scholarly journals Comparative Analyses of Sperm DNA Methylomes Among Three Commercial Pig Breeds Reveal Vital Hypomethylated Regions Associated With Spermatogenesis and Embryonic Development

2021 ◽  
Vol 12 ◽  
Author(s):  
Siqian Chen ◽  
Shuli Liu ◽  
Siyuan Mi ◽  
Wenlong Li ◽  
Shengli Zhang ◽  
...  

Identifying epigenetic changes is essential for an in-depth understanding of phenotypic diversity and pigs as the human medical model for anatomizing complex diseases. Abnormal sperm DNA methylation can lead to male infertility, fetal development failure, and affect the phenotypic traits of offspring. However, the whole genome epigenome map in pig sperm is lacking to date. In this study, we profiled methylation levels of cytosine in three commercial pig breeds, Landrace, Duroc, and Large White using whole-genome bisulfite sequencing (WGBS). The results showed that the correlation of methylation levels between Landrace and Large White pigs was higher. We found that 1,040–1,666 breed-specific hypomethylated regions (HMRs) were associated with embryonic developmental and economically complex traits for each breed. By integrating reduced representation bisulfite sequencing (RRBS) public data of pig testis, 1743 conservated HMRs between sperm and testis were defined, which may play a role in spermatogenesis. In addition, we found that the DNA methylation patterns of human and pig sperm showed high similarity by integrating public data from WGBS and chromatin immunoprecipitation sequencing (ChIP-seq) in other mammals, such as human and mouse. We identified 2,733 conserved HMRs between human and pig involved in organ development and brain-related traits, such as NLGN1 (neuroligin 1) containing a conserved-HMR between human and pig. Our results revealed the similarities and diversity of sperm methylation patterns among three commercial pig breeds and between human and pig. These findings are beneficial for elucidating the mechanism of male fertility, and the changes in commercial traits that undergo strong selection.

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 88-89
Author(s):  
Ying Yu ◽  
Siqian Chen ◽  
Shuli Liu ◽  
Lingzhao Fang ◽  
Shengli Zhang

Abstract Identification of inter-individual variations of sperm DNA methylation is very essential for elucidating phenotypic variation of reproduction and production traits. We had generated 28 sperm whole genome sequencing (WGBS) data from healthy individuals. We detected 46 variably methylated regions (VMRs) significantly (P < 5.77 × 10−5) associated with reproduction traits. These significant VMRs were also co-localized (±10 kb) with genes related to sperm motility and reproduction, including ZFP36L1, CRISP2 and HGF. To further identify epigenomic markers associated with reproduction and production traits, we generated WGBS dada for a specific pair of monozygotic twin artificial insemination Holstein bulls with moderately different sperm qualities (Bull1 > Bull2). We found 528 differentially methylated regions between the twin bulls, which spanned or overlapped with 309 differentially methylated genes (DMG). These DMG were particularly associated with reproduction, embryo development and the nervous system. To further obtain DNA methylation markers involved in the diversity of porcine reproduction and production traits due to long-term artificial selection, we profiled sperm DNA methylation of three commercial pig breeds--Duroc, Landrace and Large White. we found the hypomethylated regions (HMRs) were highly conserved among pig breeds, while 1040–1666 breed-specific HMRs were identified and associated with the QTLs of embryonic developmental and phenotypic changes. By integrating reduced representation bisulfite sequencing public data of pig testis, we further defined 1743 conservative HMRs between sperm and testis, which may play a role in spermatogenesis process. Overall, our studies demonstrated associations of sperm DNA methylation with bovine and porcine production and reproduction traits, highlighting the potential of epigenomic information in genomic improvement programs for livestock. (*: [email protected])


2021 ◽  
Author(s):  
Romain Barres ◽  
Emil Andersen ◽  
Wolf Reik ◽  
Stephen Clark ◽  
Lars Ingerslev ◽  
...  

Epigenetic marks in gametes modulate developmental programming after fertilization. Spermatozoa from obese men exhibit distinct epigenetic signatures compared to lean men, however, whether epigenetic differences are concentrated in a sub-population of spermatozoa or spread across the ejaculate population is unknown. Here, by using whole-genome single-cell bisulfite sequencing on 87 motile spermatozoa from 8 individuals (4 lean and 4 obese), we found that spermatozoa within single ejaculates are highly heterogeneous and contain subsets of spermatozoa with marked imprinting defects. Comparing lean and obese subjects, we discovered methylation differences across two large CpG dense regions located near PPM1D and LINC01237. These findings confirm that sperm DNA methylation is altered in human obesity and indicate that single ejaculates contain subpopulations of spermatozoa carrying distinct DNA methylation patterns. Distinct epigenetic patterns of spermatozoa within an ejaculate may result in different intergenerational effects and therefore influence strategies aiming to prevent epigenetic-related disorders in the offspring.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Rose Schrott ◽  
Susan K Murphy ◽  
Jennifer L Modliszewski ◽  
Dillon E King ◽  
Bendu Hill ◽  
...  

