desynaptic5 carries a spontaneous semi-dominant mutation affecting Disrupted Meiotic cDNA 1 in barley

Abstract

Despite conservation of the process of meiosis, recombination landscapes vary between species, with large genome grasses such as barley ( Hordeum vulgare L.) exhibiting a pattern of recombination that is very heavily skewed to the ends of chromosomes. We have been using a collection of semi-sterile desynaptic meiotic mutant lines to help elucidate how recombination is controlled in barley and the role of the corresponding wild-type (WT) meiotic genes within this process. Here we applied a combination of genetic segregation analysis, cytogenetics, and immunocytology to genetically map and characterize the meiotic mutant desynaptic5 ( des5 ). We identified an exonic insertion in the positional candidate ortholog of Disrupted Meiotic cDNA 1 ( HvDMC1 ) on chromosome 5H of des5 . des5 exhibits a severe meiotic phenotype with disturbed synapsis, reduced crossovers, and chromosome mis-segregation. The meiotic phenotype and reduced fertility of des5 is similarly observed in Hvdmc1 RNAi transgenic plants and HvDMC1 p:GusPlus reporter lines show DMC1 expression specifically in the developing inflorescence. The des5 mutation maintains the reading frame of the gene and exhibits semi-dominance with respect to recombination in the heterozygote indicating the value of non-knockout mutations for dissection of the control of recombination in the early stages of meiosis.

Dmc1is a candidate for temperature tolerance during wheat meiosis

“…Table 2). This conservation of aminoacid sequence between the wheat, barley and rice DMC1 proteins has also been reported by Colas et al (2019).…”

“…A mutation in one or other of these homologs does not cause problems in meiosis, but Osdmc1a Osdmc1b double mutants exhibit serious CO defects, abnormal synapsis, high numbers of univalents at metaphase and are sterile (Wang et al 2016). Barley (Hordeum vulgare) carries a single Dmc1 homolog, HvDMC1, and mutations in this gene lead to abnormal synapsis, multiple univalents and chromosome mis-segregation (Colas et al 2019;Szurman-Zubrzycka et al 2019). Thus, it appears that disruption of the barley orthologue of Dmc1 at normal temperatures leads to a phenotype similar to that of ttmei1 at low temperatures.…”

Time-resolved transcriptome of barley anthers and meiocytes reveals robust and largely stable gene expression changes at meiosis entry

“…(2017). Briefly, the primary antibody solution consisted of anti-TaASY1 (rabbit), anti-HvZYP1 (rat) and anti-guinea pig HvDMC1 at 1:1000, 1:500 and 1:200, respectively in 1x PBS blocking buffer (Colas et al, 2017 & 2019). Primary antibodies were added on the slide, incubated in a wet chamber for 30 minutes at room temperature followed by up to 36 hours at 4 – 6°C.…”

An aphid effector promotes barley susceptibility through suppression of defence gene expression

“…With 177 R. padi being a major pest of cereals, we aimed to extend aphid effector characterization 178 studies to the monocot crop barley to explore the contribution of R. padi effectors to host 7 susceptibility. We generated barley transgenic lines in the cultivar Golden Promise to 180 ectopically express the three R. padi effectors Rp1, RpC002 and Rp58 using a modified 181 version of the pBRACT214 vector (Colas et al, 2019) For M. persicae we did not find consistent significant differences in aphid performance on 203 the barley transgenic lines expressing the R. padi effectors compared to the wild-type 204 control ( Fig. 5).…”

“…Sequence verified inserts were cloned into 403 different destination vectors by LR reaction. Destination vectors pB7WGF2 (35S promoter, 404 N-terminal GFP) and pB7WG2 (35S promoter, no tag)(Karimi, et al 2002) were used for 405 transient overexpression in N. benthamiana, and pBRACT214m (maize ubiquitin promoter, 406 no tag), kindly provided by Abdellah Barakate (JHI)(Colas et al, 2019), was used for 407 generating transgenic barley lines.…”