Biology subjects

Yuan, Y.

Publications and source records attributed to Yuan, Y..

21 records · Page 2Linked to original sources

bioRxiv2017

Releasing potential power of terpene synthases by a robust precursor supply platform

Approximately 76,000 discovered makes terpenoids the largest family of natural products in nature with widespread applications. The wide-spectrum of structural diversity of the terpenoids were largely due to the variable skeletons generated by terpene synthases. The number of terpene skeletons found in nature, however, were so much more than those conceivably generated from known terpene synthases and the limited characterized terpene synthases also make no chance for some useful terpenoids overproduction in microbe. Here, we first demonstrated that the promiscuous synthases in vivo can produce more variable terpenoid products by converting precursors of different lengths (C10, C15, C20, C25). This discovery was prompted by the development of an efficient in vivo platform by combining the two promiscuous terpene synthases and three prenyltransferases to generate 50 terpenoids, at least 3 ring systems of which were completely new. Furthermore, protein engineering was further integrated to enhance product diversity. Clearly, the work is expected to dramatically reshape the terpenoid research by widening the flexibility of the terpene synthases for the fresh discovery or creation of the new terpenoid compounds by skeleton reframing.

biochemistry↗

bioRxiv2016

Incidental identification of maternal malignancies in two Asian women underwent noninvasive prenatal test

Noninvasive prenatal test (NIPT) has been widely used as a screening test for trisomy 13, 18 and 21 worldwide. Recently, coexistence of maternal malignancy and pregnancy has drawn increasing attention in NIPT studies. Malignancy in pregnant women potentially affected NIPT results, which may cause false positive results or failed tests. However, no such case has ever been reported in Asian population. In this study, for the first time, we reported a stage III dysgerminoma and advanced gastric cancer during pregnancy accidentally identified during NIPT tests. These two women showed aberrant chromosome aneuploidies in NIPT results and concordant pattern of genome disruption found in tumor samples. The findings in this study further validate the effect of maternal malignancy on NIPT results and strengthen the possibility of detecting malignant tumors through NIPT in the future.

cancer biology↗

bioRxiv2016

Subgenome dominance in an interspecific hybrid, synthetic allopolyploid, and a 140 year old naturally established neo-allopolyploid monkeyflower.

The importance and applications of polyploidy have long been recognized, from shaping the evolutionary success of flowering plants to improving agricultural productivity. Recent studies have shown that one of the parental subgenomes in ancient polyploids is generally more dominant - having both retained more genes and being more highly expressed - a phenomenon termed subgenome dominance. How quickly one subgenome dominates within a newly formed polyploid, if immediate or after millions of years, and the genomic features that determine which genome dominates remain poorly understood. To investigate the rate of subgenome dominance emergence, we examined gene expression, gene methylation, and transposable element (TE) methylation in a natural less than 140 year old allopolyploid (Mimulus peregrinus), a resynthesized interspecies triploid hybrid (M. robertsii), a resynthesized allopolyploid (M. peregrinus), and diploid progenitors (M. guttatus and M. luteus). We show that subgenome expression dominance occurs instantly following the hybridization of two divergent genomes and that subgenome expression dominance significantly increases over generations. Additionally, CHH methylation levels are significantly reduced in regions near genes and within transposons in the first generation hybrid, intermediate in the resynthesized allopolyploid, and are repatterned differently between the dominant and submissive subgenomes in the natural allopolyploid. Our analyses reveal that the subgenome differences in levels of TE methylation mirror the increase in expression bias observed over the generations following the hybridization. These findings not only provide important insights into genomic and epigenomic shock that occurs following hybridization and polyploid events, but may also contribute to uncovering the mechanistic basis of heterosis and subgenomic dominance.

genomics↗