Characterization and discovery of miRNA and miRNA targets from apomictic and sexual genotypes of Eragrostis curvula.

BACKGROUND: Weeping lovegrass (Eragrostis curvula [Shrad.] Nees) is a perennial grass found in semi-arid regions that is well adapted for growth in sandy soils and drought conditions. E. curvula constitutes a polymorphic complex that includes cytotypes with different ploidy levels (from 2x to 8x), where most polyploids are facultative apomicts, although both sexual reproduction and full apomixis have been reported in this species. Apomixis is thought to be associated with silencing of the sexual pathway, which would involve epigenetic mechanisms. However, a correlation between small RNAs and apomixis has not yet been conclusively established. RESULTS: Aiming to contribute to the elucidation of their role in the expression of apomixis, we constructed small RNA libraries from sexual and apomictic E. curvula genotypes via Illumina technology, characterized the small RNA populations, and conducted differential expression analysis by comparing these small RNAs with the E. curvula reference transcriptome. We found that the expression of two genes is repressed in the sexual genotype, which is associated with specific microRNA expression. CONCLUSION: Our results support the hypothesis that in E. curvula the expression of apomixis leads to sexual repression.

From tetraploid to diploid, a pangenomic approach to identify genes lost during synthetic diploidization of Eragrostis curvula.

Introduction: In Eragrostis curvula, commonly known as weeping lovegrass, a synthetic diploidization event of the facultative apomictic tetraploid Tanganyika INTA cv. originated from the sexual diploid Victoria cv. Apomixis is an asexual reproduction by seeds in which the progeny is genetically identical to the maternal plant. Methods: To assess the genomic changes related to ploidy and to the reproductive mode occurring during diploidization, a mapping approach was followed to obtain the first E. curvula pangenome assembly. In this way, gDNA of Tanganyika INTA was extracted and sequenced in 2x250 Illumina pair-end reads and mapped against the Victoria genome assembly. The unmapped reads were used for variant calling, while the mapped reads were assembled using Masurca software. Results: The length of the assembly was 28,982,419 bp distributed in 18,032 contigs, and the variable genes annotated in these contigs rendered 3,952 gene models. Functional annotation of the genes showed that the reproductive pathway was differentially enriched. PCR amplification in gDNA and cDNA of Tanganyika INTA and Victoria was conducted to validate the presence/absence variation in five genes related to reproduction and ploidy. The polyploid nature of the Tanganyika INTA genome was also evaluated through the variant calling analysis showing the single nucleotide polymorphism (SNP) coverage and allele frequency distribution with a segmental allotetraploid pairing behavior. Discussion: The results presented here suggest that the genes were lost in Tanganyika INTA during the diploidization process that was conducted to suppress the apomictic pathway, affecting severely the fertility of Victoria cv.

A combined transcriptome - miRNAome approach revealed that a kinesin gene is differentially targeted by a novel miRNA in an apomictic genotype of Eragrostis curvula.

Weeping lovegrass (Eragrostis curvula [Shrad.] Nees) is a perennial grass typically established in semi-arid regions, with good adaptability to dry conditions and sandy soils. This polymorphic complex includes both sexual and apomictic cytotypes, with different ploidy levels (2x-8x). Diploids are known to be sexual, while most polyploids are facultative apomicts, and full apomicts have also been reported. Plant breeding studies throughout the years have focused on achieving the introgression of apomixis into species of agricultural relevance, but, given the complexity of the trait, a deeper understanding of the molecular basis of regulatory mechanisms of apomixis is still required. Apomixis is thought to be associated with silencing or disruption of the sexual pathway, and studies have shown it is influenced by epigenetic mechanisms. In a previous study, we explored the role of miRNA-mRNA interactions using two contrasting E. curvula phenotypes. Here, the sexual OTA-S, the facultative Don Walter and the obligate apomictic Tanganyika cDNA and sRNA libraries were inquired, searching for miRNA discovery and miRNA expression regulation of genes related to the reproductive mode. This allowed for the characterization of seven miRNAs and the validation of their miRNA-target interactions. Interestingly, a kinesin gene was found to be repressed in the apomictic cultivar Tanganyika, targeted by a novel miRNA that was found to be overexpressed in this genotype, suggestive of an involvement in the reproductive mode expression. Our work provided additional evidence of the contribution of the epigenetic regulation of the apomictic pathway.

Eragrostis curvula, a Model Species for Diplosporous Apomixis.

