scholarly journals Rescue of Sly Expression Is Not Sufficient to Rescue Spermiogenic Phenotype of Mice with Deletions of Y Chromosome Long Arm

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 133 ◽  
Author(s):  
Jonathan M. Riel ◽  
Yasuhiro Yamauchi ◽  
Victor A. Ruthig ◽  
Qushay U. Malinta ◽  
Mélina Blanco ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Protein Isoforms ◽  
Mutant Mice ◽  
Deletion Mutants ◽  
Deletion Size ◽  
Fertility Problems ◽  
Deficient Mice

Mice with deletions of the Y-specific (non-PAR) region of the mouse Y chromosome long arm (NPYq) have sperm defects and fertility problems that increase proportionally to deletion size. Mice with abrogated function of NPYq-encoded gene Sly (sh367 Sly-KD) display a phenotype similar to that of NPYq deletion mutants but less severe. The milder phenotype can be due to insufficient Sly knockdown, involvement of another NPYq gene, or both. To address this question and to further elucidate the role of Sly in the infertile phenotype of mice with NPYq deletions, we developed an anti-SLY antibody specifically recognizing SLY1 and SLY2 protein isoforms and used it to characterize SLY expression in NPYq- and Sly-deficient mice. We also carried out transgene rescue by adding Sly1/2 transgenes to mice with NPYq deletions. We demonstrated that SLY1/2 expression in mutant mice decreased proportionally to deletion size, with ~12% of SLY1/2 retained in shSLY sh367 testes. The addition of Sly1/2 transgenes to mice with NPYq deletions rescued SLY1/2 expression but did not ameliorate fertility and testicular/spermiogenic defects. Together, the data suggest that Sly deficiency is not the sole underlying cause of the infertile phenotype of mice with NPYq deletions and imply the involvement of another NPYq gene.

scholarly journals Role of Dimerization of the Membrane-associated Growth Factor Kit Ligand in Juxtacrine Signaling: The Sl17H Mutation Affects Dimerization and Stability—Phenotypes in Hematopoiesis

1998 ◽  
Vol 187 (9) ◽  
pp. 1451-1461 ◽  
Author(s):  
Youichi Tajima ◽  
Eric J. Huang ◽  
Keith Vosseller ◽  
Masao Ono ◽  
Malcolm A.S. Moore ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cell Surface ◽  
Cytoplasmic Domain ◽  
Mutant Mice ◽  
Cell Surface Expression ◽  
Peritoneal Mast Cell ◽  
Deletion Mutants ◽  
Kit Ligand

The Kit ligand (KL)/Kit receptor pair functions in hematopoiesis, gametogenesis, and melanogenesis. KL is encoded at the murine steel (Sl) locus and encodes a membrane growth factor which may be proteolytically processed to produce soluble KL. The membrane-associated form of KL is critical in mediating Kit function in vivo. Evidence for a role of cytoplasmic domain sequences of KL comes from the Sl17H mutation, a splice site mutation that replaces the cytoplasmic domain with extraneous amino acids. Using deletion mutants and the Sl17H allele, we have investigated the role of the cytoplasmic domain sequences of KL in biosynthetic processing and cell surface presentation. The normal KL protein products are processed for cell surface expression, where they form dimers. Both Sl17H and the cytoplasmic deletion mutants of KL were processed to the cell surface; however, the rate of transport and protein stability were affected by the mutations. Deletion of cytoplasmic domain sequences of KL did not affect dimerization of KL. In contrast, dimerization of the Sl17H protein was reduced substantially. In addition, we have characterized the hematopoietic cell compartment in Sl17H mutant mice. The Sl17H mutation has only minor effects on hematopoiesis. Tissue and peritoneal mast cell numbers were reduced in mutant mice as well as in myeloid progenitors. Interestingly, long-term bone marrow cultures from Sl17H mice did not sustain the long-term production of hematopoietic cells. In addition, homing of normal hematopoietic progenitors to the spleen of irradiated Sl17H/Sl17H recipient mice was diminished in transplantation experiments, providing evidence for a role of Kit in homing or lodging. These results demonstrate that the membrane forms of KL exist as homodimers on the cell surface and that dimerization may play an important role in KL/Kit-mediated juxtacrine signaling.

