ORIGINAL RESEARCH article

Front. Genet., 06 July 2026

Sec. Livestock Genomics

Volume 17 - 2026 | https://doi.org/10.3389/fgene.2026.1841048

Effects of prenatal transportation stress on liver gene expression in male and female Brahman calves

  • 1. Department of Animal Science, College Station, Texas A&M University, College Station, TX, United States

  • 2. Texas A&M AgriLife Research and Extension Center, Overton, TX, United States

Abstract

The liver is a central regulator of metabolic and endocrine functions that support fetal growth and postnatal development. Prenatal stress can reprogram hepatic development in the offspring, potentially causing long-term changes in metabolism and production efficiency. However, the influence of prenatal stress on hepatic molecular function and resulting phenotypes in beef cattle remains poorly understood. Therefore, the objectives of this study were to evaluate phenotypic traits and liver tissue gene expression in Brahman heifer and bull calves from prenatal transportation stress (PNS) and control (Control) treatment groups. One group of pregnant Brahman cows were transported for a 2-h period every 20 (±5) d from 60 to 140 days of gestation. Another group of pregnant Brahman cows served as Control. Thirty-two calves, eight heifer and eight bull calves from the PNS and Control groups, respectively, were utilized. Calves were weighed at approximately 25 (±2) d of age. The following day, calves were euthanized, and liver tissues were harvested. Phenotypic traits evaluated include birth weight, harvest weight, liver weight, pen score, and liver weight:harvest weight. Interaction of sex and treatment did not explain substantial variation for any trait (P > 0.28). Sex influenced birth weight, harvest weight, liver weight (P < 0.05), and treatment influenced liver weight:harvest weight (P < 0.10). Linear regression coefficients of traits on calf age as a linear covariate were not different from 0 (P > 0.41). Controlling false discovery rate at 0.10, there were no differentially expressed genes for PNS relative to Control and 13 differentially expressed genes for male relative to female comparisons. No genes were found to be differentially expressed across all comparisons. It is possible that the few differences between sexes and treatments may be due to relatively small sample sizes or to an unknown adaptation mechanism to the stress prenatally induced by this young age. Heightening the severity of prenatal transportation stress through increased duration or frequency of transportation may result in more differentially expressed genes.

Introduction

The liver holds a vital position in various organ systems (). It is involved in several physiological processes and plays an essential role in many functions that are required for daily life (). Filtration, storage, metabolism, excretion, immune defense, and hormone production all take place in the liver during times of eustress and especially may be perturbed under a variety of stress situations (). Stress is a response that takes place when an animal recognizes a threat to homeostasis, or a stable internal environment (). Stress can elicit negative implications on the liver (). Transportation of cattle can induce both physical and psychological stress to differentially affect individual animals. Transportation of gestating Brahman cows has been confirmed to alter cortisol profiles and multiple hypothalamic-pituitary-adrenal axis functions of calves and the cows themselves (; ; ). The presence of stressors during gestation can have impacts on the physiological functions of a bovine fetus. Elevated levels of maternal cortisol due to transportation stress during gestation may have effects on the growth and development of the offspring (). Prenatal transportation stress may also influence the genes that are expressed in the liver of the calves.

Gene expression analysis may offer insight on transcriptional behavior. It provides quantitative details of RNA molecules within tissues across treatments or conditions (). Normal processes of the liver can be disrupted by physiological stressors. Due to the liver’s dynamic role in metabolism, vasculature, immunity, secretion and excretion, a change in physiological state caused by stress could impair liver function and alter gene expression (). Liver gene expression has been reported relative to bovine residual feed intake, rate of gain, and with various feed additives and nutritional restriction as treatments (; ; ). These treatment conditions were imposed to calves postnatally when dairy and beef cattle attained various ages and stages of production. The impacts of prenatal transportation stress on gene expression have been evaluated in the amygdala of mature Brahman cows and Brahman calves (; ), as well as stress axis tissues of mature Brahman cows (). Nutritional stress resulted in an enormous number of differentially expressed genes in the liver of dairy cows (), suggesting that this organ in bovine is especially stress sensitive. However, the influence of prenatal transportation stress on liver gene expression in young calves, in reasonable proximity to the stressor, has not been documented. The hypothesis was that liver gene expression would be altered by prenatal stress. The objectives of this research were to: 1) compare phenotypes expressed in Brahman heifer and bull calves exposed to prenatal transportation stress and a control, and 2) evaluate gene expression in liver tissues from Brahman heifer and bull calves within those groups.