Eragrostis curvula (Schrad.) Ness is a grass with a particular apomictic embryo sac development called Eragrostis type. Apomixis is a type of asexual reproduction that produces seeds without fertilization in which the resulting progeny is genetically identical to the mother plant and with the potential to fix the hybrid vigour from more than one generation, among other advantages. The absence of meiosis and the occurrence of only two rounds of mitosis instead of three during embryo sac development make this model unique and suitable to be transferred to economically important crops. Throughout this review, we highlight the advances in the knowledge of apomixis in E. curvula using different techniques such as cytoembryology, DNA methylation analyses, small-RNA-seq, RNA-seq, genome assembly, and genotyping by sequencing. The main bulk of evidence points out that apomixis is inherited as a single Mendelian factor, and it is regulated by genetic and epigenetic mechanisms controlled by a complex network. With all this information, we propose a model of the mechanisms involved in diplosporous apomixis in this grass. All the genetic and epigenetic resources generated in E. curvula to study the reproductive mode changed its status from an orphan to a well-characterised species.

Genes Modulating the Increase in Sexuality in the Facultative Diplosporous Grass Eragrostis curvula under Water Stress Conditions.

Eragrostis curvula presents mainly facultative genotypes that reproduce by diplosporous apomixis, retaining a percentage of sexual pistils that increase under drought and other stressful situations, indicating that some regulators activated by stress could be affecting the apomixis/sexual switch. Water stress experiments were performed in order to associate the increase in sexual embryo sacs with the differential expression of genes in a facultative apomictic cultivar using cytoembryology and RNA sequencing. The percentage of sexual embryo sacs increased from 4 to 24% and 501 out of the 201,011 transcripts were differentially expressed (DE) between control and stressed plants. DE transcripts were compared with previous transcriptomes where apomictic and sexual genotypes were contrasted. The results point as candidates to transcripts related to methylation, ubiquitination, hormone and signal transduction pathways, transcription regulation and cell wall biosynthesis, some acting as a general response to stress and some that are specific to the reproductive mode. We suggest that a DNA glycosylase EcROS1-like could be demethylating, thus de-repressing a gene or genes involved in the sexuality pathways. Many of the other DE transcripts could be part of a complex mechanism that regulates apomixis and sexuality in this grass, the ones in the intersection between control/stress and apo/sex being the strongest candidates.

Variation in cytosine methylation patterns during ploidy level conversions in Eragrostis curvula.

In many species polyploidization involves rearrangements of the progenitor genomes, at both genetic and epigenetic levels. We analyzed the cytosine methylation status in a 'tetraploid-diploid-tetraploid' series of Eragrostis curvula with a common genetic background by using the MSAP (Methylation-sensitive Amplified Polymorphism) technique. Considerable levels of polymorphisms were detected during ploidy conversions. The total level of methylation observed was lower in the diploid genotype compared to the tetraploid ones. A significant proportion of the epigenetic modifications occurring during the tetraploid-diploid conversion reverted during the diploid-tetraploid one. Genetic and expression data from previous work were used to analyze correlation with methylation variation. All genetic, epigenetic and gene expression variation data correlated significantly when compared by pairs in simple Mantel tests. Dendrograms reflecting genetic, epigenetic and expression distances as well as principal coordinate analysis suggested that plants of identical ploidy levels present similar sets of data. Twelve (12) different genomic fragments displaying different methylation behavior during the ploidy conversions were isolated, sequenced and characterized.

Envarsus, a novelty for transplant nephrologists: Observational retrospective study. / Envarsus, una novedad para los nefrólogos del trasplante: estudio observacional retrospectivo.

The aim of this study was to evaluate the trough concentrations (Cptrough) and the tacrolimus dosage regimen after the conversion of Prograf or Advagraf to Envarsus (new pharmaceutical form with MeltDose technology that improves the absorption of fat-soluble drugs) in patients with stable renal transplantation, and their renal function. We selected stable renal transplant patients who were converted to Envarsus. Two periods were defined: Baseline and Conversion (Envarsus) and they were stratified according to the pharmaceutical form used in the Baseline period. Sixty-one patients were included (24 with Advagraf and 37 with Prograf), with an average age of 52years. The mean post-transplant time at the time of conversion to Envarsus was 76.3months and the mean follow-up in the Baseline and Conversion period was 10.1months and 11.6months, respectively. In the Prograf and Envarsus group, the Cptrough medians were 6.6 vs 6.4 ng/mL (P=.636), with a mean daily dose that decreased significantly from 3mg to 2mg (P<.001), respectively, maintaining the filtration rate. The median Cptrough values in the Advagraf and Envarsus groups were 5.7ng/mL and 6.3ng/mL (P=.07), with a median daily dose of 7mg and 4mg (P<.001), respectively, and the same renal function. In stable renal transplant patients, the conversion from Advagraf to Envarsus has allowed the dose of tacrolimus to be reduced by 42.9% and, in the case of Prograf, by 33.3%, maintaining similar Cptrough values, without renal function being altered.

