scholarly journals Distinct roles of haspin in stem cell division and male gametogenesis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katerina Soupsana ◽  
Eleftheria Karanika ◽  
Fani Kiosse ◽  
Anastasia Christogianni ◽  
Yiorgos Sfikas ◽  
...  
Keyword(s):  
Histone H3 ◽  
Embryonic Stem ◽  
Docking Site ◽  
Specific Expression ◽  
Male Gametogenesis ◽  
Chromosomal Passenger ◽  
Dividing Cells ◽  
Stem Cell Division ◽  
Spatio Temporal ◽  
Testis Specific Expression

AbstractThe kinase haspin phosphorylates histone H3 at threonine-3 (H3T3ph) during mitosis. H3T3ph provides a docking site for the Chromosomal Passenger Complex at the centromere, enabling correction of erratic microtubule-chromosome contacts. Although this mechanism is operational in all dividing cells, haspin-null mice do not exhibit developmental anomalies, apart from aberrant testis architecture. Investigating this problem, we show here that mouse embryonic stem cells that lack or overexpress haspin, albeit prone to chromosome misalignment during metaphase, can still divide, expand and differentiate. RNA sequencing reveals that haspin dosage affects severely the expression levels of several genes that are involved in male gametogenesis. Consistent with a role in testis-specific expression, H3T3ph is detected not only in mitotic spermatogonia and meiotic spermatocytes, but also in non-dividing cells, such as haploid spermatids. Similarly to somatic cells, the mark is erased in the end of meiotic divisions, but re-installed during spermatid maturation, subsequent to methylation of histone H3 at lysine-4 (H3K4me3) and arginine-8 (H3R8me2). These serial modifications are particularly enriched in chromatin domains containing histone H3 trimethylated at lysine-27 (H3K27me3), but devoid of histone H3 trimethylated at lysine-9 (H3K9me3). The unique spatio-temporal pattern of histone H3 modifications implicates haspin in the epigenetic control of spermiogenesis.

scholarly journals Testis-specific expression of a novel mouse defensin-like gene, Tdl

2002 ◽  
Vol 116 (1-2) ◽  
pp. 217-221 ◽  
Author(s):  
Miwako Yamamoto ◽  
Yasuhisa Matsui
Keyword(s):  
Specific Expression ◽  
Testis Specific Expression

scholarly journals Developmental differences in genome replication program and origin activation

2020 ◽  
Vol 48 (22) ◽  
pp. 12751-12777
Author(s):  
Cathia Rausch ◽  
Patrick Weber ◽  
Paulina Prorok ◽  
David Hörl ◽  
Andreas Maiser ◽  
...  
Keyword(s):  
Dna Replication ◽  
Single Molecule ◽  
Embryonic Stem ◽  
S Phase ◽  
Developmental Differences ◽  
Centromeric Heterochromatin ◽  
Genome Replication ◽  
Origin Activation ◽  
Spatio Temporal ◽  
Mes Cells

Abstract To ensure error-free duplication of all (epi)genetic information once per cell cycle, DNA replication follows a cell type and developmental stage specific spatio-temporal program. Here, we analyze the spatio-temporal DNA replication progression in (un)differentiated mouse embryonic stem (mES) cells. Whereas telomeres replicate throughout S-phase, we observe mid S-phase replication of (peri)centromeric heterochromatin in mES cells, which switches to late S-phase replication upon differentiation. This replication timing reversal correlates with and depends on an increase in condensation and a decrease in acetylation of chromatin. We further find synchronous duplication of the Y chromosome, marking the end of S-phase, irrespectively of the pluripotency state. Using a combination of single-molecule and super-resolution microscopy, we measure molecular properties of the mES cell replicon, the number of replication foci active in parallel and their spatial clustering. We conclude that each replication nanofocus in mES cells corresponds to an individual replicon, with up to one quarter representing unidirectional forks. Furthermore, with molecular combing and genome-wide origin mapping analyses, we find that mES cells activate twice as many origins spaced at half the distance than somatic cells. Altogether, our results highlight fundamental developmental differences on progression of genome replication and origin activation in pluripotent cells.

scholarly journals A positive feedback mechanism ensures proper assembly of the functional inner centromere during mitosis in human cells

2018 ◽  
Vol 294 (5) ◽  
pp. 1437-1450 ◽  
Author(s):  
Cai Liang ◽  
Zhenlei Zhang ◽  
Qinfu Chen ◽  
Haiyan Yan ◽  
Miao Zhang ◽  
...  
Keyword(s):  
Positive Feedback ◽  
Histone H3 ◽  
Causal Link ◽  
Feedback Mechanism ◽  
Histone H2a ◽  
Defective Mutant ◽  
Chromosomal Passenger ◽  
Phosphatase 2A ◽  
Elevated Rate ◽  
Positive Feedback Mechanism

