A Comprehensive Sequencing Analysis of Testis-Born miRNAs in Immature and Mature Indigenous Wandong Cattle (Bos taurus)

Abstract

Micro RNAs (miRNAs) have been recognized as important regulators that are indispensable for testicular development and spermatogenesis. miRNAs are endogenous transcriptomic elements and mainly regulate the gene expression at post-transcriptional levels; however, the key role of miRNA in bovine testicular growth is not clearly understood. Thus, supposing to unveil the transcriptomics expression changes in the developmental processes of bovine testes, we selected three immature calves and three sexually mature bulls of the local Wandong breed for testicular-tissue sample collection. The cDNA libraries of experimental animals were established for RNA-sequencing analysis. We detected the miRNA expression in testes by using high-throughput sequencing technology, and bioinformatics analysis followed. The differentially expressed (DE) data showed that 151 miRNAs linked genes were significantly DE between immature and mature bull testes. Further, in detail, 64 were significantly up-regulated and 87 were down-regulated in the immature vs. mature testes (p-value < 0.05). Pathway analyses for miRNA-linked genes were performed and identified JAG2, BCL6, CFAP157, PHC2, TYRO3, SEPTIN6, and BSP3; these genes were involved in biological pathways such as TNF signaling, T cell receptor, PI3KAkt signaling, and functions affecting testes development and spermatogenesis. The DE miRNAs including MIR425, MIR98, MIR34C, MIR184, MIR18A, MIR136, MIR15A, MIR1388 and MIR210 were associated with cattle-bull sexual maturation and sperm production. RT-qPCR validation analysis showed a consistent correlation to the sequencing data findings. The current study provides a good framework for understanding the mechanism of miRNAs in the development of testes and spermatogenesis.

Unveiling the Transcriptomic Landscape of Holstein Bull Testes Post-Sexual Maturation: Insights into Spermatogenesis-Associated MicroRNAs and mRNA Profiles

“…Male reproductive efficiency is an essential component of cattle's production, biological breeding or reproduction, and economic efficiency (Ansari-Lari et al, 2010;Han & Peñagaricano, 2016;Liu et al, 2022). The elite genetic gain is made through enhanced production of sperm and selective gametes utilization from desirable sires to improve production and reproduction characteristics in dairy and beef industry on large scales.…”

“…MicroRNAs(miRNAs) are endogenous transcriptomic elements of small noncoding RNAs that are identified in animals, plants and viruses with 20-25 nucleotide length controlling most of the genes expression by blocking translation or inducing degradation of target messenger RNAs at posttranscriptional and transcriptional levels (Baohong et al, 2007;Liu et al, 2022;Sun et al, 2019;Vigneault et al, 2012). The miRNAs help to mediate coding and noncoding RNA molecules during fine-tuning crosstalk by sharing miRNA response elements (MRE) (Ala, 2020).…”

“…The high-tech sequencing technologies such as second generation sequencing technologies, micro RNA deep sequencing and Illumina-Solexa high throughput sequencing technologies speed up the identification and discovery of new miRNA species (Li et al, 2012;Wu et al, 2014).Multiple studies shown that miRNAs play an important role in the regulation of various biological processes and tissue systems that function as regulation of cellular differentiation, self-renewal and apoptosis (Niu et al, 2011), including mammalian spermatogenesis and reproductive system development (La et al, 2023;Liu et al, 2022;Wang et al, 2018;Wu et al, 2014;Yin et al, 2021;Zhang et al, 2022). Lots of studies indicate the involvement of miRNAs modulating gene expression in multiple cellular and biological processes, including proliferation (Kim et al, 2017), organ development, stem cell differentiation (Luo et al, 2020), hormone secretion, metabolism and reproductive regulation (Gao et al, 2020;La et al, 2023;Liu et al, 2022;Wu et al, 2014). Additionally, miRNAs can serve as epigenetic modulators, influencing target mRNAsʹ protein levels without altering gene sequences.…”

“…The miRNA-linked genes found involved in PI3KAkt signaling, TNF signaling and T cell receptor of biological pathways and functions affecting spermatogenesis and testicular development. The DE expressed miRNAs were also associated with sexual maturation and sperm production in Wandong Cattle (Bos taurus) (Liu et al, 2022).…”

“…The identification of single stranded noncoding RNA is important to determine the functional mechanisms during sexual maturation and testicular growth at transcriptional and post transcriptional levels (Liu et al, 2022).The improvement of reproductive efficiency in breeding Holstein bulls with emphasis on potential genetic resources regulating spermatogenesis and testis development at molecular level remains unexplored. Even though, the comprehensive expression profiles of miRNA in different age groups of cattle breeds and different species have been studied, the spermatogenesis related miRNAs expression in Holstein bulls has not been reported.…”