miR-34a Regulates Sperm Motility in Zebrafish

Abstract

Increasing attention has been focused on the role of microRNAs in post-transcription regulation during spermatogenesis. Recently, the miR-34 family has been shown to be involved in the spermatogenesis, but the clear function of the miR-34 family in spermatogenesis is still obscure. Here we analyzed the function of miR-34a, a member of the miR-34 family, during spermatogenesis using miR-34a knockout zebrafish generated by the clustered regularly interspaced short palindromic repeats/associated protein 9 (CRISPR/Cas9) system. miR-34a knockout zebrafish showed no obvious defects on testis morphology and sperm quantity. However, we found a significant increase in progressive sperm motility that is one of the pivotal factors influencing in vitro fertilization rates, in the knockout zebrafish. Moreover, breeding experiments showed that, when miR-34a-knockout male zebrafish mated with the wide-type females, they had a higher fertilization rate than did the wide-type males. Glycogen synthase kinase-3a (gsk3a), a potential sperm motility regulatory gene was predicted to be targeted by miR-34a, which was further supported by luciferase reporter assays, since a significant decrease of luciferase activity was detected upon ectopic overexpression of miR-34a. Our findings suggest that miR-34a downregulates gsk3a by targeting its 3′ untranslated region, and miR-34a/gsk3a interaction modulates sperm motility in zebrafish. This study will help in understanding in the role of the miR-34 family during spermatogenesis and will set paths for further studies.

Diet Supplemented with Antioxidant and Anti-Inflammatory Probiotics Improves Sperm Quality after Only One Spermatogenic Cycle in Zebrafish Model

“…Moreover, and concomitantly with total motility, progressive motility (P-MOT) was also significantly raised ( p = 0.0137) after 21 days in the PROBIO group from 15.22% ± 4.71% to 22.73% ± 5.09% (Figure 2E; Table S2). P-MOT is another key parameter in sperm quality since it influences fertilization success, and it is a focus of attention in zebrafish research [25,26]. In our experiment, we considered progressive those cell in which swimming track was forwards in 80% of a straight line.…”

Sperm miR‐15a and miR‐29b are associated with bull fertility

“…It has been shown that miR‐34a is associated with reduced cell motility and oxidative phosphorylation (Chang et al, ). In zebrafish, enhanced sperm motility and the influence on in vitro fertilisation rates were achieved when miR‐34a was inhibited (Guo et al, ). The authors showed evidence that miR‐34a downregulates glycogen synthase kinase‐3a (gsk3a), and miR‐34a/gsk3a interaction affects the motility of zebrafish spermatozoa.…”

Identification and characterization of circular RNAs in Qinchuan cattle testis

“…In this study, 758 miRNAs matched with significantly differentially expressed circRNAs, in which the bta-miR-532, bta-miR-204 and bta-miR-34 families are shown to be involved in cattle spermatogenesis [ 32 , 33 ]. Additionally, the miR-34a was reportedly associated with the spermatogenesis of zebrafish; miR-34a knockout zebrafish showed no obvious defects in terms of testis morphology and sperm quantity [ 50 ]. Hence, the related circRNAs may act as miRNA sponges for regulating testis development and spermatogenesis.…”