A High-Density Linkage Map of the Forage Grass Eragrostis curvula and Localization of the Diplospory Locus.

Eragrostis curvula (Schrad.) Nees (weeping lovegrass) is an apomictic species native to Southern Africa that is used as forage grass in semiarid regions of Argentina. Apomixis is a mechanism for clonal propagation through seeds that involves the avoidance of meiosis to generate an unreduced embryo sac (apomeiosis), parthenogenesis, and viable endosperm formation in a fertilization-dependent or -independent manner. Here, we constructed the first saturated linkage map of tetraploid E. curvula using both traditional (AFLP and SSR) and high-throughput molecular markers (GBS-SNP) and identified the locus controlling diplospory. We also identified putative regulatory regions affecting the expressivity of this trait and syntenic relationships with genomes of other grass species. We obtained a tetraploid mapping population from a cross between a full sexual genotype (OTA-S) with a facultative apomictic individual of cv. Don Walter. Phenotypic characterization of F1 hybrids by cytoembryological analysis yielded a 1:1 ratio of apomictic vs. sexual plants (34:27, X 2 = 0.37), which agrees with the model of inheritance of a single dominant genetic factor. The final number of markers was 1,114 for OTA-S and 2,019 for Don Walter. These markers were distributed into 40 linkage groups per parental genotype, which is consistent with the number of E. curvula chromosomes (containing 2 to 123 markers per linkage group). The total length of the OTA-S map was 1,335 cM, with an average marker density of 1.22 cM per marker. The Don Walter map was 1,976.2 cM, with an average marker density of 0.98 cM/marker. The locus responsible for diplospory was mapped on Don Walter linkage group 3, with other 65 markers. QTL analyses of the expressivity of diplospory in the F1 hybrids revealed the presence of two main QTLs, located 3.27 and 15 cM from the diplospory locus. Both QTLs explained 28.6% of phenotypic variation. Syntenic analysis allowed us to establish the groups of homologs/homeologs for each linkage map. The genetic linkage map reported in this study, the first such map for E. curvula, is the most saturated map for the genus Eragrostis and one of the most saturated maps for a polyploid forage grass species.

Genome polymorphisms and gene differential expression in a 'back-and-forth' ploidy-altered series of weeping lovegrass (Eragrostis curvula).

Molecular markers were used to analyze the genomic structure of an euploid series of Eragrostis curvula, obtained after a tetraploid dihaploidization procedure followed by chromosome re-doubling with colchicine. Considerable levels of genome polymorphisms were detected between lines. Curiously, a significant number of molecular markers showed a revertant behavior following the successive changes of ploidy, suggesting that genome alterations were specific and conferred genetic structures characteristic of a given ploidy level. Genuine reversion was confirmed by sequencing. Cluster analysis demonstrated grouping of tetraploids while the diploid was more distantly related with respect to the rest of the plants. Polymorphic revertant sequences involved mostly non-coding regions, although some of them displayed sequence homology to known genes. A revertant sequence corresponding to a P-type adenosine triphosphatase was found to be differentially represented in cDNA libraries obtained from the diploid and a colchiploid, but was not found expressed in the original tetraploid. Transcriptome profiling of inflorescence followed by real-time polymerase chain reaction validation showed 0.34% polymorphic bands between apomictic tetraploid and sexual diploid plants. Several of the polymorphic sequences corresponded to known genes. Possible correlation between the results observed here and a recently reported genome-wide non-Mendelian inheritance mechanism in Arabidopsis thaliana are discussed.

Apomixis frequency under stress conditions in weeping lovegrass (Eragrostis curvula).

