scholarly journals The sperm nucleus: chromatin, RNA, and the nuclear matrix

Reproduction ◽  
2011 ◽  
Vol 141 (1) ◽  
pp. 21-36 ◽  
Author(s):  
Graham D Johnson ◽  
Claudia Lalancette ◽  
Amelia K Linnemann ◽  
Frédéric Leduc ◽  
Guylain Boissonneault ◽  
...  
Keyword(s):  
Nuclear Matrix ◽  
Genomic Structure ◽  
Sperm Nucleus ◽  
Nuclear Volume ◽  
Clinical Markers ◽  
Paternal Genome ◽  
Epigenetic Effects ◽  
History Of ◽  
Low Levels ◽  
Human And Mouse

Within the sperm nucleus, the paternal genome remains functionally inert and protected following protamination. This is marked by a structural morphogenesis that is heralded by a striking reduction in nuclear volume. Despite these changes, both human and mouse spermatozoa maintain low levels of nucleosomes that appear non-randomly distributed throughout the genome. These regions may be necessary for organizing higher order genomic structure through interactions with the nuclear matrix. The promoters of this transcriptionally quiescent genome are differentially marked by modified histones that may poise downstream epigenetic effects. This notion is supported by increasing evidence that the embryo inherits these differing levels of chromatin organization. In concert with the suite of RNAs retained in the mature sperm, they may synergistically interact to direct early embryonic gene expression. Irrespective, these features reflect the transcriptional history of spermatogenic differentiation. As such, they may soon be utilized as clinical markers of male fertility. In this review, we explore and discuss how this may be orchestrated.

Population Genetics ofCaenorhabditis elegans: The Paradox of Low Polymorphism in a Widespread Species

Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Arjun Sivasundar ◽  
Jody Hey
Keyword(s):  
Genetic Variation ◽  
Microsatellite Loci ◽  
Population Expansion ◽  
Widespread Species ◽  
C Elegans ◽  
Model Research ◽  
The World ◽  
Natural Isolates ◽  
History Of ◽  
Low Levels

AbstractCaenorhabditis elegans has become one of the most widely used model research organisms, yet we have little information on evolutionary processes and recent evolutionary history of this widespread species. We examined patterns of variation at 20 microsatellite loci in a sample of 23 natural isolates of C. elegans from various parts of the world. One-half of the loci were monomorphic among all strains, and overall genetic variation at microsatellite loci was low, relative to most other species. Some population structure was detected, but there was no association between the genetic and geographic distances among different natural isolates. Thus, despite the nearly worldwide occurrence of C. elegans, little evidence was found for local adaptation in strains derived from different parts of the world. The low levels of genetic variation within and among populations suggest that recent colonization and population expansion might have occurred. However, the patterns of variation are not consistent with population expansion. A possible explanation for the observed patterns is the action of background selection to reduce polymorphism, coupled with ongoing gene flow among populations worldwide.

scholarly journals Between communism and capitalism: long-term inequality in Poland, 1892–2015

2021 ◽  
Author(s):  
Paweł Bukowski ◽  
Filip Novokmet
Keyword(s):  
Household Survey ◽  
National Accounts ◽  
Capital Income ◽  
Sharp Rise ◽  
Long Run ◽  
History Of ◽  
Low Levels ◽  
Distribution Of Income

AbstractWe construct the first consistent series on the long-term distribution of income in Poland by combining tax, household survey and national accounts data. We document a U-shaped evolution of inequalities from the end of the nineteenth century until today: (1) inequality was high before WWII; (2) abruptly fell after the introduction of communism in 1947 and stagnated at low levels during the whole communist period; (3) experienced a sharp rise with the return to capitalism in 1989. We find that official survey-based measures strongly under-estimate the rise in inequality since 1989. Our results highlight the prominent role of capital income in driving the U-shaped evolution of top income shares. The unique inequality history of Poland speaks to the central role of institutions and policies in shaping inequality in the long run.