Materials and methods

All procedures followed the Guide for the Care and Use of Agricultural Animals in Research and Teaching () and were approved by the Texas A&M AgriLife Research Animal Use and Care Committee.

Animal procedures

Mature Brahman cows, approximately 6 years of age, were utilized to evaluate differences in calf phenotype and liver gene expression. The Brahman cows were artificially inseminated with semen from a single Brahman bull in early May of 2018. Cows were assigned randomly to treatments with respect to temperament, age, and parity and were managed under the same environmental and nutrient conditions at the Texas A&M AgriLife Research and Extension Center at Overton. These include ad libitum coastal bermudagrass pastures (Cynodon dactylon) in the summer and fall, rye (Secale cereale) and ryegrass (Lolium multiflorum) overseeded pasture, and supplementation of coastal bermudagrass hay and 3:1 corn/soybean meal mix as needed. One group of pregnant Brahman cows were transported for a 2-h period every 20 days (±5 days) from 60 to 140 days of gestation as previously reported (; ; ). A 3-section trailer (2.4 b y 7.3 m) towed by a three-quarter ton truck was utilized to transport the cows. The same individual drove on smooth paved highways each time for a total of 2-h at an average speed of 75 km per hour. This prenatal transportation treatment has been previously reported to increase maternal circulating concentrations of cortisol, a key hormone used as a stress marker (). The second group of pregnant Brahman cows was preserved as a non-transported control. A total of 32 calves, eight heifer and eight bull calves from the transported (PNS) and control (Control) groups, respectively, were utilized. At approximately 25 days (±2 days) of age, the calves were weighed, and pen temperament scores were collected. A single experienced evaluator individually assigned pen temperament scores to calves in groups of 3 to 5 animals within a confined pen. Calf reactions to the evaluator were assessed on a scale of 1 to 5 (). A pen temperament score of one was defined as nonaggressive or docile, and five was defined as easily excitable, very aggressive, or dangerous. One day after weighing and collection of pen scores, the calves were humanely euthanized using jugular intravenous administration 1 mL/4 kg live weight of barbiturate overdose (1 mL = 390 mg pentobarbitol and 50 mg phenytoin; Beuthanasia-D Solution, Merck Animal Health, Whitehouse Station, NJ, United States), and tissues, including the liver, were harvested. Livers from each calf were weighed and then sections of parenchyma of the right lobe, approximately 2–3 cm in length and 0.1–3 cm in thickness, were dissected aseptically for histology. Samples were frozen in liquid nitrogen and kept at −80 °C until assays were performed. Calf birth weights, harvest weights, liver weights, pen scores, and liver weight as a proportion of harvest weight were recorded.

Preparation and sequencing

Liver tissue samples were submitted to Novogene Corporation (Davis, CA) for RNA quantification, library preparation, and transcriptome sequencing for gene expression analyses. RNA sample preparation input material consisted of 1 μg RNA per sample. NEBNext UltraTM RNA Library Prep Kit for Illumina (New England BioLabs, Ipswich, MA, United States) was utilized to generate sequencing libraries. Purification of mRNA was performed using poly-T oligo-attached magnetic beads. Fragmentation was carried out, first and second strand cDNA were synthesized, and remaining overhangs were converted into blunt ends. Ligation was conducted using NEBNext Adaptors after adenylation of 3′ ends of DNA fragments. Library fragments were purified with the AMPure XP system (Beckman Coulter, Brea, CA, United States) to select for cDNA fragments of 150–200 bp in length. Three μl of USER Enzyme (New England BioLabs) were used with size-selected, adapter-ligated cDNA at 37 °C for 15 min. The process was repeated for 5 min at 95 °C before polymerase chain reaction (PCR) was performed. Purification of the PCR products was performed (AMPure XP system) and quality of the library was evaluated using the Bioanalyzer 2,100 system (Agilent Technologies, Santa Clara, CA, United States). Index-coded samples were clustered, followed by sequencing of library preparations on an Illumina 1.9 platform (Illumina, San Diego, CA) and generation of paired-end reads.

RNA-seq libraries generated an average of 24 million reads per sample. Raw RNA FASTQ files were evaluated using FastQC (Babraham Bioinformatics, Cambridge, UK) and MultiQC (Babraham Bioinformatics) before undergoing quality control processing using TrimGalore (Babraham Bioinformatics) to remove adapters and low-quality reads. A read quality cutoff of 20 was utilized, which is the default based on phred-33 encoding (Illumina 1.9). A minimum length of 36 base pairs was required. After trimming was complete, reads were reevaluated with FastQC and MultiQC to ensure that they contained high quality, clean data for further analyses. Sequence duplication levels were approximately 70% across 32 bovine liver samples, which is consistent with the transcriptionally specialized nature of liver tissues. The average quality score after trimming was 35 and no samples had adapter contamination. All reads mapped successfully and none were duplicated.

