1
|
Ahn J, Hwang IS, Park MR, Hwang S, Lee K. Imprinting at the KBTBD6 locus involves species-specific maternal methylation and monoallelic expression in livestock animals. J Anim Sci Biotechnol 2023; 14:131. [PMID: 37817239 PMCID: PMC10565993 DOI: 10.1186/s40104-023-00931-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/21/2023] [Indexed: 10/12/2023] Open
Abstract
BACKGROUND The primary differentially methylated regions (DMRs) which are maternally hypermethylated serve as imprinting control regions (ICRs) that drive monoallelic gene expression, and these ICRs have been investigated due to their implications in mammalian development. Although a subset of genes has been identified as imprinted, in-depth comparative approach needs to be developed for identification of species-specific imprinted genes. Here, we examined DNA methylation status and allelic expression at the KBTBD6 locus across species and tissues and explored potential mechanisms of imprinting. RESULTS Using whole-genome bisulfite sequencing and RNA-sequencing on parthenogenetic and normal porcine embryos, we identified a maternally hypermethylated DMR between the embryos at the KBTBD6 promoter CpG island and paternal monoallelic expression of KBTBD6. Also, in analyzed domesticated mammals but not in humans, non-human primates and mice, the KBTBD6 promoter CpG islands were methylated in oocytes and/or allelically methylated in tissues, and monoallelic KBTBD6 expression was observed, indicating livestock-specific imprinting. Further analysis revealed that these CpG islands were embedded within transcripts in porcine and bovine oocytes which coexisted with an active transcription mark and DNA methylation, implying the presence of transcription-dependent imprinting. CONCLUSIONS In this study, our comparative approach revealed an imprinted expression of the KBTBD6 gene in domesticated mammals, but not in humans, non-human primates, and mice which implicates species-specific evolution of genomic imprinting.
Collapse
Affiliation(s)
- Jinsoo Ahn
- Department of Animal Sciences, The Ohio State University, Columbus, OH 43210 USA
| | - In-Sul Hwang
- Animal Biotechnology Division, Rural Development Administration, National Institute of Animal Science, Jeonbuk, 55365 Republic of Korea
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, Columbia University, New York, NY 10032 USA
| | - Mi-Ryung Park
- Animal Biotechnology Division, Rural Development Administration, National Institute of Animal Science, Jeonbuk, 55365 Republic of Korea
| | - Seongsoo Hwang
- Animal Welfare Research Team, National Institute of Animal Science, RDA, 1500, Kongjwipatjwi-ro, Jeollabuk-do, 55365 Republic of Korea
| | - Kichoon Lee
- Department of Animal Sciences, The Ohio State University, Columbus, OH 43210 USA
| |
Collapse
|
2
|
Ahn J, Kim DH, Park MR, Suh Y, Lee H, Hwang S, Mamuad LL, Lee SS, Lee K. A novel testis-enriched gene, Samd4a, regulates spermatogenesis as a spermatid-specific factor. Front Cell Dev Biol 2022; 10:978343. [PMID: 36274854 PMCID: PMC9579339 DOI: 10.3389/fcell.2022.978343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Spermatogenesis is the highly orchestrated process involving expression of a series of testicular genes. Testis-enriched genes are critical for cellular processes during spermatogenesis whose disruption leads to impaired spermatogenesis and male infertility. Nevertheless, among poorly investigated testicular genes are the mouse Samd4a and human SAMD4A which were identified in the current study as novel testis-enriched genes through transcriptomic analyses. In particular, as orthologous alternative splicing isoforms, mouse Samd4a E-form and human SAMD4AC-form containing the SAM domain were specific to testes. Western blot analyses revealed that the murine SAMD4AE-form was predominantly found in the testis. Analyses on GEO2R and single-cell RNA-seq datasets revealed that the Samd4a/SAMD4A expression was enriched in spermatids among various types of cells in adult testes. To investigate in vivo functions of Samd4a, Samd4a knockout mice were generated using the CRISPR/Cas9 system. The Samd4a deficiency resulted in lower testis weight, absence of elongated spermatids, and an increased number of apoptotic cells. Profiling of gene expression in human testis samples revealed that the SAMD4A expression was comparable between obstructive azoospermia patients and normal controls, but significantly lowered in nonobstructive azoospermia (NOA) patients. Among three subgroups of NOA, pre-meiotic arrest (NOA-pre), meiotic arrest (NOA-mei), and post-meiotic arrest (NOA-post), expression level of SAMD4A was higher in the NOA-post than the NOA-mei, but there was no difference between the NOA-pre and NOA-mei. The current studies demonstrated spermatid stage-specific expression of Samd4a/SAMD4A, and impairment of the late stages of spermatogenesis by disruption of the mouse Samd4a gene. These data suggest that Samd4a/SAMD4A plays an essential role in normal spermatogenesis, and SAMD4A, as a spermatid specific marker, can be used for subcategorizing NOA patients. Further understanding the molecular role of SAMD4A will advance our knowledge on genetic regulations in male infertility.
