Muscle transcriptomic investigation of late fetal development identifies candidate genes for piglet maturity

Valentin Voillet (1) , Magali San Cristobal (1) , Yannick Lippi (2) , Pascal G.P. Martin (3) , Nathalie N. Iannuccelli (1) , Christine Lascor (1) , Florence F. Vignoles (1) , Yvon Billon (4) , Laurianne L. Canario (1) , Laurence Liaubet (1)

1 GenPhySE - Génétique Physiologie et Systèmes d'Elevage
2 E23 TRiX - Transcriptomic impact of Xenobiotics
3 ToxAlim - ToxAlim
4 GenESI - Génétique, Expérimentation et Système Innovants

In pigs, the perinatal period is the most critical time for survival. Piglet maturation, which occurs atthe end of gestation, leads to a state of full development after birth. Therefore, maturity is an importantdeterminant of early survival. Skeletal muscle plays a key role in adaptation to extra-uterine life, e.g.glycogen storage and thermoregulation. In this study, we performed microarray analysis to identifythe genes and biological processes involved in piglet muscle maturity. Progeny from two breeds withextreme muscle maturity phenotypes were analyzed at two time points during gestation (gestationaldays 90 and 110). The Large White (LW) breed is a selected breed with an increased rate of mortalityat birth, whereas the Meishan (MS) breed produces piglets with extremely low mortality at birth. Theimpact of the parental genome was analyzed with reciprocal crossed fetuses. Microarray analysis identified 12,326 differentially expressed probes for gestational age and genotype.Such a high number reflects an important transcriptomic change that occurs between 90 and 110 daysof gestation. 2,000 probes, corresponding to 1,120 unique annotated genes, involved more particularlyin the maturation process were further studied. Functional enrichment and graph inference studiesunderlined genes involved in muscular development around 90 days of gestation, and genes involvedin metabolic functions, such as gluconeogenesis, around 110 days of gestation. Moreover, a differencein the expression of key genes, e.g. PCK2, LDHA or PGK1, was detected between MS and LWjust before birth. Reciprocal crossing analysis resulted in the identification of 472 genes with anexpression preferentially regulated by one parental genome. Most of these genes (366) were regulatedby the paternal genome. Among these paternally regulated genes, some known imprinted genes, suchas MAGEL2 or IGF2, were identified and could have a key role in the maturation process. These results reveal the biological mechanisms that regulate muscle maturity in piglets. Maturity isalso under the conflicting regulation of the parental genomes. Crucial genes, which could explain thebiological differences in maturity observed between LWand MS breeds, were identified. These genescould be excellent candidates for a key role in the maturity.

Mots clés: maturity; survival; birth; microarray; pig

Mots clés: muscle; system biology

Domaines: Sciences du Vivant [q-bio]; Informatique [cs]

Valentin Voillet, Magali San Cristobal, Yannick Lippi, Pascal G.P. Martin, Nathalie N. Iannuccelli, et al.. Muscle transcriptomic investigation of late fetal development identifies candidate genes for piglet maturity. BMC Genomics, 2014, 15 (797), pp.1-17. ⟨10.1186/1471-2164-15-797⟩. ⟨hal-02638427⟩