scholarly journals Hippocampal CA1 Pyramidal Neurons ofMecp2Mutant Mice Show a Dendritic Spine Phenotype Only in the Presymptomatic Stage

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Christopher A. Chapleau ◽  
Elena Maria Boggio ◽  
Gaston Calfa ◽  
Alan K. Percy ◽  
Maurizio Giustetto ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Dendritic Spine ◽  
Pyramidal Neurons ◽  
Mutant Mice ◽  
Spine Density ◽  
Ca1 Pyramidal Neurons ◽  
Dendritic Spine Density ◽  
Presymptomatic Stage ◽  
Deficient Mice

Alterations in dendritic spines have been documented in numerous neurodevelopmental disorders, including Rett Syndrome (RTT). RTT, an X chromosome-linked disorder associated with mutations inMECP2, is the leading cause of intellectual disabilities in women. Neurons inMecp2-deficient mice show lower dendritic spine density in several brain regions. To better understand the role of MeCP2 on excitatory spine synapses, we analyzed dendritic spines of CA1 pyramidal neurons in the hippocampus ofMecp2tm1.1Jaemale mutant mice by either confocal microscopy or electron microscopy (EM). At postnatal-day 7 (P7), well before the onset of RTT-like symptoms, CA1 pyramidal neurons from mutant mice showed lower dendritic spine density than those from wildtype littermates. On the other hand, at P15 or later showing characteristic RTT-like symptoms, dendritic spine density did not differ between mutant and wildtype neurons. Consistently, stereological analyses at the EM level revealed similar densities of asymmetric spine synapses in CA1stratum radiatumof symptomatic mutant and wildtype littermates. These results raise caution regarding the use of dendritic spine density in hippocampal neurons as a phenotypic endpoint for the evaluation of therapeutic interventions in symptomaticMecp2-deficient mice. However, they underscore the potential role of MeCP2 in the maintenance of excitatory spine synapses.

scholarly journals The clock gene Period1 regulates innate routine behaviour in mice

2014 ◽  
Vol 281 (1781) ◽  
pp. 20140034 ◽  
Author(s):  
Philipp Bechstein ◽  
Nils-Jörn Rehbach ◽  
Gowzekan Yuhasingham ◽  
Christoph Schürmann ◽  
Melanie Göpfert ◽  
...  
Keyword(s):  
Clock Gene ◽  
Memory Deficits ◽  
Nest Building ◽  
Partner Choice ◽  
Mutant Mice ◽  
Spatial Learning And Memory ◽  
Wild Type ◽  
Circadian Clock Gene ◽  
Deficient Mice

Laboratory mice are well capable of performing innate routine behaviour programmes necessary for courtship, nest-building and exploratory activities although housed for decades in animal facilities. We found that in mice inactivation of the clock gene Period1 profoundly changes innate routine behaviour programmes like those necessary for courtship, nest building, exploration and learning. These results in wild-type and Period1 mutant mice, together with earlier findings on courtship behaviour in wild-type and period -mutant Drosophila melanogaster , suggest a conserved role of Period- genes on innate routine behaviour. Additionally, both per -mutant flies and Period1 -mutant mice display spatial learning and memory deficits. The profound influence of Period1 on routine behaviour programmes in mice, including female partner choice, may be independent of its function as a circadian clock gene, since Period1 -deficient mice display normal circadian behaviour.