Abstract Cannabis use alters sperm DNA methylation, but the potential reversibility of these changes is unknown. Semen samples from cannabis users and non-user controls were collected at baseline and again following a 77-day period of cannabis abstinence (one spermatogenic cycle). Users and controls did not significantly differ by demographics or semen analyses. Whole-genome bisulfite sequencing identified 163 CpG sites with significantly different DNA methylation in sperm between groups (P < 2.94 × 10−9). Genes associated with altered CpG sites were enriched with those involved in development, including cardiogenesis and neurodevelopment. Many of the differences in sperm DNA methylation between groups were diminished after cannabis abstinence. These results indicate that sustained cannabis abstinence significantly reduces the number of sperm showing cannabis-associated alterations at genes important for early development.


2020 ◽  
Author(s):  
Benjamin I Laufer ◽  
Hyeyeon Hwang ◽  
Julia M Jianu ◽  
Charles E Mordaunt ◽  
Ian F Korf ◽  
...  

Abstract Neonatal dried blood spots (NDBS) are a widely banked sample source that enables retrospective investigation into early life molecular events. Here, we performed low-pass whole genome bisulfite sequencing (WGBS) of 86 NDBS DNA to examine early life Down syndrome (DS) DNA methylation profiles. DS represents an example of genetics shaping epigenetics, as multiple array-based studies have demonstrated that trisomy 21 is characterized by genome-wide alterations to DNA methylation. By assaying over 24 million CpG sites, thousands of genome-wide significant (q < 0.05) differentially methylated regions (DMRs) that distinguished DS from typical development and idiopathic developmental delay were identified. Machine learning feature selection refined these DMRs to 22 loci. The DS DMRs mapped to genes involved in neurodevelopment, metabolism, and transcriptional regulation. Based on comparisons with previous DS methylation studies and reference epigenomes, the hypermethylated DS DMRs were significantly (q < 0.05) enriched across tissues while the hypomethylated DS DMRs were significantly (q < 0.05) enriched for blood-specific chromatin states. A ~28 kb block of hypermethylation was observed on chromosome 21 in the RUNX1 locus, which encodes a hematopoietic transcription factor whose binding motif was the most significantly enriched (q < 0.05) overall and specifically within the hypomethylated DMRs. Finally, we also identified DMRs that distinguished DS NDBS based on the presence or absence of congenital heart disease (CHD). Together, these results not only demonstrate the utility of low-pass WGBS on NDBS samples for epigenome-wide association studies, but also provide new insights into the early life mechanisms of epigenomic dysregulation resulting from trisomy 21.


2021 ◽  
Author(s):  
Diao Liu ◽  
Chunlian Lu ◽  
Shang Li ◽  
Mengyu Jia ◽  
Yutao Miao ◽  
...  

Abstract Shenxian pigs are the only local black pig of Hebei Province, and were listed in the Genetics of Livestock and Poultry Resources of China in 2016. This breed of pig is considered to be a valuable local pig germplasm genetic resource in China. When compared with other introduced pig breeds, the Shenxian pig breed is characterized with early sexual maturity, short oestrus intervals, large litter sizes, and good meat quality, which are all of good research significance. However, the Shenxian pig variety was previously declared extinct in 2004 due to the introduction of a large number of foreign pig breeds. In order to preserve and study the Shenxian pig breed, the Hebei Zhengnong Animal Husbandry Co., Ltd. was established in Hebei Province for the purpose of preserving the purified Shenxian pig strain. In the present study, in order to understand the genetic variations of Shenxian pigs, identify selected regions related to superior traits, and accelerate the breeding processes of Shenxian pigs, the whole genome of the Shenxian pigs was resequenced and compared with that of large white pigs. The goal was to explore the germplasm characteristics of Shenxian pigs.The results obtained in this research investigation revealed that the genetic relationships of the Shenxian pig breed were complex, and that sub-populations could be identified within the general population. A total of 23M SNP sites were obtained by whole genome resequencing, and 1,509 selected sites were obtained via bioinformatics analyses. It was determined after annotation that a total of 19 genes were enriched in three items of bioengineering, molecular function, and cell composition.During this research investigation, the aforementioned 19 genes were subjected to GO and KEGG analyses. Subsequently, the candidate genes related to cell proliferation were obtained (DMTF1 and WDR5), which were considered to possibly be related to the slow growth and development of Shenxian pigs. In addition, the candidate genes related to lactation were obtained (CSN2 and CSN3). However, no genes related to meat quality traits were successfully screened.