The inner centromere region of a mitotic chromosome critically regulates sister chromatid cohesion and kinetochore–microtubule attachments. However, the molecular mechanism underlying inner centromere assembly remains elusive. Here, using CRISPR/Cas9-based gene editing in HeLa cells, we disrupted the interaction of Shugoshin 1 (Sgo1) with histone H2A phosphorylated on Thr-120 (H2ApT120) to selectively release Sgo1 from mitotic centromeres. Interestingly, cells expressing the H2ApT120-binding defective mutant of Sgo1 have an elevated rate of chromosome missegregation accompanied by weakened centromeric cohesion and decreased centromere accumulation of the chromosomal passenger complex (CPC), an integral part of the inner centromere and a key player in the correction of erroneous kinetochore–microtubule attachments. When artificially tethered to centromeres, a Sgo1 mutant defective in binding protein phosphatase 2A (PP2A) is not able to support proper centromeric cohesion and CPC accumulation, indicating that the Sgo1–PP2A interaction is essential for the integrity of mitotic centromeres. We further provide evidence indicating that Sgo1 protects centromeric cohesin to create a binding site for the histone H3–associated protein kinase Haspin, which not only inhibits the cohesin release factor Wapl and thereby strengthens centromeric cohesion but also phosphorylates histone H3 at Thr-3 to position CPC at inner centromeres. Taken together, our findings reveal a positive feedback–based mechanism that ensures proper assembly of the functional inner centromere during mitosis. They further suggest a causal link between centromeric cohesion defects and chromosomal instability in cancer cells.

scholarly journals Mast Cell-Specific Expression of Human Siglec-8 in Conditional Knock-in Mice

2018 ◽  
Vol 20 (1) ◽  
pp. 19 ◽  
Author(s):  
Yadong Wei ◽  
Krishan Chhiba ◽  
Fengrui Zhang ◽  
Xujun Ye ◽  
Lihui Wang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Mast Cell ◽  
Mast Cells ◽  
Es Cells ◽  
Embryonic Stem ◽  
Surface Protein ◽  
Cell Types ◽  
Mouse Strains ◽  
Specific Expression

Sialic acid-binding Ig-like lectin 8 (Siglec-8) is expressed on the surface of human eosinophils, mast cells, and basophils—cells that participate in allergic and other diseases. Ligation of Siglec-8 by specific glycan ligands or antibodies triggers eosinophil death and inhibits mast cell degranulation; consequences that could be leveraged as treatment. However, Siglec-8 is not expressed in murine and most other species, thus limiting preclinical studies in vivo. Based on a ROSA26 knock-in vector, a construct was generated that contains the CAG promoter, a LoxP-floxed-Neo-STOP fragment, and full-length Siglec-8 cDNA. Through homologous recombination, this Siglec-8 construct was targeted into the mouse genome of C57BL/6 embryonic stem (ES) cells, and chimeric mice carrying the ROSA26-Siglec-8 gene were generated. After cross-breeding to mast cell-selective Cre-recombinase transgenic lines (CPA3-Cre, and Mcpt5-Cre), the expression of Siglec-8 in different cell types was determined by RT-PCR and flow cytometry. Peritoneal mast cells (dual FcεRI+ and c-Kit+) showed the strongest levels of surface Siglec-8 expression by multicolor flow cytometry compared to expression levels on tissue-derived mast cells. Siglec-8 was seen on a small percentage of peritoneal basophils, but not other leukocytes from CPA3-Siglec-8 mice. Siglec-8 mRNA and surface protein were also detected on bone marrow-derived mast cells. Transgenic expression of Siglec-8 in mice did not affect endogenous numbers of mast cells when quantified from multiple tissues. Thus, we generated two novel mouse strains, in which human Siglec-8 is selectively expressed on mast cells. These mice may enable the study of Siglec-8 biology in mast cells and its therapeutic targeting in vivo.

Specific expression of a retinoic acid-regulated, zinc-finger gene, Rex-1, in preimplantation embryos, trophoblast and spermatocytes

Development ◽  
1991 ◽  
Vol 113 (3) ◽  
pp. 815-824 ◽  
Author(s):  
M.B. Rogers ◽  
B.A. Hosler ◽  
L.J. Gudas
Keyword(s):  
Retinoic Acid ◽  
Germ Cell ◽  
Cell Fate ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Preimplantation Embryos ◽  
Specific Expression

