Defects in meiotic recombination delay progression through pachytene in Tex19.1-/- mouse spermatocytes

Chromosoma. 2018 Dec;127(4):437-459. doi: 10.1007/s00412-018-0674-9. Epub 2018 Jun 16.


Recombination, synapsis, chromosome segregation and gene expression are co-ordinately regulated during meiosis to ensure successful execution of this specialised cell division. Studies with multiple mutant mouse lines have shown that mouse spermatocytes possess quality control checkpoints that eliminate cells with persistent defects in chromosome synapsis. In addition, studies on Trip13mod/mod mice suggest that pachytene spermatocytes that successfully complete chromosome synapsis can undergo meiotic arrest in response to defects in recombination. Here, we present additional support for a meiotic recombination-dependent checkpoint using a different mutant mouse line, Tex19.1-/-. The appearance of early recombination foci is delayed in Tex19.1-/- spermatocytes during leptotene/zygotene, but some Tex19.1-/- spermatocytes still successfully synapse their chromosomes and we show that these spermatocytes are enriched for early recombination foci. Furthermore, we show that patterns of axis elongation, chromatin modifications and histone H1t expression are also all co-ordinately skewed towards earlier substages of pachytene in these autosomally synapsed Tex19.1-/- spermatocytes. We also show that this skew towards earlier pachytene substages occurs in the absence of elevated spermatocyte death in the population, that spermatocytes with features of early pachytene are present in late stage Tex19.1-/- testis tubules and that the delay in histone H1t expression in response to loss of Tex19.1 does not occur in a Spo11 mutant background. Taken together, these data suggest that a recombination-dependent checkpoint may be able to modulate pachytene progression in mouse spermatocytes to accommodate some types of recombination defect.

Keywords: Checkpoint; Meiosis; Pachytene; Recombination; Spo11; Tex19.1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATPases Associated with Diverse Cellular Activities / genetics
  • Animals
  • Cell Cycle Proteins / genetics
  • Chromatin / genetics
  • Chromatin / metabolism
  • Chromosome Pairing / genetics
  • Endodeoxyribonucleases / genetics
  • Endodeoxyribonucleases / metabolism
  • Histones / genetics
  • Histones / metabolism
  • Male
  • Meiosis
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Nuclear Proteins / genetics*
  • Pachytene Stage / genetics*
  • Protein Processing, Post-Translational / genetics
  • RNA-Binding Proteins
  • Recombination, Genetic*
  • Seminiferous Tubules / metabolism
  • Seminiferous Tubules / pathology
  • Spermatocytes / cytology*
  • Spermatocytes / physiology


  • Cell Cycle Proteins
  • Chromatin
  • Histones
  • Nuclear Proteins
  • RNA-Binding Proteins
  • Tex19 protein, mouse
  • gamma-H2AX protein, mouse
  • Endodeoxyribonucleases
  • meiotic recombination protein SPO11
  • ATPases Associated with Diverse Cellular Activities
  • Trip13 protein, mouse