scholarly journals Xenopus hybrids provide insight into cell and organism size control

2018 ◽  
Author(s):  
Romain Gibeaux ◽  
Kelly Miller ◽  
Rachael Acker ◽  
Taejoon Kwon ◽  
Rebecca Heald
Keyword(s):  
Gene Expression ◽  
Cell Size ◽  
Size Control ◽  
Fundamental Question ◽  
Scaling Relationships ◽  
Tailbud Stage ◽  
Differential Gene ◽  
Genome Activation ◽  
Insight Into ◽  
Zygotic Genome

AbstractDetermining how size is controlled is a fundamental question in biology that is poorly understood at the organismal, cellular and subcellular levels. The Xenopus species, X. laevis and X. tropicalis differ in size at all three of these levels. Despite these differences, fertilization of X. laevis eggs with X. tropicalis sperm gives rise to viable hybrid animals that are intermediate in size. We observed that although hybrid and X. laevis embryogenesis initiates from the same sized zygote and proceeds synchronously through development, hybrid animals were smaller by the tailbud stage, and a change in the ratio of nuclear size to cell size was observed shortly after zygotic genome activation (ZGA), suggesting that differential gene expression contributes to size differences. Transcriptome analysis at the onset of ZGA identified twelve transcription factors paternally expressed in hybrids. A screen of these X. tropicalis factors by expression in X. laevis embryos revealed that Hes7 and Ventx2 significantly reduced X. laevis body length size by the tailbud stage, although nuclear to cell size scaling relationships were not affected as in the hybrid. Together, these results suggest that transcriptional regulation contributes to biological size control in Xenopus.

scholarly journals Pluripotency factors select gene expression repertoire at Zygotic Genome Activation

2020 ◽  
Author(s):  
Meijiang Gao ◽  
Marina Veil ◽  
Marcus Rosenblatt ◽  
Anna Gebhard ◽  
Helge Hass ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Early Gene ◽  
Zebrafish Embryos ◽  
Fate Specification ◽  
Pluripotency Factors ◽  
Zygotic Transcription ◽  
Simultaneous Loss ◽  
Genome Activation ◽  
Zygotic Genome

AbstractAwakening of zygotic transcription in animal embryos relies on maternal pioneer transcription factors. The interplay of global and specific functions of these proteins remains poorly understood. Here, we analyzed nucleosome positioning, H3K27 acetylation, transcription, and gastrulation rates in zebrafish embryos lacking pluripotency factors Pou5f3 and Sox19b. We show that the bulk transcriptional onset does not require Sox19b and Pou5f3, but is sensitive to their balance. Pou5f3 docks H3K27ac on the enhancers of genes involved in gastrulation and ventral fate specification. Sox19b facilitates Pou5f3 access to one-third of these enhancers. The genes regulating mesendodermal and dorsal fates are primed for activation independently on Pou5f3 and Sox19b. Strikingly, the loss of either factor results in activation of silent enhancers; simultaneous loss of both leads to premature expression of differentiation genes. Our results uncover how independent activities of maternal Pou5f3 and Sox19b add up or antagonize to determine the early gene expression repertoire.

scholarly journals Combinatorial action of NF–Y and TALE at embryonic enhancers defines distinct gene expression programs during zygotic genome activation in zebrafish

2020 ◽  
Vol 459 (2) ◽  
pp. 161-180 ◽  
Author(s):  
William Stanney ◽  
Franck Ladam ◽  
Ian J. Donaldson ◽  
Teagan J. Parsons ◽  
René Maehr ◽  
...  
Keyword(s):  
Gene Expression ◽  
Zygotic Genome Activation ◽  
Distinct Gene ◽  
Genome Activation ◽  
Zygotic Genome

scholarly journals Scaling gene expression for cell size control and senescence in Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Yuping Chen ◽  
Bruce Futcher
Keyword(s):  
Gene Expression ◽  
Cell Size ◽  
Size Control ◽  
Gene Expression Program ◽  
Set Point ◽  
Size Dependent ◽  
Large Size ◽  
Mean Size ◽  
Almost All ◽  
Expression Program

Abstract Cells divide with appropriate frequency by coupling division to growth—that is, cells divide only when they have grown sufficiently large. This process is poorly understood, but has been studied using cell size mutants. In principle, mutations affecting cell size could affect the mean size (“set-point” mutants), or they could affect the variability of sizes (“homeostasis” mutants). In practice, almost all known size mutants affect set-point, with little effect on size homeostasis. One model for size-dependent division depends on a size-dependent gene expression program: Activators of cell division are over-expressed at larger and larger sizes, while inhibitors are under-expressed. At sufficiently large size, activators overcome inhibitors, and the cell divides. Amounts of activators and inhibitors determine the set-point, but the gene expression program (the rate at which expression changes with cell size) determines the breadth of the size distribution (homeostasis). In this model, set-point mutants identify cell cycle activators and inhibitors, while homeostasis mutants identify regulators that couple expression of activators and inhibitors to size. We consider recent results suggesting that increased cell size causes senescence, and suggest that at very large sizes, an excess of DNA binding proteins leads to size induced senescence.

scholarly journals Differential gene expression in the endometrium on gestation day 12 provides insight into sow prolificacy