The Spliced Transcripts Alignment to a Reference (STAR; ) program was used to create a genome index file using the Bos taurus ARS-UCD1.2 genome assembly (). The clean, paired-end reads were then aligned to that index file and binary alignment map (BAM) files were generated for each sample. Read totals at each gene were then quantified from the BAM files using HTSeq (). Gene level quantification using HTSeq helped reduce the impact of duplicate reads on downstream differential gene expression analysis, and identified approximately 13,000 expressed genes per sample, based on non-zero read counts.

Statistical analyses

Statistical analyses of traits were performed using the lm function in R software (The R Foundation for Statistical Computing, Vienna, AT). Traits included calf birth weight, harvest weight, liver weight, pen score, and liver weight:harvest weight. Fixed classification effects investigated included sex and treatment main and interaction effects. Calf age in days was investigated as a linear covariate in all analyses except birth weight. Effects were considered significant when the F ratio of the effect had probability <0.05. Effects with F ratios that had probability between 0.05 and 0.1 were considered to be trends.

Read counts for each gene were evaluated using EdgeR () to statistically evaluate differences in liver gene expression.

Comparisons included:

  • PNS males relative to Control males

  • PNS females relative to Control females

  • PNS males relative to PNS females

  • Control males relative to Control females

  • Males relative to females (treatments combined)

  • PNS calves relative to Control calves

Multidimensional scaling (MDS) plots were generated to visualize levels of similarity for each comparison prior to filtering genes with low expression. Genes with counts per million (CPM) values above three in at least five of the libraries were kept and those with low expression were removed. Subsequently, MDS plots with filtered values were created utilizing the biological coefficient of variation (BCV) method. An outlier sample was visually detected based on the MDS plots (Supplementary Figures 1, 2) and confirmed as > 0.3 BCV from the average BCV of the remaining samples (BCV distance 2), which led to its exclusion (Figures 1, 2). Normalization factors were calculated from raw gene-level counts using the edgeR’s (v4.8.0) trimmed mean of M-values (TMM) method, which scales each library to account for differences in sequencing depth and RNA composition by down-weighting genes with very large counts or extreme fold changes (). These TMM-derived scaling factors were used to adjust library sizes, and TMM-normalized counts were converted to CPM for downstream analyses. A generalized linear model (GLM) method was used to analyze the data. A negative binomial model was fitted to the Cox-Reid transformed dispersion estimates and the GLM function was fitted to the read counts and dispersion tables to use the GLM likelihood ratio test for each comparison (PNS minus control; male minus female). Each comparison was evaluated as a single factorial model. The 15 most variable genes were identified in each comparison, and heatmaps were created for each comparison. Differential expression was defined at false discovery rate (FDR) < 0.10 (). Genes that were differentially expressed were submitted to the PANTHER Classification System v19.0 () for annotation and functional enrichment analysis, using an FDR threshold of 0.05 to define significant categories.

FIGURE 1

FIGURE 2

Results

Phenotypic analyses

Main effect means and SE were calculated for sex and treatment for each trait and estimated linear regression coefficients and SE for calf age in days are presented in Table 1. The interaction of sex and treatment was not influential on any trait (P > 0.28). Sex was influential in analyses of calf birth weight, harvest weight, and liver weight (P < 0.05). Treatment was determined to be influential for calf liver weight:harvest weight (P < 0.10). As expected, males were heavier (P < 0.05) than females at birth and harvest and had heavier liver weights. No sex differences were observed (P > 0.25) for pen score or liver weight:harvest weight. Prenatally stressed (PNS) calves had heavier liver weight:harvest weights (P < 0.10) than Control calves. No treatment differences were found for the remaining four traits (P > 0.16). Age was not influential on harvest weight, liver weight, temperament score, or liver weight:harvest weight (P > 0.41).