To overcome environmental stress, plants develop physiological responses that are triggered by genetic or epigenetic changes, some of which involve DNA methylation. It has been proposed that apomixis, the formation of asexual seeds without meiosis, occurs through the temporal or spatial deregulation of the sexual process mediated by genetic and epigenetic factors influenced by the environment. Here, we explored whether there was a link between the occurrence of apomixis and various factors that generate stress, including drought stress, in vitro culture, and intraspecific hybridization. For this purpose, we monitored the embryo sacs of different weeping lovegrass (Eragrostis curvula [Schrad.] Nees) genotypes after the plants were subjected to these stress conditions. Progeny tests based on molecular markers and genome methylation status were analyzed following the stress treatment. When grown in the greenhouse, the cultivar Tanganyika INTA generated less than 2% of its progeny by sexual reproduction. Plants of this cultivar subjected to different stresses showed an increase of sexual embryo sacs, demonstrating an increased expression of sexuality compared to control plants. Plants of the cv. Tanganyika USDA did not demonstrate the ability to generate sexual embryo sacs under any conditions and is therefore classified as a fully apomictic cultivar. We found that this change in the prevalence of sexuality was correlated with genetic and epigenetic changes analyzed by MSAP and AFLPs profiles. Our results demonstrate that different stress conditions can alter the expression of sexual reproduction in facultative tetraploid apomictic cultivars and when the stress stops the reproductive mode shift back to the apomixis original level. These data together with previous observations allow us to generate a hypothetical model of the regulation of apomixis in weeping lovegrass in which the genetic/s region/s that condition apomixis, is/are affected by ploidy, and is/are subjected to epigenetic control.

De novo transcriptome sequencing and assembly from apomictic and sexual Eragrostis curvula genotypes.

A long-standing goal in plant breeding has been the ability to confer apomixis to agriculturally relevant species, which would require a deeper comprehension of the molecular basis of apomictic regulatory mechanisms. Eragrostis curvula (Schrad.) Nees is a perennial grass that includes both sexual and apomictic cytotypes. The availability of a reference transcriptome for this species would constitute a very important tool toward the identification of genes controlling key steps of the apomictic pathway. Here, we used Roche/454 sequencing technologies to generate reads from inflorescences of E. curvula apomictic and sexual genotypes that were de novo assembled into a reference transcriptome. Near 90% of the 49568 assembled isotigs showed sequence similarity to sequences deposited in the public databases. A gene ontology analysis categorized 27448 isotigs into at least one of the three main GO categories. We identified 11475 SSRs, and several of them were assayed in E curvula germoplasm using SSR-based primers, providing a valuable set of molecular markers that could allow direct allele selection. The differential contribution to each library of the spliced forms of several transcripts revealed the existence of several isotigs produced via alternative splicing of single genes. The reference transcriptome presented and validated in this work will be useful for the identification of a wide range of gene(s) related to agronomic traits of E. curvula, including those controlling key steps of the apomictic pathway in this species, allowing the extrapolation of the findings to other plant species.

Older adults' memory for medical information, effect of number and mode of presentation: An experimental study.

OBJECTIVE: To analyze different ways of presenting medical information to older adults, tailoring the information and its presentation to the characteristics of memory function in old age. METHODS: Experimental study. We took into account the following variables: amount of information, type of information and mode of presentation, and time delay. RESULTS: The greater the number of recommendations, the lower the recall; visual presentation does not enhance verbal presentation; lifestyle information is recalled better than medication information; after ten minutes the percentage of memory decreases significantly; the first and last recommendations are better remembered. CONCLUSION: As a whole, these findings show that older adults remember more medical information when very few recommendations are provided in each session. PRACTICE IMPLICATIONS: It is inadvisable to overload older adults with a large amount of information: It is better to program more consultations and provide less information.

Medication and creativity in Attention Deficit Hyperactivity Disorder (ADHD).

BACKGROUND: The aim of this study was to determine the effect of methylphenidate (MPH) on creative potential in a group of children with attention deficit disorder with hyperactivity (ADHD). METHOD: A randomized single blind crossover study was performed with 24 children with ADHD, aged between 18 and 96 (M = 10.0, SD = 1.3), evaluating each child's creativity with and without MPH, using the Torrance Tests of Creative Thinking-Figural (TTCT). RESULTS: Children under treatment with MPH showed a lower global Creative Index and lower scores on Fluency, Originality and Creative Strengths, compared to when not under treatment. The capacities for Elaboration, Abstractness of Titles, and Resistance to Closure did not differ whether on or off pharmacological treatment. CONCLUSION: Our finding suggests that is important to take into account the impact that MPH might have on the creative potential of a child with ADHD to develop a more accurate evaluation and to develop better treatment plans.