BMC Genomics ◽  
2013 ◽  
Vol 14 (1) ◽  
pp. 45 ◽  
Author(s):  
Hao Zhang ◽  
Shouqi Wang ◽  
Manqing Liu ◽  
Ailing Zhang ◽  
Zhenfang Wu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Differential Gene Expression ◽  
Differential Gene ◽  
Insight Into

scholarly journals Differential Gene Expression with an Emphasis on Floral Organ Size Differences in Natural and Synthetic Polyploids of Nicotiana tabacum (Solanaceae)

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1097
Author(s):  
Jacob B. Landis ◽  
Amelda Kurti ◽  
Amber J. Lawhorn ◽  
Amy Litt ◽  
Elizabeth W. McCarthy
Keyword(s):  
Gene Expression ◽  
Nicotiana Tabacum ◽  
Cell Size ◽  
Corolla Tube ◽  
Floral Organ ◽  
Organ Size ◽  
Cell Width ◽  
Differential Gene ◽  
Floral Organ Size ◽  
Natural And Synthetic

Floral organ size, especially the size of the corolla, plays an important role in plant reproduction by facilitating pollination efficiency. Previous studies have outlined a hypothesized organ size pathway. However, the expression and function of many of the genes in the pathway have only been investigated in model diploid species; therefore, it is unknown how these genes interact in polyploid species. Although correlations between ploidy and cell size have been shown in many systems, it is unclear whether there is a difference in cell size between naturally occurring and synthetic polyploids. To address these questions comparing floral organ size and cell size across ploidy, we use natural and synthetic polyploids of Nicotiana tabacum (Solanaceae) as well as their known diploid progenitors. We employ a comparative transcriptomics approach to perform analyses of differential gene expression, focusing on candidate genes that may be involved in floral organ size, both across developmental stages and across accessions. We see differential expression of several known floral organ candidate genes including ARF2, BIG BROTHER, and GASA/GAST1. Results from linear models show that ploidy, cell width, and cell number positively influence corolla tube circumference; however, the effect of cell width varies by ploidy, and diploids have a significantly steeper slope than both natural and synthetic polyploids. These results demonstrate that polyploids have wider cells and that polyploidy significantly increases corolla tube circumference.

scholarly journals Prepatterning of Developmental Gene Expression by Modified Histones before Zygotic Genome Activation

2011 ◽  
Vol 21 (6) ◽  
pp. 993-1004 ◽  
Author(s):  
Leif C. Lindeman ◽  
Ingrid S. Andersen ◽  
Andrew H. Reiner ◽  
Nan Li ◽  
Håvard Aanes ◽  
...  
Keyword(s):  
Gene Expression ◽  
Zygotic Genome Activation ◽  
Developmental Gene ◽  
Developmental Gene Expression ◽  
Genome Activation ◽  
Zygotic Genome

scholarly journals Chiffon triggers global histone H3 acetylation and expression of developmental genes in Drosophila embryos

2021 ◽  
Author(s):  
Eliana F. Torres-Zelada ◽  
Smitha George ◽  
Hannah R. Blum ◽  
Vikki M. Weake
Keyword(s):  
Gene Expression ◽  
Histone Acetylation ◽  
Potential Role ◽  
Developmental Genes ◽  
Histone Acetyltransferase Gcn5 ◽  
Genome Activation ◽  
H3 Acetylation ◽  
Drosophila Embryos ◽  
Cell Cycle Kinase ◽  
Zygotic Genome

The histone acetyltransferase Gcn5 is critical for gene expression and development. In Drosophila, Gcn5 is part of four complexes (SAGA, ATAC, CHAT, and ADA) that are essential for fly viability and have key roles in regulating gene expression. Here, we show that while the SAGA, ADA, and CHAT complexes play redundant roles in embryonic gene expression, the insect-specific CHAT complex uniquely regulates expression of a subset of developmental genes. We also identify a substantial decrease in histone acetylation in chiffon mutant embryos that exceeds that observed in ada2b, suggesting broader roles for Chiffon in regulating histone acetylation outside of the Gcn5 complexes. The chiffon gene encodes two independent polypeptides that nucleate formation of either the CHAT or Dbf4-dependent kinase (DDK) complexes. DDK includes the cell cycle kinase Cdc7, which is necessary for maternally-driven DNA replication in the embryo. We identify a temporal switch between the expression of these chiffon gene products during a short window during the early nuclear cycles in embryos that correlates with the onset of zygotic genome activation, suggesting a potential role for CHAT in this process.

scholarly journals RNA Sequencing Data Sets Identifying Differentially Expressed Transcripts during Campylobacter jejuni Biofilm Formation

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Greg Tram ◽  
William P. Klare ◽  
Joel A. Cain ◽  
Basem Mourad ◽  
Stuart J. Cordwell ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Sequencing ◽  
Campylobacter Jejuni ◽  
Biofilm Formation ◽  
Foodborne Pathogen ◽  
Data Sets ◽  
Sequencing Data ◽  
Content Type ◽  
Differential Gene ◽  
Insight Into

Campylobacter jejuni is a foodborne pathogen and an important contributor to gastroenteritis in humans. C. jejuni readily forms biofilms which may play a role in the transmission of the pathogen from animals to humans. Herein, we present RNA sequencing data investigating differential gene expression in biofilm and planktonic C. jejuni. These data provide insight into pathways which may be important to biofilm formation in this organism.

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