PSVIII-23 Mycotoxin exposure on fetal skeletal muscle fiber hypertrophy and miRNA transcriptome. (8th October 2021)

• Record Type: Journal Article
• Authors: Greene, Maslyn A; Udoka, Aliute; Powell, Rhonda; Noorai, Rooksana; Bruce, Terri; Duckett, Susan K
• Is Part Of: Journal of animal science. Volume 99(2021)Supplement 3
• Page Start: 354
• Page End: 354
• Publication Date: 2021-10-08
• Subjects: sheep -- mycotoxins -- muscle fiber -- miRNA; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/skab235.650
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: The objective of this study was to evaluate the miRNA transcriptome and muscle fiber characteristics of lambs from ewes consuming endophyte-infected tall fescue (E+) seed during two stages of gestation at two animal ages. Pregnant Suffolk ewes (yr 1 n = 36; yr 2 n = 60) were randomly assigned to one of two gestational treatments: E+ seed (1.77 mg/hd/d of ergovaline/ergovalinine) during mid- (gd 35 - 85; MID) or late-gestation (gd 86 – 133/parturition; LATE). Longissimus muscle samples (n = 3/E+ treatment/time) were collected from fetuses on gd 133 (FETAL; expt. 1) or from wethers after finishing to market weight (MKT; expt. 2) from ewes from MID and LATE E+ treatments. Data were analyzed as a 2 x 2 factorial with E+ treatment (MID or LATE), time (FETAL or MKT), and the two-way interaction in the model. Exposure to E+ fescue seed during LATE gestation reduced (P = 0.03) cross-sectional area of Type II muscle fibers at MKT but not at FETAL. Cross-sectional area of Type II muscle fibers were larger (P < 0.05) at MKT than FETAL. Animal age influenced miRNA expression with 120 miRNA differentially expressed. miRNA-22-3p and -29a were down regulated (P < 0.001; > -5 log fold change) with animal age; whereas miR-3958-3p, -410-3p, -299-5p and -487b-3p (P < 0.0001; > 3 log fold change) were up-regulated. Exposure to E+ during MID or LATE gestation did not alter miRNA expression. Muscle fiber hypertrophy increased from FETAL to MKT age altered the expression of miRNA in longissimus muscle.