TABLE 1

EffectLevelBirth weight (kg)Harvest weight (kg)Liver weight (g)Temperament scorebLiver weight: Harvest weight (g/kg)
SexcFemale
Male
P Value
36.1 ± 1.29
40.5 ± 1.29
0.02
55.8 ± 2.11
63.0 ± 2.11
0.03
1,282 ± 55.4
1,475 ± 55.4
0.02
3.5 ± 0.26
3.1 ± 0.26
0.26
23.0 ± 0.51
23.5 ± 0.51
0.62
TreatmentcControl
PNS
P Value
39.6 ± 1.29
37.0 ± 1.29
0.17
60.0 ± 2.10
58.7 ± 2.10
0.68
1,360 ± 55.0
1,398 ± 55.0
0.64
3.3 ± 0.26
3.4 ± 0.26
0.80
22.6 ± 0.51
23.9 ± 0.51
0.09
Aged-
P Value
-
-
0.3 ± 0.94
0.42
−8.2 ± 24.70
0.81
0.1 ± 0.12
0.70
−0.2 ± 0.23
0.53

Means and estimates ±SE for traits (n = 32)a.

a

Effects were considered statistically significant when P < 0.05.

b

Pen temperament scores for each calf were determined by willingness to be approached by a human and range from 1 (very calm) to five (easily excitable).

c

The interaction of sex and treatment was not influential on any trait (P > 0.28).

d

Estimated linear regression coefficients of traits on calf age in days ±SE.

Differential gene expression

PNS vs. Control. No genes were determined to be differentially expressed in PNS calves relative to Control calves with FDR controlled at 0.10. A heatmap of the 15 most variable genes across samples for PNS relative to Control samples is depicted as Figure 3. Gene ID and sample interactions high above or below the mean were minimal. In the two-way comparison of male PNS and male control calves, a total of 11 genes were found to be differentially expressed (FDR< 0.08; Table 2). Of these, eight genes were upregulated, and three were downregulated in male PNS compared to male control calves. The two-way comparison of female PNS and female control calves revealed no differentially expressed genes (FDR <0.10).

FIGURE 3

TABLE 2

Gene IDGene nameFDRLog2FCaBos taurus chromosome (BTA:Mb)
ENSBTAG00000011647Solute carrier family 25 (mitochondrial carrier_ ornithine transporter) member 15 (SLC25A15)0.0021.61812:21.78
ENSBTAG00000051412Hemoglobin subunit alpha (HBA)0.0172.09425:21.64
ENSBTAG00000005998CCR4 carbon catabolite repression 4-like (S. cerevisiae) (NOCT)0.0171.72117:18.58
ENSBTAG00000010431LOC616371 protein (LURAP1L)0.0171.2658:31.50
ENSBTAG00000049496Cytochrome P450 (CYP2C281)0.0232.73726:16.55
ENSBTAG00000005244RAS like family 11 member a (RASL11A)0.023−1.34212:32.60
ENSBTAG00000038112MHC class I-like antigen recognition-like domain-containing protein (LOC100850276)0.023−2.5299:84.72
ENSBTAG00000002214Tyrosine aminotransferase (TAT)0.0430.91518:39.48
ENSBTAG00000037644Hemoglobin subunit beta (HBB)0.0442.45915:48.36
ENSBTAG00000039035Heat shock protein family a (Hsp70) member 6 (HSPA6)0.0604.0053:80.32
ENSBTAG00000001376RAD21 cohesin complex component like 1 (RAD21L1)0.070−0.90713:59.87

Differentially expressed genes in male prenatally stressed calves relative to control male calves.

a

Log2FC, Logarithmic Fold Change: positive (negative) fold change indicates that prenatally stressed males had increased (decreased) expression relative to control males.

Male vs. Female. With FDR controlled at 0.10, three genes were upregulated, and 10 genes were downregulated in male calves relative to female calves across treatments (Table 3). Visual portrayal of the 15 most variable genes across samples highlights a few detectable interactions, however none corresponded to the identified differentially expressed genes (Figure 4). Two-way analysis of PNS males and PNS females resulted in identification of three upregulated and four downregulated genes, respectively (Table 4). A total of 35 differentially expressed genes were identified in the two-way analysis of Control males and Control females (Table 5). Of these genes, seven were upregulated and 28 were downregulated in control males compared to control females.

