scholarly journals Sexual dimorphism in the Drosophila metabolome increases throughout development

2016 ◽  
Author(s):  
FC Ingleby ◽  
Edward H Morrow

AbstractThe expression of sexually dimorphic phenotypes from a shared genome between males and females is a longstanding puzzle in evolutionary biology. Increasingly, research has made use of transcriptomic technology to examine the molecular basis of sexual dimorphism through gene expression studies, but even this level of detail misses the metabolic processes that ultimately link gene expression with the whole organism phenotype. We use metabolic profiling in Drosophila melanogaster to complete this missing step, with a view to examining variation in male and female metabolic profiles, or metabolomes, throughout development. We show that the metabolome varies considerably throughout larval, pupal and adult stages. We also find significant sexual dimorphism in the metabolome, although only in pupae and adults, and the extent of dimorphism tends to increase throughout development. We compare this to transcriptomic data from the same population and find that the general pattern of increasing sex differences throughout development is mirrored in RNA expression. We discuss our results in terms of the usefulness of metabolic profiling in linking genotype and phenotype to more fully understand the basis of sexually dimorphic phenotypes.

2021 ◽  
Author(s):  
Mathias Scharmann ◽  
Anthony G Rebelo ◽  
John R Pannell

AbstractThe males and females of many dioecious plants differ in morphological (Dawson and Geber 1999; Barrett and Hough 2013; Tonnabel et al. 2017), physiological (Juvany and Munné-Bosch 2015), life-history (Delph 1999), and defence traits (Cornelissen and Stiling 2005). Ultimately, such sexual dimorphism must largely be due to differential gene expression between the sexes (Ellegren and Parsch 2007), but little is known about how sex-biased genes are recruited and how their expression evolves over time. We measured gene expression in leaves of males and females of ten species sampled across the South African Cape genus Leucadendron, which shows repeated changes in sexual dimorphism and includes the most extreme differences between males and females in flowering plants (Midgley 2010; Barrett and Hough 2013; Tonnabel et al. 2014). Even in the most dimorphic species in our sample, fewer than 2% of genes showed sex-biased gene expression (SBGE) in vegetative tissue, with surprisingly little correspondence between SBGE and vegetative dimorphism across species. The identity of sex-biased genes in Leucadendron was highly species-specific, with a rapid turnover among species. In animals, sex-biased genes often evolve more quickly than unbiased genes in their sequences and expression levels (Ranz et al. 2003; Khaitovich et al. 2005; Ellegren and Parsch 2007; Voolstra et al. 2007; Harrison et al. 2015; Naqvi et al. 2019), consistent with hypotheses invoking rapid evolution due to sexual selection. Our phylogenetic analysis in Leucadendron, however, clearly indicates that sex-biased genes are recruited from a class of genes with ancestrally rapid rates of expression evolution, perhaps due to low evolutionary or pleiotropic constraints. Nevertheless, we also find evidence for adaptive evolution of expression levels once sex bias evolves. Thus, although the expression of sex-biased genes is ultimately responsive to selection, high rates of expression evolution might usually predate the evolution of sex bias.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kim Hoa Ho ◽  
Annarita Patrizi

AbstractChoroid plexus (ChP), a vascularized secretory epithelium located in all brain ventricles, plays critical roles in development, homeostasis and brain repair. Reverse transcription quantitative real-time PCR (RT-qPCR) is a popular and useful technique for measuring gene expression changes and also widely used in ChP studies. However, the reliability of RT-qPCR data is strongly dependent on the choice of reference genes, which are supposed to be stable across all samples. In this study, we validated the expression of 12 well established housekeeping genes in ChP in 2 independent experimental paradigms by using popular stability testing algorithms: BestKeeper, DeltaCq, geNorm and NormFinder. Rer1 and Rpl13a were identified as the most stable genes throughout mouse ChP development, while Hprt1 and Rpl27 were the most stable genes across conditions in a mouse sensory deprivation experiment. In addition, Rpl13a, Rpl27 and Tbp were mutually among the top five most stable genes in both experiments. Normalisation of Ttr and Otx2 expression levels using different housekeeping gene combinations demonstrated the profound effect of reference gene choice on target gene expression. Our study emphasized the importance of validating and selecting stable housekeeping genes under specific experimental conditions.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1272
Author(s):  
Judit Tajti ◽  
Magda Pál ◽  
Tibor Janda

Oat (Avena sativa L.) is a widely cultivated cereal with high nutritional value and it is grown mainly in temperate regions. The number of studies dealing with gene expression changes in oat continues to increase, and to obtain reliable RT-qPCR results it is essential to establish and use reference genes with the least possible influence caused by experimental conditions. However, no detailed study has been conducted on reference genes in different tissues of oat under diverse abiotic stress conditions. In our work, nine candidate reference genes (ACT, TUB, CYP, GAPD, UBC, EF1, TBP, ADPR, PGD) were chosen and analysed by four statistical methods (GeNorm, Normfinder, BestKeeper, RefFinder). Samples were taken from two tissues (leaves and roots) of 13-day-old oat plants exposed to five abiotic stresses (drought, salt, heavy metal, low and high temperatures). ADPR was the top-rated reference gene for all samples, while different genes proved to be the most stable depending on tissue type and treatment combinations. TUB and EF1 were most affected by the treatments in general. Validation of reference genes was carried out by PAL expression analysis, which further confirmed their reliability. These results can contribute to reliable gene expression studies for future research in cultivated oat.


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