Collapse
Affiliation(s)
- Jinsoo Ahn
- Department of Animal Sciences, The Ohio State University, Columbus, OH, United States
| | - Dong-Hwan Kim
- Department of Animal Sciences, The Ohio State University, Columbus, OH, United States
| | - Mi-Ryung Park
- Animal Biotechnology Division, National Institute of Animal Science, Wanju, South Korea
| | - Yeunsu Suh
- Department of Animal Sciences, The Ohio State University, Columbus, OH, United States
| | - Haesun Lee
- Animal Biotechnology Division, National Institute of Animal Science, Wanju, South Korea
| | - Seongsoo Hwang
- Animal Biotechnology Division, National Institute of Animal Science, Wanju, South Korea
| | - Lovelia L. Mamuad
- Department of Animal Science and Technology, Sunchon National University, Suncheon, South Korea
| | - Sang Suk Lee
- Department of Animal Science and Technology, Sunchon National University, Suncheon, South Korea
- *Correspondence: Sang Suk Lee, ; Kichoon Lee,
| | - Kichoon Lee
- Department of Animal Sciences, The Ohio State University, Columbus, OH, United States
- *Correspondence: Sang Suk Lee, ; Kichoon Lee,
| |
Collapse
|
3
|
Daigneault BW. Insights to maternal regulation of the paternal genome in mammalian livestock embryos: A mini-review. Front Genet 2022; 13:909804. [PMID: 36061209 PMCID: PMC9437210 DOI: 10.3389/fgene.2022.909804] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/22/2022] [Indexed: 11/25/2022] Open
Abstract
This mini-review focuses on current knowledge regarding maternal regulation of the paternal genome in early embryos of mammalian livestock species. Emphasis has been placed on regulatory events described for maternally imprinted genes and further highlights transcriptional regulation of the post-fertilization paternal genome by maternal factors. Specifically, the included content aims to summarize genomic and epigenomic contributions of paternally expressed genes, their regulation by the maternal embryo environment, and chromatin structure that are indispensable for early embryo development. The accumulation of current knowledge will summarize conserved allelic function among species to include molecular and genomic studies across large domestic animals and humans with reference to founding experimental animal models.
Collapse
|
4
|
Ahn J, Lee J, Kim DH, Hwang IS, Park MR, Cho IC, Hwang S, Lee K. Loss of Monoallelic Expression of IGF2 in the Adult Liver Via Alternative Promoter Usage and Chromatin Reorganization. Front Genet 2022; 13:920641. [PMID: 35938007 PMCID: PMC9355166 DOI: 10.3389/fgene.2022.920641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
In mammals, genomic imprinting operates via gene silencing mechanisms. Although conservation of the imprinting mechanism at the H19/IGF2 locus has been generally described in pigs, tissue-specific imprinting at the transcript level, monoallelic-to-biallelic conversion, and spatio-temporal chromatin reorganization remain largely uninvestigated. Here, we delineate spatially regulated imprinting of IGF2 transcripts, age-dependent hepatic mono- to biallelic conversion, and reorganization of topologically associating domains at the porcine H19/IGF2 locus for better translation to human and animal research. Whole-genome bisulfite sequencing (WGBS) and RNA sequencing (RNA-seq) of normal and parthenogenetic porcine embryos revealed the paternally hypermethylated H19 differentially methylated region and paternal expression of IGF2. Using a polymorphism-based approach and omics datasets from chromatin immunoprecipitation sequencing (ChIP–seq), whole-genome sequencing (WGS), RNA-seq, and Hi-C, regulation of IGF2 during development was analyzed. Regulatory elements in the liver were distinguished from those in the muscle where the porcine IGF2 transcript was monoallelically expressed. The IGF2 transcript from the liver was biallelically expressed at later developmental stages in both pigs and humans. Chromatin interaction was less frequent in the adult liver compared to the fetal liver and skeletal muscle. The duration of genomic imprinting effects within the H19/IGF2 locus might be reduced in the liver with biallelic conversion through alternative promoter usage and chromatin remodeling. Our integrative omics analyses of genome, epigenome, and transcriptome provided a comprehensive view of imprinting status at the H19/IGF2 cluster.
Collapse
Affiliation(s)
- Jinsoo Ahn
- Functional Genomics Laboratory, Department of Animal Sciences, The Ohio State University, Columbus, OH, United States
| | - Joonbum Lee
- Functional Genomics Laboratory, Department of Animal Sciences, The Ohio State University, Columbus, OH, United States
- The Ohio State University Interdisciplinary Human Nutrition Program, The Ohio State University, Columbus, OH, United States
| | - Dong-Hwan Kim
- Functional Genomics Laboratory, Department of Animal Sciences, The Ohio State University, Columbus, OH, United States
| | - In-Sul Hwang
- Animal Biotechnology Division, National Institute of Animal Science, Rural Development Administration, Jeonbuk, South Korea
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, Columbia University, New York, NY, United States
| | - Mi-Ryung Park
- Animal Biotechnology Division, National Institute of Animal Science, Rural Development Administration, Jeonbuk, South Korea
| | - In-Cheol Cho
- National Institute of Animal Science, Rural Development Administration, Jeju, South Korea
| | - Seongsoo Hwang
- Animal Biotechnology Division, National Institute of Animal Science, Rural Development Administration, Jeonbuk, South Korea
| | - Kichoon Lee
- Functional Genomics Laboratory, Department of Animal Sciences, The Ohio State University, Columbus, OH, United States
- The Ohio State University Interdisciplinary Human Nutrition Program, The Ohio State University, Columbus, OH, United States
- *Correspondence: Kichoon Lee,
| |
Collapse
|