[Efficacy of motivational interventions in the treatment of overweight and obesity]. / Eficacia de las estrategias de motivacion en el tratamiento del sobrepeso y obesidad.

INTRODUCTION AND OBJECTIVES: Changing unhealthy behaviors: Diet and physical activity are key to treating obesity. The objective of this study is to determine whether an intervention group motivational intervention group by nurses trained by expert psychologist, complementary to the usual intervention is more effective than the latter in the treatment of overweight and obesity in relation to weight reduction percentage and the persistence over time of the reduction achieved. METHODS: A multicenter randomized clinical trial of intervention in overweight and obese patients. Randomization of the intervention by health areas (ZBS). Two groups located in different centers separated, one of which will receive motivational intervention group (study group) and the other routine monitoring (control group) were established. VARIABLES: Sociodemographic, results: percentage of patients reduced by 5% of its weight and maintenance over time, anthropometric assessment, assessment of cardiovascular risk factors and laboratory data. RESULTS: 696 patients were studied; 377 control and 319 study group. In both groups the weight down in each of the visits. The mean percentage weight reduction stood at 1% for the control group and 2.5% in the intervention group (p -value = 0.009). 55.8% of patients reduced the weight in the control group and 65.5% of the study group (p -value = 0.0391). 18.1% of the control patient lost more than 5% by weight, in the intervention group, this percentage increased to 26.9%; statistically significant ( p -value = 0.0304). For the 10% target no significant differences at 2 years were detected (5% vs. 8%). It was found that after two years the BMI in the control group an average 0.9 kg/m2 and 2.4 kg/m2 was reduced in the study group ( p -value = 0.0237). CONCLUSION: based motivational group intervention program can improve anthropometric and lifestyle parameters in obese patients treated in a primary care center.

Introducción y objetivos: La modificación de conductas no saludables: dietas y actividad física son fundamentales para tratar la obesidad. El objetivo de este estudio es determinar si una intervención de motivación en grupo, por profesionales de enfermería entrenados por psicólogo experto, complementariamente a la intervención habitual, es más eficaz que esta última en el tratamiento del sobrepeso y obesidad en relación a reducción porcentual del peso, y la persistencia en el tiempo de la reducción conseguida. Métodos: Ensayo clínico aleatorio multicéntrico de intervención en pacientes con sobrepeso y obesidad. Asignación aleatoria de la intervención por Zonas Básicas de Salud (ZBS). Se establecen dos grupos situados en centros diferentes separados, uno de los cuales recibirá la intervención de motivación en grupo (grupo de estudio) y el otro el seguimiento habitual (grupo control). Variables: Sociodemográficas, de resultados: porcentaje de pacientes que reducen un 5 % de su peso y mantenimiento en el tiempo, valoración antropométrica, valoración de factores de riesgo cardiovascular y datos analíticos. Resultados: Se evaluaron 696 pacientes; 377 grupo control y 319 del de estudio. En ambos grupos el peso descendía en cada una de las visitas. La reducción porcentual media del peso se situó en el 1% para el grupo control y del 2,5% en el grupo intervención (p-valor = 0,009). El 55,8% de los pacientes redujeron el peso en el grupo control y el 65,5% del grupo de estudio (p-valor = 0,0391). El 18,1% de los paciente del grupo control redujeron más del 5% del peso, en el grupo intervención este porcentaje aumentó hasta el 26.9%; estadísticamente significativo (p-valor = 0,0304). En el caso del objetivo del 10% no se detectaron diferencias significativas a los 2 años (5% vs. 8%). Se detectó que a los dos años el IMC en el grupo control se redujo una media 0,9 kg/m2 y 2,4 kg/ m2 en el grupo de estudio (p-valor = 0,0237). Conclusión: el programa basado en intervención motivacional en grupo puede mejorar parámetros antropométricos y estilos de vida en pacientes obesos tratados en un centro de Atención Primaria.

Life review therapy using autobiographical retrieval practice for older adults with clinical depression.