TABLE 3

Gene IDGene nameFDRLog2FCaBos taurus chromosome (BTA:Mb)
ENSBTAG00000054758Unknown<0.001−6.201X:77.19
ENSBTAG00000024874Mitotic arrest deficient 2 like 1 (MAD2L1)<0.001−1.358Un_NW_020190807v1:7,006–14630
ENSBTAG00000014337Eukaryotic translation initiation factor 2 subunit 3 (EIF2S3)0.002−0.440X:11.92
ENSBTAG00000019616Serum amyloid P-component (APCS)0.003−2.4483:10.13
ENSBTAG00000003740[Histone H3]-trimethyl-L-lysine (27) demethylase (KDM6A)0.003−0.427X:98.64
ENSBTAG00000017716Brain enriched guanylate kinase associated (BEGAIN)0.011−0.91421:65.42
ENSBTAG00000053806Bone marrow stromal antigen 2 (BST2)0.019−2.4547:57.45
ENSBTAG00000000277Interleukin-18 (IL18)0.064−0.66515:22.48
ENSBTAG00000000207Haloacid dehalogenase-like hydrolase domain containing 1 A (PUDP)0.0670.581X:13.56
ENSBTAG00000007881Interferon induced protein with tetratricopeptide repeats 1 (IFIT1)0.070−2.23226:11.07
ENSBTAG00000006185Kinetochore protein Spc24 (SPC24)0.0730.6977:15.59
ENSBTAG00000008471Interferon induced GTP-binding protein Mx2 (MX2)0.073−2.1691:14.16
ENSBTAG00000044427Unknown0.0832.84810:26.78

Differentially expressed genes in male calves relative to female calves across treatments.

a

Log2FC, Logarithmic Fold Change: positive (negative) fold change indicates that males had increased (decreased) expression relative to females.

FIGURE 4

TABLE 4

Gene IDGene nameFDRLog2FCaBos taurus chromosome (BTA:Mb)
ENSBTAG00000017716Brain enriched guanylate kinase associated (BEGAIN)<0.001−1.23921:65.42
ENSBTAG00000054758Unknown<0.001−5.189X:77.19
ENSBTAG00000020406Glypican 3 (GPC3)0.0061.485X:17.37
ENSBTAG00000043553Glutathione peroxidase 3 (GPX3)0.0113.0657:62.28
ENSBTAG00000032617F-box protein 44 (FBXO44)0.082−1.60116:42.02
ENSBTAG00000009788Uncharacterized protein (ACOT2)0.0911.45710:85.02
ENSBTAG00000014698Caspase recruitment domain family member 11 (CARD11)0.091−0.66925:40.42

Differentially expressed genes in prenatally stressed (PNS) male calves relative to female calves.

a

Log2FC, Logarithmic Fold Change: positive (negative) fold change indicates that prenatally stressed males had increased (decreased) expression relative to prenatally stressed females.

TABLE 5

Gene IDGene nameFDRLog2FCaBos taurus chromosome (BTA:Mb)
ENSBTAG00000054758​<0.001−11.226X:77.19
ENSBTAG00000024874Mitotic arrest deficient 2 like 1 (MAD2L1)<0.001−1.691Un_NW_020190807v1:6,359–14611
ENSBTAG00000007881Interferon induced protein with tetratricopeptide repeats 1 (IFIT1)0.001−3.28426:11.07
ENSBTAG00000043250​0.0014.04123:25.22
ENSBTAG00000044427​0.0013.76810:26.78
ENSBTAG00000019616Serum amyloid P-component (APCS)0.001−3.1233:10.13
ENSBTAG00000049916​0.0023.43010:42.63
ENSBTAG00000053806Bone marrow stromal antigen 2 (BST2)0.003−3.1667:57.46
ENSBTAG00000008471Interferon induced GTP-binding protein Mx2 (MX2)0.004−2.9271:14.16
ENSBTAG00000054661​0.0043.0632:12.16
ENSBTAG00000014707Ubiquitin-like protein ISG15 (ISG15)0.008−2.70016:51.46
ENSBTAG00000030913Interferon-induced GTP-binding protein Mx1 (MX1)0.008−2.2871:14.17
ENSBTAG00000006694C-X-C motif chemokine ligand 14 (CXCL14)0.0101.6787:47.07
ENSBTAG00000019979Cytidine/Uridine monophosphate kinase 2 (CMPK2)0.014−2.15711:90.07
ENSBTAG00000020536HECT and RLD domain containing E3 ubiquitin protein ligase family member 6 (HERC6)0.021−2.4376:36.31
ENSBTAG00000016061Radical S-adenosyl methionine domain-containing protein 2 (RSAD2)0.034−2.45111:90.04
ENSBTAG00000008021Uncharacterized protein (LOC112441507)0.035−2.2717:57.35
ENSBTAG00000016661Ubiquitin specific peptidase 18 (USP18)0.036−1.8855:76.00
ENSBTAG00000045588Uncharacterized protein (LOC100298356)0.037−2.2547:57.26
ENSBTAG00000052369​0.042−1.085Un_NW_020192089v1:77,605–79758
ENSBTAG000000538072′-5′ oligoadenylate synthase (OAS1X)0.048−2.83517:61.38
ENSBTAG00000030932Interferon induced protein 44 like (IFI44L)0.048−1.7933:66.05
ENSBTAG00000034349Interferon induced protein 44 (IFI44)0.048−1.9503:66.02
ENSBTAG000000398612′-5′ oligoadenylate synthase (OAS1Y)0.054−2.13617:61.36
ENSBTAG00000009768Interferon-induced protein with tetratricopeptide repeats 3 (IFIT3)0.063−1.53826:11.05
ENSBTAG00000050459Family with sequence similarity 222 member a (FAM222A)0.0630.84917:63.46
ENSBTAG00000003366RNA helicase (DDX58)0.064−1.5658:11.56
ENSBTAG00000001292Lactotransferrin (LTF)0.0722.15522:52.95
ENSBTAG00000052306Interferon induced transmembrane protein 3 (LOC777594)0.073−1.36029:50.93
ENSBTAG00000012335Ubiquitin like modifier activating enzyme 7 (UBA7)0.086−1.77422:50.42
ENSBTAG00000008909Polyribonucleotide nucleotidyltransferase (PNPT1)0.095−1.19911:38.31
ENSBTAG00000012406Z-DNA binding protein 1 (ZBP1)0.095−1.38313:58.56
ENSBTAG00000020166Zinc finger NFX1-type containing 1 (ZNFX1)0.095−1.59313:77.35
ENSBTAG00000046580RNA helicase (DHX58)0.095−1.41719:42.24
ENSBTAG00000009933E3 ubiquitin-protein ligase (DTX3L)0.095−1.4941:66.99

