scholarly journals Developmental role of plk4 in Xenopus laevis and Danio rerio: implications for Seckel Syndrome

2015 ◽  
Vol 93 (4) ◽  
pp. 396-404 ◽  
Author(s):  
Candace Elaine Rapchak ◽  
Neeraj Patel ◽  
John Hudson ◽  
Michael Crawford

The polo-like kinases are a family of conserved serine/threonine kinases that play multiple roles in regulation of the cell cycle. Unlike its four other family members, the role of Plk4 in embryonic development has not been well characterized. In mice, Plk4−/− embryos arrest at E7.5, just prior to the initiation of somitogenesis. This has led to the hypothesis that Plk4 expression may be essential to somitogenesis. Recently characterized human mutations lead to Seckel Syndrome. Riboprobe in situ hybridization revealed that plk4 is ubiquitously expressed during early stages of development of Xenopus and Danio; in later stages, expression in frogs restricts to somites as well as eye, otic vesicle, and branchial arch, and brain. Expression patterns in fish remain ubiquitous. Both somite and eye development require planar cell polarity, and disruption of plk4 function in frog by means of morpholino-mediated translational knockdown yields orientational disorganization of both these structures. These results provide the first steps in defining a new role for plk4 in organogenesis and implies a role in planar cell polarity, segmentation, and in recently described PLK4 mutations in human.

2020 ◽  
Author(s):  
Tong Zhao ◽  
Alma Piñeyro-Nelson ◽  
Qianxia Yu ◽  
Xiaoying Hu ◽  
Huanfang Liu ◽  
...  

Abstract Background:The flower of Hedychium coronarium possesses highly specialized floral organs: a synsepalous calyx, petaloid staminodes and a labellum. The formation of these organs is controlled by two gene categories: floral organ identity genes and organ boundary genes, which may function individually or jointly during flower development. Although the floral organogenesis of H. coronarium has been studied at the morphological level, the underlying molecular mechanisms involved in its floral development still remain poorly understood. In addition, previous works analyzing the role of MADS-box genes in controlling floral organ specification in some Zingiberaceae did not address the molecular mechanisms involved in the formation of particular organ morphologies that emerge later in flower development, such as the synsepalous calyx formed through intercalary growth of adjacent sepals. Results:Here, we used comparative transcriptomics combined with Real-time quantitative PCR and mRNA in situ hybridization to investigate gene expression patterns of ABC-class genes in H. coronarium flowers, as well as the homolog of the organ boundary gene PETAL LOSS (HcPTL). qRT-PCR detection showed that HcAP3 and HcAG were expressed in both the petaloid staminode and the fertile stamen. mRNA in situ hybridization showed that HcPTL was expressed in developing meristems, including cincinnus primordia, floral primordia, common primordia and almost all new initiating floral organ primordia.Conclusions:Our studies found that stamen/petal identity or stamen fertility in H. coronarium was not necessarily correlated with the differential expression of HcAP3 and HcAG. We also found a novel spatio-temporal expression pattern for HcPTL mRNA, suggesting it may have evolved a lineage-specific role in the morphogenesis of the Hedychium flower. Our study provides a new transcriptome reference and a functional hypothesis regarding the role of a boundary gene in organ fusion that should be further addressed through phylogenetic analyzes of this gene, as well as functional studies.


2020 ◽  
Vol 11 ◽  
Author(s):  
Qianxia Yu ◽  
Xueyi Tian ◽  
Canjia Lin ◽  
Chelsea D. Specht ◽  
Jingping Liao

The asymmetric flower, lacking any plane of symmetry, is rare among angiosperms. Canna indica L. has conspicuously asymmetric flowers resulting from the presence of a half-fertile stamen, while the other androecial members develop as petaloid staminodes or abort early during development. The molecular basis of the asymmetric distribution of fertility and petaloidy in the androecial whorls remains unknown. Ontogenetic studies have shown that Canna flowers are borne on monochasial (cincinnus) partial florescences within a racemose inflorescence, with floral asymmetry likely corresponding to the inflorescence architecture. Given the hypothesized role of CYC/TB1 genes in establishing floral symmetry in response to the influence of the underlying inflorescence architecture, the spatiotemporal expression patterns of three Canna CYC/TB1 homologs (CiTBL1a, CiTBL1b-1, and CiTBL1b-2) were analyzed during inflorescence and floral development using RNA in situ hybridization and qRT-PCR. In the young inflorescence, both CiTBL1a and CiTBL1b-1 were found to be expressed in the bracts and at the base of the lateral florescence branches, whereas transcripts of CiTBL1b-2 were mainly detected in flower primordia and inflorescence primordia. During early flower development, expression of CiTBL1a and CiTBL1b-1 were both restricted to the developing sepals and petals. In later flower development, expression of CiTBL1a was reduced to a very low level while CiTBL1b-1 was detected with extremely high expression levels in the petaloid androecial structures including the petaloid staminodes, the labellum, and the petaloid appendage of the fertile stamen. In contrast, expression of CiTBL1b-2 was strongest in the fertile stamen throughout flower development, from early initiation of the stamen primordium to maturity of the ½ anther. Heterologous overexpression of CiTBL genes in Arabidopsis led to dwarf plants with smaller petals and fewer stamens, and altered the symmetry of mature flowers. These data provide evidence for the involvement of CYC/TB1 homologs in the development of the asymmetric Cannaceae flower.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Gang Wu ◽  
Jiao Ge ◽  
Xupei Huang ◽  
Yimin Hua ◽  
Dezhi Mu

