Transcriptome-wide analysis of the SCNT bovine abnormal placenta during mid- to late gestation

Guangqi Gao,Guanghua Su,Xiuying Wang,Li Zhang,Chunling Bai,Shenyuan Wang,Xiaohu Su,Jiaqi Zhang,Zhuying Wei,Zhong Zheng,Lei Yang,Ziru Guo,Guangpeng Li,Xiao Liu

doi:10.1038/s41598-019-56566-w

Abstract

The dysfunction of placenta is common in somatic cell nuclear transfer (SCNT) cloned cattle and would cause aberrant fetal development and even abortion, which occurred with highest rate at the mid- to late gestation. However, the mechanism of abnormal placentas was unclear. To analyze the transcriptome-wide characteristics of abnormal placentas in SCNT cloned cattle, the mRNA, lncRNA and miRNA of placental cotyledon tissue at day 180 after gestation were sequenced. A total of 19,055 mRNAs, 30,141 lncRNAs and 684 miRNAs were identified. Compared with control group, 362 mRNAs, 1,272 lncRNAs and nine miRNAs (six known and three novel miRNAs) were differentially expressed (fold change ≥ 2 and P-value < 0.05). The differentially expressed genes were functionally enriched in urea and ions transmembrane transport, which indicated that the maternal-fetal interactions were disturbed in impaired placentas. Furthermore, the competing endogenous RNAs (ceRNAs) networks were identified to illustrate their roles in abnormal placental morphology. The present research would be helpful to discover the mechanism of late gestational abnormality of SCNT cattle by provides important genomic information and insights.

Highlights

The establishment of somatic cell nuclear transfer (SCNT) technology supplies a powerful impetus for the development of animal cloning
Our previous work found that aberrant large abdominal circumference of recipient cows carrying SCNT fetuses at 150 to 200 days of gestation had a tight connection with hydrops allantois, placental hypertrophy and fetal overgrowth
The development of SCNT bovine fetus was affected by placental abnormality

Summary

Results

The development of SCNT bovine fetus was affected by placental abnormality. Our previous studies showed that the bovine embryos derived from artificial technology (especially asexual reproduction) with high abortion rate throughout the pregnancy process, during the mid and late-gestation. The minimum rates of removed reads were at a suitable level and the Q30 of raw or clean data were high enough to indicate the high-quality of small RNA sequencing (Table S2). Identification of differentially expressed mRNAs, lncRNAs and miRNAs between bovine normal and abnormal placentas. 362 mRNAs, 1,272 lncRNAs and 9 miRNAs (6 known and 3 novel miRNAs) were found to be differentially expressed between abnormal and normal groups. Expression patterns of mRNA, lncRNA and miRNA were shown by hierarchical clustering (Fig. 2). These differentially expressed non-coding RNAs (ncRNAs) were intersected with predicted target genes. The results suggested that the abnormal ncRNAs expression may affect the material metabolism and hormone secretion of bovine placenta via regulate target genes.

Discussion

Conclusions

Methods