Differentially expressed genes in Control male calves relative to female calves.

a

Log2FC, Logarithmic Fold Change: positive (negative) fold change indicates that control males had increased (decreased) expression relative to control females.

Gene ontology

PNS vs. Control. A single molecular function was significantly enriched (FDR < 0.05): “tetrapyrrole binding”. Differentially expressed genes were also enriched in the cellular component terms “haptoglobin–hemoglobin complex” and “hemoglobin complex” (Table 6). Pathways and functions of differentially expressed genes were not evaluated in PNS relative to control calves, both across sexes and within females, because no genes identified as differentially expressed in those comparisons. (FDR < 0.10).

TABLE 6

TermOntologyFDRGenes
Tetrapyrrole binding (GO:0046906)Molecular function0.0466ENSBTAG00000037644; ENSBTAG00000051412; ENSBTAG00000049496
Haptoglobin–hemoglobin complex (GO:0031838)Cellular component0.0191ENSBTAG00000037644; ENSBTAG00000051412
Hemoglobin complex (GO:0005833)Cellular component0.0136ENSBTAG00000037644; ENSBTAG00000051412

Significant (FDR < 0.05) Gene ontology molecular function and cellular component terms for genes differentially expressed between male prenatally stressed and male control calves.

Male vs. Female. No gene ontology categories reached significance (FDR < 0.05) for genes differentially expressed between males and females or for genes differentially expressed between PNS males and females. Within the Control male vs. Control female comparison, numerous (Figure 5) biological processes identified as significant, with many genes involved in processes relating to the immune system including “immune response”, “response to cytokine” and “defense response to virus” (Supplementary Table 1). No molecular function, cellular component, or pathway terms were identified as significant (FDR <0.05) using these genes.

FIGURE 5

Discussion

Phenotypic analyses

The interaction of calf sex and treatment was not detected in analyses of calf birth weight, harvest weight, liver weight, pen score, or liver weight:harvest weight. Calf sex was influential in analyses of birth weight, harvest weight, and liver weight. As expected, male calves were heavier than female calves for these weight traits, which agrees with reported sex differences in birth weight for calves subjected to the same prenatal stress (). However, birth weights, harvest weights, and liver weights did not differ (P > 0.16) between the PNS and Control groups. This corresponds to results from and , in which liver weights and cattle growth traits, respectively, were not found to be different between nutritional treatment groups. Physiological changes related to fat were found between cattle consuming different diet treatments (). In the present study, significant treatment differences were observed only for calf liver weight:harvest weight. PNS calves had larger liver weights and smaller harvest weights compared to Control calves, but neither of these differences were significant (P > 0.63). also reported that prenatal transportation stress had no effect on calf birth weight. Neither sex nor treatment explained significant variation in calf pen temperament scores. This contradicts almost all reports that female cattle were more temperamental than males (e.g., ; ; ). Consistent with , PNS calves had worse temperament than Control calves. The present study is unique from others in that calves were not weaned, that is, they were nursing dams.

