Mouse Strains with an Active H2-Ea Meiotic Recombination Hot Spot Exhibit Increased Levels of H2-Ea-Specific DNA Breaks in Testicular Germ Cells

AUTOR(ES)

Qin, Jian

FONTE

American Society for Microbiology

RESUMO

We devised a sensitive method for the site-specific detection of rare meiotic DNA strand breaks in germ cell-enriched testicular cell populations from mice that possess or lack an active recombination hot spot at the H2-Ea gene. Using germ cells from adult animals, we found an excellent correlation between the frequency of DNA breaks in the 418-bp H2-Ea hot spot and crossover activity. The temporal appearance of DNA breaks was also studied in 7- to 18-day-old mice with an active hot spot during the first waves of spermatogenesis. The number of DNA breaks detected rose as leptotene and zygotene spermatocytes populate the testis with a peak at day 14 postpartum, when leptotene, zygotene, and early pachytene spermatocytes are the most common meiotic prophase I cell types. The number of DNA breaks drops precipitously 1 day later, when middle to late pachytene spermatocytes become the dominant subtype. The recombination-related breaks in the hot spot likely reflect SPO11-induced double-strand breaks and/or recombination intermediates containing free 3′ hydroxyl groups.

Documentos Relacionados

• Double strand breaks at the HIS2 recombination hot spot in Saccharomyces cerevisiae
• Evolution of the Mouse H-2k Region: A Hot Spot of Mutation Associated with Genes Transcribed in Embryos and/or Germ Cells
• Sequence non-specific double-strand breaks and interhomolog interactions prior to double-strand break formation at a meiotic recombination hot spot in yeast.
• Recombination hot spot in the human beta-globin gene cluster: meiotic recombination of human DNA fragments in Saccharomyces cerevisiae.
• Meiosis-specific double-strand DNA breaks at the HIS4 recombination hot spot in the yeast Saccharomyces cerevisiae: control in cis and trans.