Non-Additive and Asymmetric Allelic Expression of p38 mapk in Hybrid Tilapia (Oreochromis niloticus ♀ × O. aureus ♂)
by
, , and
Zihui Liu
1,2,†,
Binglin Chen
2,†,
Zhiying Zou
2,
Dayu Li
2,
Jinglin Zhu
2,
Jie Yu
2,
Wei Xiao
1,2,* and
Hong Yang
2,* 1
Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China
2
Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Animals 2024, 14(2), 266; https://doi.org/10.3390/ani14020266
Submission received: 30 October 2023
/
Revised: 22 December 2023
/
Accepted: 12 January 2024
/
Published: 15 January 2024
(This article belongs to the Section Aquatic Animals)
Simple Summary
Mitogen-activated protein kinases (MAPKs) are serine/threonine kinases that play a crucial role in regulating multiple processes, including protein degradation and localization, mRNA stability, endocytosis, apoptosis, cytoskeleton dynamics, and cell migration. To investigate the regulation of MAPKs’ gene expression variation in hybrid tilapia (Oreochromis niloticus ♀ × O. aureus ♂), we focused on p38 mapk. Our study uncovered a compensatory interaction between cis- and trans-acting elements of the Nile tilapia and blue tilapia sub-genomes, resulting in a nonadditive expression pattern of p38 in hybrid tilapia. In addition, we identified eight specific single-nucleotide polymorphisms (SNPs) in transcription factor binding sites between Nile tilapia and blue tilapia and demonstrated that it is promoter differences that differentiate parental gene expression using a dual-luciferase reporting system. Overall, this study reveals the non-additive expression patterns of functionally important genes in hybrid fish, particularly in growth and immune responses.
Abstract
Hybridization is a widely used breeding technique in fish species that enhances desirable traits in cultured species through heterosis. However, the mechanism by which hybrids alter gene expression to form heterosis remains unclear. In this study, a group of hybrid tilapia was used to elucidate heterosis through interspecies crossing. Specifically, p38 was analyzed to describe the regulation of gene expression variation in hybrid tilapia. Transcripts from the Nile tilapia allele were found to be significantly higher than those from the blue tilapia allele in hybrid individuals, indicating that the expression of p38 was dominated by Nile tilapia sub-genomic alleles. The study also found a compensatory interaction of cis- and trans-acting elements of the Nile tilapia and blue tilapia sub-genomes, inducing a non-additive expression of p38 in hybrids. Eight specific SNPs were identified in the p38 promoter regions of Nile tilapia and blue tilapia, and were found to be promoter differences leading to differences in gene expression efficiencies between parental alleles using a dual-luciferase reporter system. This study provides insights into the non-additive expression patterns of key functional genes in fish hybrids related to growth and immunity response.
