Combinatorial control of Spo11 alternative splicing by modulation of RNA polymerase II dynamics and splicing factor recruitment during meiosis

Abstract

Homologous recombination and chromosome segregation in meiosis rely on the timely expression of two splice variants of the endonuclease SPO11, named α and β, which respectively skip or include exon 2. However, in spite of its physiological importance, the mechanism underlying Spo11 alternative splicing in meiosis is still unknown. By screening the activity of factors that are predicted to bind the alternatively spliced region of Spo11, we identified hnRNPH as a key regulator of SPO11α splicing in mouse spermatocytes. Although hnRNPH was not upregulated in meiosis concomitantly with the switch in splicing, its recruitment to Spo11 pre-mRNA was favored by selective modulation of RNA polymerase II (RNAPII) phosphorylation and processivity in proximity of exon 2. The hnRNPH binding sites were localized near those of splicing factors that promote SPO11β splicing, suggesting that hnRNPH favors exon 2 skipping by competing out positive regulators. Indeed, hnRNPH binds proximal to a consensus motif for Sam68, a positive regulator of SPO11β splicing in vitro and in vivo, and it interferes with Sam68 binding to the Spo11 pre-mRNA. Thus, our work reveals that modulation of RNAPII dynamics in concert with hnRNPH recruitment exerts a combinatorial control of the timely regulated Spo11 splicing during meiosis.

hnRNPH1 recruits PTBP2 and SRSF3 to cooperatively modulate alternative pre-mRNA splicing in germ cells and is essential for spermatogenesis and oogenesis

“…As previously reported 33 , Spo11 showed a signi cantly changed alternative splicing (Spo11α/β) from P14 to P18, and the inclusion of its exon 2 is suppressed at the latter stage (Fig. 5i-j).…”

“…Given that previous studies reported that unpaired sex chromosomes in male mice could be caused by abnormal Spo11 pre-mRNA splicing 32 and hnRNPH1 was identi ed as a key regulator of Spo11α splicing in mouse spermatocytes 33 , we next wanted to examine whether the Spo11 pre-mRNA splicing is changed in hnRNPH1 cKO spermatocytes. Although changed alternative splicing of Spo11 was not identi ed in our RNA-Seq data, considering the imperfect accuracy of RNA-seq, we decided to re-examine Spo11 splicing in P14 and P18 testes, isolated spermatocytes and spermatids from adult testis by RT-PCR, respectively.…”

Comparative Transcriptome Profiling of mRNA and lncRNA of Ovaries in High and Low Egg Production Performance in Domestic Pigeons (Columba livia)

“…For example, ATP binding has been shown to be involved in the regulation of oocyte formation ( Quiroz et al, 2020 ). The RNA polymerase II involved in a combinatorial control of the timely regulated Spo11 splicing during the process of meiosis ( Cesari et al, 2020 ).…”

Mechanisms of Oogenesis-Related Long Non-coding RNAs in Porcine Ovaries Treated With Recombinant Pig Follicle-Stimulating Hormone

“…It can be illustrated that ATP binding has been reported to participate in the oogenesis regulation ( 34 ). The RNA polymerase II was reported to be involved in the combinatorial control of Spo11 splicing, which is timely regulated during meiosis ( 35 ).…”