<i>Tex19</i>.<i>1</i> promotes <i>Spo11</i>-dependent meiotic recombination in mouse spermatocytes - Fig 6

<p><b><i>Ubr2</i>^<i>-/-</i> Spermatocytes Phenocopy the Retrotransposon Derepression and Asynapsis Phenotypes Present in <i>Tex19</i>.<i>1</i>^<i>-/-</i> Mutants.</b> (A) In situ hybridisation for <i>MMERVK10C</i> retrotransposon RNA in <i>Ubr2</i>^<i>-/-</i> testes. Specific signal (dark purple precipitate) is present in <i>Ubr2</i>^<i>-/-</i> spermatocytes hybridised with an antisense <i>MMERVK10C</i> probe. Scale bar 100 μm. (B) qRT-PCR for <i>MMERVK10C</i>, <i>IAP</i> and <i>LINE-1</i> retrotransposons in P16 <i>Ubr2</i>^<i>-/-</i> testes. Mean abundance of retrotransposon RNAs relative to β-actin is shown for two <i>Ubr2</i>^<i>+/+</i> and three <i>Ubr2</i>^<i>-/-</i> animals. ns indicates no significant difference, * indicates p<0.05 (Student's t-test). (C) Chromosome spreads from testes from three <i>Ubr2</i>^<i>+/+</i> and three <i>Ubr2</i>^<i>-/-</i> animals were immunostained with antibodies to SYCP3 and SYCP1, and SYCP3-positive nuclei scored for meiotic substage (n = 398, 595). <i>Ubr2</i>^<i>-/-</i> spreads contained a significant proportion of aberrant pachyene nuclei containing asynapsed chromosomes, but few diplotene or metaphase I nuclei compared to <i>Ubr2</i>^<i>+/+</i> controls. (D) Immunostaining of chromosome spreads from <i>Ubr2</i>^<i>+/+</i> and <i>Ubr2</i>^<i>-/-</i> spermatocytes for SYCP3 (red) and SYCP1 (green). Asynapsed chromosomes assemble SYCP3 but not SYCP1, and examples involving non-homologous interactions (NH), incomplete synapsis between homologs (IS), and isolated chromosomes (IC) are labelled. Scale bar 10 μm. (E) Percentage of asynapsed pachytene <i>Ubr2</i>^<i>+/+</i> and <i>Ubr2</i>^<i>-/-</i> spermatocytes exhibiting the indicated categories of asynapsed chromosomes (n = 17, 99 respectively from a total of three <i>Ubr2</i>^<i>+/+</i> and three <i>Ubr2</i>^<i>-/-</i> mice). Each nucleus is typically represented in more than one category. Fully autosomally synapsed pachytene nuclei are not included in this analysis, and only asynapsed pachytene nuclei containing clearly distinguishable asynapsed chromosome configurations were scored.