VaAPRT3 Gene is Associated With Sex Determination in Vitis amurensis

In the past decade, progress has been made in sex determination mechanism in Vitis. However, genes responsible for sexual differentiation and its mechanism in V. amurensis remain unknown. Here, we identify a sex determination candidate gene coding adenine phosphoribosyl transferase 3 (VaAPRT3) in V. amurensis. Cloning and sequencing of the VaAPRT3 gene allowed us to develop a molecular marker able to discriminate female individuals from males or hermaphrodites based on a 22-bp InDel. Gene expression and endogenous cytokinin content analysis revealed that the VaAPRT3 gene is involved in sex determination or, to be precise, in female organ differentiation, through regulating cytokinin metabolism in V. amurensis. This study enlarged the understanding of sex determination mechanism in the genus Vitis, and the sex marker could be used as a helpful tool for sexual identification in breeding programs as well as in investigation and collection of V. amurensis germplasms.

Single-cell protein analysis reveals metastable states during the transition to a sensory organ fate

Cell fate decisions can be envisioned as bifurcating dynamical systems, and the decision that Drosophila cells make to undergo sensory organ differentiation has been sucessfully described as such. We have extended these studies by focusing on the Senseless protein, which orchestrates the sensory fate transition. Wing cells contain intermediate Senseless numbers prior to their fate transition, after which they express much greater numbers of Senseless molecules as they differentiate. However, the dynamics are not consistent with it being a simple bistable system. Cells with intermediate Senseless are best modeled as residing in four discrete states, each with a distinct protein number and occupying a specific region of the tissue. Although the four states are stable over time, the number of molecules in each state vary with time. Remarkably, the fold-change in molecule number between adjacent states is invariant and robust to absolute protein number variation. Thus, cells transitioning to sensory fates exhibit metastability with relativistic properties.

Functional analysis of co-expression networks of zebrafish ace2 reveals enrichment of pathways associated with development and disease.

Human Angiotensin I Converting Enzyme 2 (ACE2) plays essential roles in blood pressure regulation and SARS-CoV-2 entry. ACE2 has a highly conserved, one-to-one ortholog, called ace2, in zebrafish, which is an important model for human diseases. However, zebrafish ace2 expression profile has not yet been studied during early development, between genders, across different genotypes, or in disease. Moreover, a network-based meta-analysis for the extraction of functionally enriched pathways associated with differential ace2 expression is lacking in the literature. Herein, we first identified significant development-, tissue-, genotype- and gender-specific modulations in ace2 expression via meta-analysis of zebrafish Affymetrix transcriptomics datasets (ndatasets=107); and the correlation analysis of ace2 meta-differential expression profile revealed distinct positively and negatively correlated local functionally enriched gene networks. Moreover, we demonstrated that ace2 expression was significantly modulated under different physiological and pathological conditions related to development, tissue, gender, diet, infection, and inflammation using additional RNAseq datasets. Our findings implicate a novel translational role for zebrafish ace2 in organ differentiation and pathologies observed in the intestines and liver.

Characterization of Japanese Apricot (Prunus mume) Floral Bud Development Using a Modified BBCH Scale and Analysis of the Relationship between BBCH Stages and Floral Primordium Development and the Dormancy Phase Transition

Bud dormancy is an important developmental stage that ensures that trees can tolerate environmental stresses in winter and bloom uniformly in the following spring. Regarding Rosaceae floral buds, exposure to chilling conditions promotes floral primordium development and the transition from endodormancy to ecodormancy. A subsequent period of warm conditions induces blooming. In Japanese apricot (Prunus mume), dormancy progression is accompanied by morphological changes that alter the bud appearance and internal structures. We used a modified BBCH scale and conducted microscopy analyses to elucidate the bud developmental stage of three cultivars with contrasting chilling requirements. The floral bud developmental period corresponding to BBCH stages 51–53 includes the transition from endodormancy to ecodormancy in all three cultivars. Male meiosis and microspore development occurred during this transition in high-chill cultivars, but were detected considerably later than the transition in the low-chill cultivar. A slow or suspended developmental phase was observed only for the high-chill cultivars upon completion of floral primordium organ differentiation, suggesting that chilling may be required to induce floral bud maturation and dormancy release only in high-chill cultivars. Possible relationships among BBCH stages, flowering-related morphological characteristics, and the dormancy phase transition in Japanese apricot are discussed.