Differential gene expression and gene ontology

Differential expression of genes between animals is an appropriate method to identify candidate genes and target certain traits (). Gene expression analysis of liver tissues indicated few differentially expressed genes by prenatal stress category. This aligns with prior research in which few differences in gene expression were identified in amygdala between of PNS and Control 5-year-old Brahman cows and 25-day-old Brahman calves (; ). One gene that had increased expression in prenatally stressed male calves was tyrosine aminotransferase (TAT), a glucocorticoid-responsive enzyme. Prior work has shown that glucocorticoid receptor activation can induce stable epigenetic changes at the TAT promoter in liver (), suggesting a potential pathway by which prenatal stress-related glucocorticoid exposure could contribute to altered hepatic gene expression in offspring. The gene that showed the largest difference in expression between prenatally stressed and control males (log2FC = 4.005) was Heat shock protein family A (Hsp70) member 6 (HSPA6), an inducible Hsp70-family chaperone. Higher hepatic Hsp70 protein levels have been reported in neonatal intrauterine growth-restricted piglets compared with normal-birth-weight piglets ().

The timing and level of severity of stress may have influence on the extent of gene expression alterations. Offspring of mothers exposed to an acute natural disaster at different stages of gestation showed stage-dependent differences in placental expression of stress-related genes (), and more severe maternal stress has been linked to more pronounced alterations in offspring stress-related gene regulation (). Given the dynamic nature of liver development across gestation (), the timing of prenatal stress is also likely to influence the extent to which it can alter hepatic growth and gene expression. Therefore, the level of prenatal transportation stress utilized may not be considerable enough to result in significant effects.

Controlling FDR at 0.10, more genes were differentially expressed between sexes than between treatment groups. Sex differences in liver transcriptome profiles have been observed previously in dairy calves (). Sex differences in hepatic gene expression are well documented in mammals, particularly in rodent models, where they are strongly influenced by growth hormone signaling (). Five genes were differentially expressed between male and female calves, as well as control male and control female calves. These include mitotic arrest deficient two like 1 (MAD2L1), serum amyloid P-component (APCS), bone marrow stromal antigen 2 (BST2), interferon induced protein with tetratricopeptide repeats 1 (IFIT1), and interferon induced GTP-binding protein Mx2 (MX2). These genes are related to checkpoint signaling (), innate immune response (), pain (), and defense response to virus (; ). Additionally, these genes were annotated to various cellular components such as “cytoplasm”, “extracellular space”, “synapse”, “Golgi apparatus”, “cell surface”, “cytosol” and “nucleus”. These biological processes and cellular components align with those found in research by and . One gene, brain enriched guanylate kinase associated (BEGAIN), was differentially expressed in both the male and female calf comparison, and the PNS male and PNS female comparison. Brain enriched guanylate kinase associated encodes a brain-enriched synaptic protein implicated in learning, memory, and neuropathic pain signaling (); however, its involvement in prenatal stress responses or liver function has not, to our knowledge, been described.

The liver has a central role in innate immunity, where hepatocytes and innate immune cells mediate pattern-recognition and type I interferon–driven antiviral defense (). Functional enrichment analysis of genes that were differentially expressed between control males and females indicated a strong enrichment of innate immune and antiviral defense processes, particularly type I interferon signaling and pathways involved in viral response and host defense. In humans, liver innate and type I interferon–mediated antiviral responses have been linked to sex specific differences in the course and outcome of chronic HBV and HCV infection, reflecting the impact of sex hormones on antiviral and inflammatory signaling in this tissue (). These sex differences in hepatic immunity exist even in the absence of infection (). Genes involved with immune function were also identified in prior bovine gene expression research (; ).

Several genes that had increased expression in females relative to males are located on the X chromosome. While dosage compensation through X inactivation typically equalizes X-linked gene expression between sexes, some X-linked genes escape this process and therefore can show higher mRNA expression in females. The histone demethylase gene Utx (UTX) is one gene that escapes X inactivation in both mice and humans (). The translation-initiation factor subunit gene (EIF2S3) likewise escapes X inactivation and has been reported to exhibit female-biased mRNA expression in adult liver (). Our findings are consistent with incomplete dosage compensation of X-escapee genes, as reflected by the higher hepatic expression of UTX and EIF2S3 in females.

