title: Weaning Markedly Affects Transcriptome Profiles and Peyer's Patch Development in Piglet Ileum.
abstract: Transcriptome analyses were conducted on the ileal mucosa of 14- to 35-day-old piglets to investigate postnatal gut development during suckling and postweaning. The transcriptome profiles of 14-day-old suckling piglets showed a considerably higher number of differentially expressed genes than did those of 21-, 28-, and 35-day olds, indicating an intensive gut development during the first 14-21 postnatal days. In addition, the analysis of biological pathways indicated that Chemotaxis Leucocyte chemotaxis was the most significantly affected pathway in suckling piglets between 14 and 21 days of age. Weaning negatively affected pathways associated with acquired immunity, but positively affected those associated with innate immunity. Interestingly, pathway Chemotaxis Leucocyte chemotaxis was found positively affected when comparing 14- and 21-day-old suckling piglets, but negatively affected in 28-day-old piglets weaned at 21 days of age, when compared with 28-day-old suckling piglets. Genes CXCL13, SLA-DOA (MHC class II), ICAM1, VAV1, and VCAM1 were involved in the pathway Chemotaxis Leukocyte chemotaxis and they were found to significantly change between 14- and 21-day-old suckling piglets and between groups of suckling and weaned piglets. The expression of these genes significantly declined after weaning at 14, 21, and 28 days of age. This decline indicated that CXCL13, SLA-DOA, ICAM1, VAV1, and VCAM1 may be involved in the development of Peyer's patches (PP) because lower gene expression clearly corresponded with smaller areas of PP in the ileal mucosa of piglets. Moreover, weaning piglets prior to a period of intensive gut development, i.e., 14 days of age, caused significant adverse effects on the size of PP, which were not reverted even 14 days postweaning.
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan ; Gut Immunology Group, Rowett Institute of Nutrition and Health, University of Aberdeen , Aberdeen , UK.
authors.forename: Ryo
authors.initials: R
authors.lastname: Inoue
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan ; Kyoto Institute of Nutrition and Pathology , Kyoto , Japan.
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Tsukahara
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Nakatani
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan.
authors.forename: Mie
authors.initials: M
authors.lastname: Okutani
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan.
authors.forename: Ryoichiro
authors.initials: R
authors.lastname: Nishibayashi
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Ogawa
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Harayama
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nagino
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Hatanaka
authors.affiliation: Technical Center, Toyohashi Feed Mills , Shinshiro , Japan.
authors.forename: Kikuto
authors.initials: K
authors.lastname: Fukuta
authors.affiliation: Kyoto Institute of Nutrition and Pathology , Kyoto , Japan.
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Romero-Pérez
authors.affiliation: Laboratory of Animal Science, Kyoto Prefectural University , Kyoto , Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Ushida
authors.affiliation: Gut Immunology Group, Rowett Institute of Nutrition and Health, University of Aberdeen , Aberdeen , UK.
authors.forename: Denise
authors.initials: D
authors.lastname: Kelly
keywords: DNA microarray; Peyer’s patches; ileal mucosa; metacore pathway analysis; neonatal piglets; transcriptome; weaning