Genome-wide associations for birth weight and correlations with adult disease

Intrauterine growth restriction (IUGR) remains a major problem in swine production since the associated low birth weight leads to high rates of pre-weaning morbidity and mortality, and permanent retardation of growth and development. The underlying regulatory mechanisms from the aspects of epigenetic modification has received widespread attention. Studies explore the changes in genome wide methylation in small intestine (SI), liver and longissimus dorsi muscle (LDM) between IUGR and normal birth weight (NBW) newborn piglets using a methylated DNA immunoprecipitation-sequencing (MeDIP-Seq) approach. The data demonstrated that methylated peaks were prominently distributed in distal intergenic regions and the quantities of peaks in IUGR piglets were more than that of NBW piglets. IUGR piglets had relatively high methylated level in promoters, introns and coding exons in all the three tissues. Through KEGG pathway analysis of differentially methylated genes found that 33, 54 and 5 differentially methylated genes in small intestine, liver and longissimus dorsi muscle between NBW and IUGR piglets, respectively, which are related to development and differentiation, carbohydrate and energy metabolism, lipid metabolism, protein turnover, immune response, detoxification, oxidative stress and apoptosis pathway. The objective of this review is to assess the impact of differentially methylation status on developmental delay, metabolic disorders and immune deficiency of IUGR piglets.

Download Full-text

Genomic prediction for growth using a low-density SNP panel in dromedary camels

Scientific Reports ◽

10.1038/s41598-021-87296-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Morteza Bitaraf Sani ◽

Javad Zare Harofte ◽

Mohammad Hossein Banabazi ◽

Saeid Esmaeilkhanian ◽

Ali Shafei Naderi ◽

...

Keyword(s):

Body Weight ◽

Birth Weight ◽

Sample Size ◽

Genetic Improvement ◽

Growth Traits ◽

P Value ◽

Dromedary Camels ◽

Genome Wide ◽

A Genome ◽

Daily Gain

AbstractFor thousands of years, camels have produced meat, milk, and fiber in harsh desert conditions. For a sustainable development to provide protein resources from desert areas, it is necessary to pay attention to genetic improvement in camel breeding. By using genotyping-by-sequencing (GBS) method we produced over 14,500 genome wide markers to conduct a genome- wide association study (GWAS) for investigating the birth weight, daily gain, and body weight of 96 dromedaries in the Iranian central desert. A total of 99 SNPs were associated with birth weight, daily gain, and body weight (p-value < 0.002). Genomic breeding values (GEBVs) were estimated with the BGLR package using (i) all 14,522 SNPs and (ii) the 99 SNPs by GWAS. Twenty-eight SNPs were associated with birth weight, daily gain, and body weight (p-value < 0.001). Annotation of the genomic region (s) within ± 100 kb of the associated SNPs facilitated prediction of 36 candidate genes. The accuracy of GEBVs was more than 0.65 based on all 14,522 SNPs, but the regression coefficients for birth weight, daily gain, and body weight were 0.39, 0.20, and 0.23, respectively. Because of low sample size, the GEBVs were predicted using the associated SNPs from GWAS. The accuracy of GEBVs based on the 99 associated SNPs was 0.62, 0.82, and 0.57 for birth weight, daily gain, and body weight. This report is the first GWAS using GBS on dromedary camels and identifies markers associated with growth traits that could help to plan breeding program to genetic improvement. Further researches using larger sample size and collaboration of the camel farmers and more profound understanding will permit verification of the associated SNPs identified in this project. The preliminary results of study show that genomic selection could be the appropriate way to genetic improvement of body weight in dromedary camels, which is challenging due to a long generation interval, seasonal reproduction, and lack of records and pedigrees.

Download Full-text

Common genetic variants with fetal effects on birth weight are enriched for proximity to genes implicated in rare developmental disorders

Human Molecular Genetics ◽

10.1093/hmg/ddab060 ◽

2021 ◽

Author(s):

Robin N Beaumont ◽

Isabelle K Mayne ◽

Rachel M Freathy ◽

Caroline F Wright

Keyword(s):

Birth Weight ◽

Statistical Power ◽

Developmental Disorders ◽

Association Studies ◽

Later Life ◽

Genome Wide Association Studies ◽

Nucleotide Polymorphisms ◽

Genome Wide ◽

Common Genetic Variants ◽

Causal Genes

Abstract Birth weight is an important factor in newborn survival; both low and high birth weights are associated with adverse later-life health outcomes. Genome-wide association studies (GWAS) have identified 190 loci associated with maternal or fetal effects on birth weight. Knowledge of the underlying causal genes is crucial to understand how these loci influence birth weight and the links between infant and adult morbidity. Numerous monogenic developmental syndromes are associated with birth weights at the extreme ends of the distribution. Genes implicated in those syndromes may provide valuable information to prioritize candidate genes at the GWAS loci. We examined the proximity of genes implicated in developmental disorders (DDs) to birth weight GWAS loci using simulations to test whether they fall disproportionately close to the GWAS loci. We found birth weight GWAS single nucleotide polymorphisms (SNPs) fall closer to such genes than expected both when the DD gene is the nearest gene to the birth weight SNP and also when examining all genes within 258 kb of the SNP. This enrichment was driven by genes causing monogenic DDs with dominant modes of inheritance. We found examples of SNPs in the intron of one gene marking plausible effects via different nearby genes, highlighting the closest gene to the SNP not necessarily being the functionally relevant gene. This is the first application of this approach to birth weight, which has helped identify GWAS loci likely to have direct fetal effects on birth weight, which could not previously be classified as fetal or maternal owing to insufficient statistical power.

Download Full-text