Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

“Bioinformatics” 특집을 내면서

Oilseed rape (Brassica napus L.) was formed ~7500 years ago by hybridization between B. rapa and B. oleracea, followed by chromosome doubling, a process known as allopolyploidy. Together with more ancient polyploidizations, this conferred an aggregate 72× genome multiplication since the origin of angiosperms and high gene content. We examined the B. napus genome and the consequences of its recent duplication. The constituent An and Cn subgenomes are engaged in subtle structural, functional, and epigenetic cross-talk, with abundant homeologous exchanges. Incipient gene loss and expression divergence have begun. Selection in B. napus oilseed types has accelerated the loss of glucosinolate genes, while preserving expansion of oil biosynthesis genes. These processes provide insights into allopolyploid evolution and its relationship with crop domestication and improvement.

http://science.sciencemag.org/content/sci/345/6199/950.full.pdf

Early allopolyploid evolution in the post-Neolithic Brassica napus oilseed genome

Universal sample preparation method for proteome analysis

生活習慣病とgenome-wide association study

Early maturity is a particularly important agronomic trait for cotton breeding in China and is determined by many morphological and phenological traits. The time of floral initiation is one of most important factors related to early maturation of cotton. The aim of this study was to identify differentially expressed (DE) genes related to floral initiation using the Arabidopsis thaliana GeneChip® system on the shoot apical meristems (SAMs) of an early-maturing cotton cultivar. Compared with SAMs at 10 days, 365 genes were differentially expressed in the SAMs at 20 days. Of these, 210 and 155 transcripts were up- and down- regulated, respectively. The results of Gene Ontology (GO) annotation indicated that most genes fell into the four largest functional groups: metabolism, transposable elements, protein binding or cofactor requirements, and protein fate. These groups constituted 18.9, 11.8, 12.8 and 6.8% of the total DE genes, respectively. Many DE genes were identified, including those encoding the transcription factors SOC1-like floral activator MADS4, B3-domain containing transcription factor, MYB2, MYB85 and GHMADS-1. Our research found that the B3-domain containing transcription factor was similar to Arabidopsis genes encoding auxin response factor 36 and VERNALIZATION 1 (VRN1) and was one of 155 down-regulated ‘Apex-unique’ transcripts. The B3-domain containing transcription factor was 1128 bp long and was named GhV1 (GenBank accession No. GU929695). The induction of the transcripts we identified in the cotton SAM after 10 days of SD revealed that the transition to reproductive development occurred at this particular time point. These results allowed for a detailed description of temporal gene expression changes in the cotton SAM as it undergoes the floral initiation process.

Gene expression profiling in shoot apical meristem of Gossypium hirsutum

Association mapping of genetic network for plant morphological traits in cotton

Lint percentage is a major yield component in cotton breeding programmes. To identify quantitative trait loci (QTLs) and candidate genes related to lint percentage, we used an intraspecific recombinant inbred line population of 137 lines derived from Gossypium hirsutum cv. CCRI36 and G. hirsutum acc. G2005 for QTL mapping of lint percentage. Based on a high-density genetic map and phenotype data collected in four growing environments, we identified a total of 28 QTLs for lint percentage. Three stable QTLs (qLP-At5-2, qLP-Dt7-1 and qLP-Dt7-2) were detected in at least two environments. Two genes (Gh_A05G1584 and Gh_A05G1689) containing nonsynonymous single nucleotide polymorphisms (SNPs) were identified by association analysis using published data. The quantitative real-time PCR results showed that the expression levels of Gh_A05G1584 were higher in cv. CCRI36 than in acc. G2005 during all fibre development stages; Gh_A05G1689 was mainly expressed in 15 and 25 days post-anthesis fibres and its expression level was higher in cv. CCRI36. These results suggest candidate genes for lint percentage and provide molecular information for use in cotton breeding programmes aimed at improving yield.