We have previously isolated a cDNA clone for a gene whose expression is reduced by retinoic acid (RA) treatment of F9 embryonal carcinoma cells. The nucleotide sequence indicated that this gene, Rex-1, encodes a zinc-finger protein and thus may be a transcriptional regulator. The Rex-1 message level is high in two lines of embryonic stem cells (CCE and D3) and is reduced when D3 cells are induced to differentiate using four different growth conditions. As expected for a stem-cell-specific message, Rex-1 mRNA is present in the inner cell mass (ICM) of the day 4.5 mouse blastocyst. It is also present in the polar trophoblast of the blastocyst. One and two days later, Rex-1 message is found in the ectoplacental cone and extraembryonic ectoderm of the egg cylinder (trophoblast-derived tissues), but its abundance is much reduced in the embryonic ectoderm which is directly descended from the ICM. Rex-1 is expressed in the day 18 placenta (murine gestation is 18 days), a tissue which is largely derived from trophoblast. The only tested adult tissue that contains detectable amounts of Rex-1 mRNA is the testis. In situ hybridization and northern analyses of RNA from germ-cell-deficient mouse testis and stage-specific germ cell preparations suggest that Rex-1 expression is limited to spermatocytes (germ cells undergoing meiosis). These results suggest that Rex-1 is involved in trophoblast development and spermatogenesis, and is a useful marker for studies of early cell fate determination in the ICM.

scholarly journals Epiplakin Is Dispensable for Skin Barrier Function and for Integrity of Keratin Network Cytoarchitecture in Simple and Stratified Epithelia

2006 ◽  
Vol 26 (2) ◽  
pp. 559-568 ◽  
Author(s):  
Daniel Spazierer ◽  
Peter Fuchs ◽  
Siegfried Reipert ◽  
Irmgard Fischer ◽  
Matthias Schmuth ◽  
...  
Keyword(s):  
Actin Filaments ◽  
Primary Cultures ◽  
Embryonic Stem ◽  
Skin Barrier ◽  
Skin Barrier Function ◽  
Wild Type ◽  
Primary Hepatocytes ◽  
Specific Expression ◽  
Keratin Filament ◽  
Deficient Mice

ABSTRACT Epiplakin, a giant epithelial protein of >700 kDa, belongs to the plakin family of cytolinker proteins. It represents an atypical family member, however, as it consists entirely of plakin repeat domains but lacks any of the other domains commonly shared by plakins. Hence, its putative function as a cytolinker protein remains to be shown. To investigate epiplakin's biological role, we generated epiplakin-deficient mice by gene targeting in embryonic stem cells. Epiplakin-deficient mice were viable and fertile, without developing any discernible phenotype. Ultrastructurally, their epidermis revealed no differences compared to wild-type littermates, and cornified envelopes isolated from skin showed no alterations in shape or stability. Furthermore, neither embryonal formation nor later function of the epithelial barrier was affected. In primary cultures of epiplakin-deficient keratinocytes, the organization of actin filaments, microtubules, and keratin networks was found to be normal. Similarly, no alterations in keratin network organization were observed in simple epithelia of small intestine and liver or in primary hepatocytes. We conclude that, despite epiplakin's abundant and highly specific expression in stratified and simple epithelia, its absence in mice does not lead to severe skin dysfunctions, nor has it detectable consequences for keratin filament organization and cytoarchitecture of cells.

The testis-specific expression pattern of the growth hormone/placental lactogen (GH/PL) gene cluster changes with malignancy

1999 ◽  
Vol 30 (10) ◽  
pp. 1201-1206 ◽  
Author(s):  
Peter Berger ◽  
Gerold Untergasser ◽  
Martin Hermann ◽  
Anton Hittmair ◽  
Stephan Madersbacher ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Gene Cluster ◽  
Expression Pattern ◽  
Placental Lactogen ◽  
Specific Expression ◽  
Specific Expression Pattern ◽  
Testis Specific Expression

scholarly journals Emerging mechanisms of asymmetric stem cell division

2018 ◽  
Vol 217 (11) ◽  
pp. 3785-3795 ◽  
Author(s):  
Zsolt G. Venkei ◽  
Yukiko M. Yamashita
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Division ◽  
Asymmetric Cell Division ◽  
Binary Outcomes ◽  
Cellular Mechanisms ◽  
Asymmetric Cell Divisions ◽  
Cell Divisions ◽  
Dividing Cells ◽  
Stem Cell Division

The asymmetric cell division of stem cells, which produces one stem cell and one differentiating cell, has emerged as a mechanism to balance stem cell self-renewal and differentiation. Elaborate cellular mechanisms that orchestrate the processes required for asymmetric cell divisions are often shared between stem cells and other asymmetrically dividing cells. During asymmetric cell division, cells must establish asymmetry/polarity, which is guided by varying degrees of intrinsic versus extrinsic cues, and use intracellular machineries to divide in a desired orientation in the context of the asymmetry/polarity. Recent studies have expanded our knowledge on the mechanisms of asymmetric cell divisions, revealing the previously unappreciated complexity in setting up the cellular and/or environmental asymmetry, ensuring binary outcomes of the fate determination. In this review, we summarize recent progress in understanding the mechanisms and regulations of asymmetric stem cell division.

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