Other bovine gene expression studies have reported differentially expressed genes between different sexes or nutritional treatments; however, those genes did not align with those identified in this research (; ). This may be due to liver transcriptomes of different cattle breeds having divergent genetic profiles (). No genes were differentially expressed across all comparisons in the study.

Results must be considered with respect to age of calves. Age-dependent changes in gene expression must be likely in many tissues (e.g., ; ). This has been characterized in bovine associated with sexual maturation () but is not documented in liver. Profound changes associated with diet and weaning undoubtedly alter the gene expression profiles in some ways. The calves sampled likely had almost entirely milk as their primary source of nutrients; milk as compared to other later diets has not been characterized with respect to gene expression and certainly would have age confounding. The sample size may be responsible for the limited numbers of differentially expressed genes in the different comparisons.

Conclusion

No interaction of sex with prenatal stress treatment was evident in analyses of birth weight, harvest weight, liver weight, pen score, or liver weight harvest weight in 25-day-old Brahman calves. Not surprisingly, bull calves had heavier birth, harvest, and liver weights. Calves exposed to prenatal transportation stress resulted in heavier liver weight as a proportion of harvest weight relative to controls. The minor differences in age were not influential in any phenotypic assessments. There were few differentially expressed genes between sexes and treatments. A partial natural offsetting of the negative impacts of prenatal stress may be possible by this young age in calves. Heightening the severity of prenatal transportation stress through increased duration or frequency of transportation may result in more differentially expressed genes. Alteration of prenatal transportation stress severity, time of year for transportation, animal age at harvest, and tissue sample collection area may be required to better understand the influence of prenatal transportation stress on phenotypic and genetic expression in beef cattle.

Statements

Data availability statement

The original contributions presented in the study are publicly available. This data can be found in the NCBI Sequence Read Archive (SRA) repository with the BioProject accession number PRJNA1478047 (SRA Study: SRP709295).

Ethics statement

The animal study was approved by Texas A&M AgriLife Research Institutional Animal Care and Use Committee. The study was conducted in accordance with the local legislation and institutional requirements.

Author contributions

SS: Formal Analysis, Investigation, Writing – original draft, Writing – review and editing. EB: Data curation, Formal Analysis, Investigation, Methodology, Writing – original draft, Writing – review and editing. KC: Formal Analysis, Writing – review and editing. RC: Data curation, Funding acquisition, Investigation, Writing – review and editing. TH: Data curation, Writing – review and editing. CL: Funding acquisition, Resources, Writing – review and editing. RR: Conceptualization, Data curation, Funding acquisition, Resources, Writing – review and editing. TW: Data curation, Funding acquisition, Investigation, Resources, Writing – review and editing. DR: Data curation, Formal Analysis, Funding acquisition, Investigation, Supervision, Writing – original draft, Writing – review and editing.

Funding

The author(s) declared that financial support was received for this work and/or its publication. Stipend support for S.R.S. was provided by the Department of Animal Science. This work was supported in part by USDA-NIFA grants (#2018-67015-28131 and #2019-67015-29573) and contributes to USDA Multistate Hatch Projects S1086 (D.G.R.), W4112 (RR), and W4173 (TW) and the Texas A&M University One Health Initiative (TW).

Acknowledgments

The authors thank Don Neuendorff, Dustin Law, and Catherine Wellman (Texas A&M AgriLife Research Center, Overton, TX), and Sarah West (Texas A&M University) for their technical support.

Generative AI statement

The author(s) declared that generative AI was not used in the creation of this manuscript.

Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fgene.2026.1841048/full#supplementary-material

Conflicts of interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

Summary

Keywords

BEGAIN, HSPA6, TAT, stress, sex differences

Citation

Sebesta SR, Baker EC, Cilkiz KZ, Cardoso RC, Hairgrove TB, Long CR, Randel RD, Welsh Jr. TH and Riley DG (2026) Effects of prenatal transportation stress on liver gene expression in male and female Brahman calves. Front. Genet. 17:1841048. doi: 10.3389/fgene.2026.1841048

Received

27 March 2026

Revised

19 May 2026

Accepted

30 May 2026

Published

06 July 2026

Volume

17 - 2026

Edited by

Honglin Jiang, Virginia Tech, United States

Reviewed by

Mariana Carriquiry, Universidad de la República, Uruguay

Madhuri S. Lahamge, National Dairy research Institute Karnal, India

Updates

Copyright

*Correspondence: David G. Riley,

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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