IX. Mast cell-deficient mice and intestinal biology

2000 ◽  
Vol 278 (3) ◽  
pp. G343-G348 ◽  
Author(s):  
Barry K. Wershil
Keyword(s):  
Mast Cell ◽  
Cell Biology ◽  
Cell Development ◽  
Mutant Mice ◽  
Gene Products ◽  
Gastrointestinal Pathology ◽  
Deficient Mice

Mutant mice that express abnormalities in mast cell development represent a powerful tool for the investigation of multiple aspects of mast cell biology. In addition, the identification of the genes affected by these mutations has not only increased our knowledge about the mast cell but has opened new areas of investigation as to the role of these gene products in gastrointestinal pathology, immunology, and physiology.

scholarly journals Role of Androgens in Testicular Tumor Development in Inhibin-Deficient Mice*

Endocrinology ◽  
1997 ◽  
Vol 138 (11) ◽  
pp. 5000-5005 ◽  
Author(s):  
Weinian Shou ◽  
Teresa K. Woodruff ◽  
Martin M. Matzuk
Keyword(s):  
Cancer Cachexia ◽  
Tumor Development ◽  
Testicular Tumor ◽  
Mutant Mice ◽  
Male Mice ◽  
Testicular Tumors ◽  
Wasting Syndrome ◽  
Deficient Mice ◽  
Mutant Male

To understand gonadal tumor development, we have previously created a mouse model in which mice deficient in the inhibins develop gonadal sex cord-stromal tumors with essentially 100% penetrance. These tumors develop as early as 4 weeks of age and cause cancer cachexia-like symptoms and subsequent death in the inhibin-deficient mice. Gonadectomized inhibin-deficient mice eventually develop adrenal cortical tumors with nearly 100% penetrance. These studies have identified inhibin as a novel secreted tumor suppressor protein with specificity for the gonads and adrenal glands. Sex steroids have been implicated to influence gonadal tumor development in humans and mice. To determine the role of androgens in gonadal tumorigenesis in inhibin-deficient male mice, we have used a genetic intercross strategy, breeding inhibin α mutant mice with tfm (testicular feminization, a naturally occurring androgen receptor mutant) carrying females to eventually generate compound mutant male mice that lack inhibins and carry the tfm mutation. These compound mutant mice, like inhibin-deficient mice, continue to develop testicular tumors and the accompanying cancer cachexia-like wasting syndrome. Consistent with these findings, elevated levels of activins A and B secreted from the gonadal tumors are seen in the adult compound mutant mice as well as the secondary pathological consequences of these high activin levels in the livers and glandular stomachs. However, in contrast to male mice lacking only inhibin, in which essentially 100% of the testicular tumors are hemorrhagic, 65% of the tumors in these compound mutant male mice are less hemorrhagic, and approximately 50% of the compound mutants live longer than 17 weeks of age (95% of the male mice lacking only inhibin die by 12 weeks). These results suggest that androgens are not required for testicular tumor development in inhibin-deficient mice, but may play a regulatory role in testicular tumor progression.

scholarly journals Neutrophil Emigration in the Skin, Lungs, and Peritoneum: Different Requirements for CD11/CD18 Revealed by CD18-deficient Mice

1997 ◽  
Vol 186 (8) ◽  
pp. 1357-1364 ◽  
Author(s):  
Joseph P. Mizgerd ◽  
Hiroshi Kubo ◽  
Gregory J. Kutkoski ◽  
Sabrina D. Bhagwan ◽  
Karin Scharffetter-Kochanek ◽  
...  
Keyword(s):  
Peritoneal Lavage ◽  
Lavage Fluid ◽  
Mutant Mice ◽  
Wild Type ◽  
Peritoneal Lavage Fluid ◽  
Alternative Pathways ◽  
Irritant Dermatitis ◽  
Blocking Antibodies ◽  
Deficient Mice

To determine the role of CD11/CD18 complexes in neutrophil emigration, inflammation was induced in the skin, lungs, or peritoneum of mutant mice deficient in CD18 (CD18−/− mutants). Peripheral blood of CD18−/− mutants contained 11-fold more neutrophils than did blood of wild-type (WT) mice. During irritant dermatitis induced by topical application of croton oil, the number of emigrated neutrophils in histological sections of dermis was 98% less in CD18−/− mutants than in WT mice. During Streptococcus pneumoniae pneumonia, neutrophil emigration in CD18−/− mutants was not reduced. These data are consistent with expectations based on studies using blocking antibodies to inhibit CD11/CD18 complexes, and on observations of humans lacking CD11/CD18 complexes. The number of emigrated neutrophils in lung sections during Escherichia coli pneumonia, or in peritoneal lavage fluid after 4 h of S. pneumoniae peritonitis, was not reduced in CD18−/− mutants, but rather was greater than the WT values (240 ± 30 and 220 ± 30% WT, respectively). Also, there was no inhibition of neutrophil emigration during sterile peritonitis induced by intraperitoneal injection of thioglycollate (90 ± 20% WT). These data contrast with expectations. Whereas CD11/CD18 complexes are essential to the dermal emigration of neutrophils during acute dermatitis, CD18−/− mutant mice demonstrate surprising alternative pathways for neutrophil emigration during pneumonia or peritonitis.

