Biology subjects

Qi, L.

Publications and source records attributed to Qi, L..

3 recordsLinked to original sources

bioRxiv2018

The homoeologous genes for the Rec8-like meiotic cohesin in wheat: structure, function, and evolutionary implication

The Rec8-like cohesin is a cohesion protein essential for orderly chromosome segregation in meiosis. Here, we cloned two Rec8-like homoeologous genes (homoeoalleles) from tetraploid wheat (TtRec8-A1 and TtRec8-B1) and one from hexaploid wheat (TaRec8-D1), and performed expression and functional analyses of the homoeoalleles. Also, we identified other two Rec8 homoeoalleles in hexaploid wheat (TaRec8-A1 and TaRec8-B1) and the one in Aegilops tauschii (AetRec8-D1) by comparative analysis. The coding DNA sequences (CDS) of these six Rec8 homoeoalleles are all 1,827 bp in length, encoding 608 amino acids. They differed from each other primarily in introns although single nucleotide polymorphisms were detected in CDS. Substantial difference was observed between the homoeoalleles from the subgenome B (TtRec8-B1 and TaRec8-B1) and those from the subgenomes A and D (TtRec8-A1, TaRec8-A1, and TaRec8-D1). TtRec8-A1 expressed dominantly over TtRec8-B1, but comparably to TaRec8-D1. Therefore, the Rec8 homoeoalleles from the subgenomes A and D may be functionally more active than the one from the subgenome B in wheat. The structural variation and differential expression of the Rec8 homoeoalleles indicate a unique cross-genome coordination of the homoeologous genes in the polyploid, and imply the distinction of the wheat subgenome B from other subgenomes in the origin and evolution.\n\nHIGHLIGHTThis work revealed the structural and expression patterns of the Rec8-like homoeologous genes in polyploid wheat, implying a unique origin and evolutionary route of the wheat B subgenome.

genetics↗

bioRxiv2018

Elongator is required for root stem cell maintenance by regulating SHORT ROOT transcription

SHORTROOT (SHR) is essential for stem cell maintenance and radial patterning in Arabidopsis thaliana roots, but how its expression is regulated is still unknown. Here, we report that Elongator regulates the transcription of SHR. The depletion of Elongator drastically reduced SHR expression and led to defective root stem cell maintenance and radial patterning. The importance of the nuclear localization of Elongator for its functioning, together with the insensitivity of the elp1 mutant to the transcription elongation inhibitor 6-azauracil and the direct interaction of the ELP4 subunit with the C-terminal domain of RNA polymerase II (RNAPII CTD), support the notion that Elongator plays important roles in transcription elongation. Indeed, we found that ELP3 associates with the pre-mRNA of SHR and that mutation of Elongator reduces the enrichment of RNAPII on the SHR gene body. Moreover, Elongator interacted in vivo with SUPPRESSOR OF Ty4 (SPT4), a well-established transcription elongation factor that was recruited to the SHR locus. Together, these results demonstrate that Elongator acts in concert with SPT4 to regulate the transcription of SHR.

plant biology↗

bioRxiv2017

Sublethal effects of the neonicotinoid insecticide thiamethoxam on the transcriptome of the honeybee (Apis mellifera)

Neonicotinoid insecticides are now the most widely used insecticides in the world. Previous studies have indicated that sublethal doses of neonicotinoids impair learning, memory capacity, foraging and immunocompetence in honeybees (Apis mellifera). Despite this, few studies have been carried out on the molecular effects of neonicotinoids. In this study, we focus on the second-generation neonicotinoid thiamethoxam, which is currently widely used in agriculture to protect crops. Using high-throughput RNA-Seq, we investigated the transcriptome profile of honeybees after subchronic exposure to thiamethoxam (10 ppb) over 10 days. In total, 609 differentially-expressed genes (DEGs) were identified, of which 225 were up-regulated and 384 were down-regulated. The functions of some DEGs were identified, and GO enrichment analysis showed that the enriched DEGs were mainly linked to metabolism, biosynthesis and translation. KEGG pathway analysis showed that thiamethoxam affected biological processes including ribosomes, the oxidative phosphorylation pathway, tyrosine metabolism pathway, pentose and glucuronate interconversions and drug metabolism. Overall, our results provide a basis for understanding the molecular mechanisms of the complex interactions between neonicotinoid insecticides and honeybees.\n\nSummary statementNR1, Cyp6as5, nAChRa9 and nAChR{beta}2 were up-regulated in honeybees exposed to thiamethoxam, while CSP3, Obp21, defensin-1, Mrjp1, Mrjp3 and Mrjp4 were down-regulated.

molecular biology↗