2010 ◽  
Vol 94 (5) ◽  
pp. 1728-1733 ◽  
Author(s):  
Saher Sue Hammoud ◽  
Jahnvi Purwar ◽  
Christian Pflueger ◽  
Bradley R. Cairns ◽  
Douglas T. Carrell

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 87-88
Author(s):  
Luiz F Brito ◽  
Jacob M Maskal ◽  
Shi-Yi Chen ◽  
Hinayah R Oliveira ◽  
Jason R Graham ◽  
...  

Abstract In utero heat stress (IUHS) has several postnatal consequences in pigs that compromise health, increase stress response, and reduce performance. These phenotypes may be caused by epigenetic modifications such as DNA methylation, which are heritable molecular modifications that impact gene expression and phenotypic outcomes without changing the DNA sequence. Therefore, we aimed to compare the DNA methylation profiles between in-utero thermoneutral (IUTN) and IUHS pigs to identify differentially methylated regions. Twenty-four pregnant gilts were evenly assigned to either a thermoneutral (17.5 ± 2.1°C) or heat stress (cycling 26 to 36°C) chamber from d 0 to 59 of gestation, followed by thermoneutral conditions (20.9 ± 2.3°C) for the rest of gestation and until the piglets were weaned. At 105 d of age, 10 IUTN and 10 IUHS piglets were euthanized and Longissimus dorsi muscle samples were collected and used to perform whole-genome bisulfite sequencing (WGBS). Purified genomic DNA was fragmented and bisulfite conversion was performed. Illumina platforms were used to sequence WGBS libraries. All pigs had similar proportions of methylation at CpG sites. Two-hundred-sixty-eight genomic regions were differentially methylated between IUTN and IUHS pigs. These identified regions are located across all pig chromosomes and ranged from 2 (SSC18) to 40 (SSC10). Eighty-five unique differentially-methylated genes were identified. These genes have been reported to be involved in key biological processes such as transcriptional repressor activity and tRNA processing (e.g., SKOR2,TRMT6, TSEN2), cellular response to heat stress (e.g.,CCAR2), placental vascularization (e.g.,FZD5), central nervous system (e.g.,VEPH1), cholesterol biosynthesis (e.g., CYB5R1), insulin receptor substrate (e.g.,IRS2), synaptic transmission (e.g.,RIMBP2), neurotrophic factor receptor activity (e.g.,LIFR), immune response (e.g., CD84), DNA repair (e.g., CHD1L), and cell proliferation and endocrine signaling (e.g., SSTR1, CYB5R1). These findings contribute to a better understanding of the epigenomic mechanisms underlying postnatal consequences of IUHS in pigs.


2020 ◽  
Vol 60 (6) ◽  
pp. 1517-1530 ◽  
Author(s):  
Kees van Oers ◽  
Bernice Sepers ◽  
William Sies ◽  
Fleur Gawehns ◽  
Koen J F Verhoeven ◽  
...  

Synopsis The search for the hereditary mechanisms underlying quantitative traits traditionally focused on the identification of underlying genomic polymorphisms such as single-nucleotide polymorphisms. It has now become clear that epigenetic mechanisms, such as DNA methylation, can consistently alter gene expression over multiple generations. It is unclear, however, if and how DNA methylation can stably be transferred from one generation to the next and can thereby be a component of the heritable variation of a trait. In this study, we explore whether DNA methylation responds to phenotypic selection using whole-genome and genome-wide bisulfite approaches. We assessed differential erythrocyte DNA methylation patterns between extreme personality types in the Great Tit (Parus major). For this, we used individuals from a four-generation artificial bi-directional selection experiment and siblings from eight F2 inter-cross families. We find no differentially methylated sites when comparing the selected personality lines, providing no evidence for the so-called epialleles associated with exploratory behavior. Using a pair-wise sibling design in the F2 intercrosses, we show that the genome-wide DNA methylation profiles of individuals are mainly explained by family structure, indicating that the majority of variation in DNA methylation in CpG sites between individuals can be explained by genetic differences. Although we found some candidates explaining behavioral differences between F2 siblings, we could not confirm this with a whole-genome approach, thereby confirming the absence of epialleles in these F2 intercrosses. We conclude that while epigenetic variation may underlie phenotypic variation in behavioral traits, we were not able to find evidence that DNA methylation can explain heritable variation in personality traits in Great Tits.


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