QTL mapping and candidate gene identification of lint percentage based on a recombinant inbred line population of upland cotton

Glycerol-3-phosphate acyltransferases (GPATs), critical for multiple biological processes like male fertility, have been extensively characterized. However, their precise functions and underlying regulatory mechanism in cotton anther development are unclear. This research demonstrated the importance of GhGPAT12/25 (a paralogs pair on A12/D12 sub-chromosome of cotton) to regulate the degradation of tapetum, anther cuticle formation, and pollen exine development. GhGPAT12 and GhGPAT25 exhibited specifically detected transcripts in tapetum and pollen exine during the early anther developmental stages. GhGPAT12/25 are sn-2 glycerol-3-phosphate acyltransferases and can transfer the acyl group of palmitoyl-CoA to glycerol-3-phosphate (G3P). CRISPR/Cas9-mediated knockout identified the functional redundancy of GhGPAT12 and GhGPAT25. Knockout of both genes caused completely male sterility associated with abnormal anther cuticle, swollen tapetum, and inviable microspores with defective exine and irregular unrestricted shape. RNA-seq analysis showed that the loss of function of GhGPAT12/25 affects the processes of wax metabolic, glycerol monomer biosynthesis, and transport. Consistently, cuticular waxes were dramatically reduced in mutant anthers. Yeast one-hybrid system (Y1H), virus-induced gene silencing (VIGS), and dual-luciferase (LUC) assays illustrated that GhMYB80s are likely to directly activate the expression of GhGPAT12/25. This study provides important insights for revealing the regulatory mechanism underlying anther development in cotton.

/pdf/ghgpat12-25-are-essential-for-the-formation-of-anther-58xypmrex7.pdf

GhGPAT12/25 Are Essential for the Formation of Anther Cuticle and Pollen Exine in Cotton (Gossypium hirsutum L.).

Senescence in plants is a complex trait, which is controlled by both genetic and environmental factors and can affect the yield and quality of cotton. However, the genetic basis of cotton senescence remains relatively unknown. In this study, we reported genome-wide association studies (GWAS) based on 185 accessions of upland cotton and 26,999 high-quality single-nucleotide polymorphisms (SNPs) to reveal the genetic basis of cotton senescence. To determine cotton senescence, we evaluated eight traits/indices. Our results revealed a high positive correlation (r>0.5) among SPAD value 20 days after topping (SPAD20d), relative difference of SPAD (RSPAD), nodes above white flower on topping day (NAWF0d), nodes above white flower 7 days after topping (NAWF7d), and number of open bolls on the upper four branches (NB), and genetic analysis revealed that all traits had medium or high heritability ranging from 0.53 to 0.86. Based on a multi-locus method (FASTmrMLM), a total of 63 stable and significant quantitative trait nucleotides (QTNs) were detected, which represented 50 genomic regions (GWAS risk loci) associated with cotton senescence. We observed three reliable loci located on chromosomes A02 (A02_105891088_107196428), D03 (D03_37952328_38393621) and D13 (D13_59408561_60730103) because of their high repeatability. One candidate gene (Ghir_D03G011060) was found in the locus D03_37952328_38393621, and its Arabidopsis thaliana homologous gene (AT5G23040) encodes a cell growth defect factor-like protein (CDF1), which might be involved in chlorophyll synthesis and cell death. Moreover, qRT-PCR showed that the transcript level of Ghir_D03G011060 was down-regulated in old cotton leaves, and virus-induced gene silencing (VIGS) indicated that silencing of Ghir_D03G011060 resulted in leaf chlorosis and promoted leaf senescence. In addition, two candidate genes (Ghir_A02G017660 and Ghir_D13G021720) were identified in loci A02_105891088_107196428 and D13_59408561_60730103, respectively. These results provide new insights into the genetic basis of cotton senescence and will serve as an important reference for the development and implementation of strategies to prevent premature senescence in cotton breeding programs.

https://www.frontiersin.org/articles/10.3389/fpls.2021.809522/pdf

Uncovering Novel Genomic Regions and Candidate Genes for Senescence-Related Traits by Genome-Wide Association Studies in Upland Cotton (Gossypium hirsutum L.)

Shuxun Yu

Papers

Gene expression profiling in shoot apical meristem of Gossypium hirsutum

Association mapping of genetic network for plant morphological traits in cotton

QTL mapping and candidate gene identification of lint percentage based on a recombinant inbred line population of upland cotton

GhGPAT12/25 Are Essential for the Formation of Anther Cuticle and Pollen Exine in Cotton (Gossypium hirsutum L.).

Uncovering Novel Genomic Regions and Candidate Genes for Senescence-Related Traits by Genome-Wide Association Studies in Upland Cotton (Gossypium hirsutum L.)