[show abstract][hide abstract] ABSTRACT: During meiotic cell division, proper chromosome synapsis and accurate repair of DNA double strand breaks (DSBs) are required to maintain genomic integrity, loss of which leads to apoptosis or meiotic defects. The mechanisms underlying meiotic chromosome synapsis, DSB repair and apoptosis are not fully understood. Here, we report that the chromodomain-containing protein MRG-1 is an important factor for genomic integrity in meiosis in Caenorhabditis elegans. Loss of mrg-1 function resulted in a significant increase in germ cell apoptosis that was partially inhibited by mutations affecting DNA damage checkpoint genes. Consistently, mrg-1 mutant germ lines exhibited SPO-11-generated DSBs and elevated exogenous DNA damage-induced chromosome fragmentation at diakinesis. In addition, the excessive apoptosis in mrg-1 mutants was partially suppressed by loss of the synapsis checkpoint gene pch-2, and a significant number of meiotic nuclei accumulated at the leptotene/zygotene stages with an elevated level of H3K9me2 on the chromatin, which was similarly observed in mutants deficient in the synaptonemal complex, suggesting that the proper progression of chromosome synapsis is likely impaired in the absence of mrg-1. Altogether, these findings suggest that MRG-1 is critical for genomic integrity by promoting meiotic DSB repair and synapsis progression in meiosis.
Cell Research 01/2012; 22(5):886-902. · 10.53 Impact Factor
[show abstract][hide abstract] ABSTRACT: It has been reported that the disaccharide trehalose is capable of increasing the thermostability and thermoactivity of reverse transcriptase, and therefore improving the length of cDNA synthesis. However, no test has been done on how the disaccharide trehalose performs in the context of the entire cDNA synthesis processes, or whether it can seamlessly integrate into the commercially available cDNA synthesis kit. In this report, we optimized a protocol to incorporate trehalose in the Stratagene's cDNA library construction kit in order to demonstrate great improvement in cDNA's length (average length of 1.8 kb in the trehalose group versus 1.0 kb in the control). Sequence analysis of the cDNA clones showed that the addition of trehalose did not increase the error rate of the RT products but greatly increase the quantity of full-length in cDNA library.
Journal of Biotechnology 02/2007; 127(3):402-7. · 3.18 Impact Factor