The aim of this experiment was to examine the efficacy of life review based on autobiographical retrieval practice for treating depression in older adults. Thirty-seven clinically depressed older adults aged 64-83, who were also receiving pharmacological treatment, were randomly assigned to life review therapy or to a placebo condition with supportive therapy. Results indicated decreased depression for both conditions, with no significant differences between the two therapies. There was some indication of greater gain in production of specific memories among those in life review therapy. Patients who produced higher numbers of specific memories decreased their depression scores at a faster rate.

[Quality of life of males with spinal cord injury and sexual dysfunction]. / Calidad de vida del varón con lesión medular traumática y disfunción sexual.

AIMS: the aims of this study are to assess the quality of life (QOL) of males with spinal cord injury (SCI) and to know their sexual health. We also analyze the links among clinic and sociodemographic variables, the sexual health of males with SCI and their QOL. METHOD: This is a transversal cross-sectional study that was made in the hospital of Paraplegics of Toledo. The sample included 45 men presenting SCI and sexual dysfunction. Life Satisfaction Checklist and Sexual Health Measurement Scale were used to gather data. RESULTS: The 97, 8% of all participants are interested in having sexual relationships; the 70% of all participants have a steady sexual couple while the 51% often maintain sexual relations. The 86% of the sample admit to suffer from erectile dysfunction and the 71% can't ejaculate. The score of the group which has erectile dysfunction are significantly low in sexual QOL (p t-Student 0.000) and in general QOL (p t-Student 0.001). The sample had an average in general QOL of 34,27 (standard deviation: 2,8), in social QOL 20,16 (SD:2,7), in sexual QOL 7,62 (SD:2,7) and in economic QOL 7,71 (SD:2,6). There isn't a significant relationship among the QOL and the etiology, the degree and the time of evolution of the SCI. CONCLUSIONS: The individuals who have participated in this study generally experienced a good general QOL, but their sexual life is the aspect which causes them a greater dissatisfaction. In fact, those who suffer from erectile dysfunction show less satisfaction with their general and sexual QOL.

Effect of the evaluation of recall on the rate of information recalled by patients in Primary Care.

OBJECTIVE: To analyse whether asking the patient to restate the recommendations they receive before leaving the surgery improves the recall rate once the consultation is finished. METHODS: Observational study in 37 Primary Care Consultant (PCC) in health centres of the city of Albacete. The final sample had 963 patients. RESULTS: The mean rate of recommendations remembered after leaving the surgery was better in the group of patients that restated the recommendations before finishing the doctor-patient encounter than in the group where there was no restatement (p = 0.000). The amount of recommendations showed a negative correlation with the recall rate (r = -0.215). CONCLUSION: Asking patients to repeat treatment recommendations is an effective method of improving the recall of these prescriptions at the end of doctor-patient encounter. PRACTICAL IMPLICATIONS: The importance of communication between health-care professionals and patients justifies the performance of studies so that it can be improved and, according to the results of this study, it would be advisable to use the method proposed on a more regular basis by the PCC as a way of improving communication and recall of medical advice.

Gene expression in diplosporous and sexual Eragrostis curvula genotypes with differing ploidy levels.

The molecular nature of gene expression during the initiation and progress of diplosporous apomixis is still unknown. Moreover, the basis of the close correlation between diplospory and polyploidy is not clarified yet. A comparative expression analysis was performed based on expressed sequence tags (ESTs) sequencing and differential display in an Eragrostis curvula diplosporous tetraploid genotype (T, 4x apo), a sexual diploid derivative obtained from tissue culture (D, 2x sex) and an artificial sexual tetraploid obtained from the diploid seeds after colchicine treatment (C, 4x sex). From a total of 8,884 unigenes sequenced from inflorescence-derived libraries, 112 (1.26%) showed significant differential expression in individuals with different ploidy level and/or variable reproductive mode. Independent comparisons between plants with different reproductive mode (same ploidy) or different ploidy level (same reproductive mode) allowed the identification of genes modulated in response to diplosporous development or polyploidization, respectively. Surprisingly, a group of genes (Group 3) were differentially expressed or silenced only in the 4x sex plant, presenting similar levels of expression in the 4x apo and the 2x sex genotypes. A group of randomly selected differential genes was validated by QR-PCR. Differential display analysis showed that in general the 4x apo and 4x sex expression profiles were more related and different from the 2x sex one, but confirmed the existence of Group 3-type genes, in both inflorescences and leaves. The possible biological significance for the occurrence of this particular group of genes is discussed. In silico mapping onto the rice genome was used to identify candidates mapping to the region syntenic to the diplospory locus.