Morphological, genic and epigenetic differences often exist in separate sexes of dioecious and trioecious plants. However, the connections and relationships among them in different breeding systems are still unclear. Papaya has three sex types, which is genetically determined and epigenetically regulated, and was chosen as a model to study sex differentiation. Bisulfite sequencing of genomic DNA extracted from early-stage flowers revealed sex-specific genomic methylation landscapes and seasonally methylome reprogramming processes in dioecious and gynodioecious papaya grown in spring and summer. Extensive methylation of sex-determining region (SDR) was the distinguishing epigenetic characteristics of nascent XY sex chromosomes in papaya. Seasonal methylome reprogramming of early-stage flowers in both dioecy and gynodioecy systems were detected, resulting from transcriptional expression pattern alterations of methylation-modification-related and chromatin-remodeling-related genes, particularly from those genes involved in active demethylation. Genes involved in phytohormone signal transduction pathway in male flowers have played an important role in the formation of male-specific characteristics. These findings enhanced the understanding of the genetic and epigenetic contributions to sex differentiation and the complexity of sex chromosome evolution in trioecious plants.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8935930 | PMC |
http://dx.doi.org/10.1093/hr/uhab065 | DOI Listing |
G3 (Bethesda)
January 2025
Ecologie Systematique et Evolution, CNRS, Université Paris-Saclay, AgroParisTech, 91198 Gif-sur-Yvette, France.
Recombination is advantageous over the long-term, as it allows efficient selection and purging deleterious mutations. Nevertheless, recombination suppression has repeatedly evolved in sex and mating-type chromosomes. The evolutionary causes for recombination suppression and the proximal mechanisms preventing crossing overs are poorly understood.
View Article and Find Full Text PDFG3 (Bethesda)
January 2025
Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S3G5, Canada.
Sex-determining region Y box 2 (Sox2) is a critical transcription factor for embryogenesis and neural stem and progenitor cell (NSPC) maintenance. While distal enhancers control Sox2 in embryonic stem cells (ESCs), enhancers closer to the gene are implicated in Sox2 transcriptional regulation in neural development. We hypothesize that a downstream enhancer cluster, termed Sox2 regulatory regions 2-18 (SRR2-18), regulates Sox2 transcription in neural stem cells and we investigate this in NSPCs derived from mouse ESCs.
View Article and Find Full Text PDFGenome Biol Evol
January 2025
Department of Molecular and Cell Biology, University of California-Merced, Merced, CA 95343.
Eukaryotic genome size varies considerably, even among closely related species. The causes of this variation are unclear, but weak selection against supposedly costly "extra" genomic sequences has been central to the debate for over 50 years. The mutational hazard hypothesis, which focuses on the increased mutation rate to null alleles in superfluous sequences, is particularly influential, though challenging to test.
View Article and Find Full Text PDFFish Shellfish Immunol
January 2025
Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China. Electronic address:
Sexual dimorphism is well-documented in aquaculture, particularly regarding growth differences, wherein one sex often grows faster than the other. However, despite the phenomenon being so widely documented, its underlying molecular mechanisms remain poorly understood. As an important digestive and immune organ, the gut plays key roles in the regulation of fish growth.
View Article and Find Full Text PDFJACC Adv
January 2025
Department of Heart Disease, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway. Electronic address:
Background: Biomarkers are used for long-term risk prediction of cardiovascular (CV) events in patients presenting with suspected acute coronary syndromes.
Objectives: This study investigated whether there are sex differences in the long-term prognostic value of biomarkers in patients presenting with suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS).
Methods: High-sensitivity cardiac troponin (hs-cTn), hs-cTnI, N-terminal pro-B-type natriuretic peptide (NT-proBNP), growth differentiation factor (GDF)-15, and C-reactive protein (CRP) concentrations were measured in 1,476 patients admitted with suspected NSTE-ACS.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!