns, genomic location, and network interactions.
authors.affiliation: Mejora Genética Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain;
authors.forename: Dafne
authors.initials: D
authors.lastname: Pérez-Montarelo
authors.forename: Ole
authors.initials: O
authors.lastname: Madsen
authors.forename: Estefânia
authors.initials: E
authors.lastname: Alves
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Rodríguez
authors.forename: Josep María
authors.initials: JM
authors.lastname: Folch
authors.forename: José Luis
authors.initials: JL
authors.lastname: Noguera
authors.forename: Martien A M
authors.initials: MA
authors.lastname: Groenen
authors.forename: Ana I
authors.initials: AI
authors.lastname: Fernández
mesh_terms: D000273:Adipose Tissue / Q000254:growth & development* / Q000378:metabolism*; D000818:Animals; D005260:Female; D020869:Gene Expression Profiling; D063990:Gene Ontology; D053263:Gene Regulatory Networks; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D008957:Models, Genetic; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D025341:Principal Component Analysis; D040641:Quantitative Trait Loci / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017423:Sequence Analysis, RNA; D013552:Swine
keywords: RNA-Seq; fatness; growth; hypothalamus; porcine