Congenital heart disease (CHD) is a common cardiac disorder in humans. Despite many advances in the understanding of CHD and the identification of many associated genes, the fundamental etiology for the majority of cases remains unclear. The planar cell polarity (PCP) signaling pathway, responsible for tissue polarity inDrosophilaand gastrulation movements and cardiogenesis in vertebrates, has been shown to play multiple roles during cardiac differentiation and development. The disrupted function of PCP signaling is connected to some CHDs. Here, we summarize our current understanding of how PCP factors affect the pathogenesis of CHD.


2014 ◽  
Vol 43 (31) ◽  
pp. 11843-11854 ◽  
Author(s):  
Apurav Guleria ◽  
Ajay K. Singh ◽  
Madhab C. Rath ◽  
Sisir K. Sarkar ◽  
Soumyakanti Adhikari

Influence of the intrinsic structure of RTIL on the morphology of as synthesized CdSe nanoparticles is demonstrated. IL plays multiple roles,i.e.as a solvent, stabilizer and shape directing template.


Reproduction ◽  
2007 ◽  
Vol 133 (2) ◽  
pp. 487-493 ◽  
Author(s):  
Haengseok Song ◽  
Kyuyong Han ◽  
Hyunjung Lim

We previously showed that blastocyst can initiate implantation beyond the normal ‘window’ of uterine receptivity on day 5 of pregnancy and pseudopregnancy (PSP) in mice. In this study, we investigated whether uterine receptivity for blastocyst implantation can be further extended on day 6 of PSP and the role of progesterone (P4) on this event. Embryo transfers, experimentally induced decidualization,in situhybridization and [3H]thymidine incorporation were performed. Blastocysts initiate attachment reaction within 48 h when transferred on day 5, but not on day 6 of PSP. Likewise, decidualization reaction occurred on days 4 and 5 of PSP, but completely failed on day 6. However, P4supplementation partially retains uterine receptivity for blastocyst implantation and decidualization on day 6 of PSP. In addition, certain indicators of uterine receptivity, such as cell proliferation profile and expression patterns of implantation-related genes were similarly observed on days 4 and 5 of PSP, but not on day 6. Consistent with embryo transfer and decidualization, exogenous administration of P4partially restores these indicators on day 6 of PSP. We concluded that critical physiological changes occur between days 4 and 5 of PSP, leading to uterine non-receptivity on day 6, but P4is able to extend the uterine receptivity through day 6.


2015 ◽  
Vol 1615 ◽  
pp. 22-30 ◽  
Author(s):  
Xiao-yu Yang ◽  
Kai Jin ◽  
Rui Ma ◽  
Juan-mei Yang ◽  
Wen-wei Luo ◽  
...  

Open Biology ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 200290
Author(s):  
Stefano Pietra ◽  
KangBo Ng ◽  
Peter A. Lawrence ◽  
José Casal

We investigate planar cell polarity (PCP) in the Drosophila larval epidermis. The intricate pattern of denticles depends on only one system of PCP, the Dachsous/Fat system. Dachsous molecules in one cell bind to Fat molecules in a neighbour cell to make intercellular bridges. The disposition and orientation of these Dachsous–Fat bridges allows each cell to compare two neighbours and point its denticles towards the neighbour with the most Dachsous. Measurements of the amount of Dachsous reveal a peak at the back of the anterior compartment of each segment. Localization of Dachs and orientation of ectopic denticles help reveal the polarity of every cell. We discuss whether these findings support our gradient model of Dachsous activity. Several groups have proposed that Dachsous and Fat fix the direction of PCP via oriented microtubules that transport PCP proteins to one side of the cell. We test this proposition in the larval cells and find that most microtubules grow perpendicularly to the axis of PCP. We find no meaningful bias in the polarity of microtubules aligned close to that axis. We also reexamine published data from the pupal abdomen and find no evidence supporting the hypothesis that microtubular orientation draws the arrow of PCP.


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