ELECTROLYTE AND NITROGEN BALANCE STUDIES IN INFANTS FOLLOWING CESSATION OF VOMITING

PEDIATRICS ◽  
1950 ◽  
Vol 5 (1) ◽  
pp. 57-67
Author(s):  
T. S. DANOWSKI ◽  
A. C. AUSTIN ◽  
R. C. GOW ◽  
F. M. MATEER ◽  
F. A. WEIGAND ◽  
...  
Keyword(s):  
Serum Potassium ◽  
Nitrogen Balance ◽  
Body Fluids ◽  
Therapeutic Implications ◽  
Low Potassium ◽  
Recurrent Vomiting ◽  
History Of ◽  
Low Levels

Abnormally low levels of serum potassium were observed prior to or during therapy of infants with a history of prolonged or recurrent vomiting. Balance studies indicate that either dilution of body fluids with low potassium solution, or transfers of potassium into cells, or both processes were responsible for the hypokalemia. The probable existence of deficits of body potassium incurred prior to the balance studies and their therapeutic implications have been discussed.

A population-based twin study in women of smoking initiation and nicotine dependence

1999 ◽  
Vol 29 (2) ◽  
pp. 299-308 ◽  
Author(s):  
K. S. KENDLER ◽  
M. C. NEALE ◽  
P. SULLIVAN ◽  
L. A. COREY ◽  
C. O. GARDNER ◽  
...  
Keyword(s):  
Risk Factors ◽  
Nicotine Dependence ◽  
Structural Equation ◽  
Substance Dependence ◽  
Smoking Initiation ◽  
Population Based ◽  
Familial Factors ◽  
Wide Range ◽  
History Of ◽  
Low Levels

Background. The development of drug dependence requires prior initiation. What is the relationship between the risk factors for initiation and dependence?Methods. Using smoking as a model addiction, we assessed smoking initiation (SI) and nicotine dependence (ND) by personal interview in 1898 female twins from the population-based Virginia Twin Registry. We developed a twin structural equation model that estimates the correlation between the liability to SI and the liability to ND, given SI.Results. The liabilities to SI and ND were substantially correlated but not identical. Heritable factors played an important aetiological role in SI and in ND. While the majority of genetic risk factors for ND were shared with SI, a distinct set of familial factors, which were probably partly genetic, solely influenced the risk for ND. SI was associated with low levels of education and religiosity, high levels of neuroticism and extroversion and a history of a wide range of psychiatric disorders. ND was associated with low levels of education, extroversion, mastery, and self-esteem, high levels of neuroticism and dependency and a history of mood and alcohol use disorders.Conclusions. The aetiological factors that influence SI and ND, while overlapping, are not perfectly correlated. One set of genetic factors plays a significant aetiological role in both SI and ND, while another set of familial factors, probably in part genetic, solely influences ND. Some risk factors for SI and ND impact similarly on both stages, some act at only one stage and others impact differently and even in opposite directions at the two stages. The pathway to substance dependence is complex and involves multiple genetic and environmental risk factors.

Carriers with excessively low factor VIII procoagulant activity (VIII AHF): a study of two unrelated families with mild hemophilia A

Blood ◽  
1977 ◽  
Vol 49 (4) ◽  
pp. 607-618 ◽  
Author(s):  
ME Eyster ◽  
RL Ladda ◽  
HS Bowman
Keyword(s):  
Hemophilia A ◽  
Postoperative Bleeding ◽  
Hemorrhagic Diathesis ◽  
Normal Range ◽  
Paternal Aunt ◽  
History Of ◽  
Paternal Grandmother ◽  
Low Levels ◽  
Lyon Hypothesis ◽  
Successive Generations

