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Gene & Protein in Disease                      DNA methylation and gene expression on rats with protein malnutrition




            A                                B                              C




























            Figure 6. Cluster analysis of the expression level of differentially expressed genes. (A) is for early-life low-protein group (LPE) versus control group (CON);
            (B) is for fetal low-protein group (LPF) versus CON; and (C) is for LPF versus LPE.

            3.5. KEGG enrichment analysis of differential      depth (=6.10  g/species genome size), and sequencing
            gene                                               quality (98.8% of Q20), as shown in Table 9.
            In KEGG  database (https://www.kegg.jp/kegg/),  the   WALT, which is a fast and accurate read mapping
            difference in genes involved in the metabolic pathways   for bisulfite sequencing available under the GPL v3
            of further analysis, according to the P < 0.01, the number   license and downloadable from https://github.com/
            of genes involved in three or more screenings, and   smithlabcode/walt,  was  used  to  perform  reference
            the metabolic pathways mainly regulated by early-life   genome sequence alignment on the pre-processed
            malnutrition in the later growth and development of rats   valid data, and the results of genome alignment as well
            are shown in Tables S4-S6 of the Raw Data file. Scatter plots   as the depth of sequencing were statistically analyzed
            of KEGG enrichment of differentially expressed genes are   (Table 11).
            shown in Figures 8 and 9.
                                                               3.9. Sample correlation analysis
            3.6. SNP and indel analysis
                                                               Principal component analysis (PCA) analysis was used
              We  analyzed  SNP  sites  in  the  coding  region  at  the   to investigate the distribution of samples to evaluate the
            transcriptomic level. According to the Hisat results of each   uniformity of biological replicates (Figure 12).
            sample and the reference genome, the Samtools software
            was used for MPileup processing, and the possible SNP and   3.10. Statistical distribution of methylation on
            indel information about each sample were then annotated   chromosomes
            with Annovar (Tables 6-9).                         The number of occurrences of methylated CpG, CHG, and
            3.7. Variable shear analysis                       CHH on each chromosome was counted according to the
                                                               results of genome analysis (Figure 13).
            We used ASprofile software to perform qualitative analysis
            of variable shear events for each sample using the gene   3.11. Distribution of DMRs in different segments of
            model predicted by Stringtie (Figure 11 and Table 10).  the genome

            3.8. Pre-processing of sequencing data             Compared with normal group, there were 48,149 DMRs
                                                               in the LPF group, among which 29,033  (60.3%) were
            In  general,  data  required  include  volume  of  sequencing   hypermethylated DMRs. Compared with the normal group,
            data (e.g., the volume of sequencing data of sample   there were 52,185 DMRs in the LPE group, among which
            T1  was   61,004,256  reads),  average  sequencing  32,947 (62.3%) were hypermethylated DMRs. There were


            Volume 1 Issue 2 (2022)                         9                      https://doi.org/10.36922/gpd.v1i2.169
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