Genomic analyses reveal the stepwise domestication and genetic mechanism of curd biogenesis in cauliflower.

Cauliflower (Brassica oleracea L. var. botrytis) is a distinctive vegetable that supplies a nutrient-rich edible inflorescence meristem for the human diet. However, the genomic bases of its selective breeding have not been studied extensively. Herein, we present a high-quality reference genome assembly C-8 (V2) and a comprehensive genomic variation map consisting of 971 diverse accessions of cauliflower and its relatives. Genomic selection analysis and deep-mined divergences were used to explore a stepwise domestication process for cauliflower that initially evolved from broccoli (Curd-emergence and Curd-improvement), revealing that three MADS-box genes, CAULIFLOWER1 (CAL1), CAL2 and FRUITFULL (FUL2), could have essential roles during curd formation. Genome-wide association studies identified nine loci significantly associated with morphological and biological characters and demonstrated that a zinc-finger protein (BOB06G135460) positively regulates stem height in cauliflower. This study offers valuable genomic resources for better understanding the genetic bases of curd biogenesis and florescent development in crops.

Separation and identification of oligomeric vinylmethoxysiloxanes by gradient elution chromatography coupled with electrospray ionization mass spectrometry.

A high-performance liquid chromatography with online electrospray ionization mass spectrometry (HPLC-ESI-MS) has been used to separate and identify the reaction products resulting from controlled acid-catalyzed hydrolytic polycondensation of vinyltrimethoxysilane (VMS). The reaction products were prepared in the molar ratio of water to VMS (r1) ranging from 0.6 to 1.2, characterized by standard spectroscopic techniques, and subsequently analyzed by HPLC-UV absorbance detection and HPLC-ESI-MS. Linear vinylmethoxysiloxane oligomers with the number of repeat units (n) ranging from 3 to 11 are predominant species at the beginning of the reaction (for r1=0.6). Then they transform into monocyclic (for r1=1.0) and bicyclic (for r1=1.2) species with gradually increasing amount of water in the reaction mixture. The oligomer conversions suggest that structure growth of vinylmetoxysiloxanes proceeds by nonrandom cyclization reactions, which are favored over chain extension under the chosen reaction conditions. Direct ESI-MS, HPLC-ESI-MS and HPLC-UV were used to determine the molar mass distributions for the vinylmethoxysiloxane oligomers prepared in three different values of r1. The molar mass averages increase slightly with the amount of water in the reaction mixture and vary somewhat with the method used. Our results indicate that with the combined capability of separation, sensitivity and identification, HPLC-ESI-MS is especially useful to study highly complex silicon-based compounds with hyperbranched, caged or cubic structures as building blocks for hybrid materials.

[The relationship between gene polymorphism of catechol-O-methyltransferase and survival of oral pesticides suicide attempters].

OBJECTIVE: To understand the association between gene polymorphism of catechol-O-methyltransferase (COMT) and suicide attempters taking pesticides orally and to provide a scientific base for the prevention of suicidal behavior. METHODS: 107 suicide attempters taking pesticides orally were collected from The People's Hospitals in Shandong Province from January 2003 through December 2003. The informations of all the attempters were obtained and 1 ml whole blood from of them were collected. Molecular biological techniques were used to study the gene type of each subject. RESULTS: In the 107 suicide attempters, the ratio of male to female is 1:1.55; 67.3% of them were in age range of 20 - 44 years; 59.8% of them had education level of elementary school or lower. 13 suicide attempters (12.1% of all the attempters) had psychiatric disorders. 84 suicide attempters (78.5% of all the attempters) had affective conflicts with others in the recent year. 30 suicide attempters (28.0% of the suicide attempters) had impulsive behavior. Multivariate logistic regression model analysis showed that suicide impulsion and psychiatric disorders were significantly associated with COMT Val/Val, their OR values were 0.052 (95% CI: 0.006 - 0.437), 2.917 (95% CI: 1.097 - 7.760). CONCLUSION: In this population, more attention should be paid to young female people with psychiatric disorders or having affective conflicts with others in the recent year so as to prevent suicide. This study supported that there is heterogeneity in COMT gene in suicide attempters and there is interaction between COMT Val/Val and suicide impulsion and psychiatric disorders.