scholarly journals Generation and Characterization of dickkopf3 Mutant Mice

2006 ◽  
Vol 26 (6) ◽  
pp. 2317-2326 ◽  
Author(s):  
Ivan del Barco Barrantes ◽  
Ana Montero-Pedrazuela ◽  
Ana Guadaño-Ferraz ◽  
Maria-Jesus Obregon ◽  
Raquel Martinez de Mena ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Clinical Chemistry ◽  
Lung Ventilation ◽  
Immunoglobulin M ◽  
Mutant Mice ◽  
Phenotypic Analysis ◽  
Thyroid Hormone Metabolism ◽  
Hormone Binding Protein ◽  
Deficient Mice

ABSTRACT dickkopf (dkk) genes encode a small family of secreted Wnt antagonists, except for dkk3, which is divergent and whose function is poorly understood. Here, we describe the generation and characterization of dkk3 mutant mice. dkk3-deficient mice are viable and fertile. Phenotypic analysis shows no major alterations in organ morphology, physiology, and most clinical chemistry parameters. Since Dkk3 was proposed to function as thyroid hormone binding protein, we have analyzed deiodinase activities, as well as thyroid hormone levels. Mutant mice are euthyroid, and the data do not support a relationship of dkk3 with thyroid hormone metabolism. Altered phenotypes in dkk3 mutant mice were observed in the frequency of NK cells, immunoglobulin M, hemoglobin, and hematocrit levels, as well as lung ventilation. Furthermore, dkk3-deficient mice display hyperactivity.

scholarly journals Intracellular Na+ Modulates Pacemaking Activity in Murine Sinoatrial Node Myocytes: An In Silico Analysis

2021 ◽  
Vol 22 (11) ◽  
pp. 5645
Author(s):  
Stefano Morotti ◽  
Haibo Ni ◽  
Colin H. Peters ◽  
Christian Rickert ◽  
Ameneh Asgari-Targhi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Membrane Potential ◽  
In Silico ◽  
Sinoatrial Node ◽  
In Silico Analysis ◽  
Ankyrin B ◽  
Deficient Mice ◽  
Silico Analysis ◽  
Bursting Activity

Background: The mechanisms underlying dysfunction in the sinoatrial node (SAN), the heart’s primary pacemaker, are incompletely understood. Electrical and Ca2+-handling remodeling have been implicated in SAN dysfunction associated with heart failure, aging, and diabetes. Cardiomyocyte [Na+]i is also elevated in these diseases, where it contributes to arrhythmogenesis. Here, we sought to investigate the largely unexplored role of Na+ homeostasis in SAN pacemaking and test whether [Na+]i dysregulation may contribute to SAN dysfunction. Methods: We developed a dataset-specific computational model of the murine SAN myocyte and simulated alterations in the major processes of Na+ entry (Na+/Ca2+ exchanger, NCX) and removal (Na+/K+ ATPase, NKA). Results: We found that changes in intracellular Na+ homeostatic processes dynamically regulate SAN electrophysiology. Mild reductions in NKA and NCX function increase myocyte firing rate, whereas a stronger reduction causes bursting activity and loss of automaticity. These pathologic phenotypes mimic those observed experimentally in NCX- and ankyrin-B-deficient mice due to altered feedback between the Ca2+ and membrane potential clocks underlying SAN firing. Conclusions: Our study generates new testable predictions and insight linking Na+ homeostasis to Ca2+ handling and membrane potential dynamics in SAN myocytes that may advance our understanding of SAN (dys)function.

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