Adipose Tissue Gene Expression of Entire Male, Immunocastrated and Surgically Castrated Pigs

Abstract

Differences in adipose tissue deposition and properties between pig male sex categories, i.e., entire males (EM), immunocastrates (IC) and surgical castrates (SC) are relatively well-characterized, whereas the underlying molecular mechanisms are still not fully understood. To gain knowledge about the genetic regulation of the differences in adipose tissue deposition, two different approaches were used: RNA-sequencing and candidate gene expression by quantitative PCR. A total of 83 differentially expressed genes were identified between EM and IC, 15 between IC and SC and 48 between EM and SC by RNA-sequencing of the subcutaneous adipose tissue. Comparing EM with IC or SC, upregulated genes related to extracellular matrix dynamics and adipogenesis, and downregulated genes involved in the control of lipid and carbohydrate metabolism were detected. Differential gene expression generally indicated high similarity between IC and SC as opposed to EM, except for several heat shock protein genes that were upregulated in EM and IC compared with SC. The candidate gene expression approach showed that genes involved in lipogenesis were downregulated in EM compared with IC pigs, further confirming RNA-sequencing results.

Identification of Key Pathways and Genes in the Subcutaneous Fat Tissue from Different Sexes of Pigs using WGCNA Method

“…Functional enrichment analysis showed that these genes were signi cantly enriched in AGE-RAGE signaling pathway in diabetic complications, Relaxin signaling pathway, Extracellular matrix (ECM) organization, Extracellular structure organization, ECM, Collagen-containing ECM, Collagen binding and ECM binding. The result was very similar to that from the study of Poklukar et al [30], and their ndings showed that the upregulated genes in entire males as compared with immunocastrated males and surgical castrates were signi cantly enriched in extracellular region/matrix (ECM) cellular components, ECM receptor interaction and focal adhesion pathways. Some genes responsible for the differences in backfat deposition between the three male sex categories were identi ed including COL1A2, COL6A3, POSTN, P4HA3, DCN, FMOD, MMP2 and MMP27 [30].…”

“…The result was very similar to that from the study of Poklukar et al [30], and their ndings showed that the upregulated genes in entire males as compared with immunocastrated males and surgical castrates were signi cantly enriched in extracellular region/matrix (ECM) cellular components, ECM receptor interaction and focal adhesion pathways. Some genes responsible for the differences in backfat deposition between the three male sex categories were identi ed including COL1A2, COL6A3, POSTN, P4HA3, DCN, FMOD, MMP2 and MMP27 [30]. In our study, COL1A2 gene was identi ed to have the highest degree in the PPI network, which indicated that the gene was at the core of the network.…”

“…A study showed that male gonosteroids in boars could signi cantly reduce blood lipid levels and fat accumulation in pigs. Moreover, functional enrichment analysis showed that the downregulated genes in entire males as compared with immunocastrated males were signi cantly enriched in Adipocytokine signaling pathway, AMPK signaling pathway, Insulin signaling pathway and PPAR signaling pathway [30]. However, The genes in the magenta module were mainly involved in some pathways related to disease immunity, such as In uenza A, Hepatitis C, Measles, Herpes simplex infection, Defense response to virus and Response to virus, and so on.…”

“…Jeong et al measured the expression levels of ECM-related genes in different adipose tissues from bulls, cows and steers of Korean cattle (Hanwoo), and found that the expressions of ECM-related genes in the omental adipose tissue of cows and steers are decreased, and expression levels of most ECM-related genes were generally similar between cows and steers [43]. Poklukar et al found that castration of male pigs resulted in the downregulation of genes involved in ECM dynamics [30]. The results of these studies are similar to this study.…”

“…Functional enrichment analysis showed that IGF1 participated in Ras signaling pathway, and FGF10 and FGFR2 participated in Ras signaling pathway and MAPK signaling pathway, while CACNA1G participated in Aldosterone synthesis and secretion and MAPK signaling pathway. A study showed that IGF1 action is inhibited in castrated animals, which affects adipocyte proliferation and differentiation [30]. FGF10, belongs to the broblast growth factor family, which is widely involved in the regulation of cell growth, proliferation, differentiation and regulation of metabolism [53,54].…”