Abstract Two unrelated families are described with mild hemophilia A in whom six obligate carriers had unusually low VIII AHF levels. In each family, successive generations of males were affected with hemophilia A as determined by low VIII AHF in the presence of normal VIII AGN and VIII VWF levels. In the first family, two of five obligate carriers had low VIII AHF levels associated with clinical bleeding and one other had a history of bleeding. While receiving oral contraceptives, one of these two carriers was found to have a normal VIII AHF level. In the second family, four cousins below age 10 who were obligate carriers had significantly low VIII AHF levels, while a paternal aunt and paternal grandmother who were also obligate carriers had VIII AHF levels within the normal range. Hemorrhagic diathesis in multiple obligate carriers in these families is not readily explained by the Lyon hypothesis, and suggests that these families may be exmaples of an unusual allelic form of hemophilia A or that they may be transmitting several independent genes affecting VIII AHF levels. Our experience suggests that VIII AHF levels should be determined on all obligate or possible carriers prior to surgery to identify those individuals at risk for postoperative bleeding. Furthermore, it is suggested that hormonal therapy might be effective in the management of carriers with low levels of VIII AHF and clinical bleeding.

scholarly journals Genetic structure and biogeographic history of the Bicknell’s Thrush/ Gray-cheeked Thrush species complex

The Auk ◽  
2019 ◽  
Vol 137 (1) ◽  
Author(s):  
Alyssa M Fitzgerald ◽  
Jason Weir ◽  
Joel Ralston ◽  
Ian G Warkentin ◽  
Darroch M Whitaker ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Late Pleistocene ◽  
Species Complex ◽  
Extended Period ◽  
Genetic Data ◽  
Distribution Models ◽  
Biogeographic History ◽  
History Of ◽  
Low Levels ◽  
Bicknell's Thrush

Abstract We examined species limits, admixture, and genetic structure among populations in the Bicknell’s Thrush (Catharus bicknelli)–Gray-cheeked Thrush (C. minimus) species complex to establish the geographic and temporal context of speciation in this group, which is a model system in ecology and a high conservation priority. We obtained mitochondrial ND2 sequences from 186 Bicknell’s Thrushes, 77 Gray-cheeked Thrushes, and 55 individuals of their closest relative, the Veery (C. fuscescens), and genotyped a subset of individuals (n = 72) at 5,633 anonymous single nucleotide polymorphic (SNP) loci. Between-species sequence divergence was an order of magnitude greater than divergence within each species, divergence was dated to the late Pleistocene (420 kbp) based on Bayesian coalescence estimation, and a coalescent model (IMa) revealed almost no gene flow between species based on ND2. SNP data were consistent with mitochondrial results and revealed low levels of admixture among species (3 of 37 Bicknell’s Thrushes, no Gray-cheeked Thrushes, and no Veeries were >2% admixed). Species distribution models projected to the Last Glacial Maximum suggest that Bicknell’s Thrush and Gray-cheeked Thrush resided in primarily allopatric refugia in the late Pleistocene, consistent with the genetic data that support reproductive isolation over an extended period of time. Our genetic data suggest that both species underwent demographic expansions, possibly as they expanded out of Pleistocene refugia into their current ranges. We conclude that Bicknell’s Thrush and Gray-cheeked Thrush are 2 distinct species-level lineages despite low levels of Gray-cheeked Thrush introgression in Bicknell’s Thrushes, and divergence has been maintained by a long history of allopatry in subtly different habitats. Their unique phylogeography among boreal forest birds indicates that either cryptic species breaks in eastern North America are still undiscovered, or another factor, such as divergent natural selection, high migratory connectivity, or interspecific competition, played a role in their divergence.

