TY  - GEN
T1  - Meiotic H3K9me2 distribution is influenced by the ALG-3 and ALG-4 pathway and by poly(U) polymerase activity
AU  - Li, Yini
AU  - Snyder, Matthew
AU  - Maine, Eleanor M.
DO  - 10.17912/micropub.biology.000455
UR  - http://beta.micropublication.org/journals/biology/micropub-biology-000455/
AB  - Histone modifications are precisely controlled within the developing germ line. During first meiotic prophase in C. elegans, H3K9me2 immunolabeling detects a relatively bright focus of signal on unsynapsed chromosomes and a relatively weak, diffuse signal on synapsed chromosomes (Bean et al. 2004, Kelly et al. 2002, Reuben and Lin 2002). The naturally occurring unsynapsed chromosome is the single male X. Examples of other chromatin that is enriched for H3K9me2 at pachytene stage include single-copy free chromosomal duplications, chromosomes that fail to pair due to certain mutations, and multicopy extrachromosomal arrays. In all cases, the enriched H3K9me2 signal decreases sharply as nuclei move into diplotene stage, and H3K9me2 is not detected in diakinesis nuclei. As the naturally occurring example of H3K9me2 enrichment, the male X is commonly used to evaluate this meiotic targeting phenomenon (Fig. 1). We previously showed that meiotic H3K9me2 distribution is altered in males lacking CSR-1 Argonaute or factors required for accumulation of CSR-1-associated 22G RNAs, including EGO-1 RdRP, DRH-3 helicase, and the Tudor domain protein, EKL-1 (Maine et al. 2005, She et al. 2009). In mutants lacking any of these factors, pachytene H3K9me2 signal intensity is reduced on unsynapsed chromosomes and, in all cases except ego-1(null) mutants, ectopic H3K9me2 foci are detected on synapsed chromosomes. Interestingly, as in wildtype, H3K9me2 signal is not detected in diakinesis nuclei in these mutants. CSR-1 pathway activity is essential for germ line development where it is thought to license the correct pattern of gene expression (Yigit et al. 2006, Ashe et al. 2012, Shirayama et al. 2012). EGO-1, DRH-3, and EKL-1 are critical for biogenesis and stability of 22G RNAs that associate with CSR-1 (reviewed in Billi et al. 2014).
PY  - 2021
JO  - microPublication Biology
ER  -