Table1.DOCX

<p>Drought is the most important factor limiting rice yield in most rainfed areas of Asia and Africa. Four large BC₂F₂ populations consisted of 3,200 individuals, which were derived from crosses between an elite Geng variety, Jigeng88, and four donors from three different countries, were screened and progeny tested under severe drought stress, resulting in the development of 72 introgression lines (ILs) with significantly improved yield compared to the recurrent parent Jigeng88. These DT ILs plus four random populations (without drought selection population) from the same crosses were evaluated in replicated trials under both drought stress and non-stress conditions in two environments, and characterized with simple sequence repeat (SSR) markers to understand how directional selection was operating on the genetic variation of DT of rice. Thirteen DT QTLs of large effect were identified based on the significant allelic and genotypic frequency shits in the DT ILs by using the joint segregation distortion method. The 13 QTLs were validated by the genotypic differences at individual QTL in the random populations. Putative genetic networks consisting of 30 loci in 29 functional genetic units underlying DT were detected by X² tests and non-random associations between or among DT loci in DT ILs from the four populations. Most large-effect DT QTLs were previously reported and located in the upstream of the genetic networks as putative regulators, and were either mapped to important regulatory genes for DT or drought responsiveness reported previously. In our study, five promising ILs with significantly improved yield were selected under both drought and normal irrigated conditions. The QTLs and their genetic networks underlying DT detected provided useful genetic information for further improving DT and yield using designed QTL pyramiding.</p

Extensive Microsatellite Variation in Rice Induced by Introgression from Wild Rice (<i>Zizania latifolia</i> Griseb.)

<div><p>Background</p><p>It is widely accepted that interspecific hybridization may induce genomic instability in the resultant hybrids. However, few studies have been performed on the genomic analysis of homoploid hybrids and introgression lines. We have reported previously that by introgressive hybridization, a set of introgression lines between rice (<i>Oryza sativa</i> L.) and wild rice (<i>Zizania latifolia</i> Griseb.) was successfully generated, and which have led to the release of several cultivars.</p><p>Methodology</p><p>Using 96 microsatellite markers located in the nuclear and organelle genomes of rice, we investigated microsatellite stability in three typical introgression lines. Expression of a set of mismatch repair (MMR) genes and microsatellite-containing genes was also analyzed.</p><p>Results/Conclusions</p><p>Compared with the recipient rice cultivar (Matsumae), 55 of the 96 microsatellite loci revealed variation in one or more of the introgression lines, and 58.2% of the altered alleles were shared by at least two lines, indicating that most of the alterations had occurred in the early stages of introgression before their further differentiation. 73.9% of the non-shared variations were detected only in one introgression line, i.e. RZ2. Sequence alignment showed that the variations included substitutions and indels that occurred both within the repeat tracts and in the flanking regions. Interestingly, expression of a set of MMR genes altered dramatically in the introgression lines relative to their rice parent, suggesting participation of the MMR system in the generation of microsatellite variants. Some of the altered microsatellite loci are concordant with changed expression of the genes harboring them, suggesting their possible <i>cis</i>-regulatory roles in controlling gene expression. Because these genes bear meaningful homology to known-functional proteins, we conclude that the introgression-induced extensive variation of microsatellites may have contributed to the novel phenotypes in the introgression lines.</p></div

The relationship between the number of positive factors and the number of help-seekers.

<p>The relationship between the number of positive factors and the number of help-seekers.</p

Chinese college freshmen’s mental health problems and their subsequent help-seeking behaviors: A cohort design (2005-2011)

<div><p>Based on cohort data obtained from 13,085 college freshmen’s (2005 to 2011) SCL-90 (the Symptom Check-List-90) reports and their subsequent 4-year psychological counseling help-seeking records, this study examined the association between college students’ mental health problems and help-seeking behaviors across four college years. Female students’ mental health problems and help-seeking behaviors increased from the 2005 to the 2011 cohorts and no changes emerged for male students across cohorts. Overall, male students reported higher levels of mental health problems than did female students in the first college year, whereas female students reported more help-seeking behaviors than did male students in the following four college years. College students’ mental health problems was associated positively with help-seeking behaviors. College students were more likely to seek help from the college psychological counselling center when they experienced relatively few or quite a lot of mental health issues (i.e., an inversed U shape). Implications for future studies and practices are discussed.</p></div

Evaluation of the relative transcript levels of the eight MMR genes in Matsumae, RZ1, RZ2 and RZ35, by quantitative RT-PCR.