Human and Mouse ISLR (Immunoglobulin Superfamily Containing Leucine-Rich Repeat) Genes: Genomic Structure and Tissue Expression

Genomics ◽  
1999 ◽  
Vol 61 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Akemi Nagasawa ◽  
Jun Kudoh ◽  
Setsuko Noda ◽  
Yukihiko Mashima ◽  
Alan Wright ◽  
...  
Keyword(s):  
Genomic Structure ◽  
Tissue Expression ◽  
Immunoglobulin Superfamily ◽  
Leucine Rich Repeat ◽  
Human And Mouse

scholarly journals Expression ofFOXP3,CD14, andARG1in Neuroblastoma Tumor Tissue from High-Risk Patients Predicts Event-Free and Overall Survival

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Sara Stigliani ◽  
Michela Croce ◽  
Fabio Morandi ◽  
Paola Scaruffi ◽  
Valentina Rigo ◽  
...  
Keyword(s):  
Overall Survival ◽  
High Risk ◽  
Immune Status ◽  
Primary Tumors ◽  
Neuroblastoma Tumor ◽  
Elevated Expression ◽  
Risk Patients ◽  
History Of ◽  
Low Levels ◽  
Positive Correlations

The prognosis of children with metastatic neuroblastoma (NB) > 18 months at diagnosis is dismal. Since the immune status of the tumor microenvironment could play a role in the history of disease, we evaluated the expression ofCD45,CD14,ARG1,CD163,CD4,FOXP3,Perforin-1(PRF1),Granzyme B (GRMB), andIL-10mRNAs in primary tumors at diagnosis from children with metastatic NB and tested whether the transcript levels are significantly associated to event-free and overall survival (EFS and OS, resp.). Children with high expression ofCD14,ARG1andFOXP3mRNA in their primary tumors had significantly better EFS. Elevated expression ofCD14, andFOXP3mRNA was significantly associated to better OS.CD14mRNA expression levels significantly correlated to all markers, with the exception ofCD4. Strong positive correlations were found betweenPRF1andCD163, as well as betweenPFR1andFOXP3. It is worth noting that the combination of high levels ofCD14,FOXP3, andARG1mRNAs identified a small group of patients with excellent EFS and OS, whereas low levels ofCD14were sufficient to identify patients with dismal survival. Thus, the immune status of the primary tumors of high-risk NB patients may influence the natural history of this pediatric cancer.

Signatures of mito-nuclear discordance in Schistosoma turkestanicum indicate a complex evolutionary history of emergence in Europe

Parasitology ◽  
2017 ◽  
Vol 144 (13) ◽  
pp. 1752-1762 ◽  
Author(s):  
SCOTT P. LAWTON ◽  
LAUREN I. BOWEN ◽  
AIDAN M. EMERY ◽  
GÁBOR MAJOROS
Keyword(s):  
Evolutionary History ◽  
Molecular Diversity ◽  
Population Expansion ◽  
Its Sequences ◽  
Cox1 Gene ◽  
Internal Transcribed Spacer Region ◽  
Recent Population Expansion ◽  
Haplotype Frequencies ◽  
History Of ◽  
Low Levels

SUMMARYHigh levels of molecular diversity were identified in mitochondrial cytochrome c oxidase (cox1) gene sequences of Schistosoma turkestanicum from Hungary. These cox1 sequences were all specific to Hungary which contrasted with the low levels of diversity seen in the nuclear internal transcribed spacer region (ITS) sequences, the majority of which were shared between China and Iran isolates. Measures of within and between host molecular variation within S. turkestanicum showed there to be substantial differences in molecular diversity, with cox1 being significantly more diverse than the ITS. Measures of haplotype frequencies revealed that each host contained its own subpopulation of genetically unique parasites with significant levels of differentiation. Pairwise mismatch analysis of cox1 sequences indicated S. turkestanicum populations to have a bimodal pairwise difference distribution and to be stable unlike the ITS sequences, which appeared to have undergone a recent population expansion event. Positive selection was also detected in the cox1 sequences, and biochemical modelling of the resulting protein illustrated significant mutational events causing an alteration to the isoelectric point of the cox1 protein, potentially altering metabolism. The evolutionary signature from the cox1 indicates local adaptation and long establishment of S. turkestanicum in Hungary with continual introgression of nuclear genes from Asian isolates. These processes have led to the occurrence of mito-nuclear discordance in a schistosome population

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