The VIL gene CRAWLING ELEPHANT controls maturation and differentiation in tomato via polycomb silencing

VERNALIZATION INSENSITIVE 3-LIKE (VIL) proteins are PHD-finger proteins that recruit the repressor complex Polycomb Repressive Complex 2 (PRC2) to the promoters of target genes. Most known VIL targets are flowering repressor genes. Here, we show that the tomato VIL gene CRAWLING ELEPHANT ( CREL ) promotes differentiation throughout plant development by facilitating the trimethylation of Histone H3 on lysine 27 (H3K27me3). We identified the crel mutant in a screen for suppressors of the simple-leaf phenotype of entire ( e ), a mutant in the AUX/IAA gene ENTIRE/SlIAA9, involved in compound-leaf development in tomato. crel mutants have increased leaf complexity, and suppress the ectopic blade growth of e mutants. In addition, crel mutants are late flowering, and have delayed and aberrant stem, root and flower development. Consistent with a role for CREL in recruiting PRC2, crel mutants present altered H3K27me3 modifications at a subset of PRC2 targets throughout the genome. Our results uncover a wide role for CREL in plant and organ differentiation in tomato and suggest that CREL is required for targeting PRC2 activity to, and thus silencing, a specific subset of polycomb targets.

New Insights into Cellular Functions of Nuclear Actin

Actin is one of the most abundant proteins in eukaryotic cells. There are different pools of nuclear actin often undetectable by conventional staining and commercial antibodies used to identify cytoplasmic actin. With the development of more sophisticated imaging and analytical techniques, it became clear that nuclear actin plays a crucial role in shaping the chromatin, genomic, and epigenetic landscape, transcriptional regulation, and DNA repair. This multifaceted role of nuclear actin is not only important for the function of the individual cell but also for the establishment of cell fate, and tissue and organ differentiation during development. Moreover, the changes in the nuclear, chromatin, and genomic architecture are preamble to various diseases. Here, we discuss some of the newly described functions of nuclear actin.

Importance of the lactation period in developmental programming in rodents

Lactation is a critical period during which maternal nutritional and environmental challenges affect milk composition and, therefore, organ differentiation, structure, and function in offspring during the early postnatal period. Evidence to date shows that lactation is a vulnerable time during which transient insults can have lasting effects, resulting in altered health outcomes in offspring in adult life. Despite the importance of the developmental programming that occurs during this plastic period of neonatal life, there are few comprehensive reviews of the multiple challenges—especially to the dam—during lactation. This review presents milk data from rodent studies involving maternal nutritional challenges and offspring outcome data from studies involving maternal manipulations during lactation. Among the topics addressed are maternal nutritional challenges and the effects of litter size and artificial rearing on offspring metabolism and neural and endocrine outcomes. The lactation period is an opportunity to correct certain functional deficits resulting from prenatal challenges to the fetus, but, if not personalized, can also lead to undesirable outcomes related to catch up-growth and overnutrition.

Interactions between WUSCHEL- and CYC2-like Transcription Factors in Regulating the Development of Reproductive Organs in Chrysanthemum morifolium

Chrysanthemum morifolium is a gynomonoecious plant that bears both female zygomorphic ray florets and bisexual actinomorphic disc florets in the inflorescence. This sexual system is quite prevalent in Asteraceae, but poorly understood. CYCLOIDEA (CYC) 2 subclade transcription factors, key regulators of flower symmetry and floret identity in Asteraceae, have also been speculated to function in reproductive organs and could be an entry point for studying gynomonoecy. However, the molecular mechanism is still unclear. On the other hand, the Arabidopsis WUSCHEL (WUS) transcription factor has been proven to play a vital role in the development of reproductive organs. Here, a WUS homologue (CmWUS) in C. morifolium was isolated and characterized. Overexpression of CmWUS in A. thaliana led to shorter siliques and fewer stamens, which was similar to CYC2-like genes reported before. In addition, both CmWUS and CmCYC2 were highly expressed in flower buds during floral organ differentiation and in the reproductive organs at later development stages, indicating their involvement in the development of reproductive organs. Moreover, CmWUS could directly interact with CmCYC2d. Thus, our data suggest a collaboration between CmWUS and CmCYC2 in the regulation of reproductive organ development in chrysanthemum and will contribute to a further understanding of the gynomonoecious sexual system in Asteraceae.