<p>Total RNA samples were prepared from the leaves at three-leaf stage, and were used for cDNA synthesis and the subsequent quantitative PCR with gene specific primers. Each data point was calculated with the results of three technical repeats.</p

Transgenerational Inheritance of Modified DNA Methylation Patterns and Enhanced Tolerance Induced by Heavy Metal Stress in Rice (<em>Oryza sativa</em> L.)

<div><h3>Background</h3><p>DNA methylation is sensitive and responsive to stressful environmental conditions. Nonetheless, the extent to which condition-induced somatic methylation modifications can impose transgenerational effects remains to be fully understood. Even less is known about the biological relevance of the induced epigenetic changes for potentially altered well-being of the organismal progenies regarding adaptation to the specific condition their progenitors experienced.</p> <h3>Methodology/Principal Findings</h3><p>We analyzed DNA methylation pattern by gel-blotting at genomic loci representing transposable elements and protein-coding genes in leaf-tissue of heavy metal-treated rice (<em>Oryza sativa</em>) plants (S0), and its three successive organismal generations. We assessed expression of putative genes involved in establishing and/or maintaining DNA methylation patterns by reverse transcription (RT)-PCR. We measured growth of the stressed plants and their unstressed progenies <em>vs.</em> the control plants. We found (1) relative to control, DNA methylation patterns were modified in leaf-tissue of the immediately treated plants, and the modifications were exclusively confined to CHG hypomethylation; (2) the CHG-demethylated states were heritable via both maternal and paternal germline, albeit often accompanying further hypomethylation; (3) altered expression of genes encoding for DNA methyltransferases, DNA glycosylase and <em>SWI/SNF</em> chromatin remodeling factor (<em>DDM1</em>) were induced by the stress; (4) progenies of the stressed plants exhibited enhanced tolerance to the same stress their progenitor experienced, and this transgenerational inheritance of the effect of condition accompanying heritability of modified methylation patterns.</p> <h3>Conclusions/Significance</h3><p>Our findings suggest that stressful environmental condition can produce transgenerational epigenetic modifications. Progenies of stressed plants may develop enhanced adaptability to the condition, and this acquired trait is inheritable and accord with transmission of the epigenetic modifications. We suggest that environmental induction of heritable modifications in DNA methylation provides a plausible molecular underpinning for the still contentious paradigm of inheritance of acquired traits originally put forward by Jean-Baptiste Lamarck more than 200 years ago.</p> </div

Distribution of the nuclear microsatellite markers in the 12 rice chromosomes.

<p>For each chromosome, the black vertical line represents Matsumae, and the three red vertical lines represent the introgression lines, RZ1, RZ2 and RZ35, respectively. Locations of the microsatellite markers were labeled by horizontal bars in Matsumae, while the horizontal bars in the three introgression lines denote microsatellites that showed polymorphism in the given introgression line(s). Different colors of the horizontal bars represent the different categories of microsatellite markers specified in the main text.</p

A UPGMA dendrogram to show the overall genomic differentiation of the introgression lines from their rice parental cultivar.

<p>The Dendrogram was generated by NTSYS software using the Jaccard’s coefficient of similarity calculated on the microsatellite markers.</p

Total mean scores of SCL-90 of freshmen from 2005 to 2011.

<p>Total mean scores of SCL-90 of freshmen from 2005 to 2011.</p

Microsatellite Variation patterns in the introgression lines.

*<p>Indictes the variations happened only in RZ2.</p