scholarly journals Are sex-biased genes more dispensable?

2009 ◽  
Vol 5 (3) ◽  
pp. 409-412 ◽  
Author(s):  
Judith E. Mank ◽  
Hans Ellegren
Keyword(s):  
Gene Expression ◽  
Sexual Selection ◽  
Molecular Evolution ◽  
Gene Expression Pattern ◽  
Selective Constraint ◽  
Sexually Dimorphic ◽  
Males And Females ◽  
Natural And Sexual Selection ◽  
Rates Of Molecular Evolution

Many genes show different expression levels in males and females, and these form the basis of sexually dimorphic phenotypes. Sex-biased genes experience accelerated rates of protein evolution, which has been attributed to sexual selection. However, it is possible that the increased rates of molecular evolution, and more importantly the sex-biased gene expression pattern itself, are due to decreased selective constraint. This notion may explain many of the patterns associated with sex-biased gene expression, and changes how we should view the role of natural and sexual selection in relation to these genes.

scholarly journals The Nuclear Receptor Corepressor Has Organizational Effects within the Developing Amygdala on Juvenile Social Play and Anxiety-Like Behavior

Endocrinology ◽  
2010 ◽  
Vol 151 (3) ◽  
pp. 1212-1220 ◽  
Author(s):  
Heather M. Jessen ◽  
Mira H. Kolodkin ◽  
Meaghan E. Bychowski ◽  
Catherine J. Auger ◽  
Anthony P. Auger
Keyword(s):  
Gene Expression ◽  
Nuclear Receptor ◽  
Social Play ◽  
Play Behavior ◽  
Sexually Dimorphic ◽  
Mrna Levels ◽  
Estradiol Treatment ◽  
Nuclear Receptor Corepressor ◽  
Males And Females

Nuclear receptor function on DNA is regulated by the balanced recruitment of coregulatory complexes. Recruited proteins that increase gene expression are called coactivators, and those that decrease gene expression are called corepressors. Little is known about the role of corepressors, such as nuclear receptor corepressor (NCoR), on the organization of behavior. We used real-time PCR to show that NCoR mRNA levels are sexually dimorphic, that females express higher levels of NCoR mRNA within the developing amygdala and hypothalamus, and that NCoR mRNA levels are reduced by estradiol treatment. To investigate the functional role of NCoR on juvenile social behavior, we infused small interfering RNA targeted against NCoR within the developing rat amygdala and assessed the enduring impact on juvenile social play behavior, sociability, and anxiety-like behavior. As expected, control males exhibited higher levels of juvenile social play than control females. Reducing NCoR expression during development further increased juvenile play in males only. Interestingly, decreased NCoR expression within the developing amygdala had lasting effects on increasing juvenile anxiety-like behavior in males and females. These data suggest that the corepressor NCoR functions to blunt sex differences in juvenile play behavior, a sexually dimorphic and hormone-dependent behavior, and appears critical for appropriate anxiety-like behavior in juvenile males and females.

Distinct gene expression patterns in chronic lymphocytic leukemia defined by usage of specific VH genes

Blood ◽  
2006 ◽  
Vol 107 (5) ◽  
pp. 2090-2093 ◽  
Author(s):  
Dirk Kienle ◽  
Axel Benner ◽  
Alexander Kröber ◽  
Dirk Winkler ◽  
Daniel Mertens ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Lymphocytic Leukemia ◽  
Expression Patterns ◽  
Gene Expression Pattern ◽  
Cell Receptor ◽  
Lymphocytic Leukemia ◽  
Expression Of Genes ◽  
Vh Genes ◽  
Signaling Activation

The mutation status and usage of specific VH genes such as V3-21 and V1-69 are potentially independent pathogenic and prognostic factors in chronic lymphocytic leukemia (CLL). To investigate the role of antigenic stimulation, we analyzed the expression of genes involved in B-cell receptor (BCR) signaling/activation, cell cycle, and apoptosis control in CLL using these specific VH genes compared to VH mutated (VH-MUT) and VH unmutated (VH-UM) CLL not using these VH genes. V3-21 cases showed characteristic expression differences compared to VH-MUT (up: ZAP70 [or ZAP-70]; down: CCND2, P27) and VH-UM (down: PI3K, CCND2, P27, CDK4, BAX) involving several BCR-related genes. Similarly, there was a marked difference between VH unmutated cases using the V1-69 gene and VH-UM (up: FOS; down: BLNK, SYK, CDK4, TP53). Therefore, usage of specific VH genes appears to have a strong influence on the gene expression pattern pointing to antigen recognition and ongoing BCR stimulation as a pathogenic factor in these CLL subgroups.

scholarly journals Variation in Chin and Mandibular Symphysis Size and Shape in Males and Females: A CT-Based Study

2020 ◽  
Vol 17 (12) ◽  
pp. 4249
Author(s):  
Tatiana Sella Tunis ◽  
Israel Hershkovitz ◽  
Hila May ◽  
Alexander Dan Vardimon ◽  
Rachel Sarig ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Anatomical Landmark ◽  
Anatomical Structure ◽  
Sexually Dimorphic ◽  
Selection Theory ◽  
Size And Shape ◽  
Size Index ◽  
Sexual Selection Theory ◽  
Males And Females ◽  
Anthropological Literature

The chin is a unique anatomical landmark of modern humans. Its size and shape play an important role from the esthetic perspective. However, disagreement exists in the dental and anthropological literature regarding the sex differences in chin and symphysis morphometrics. The “sexual selection” theory is presented as a possible reason for chin formation in our species; however, many other contradictory theories also exist. This study’s aims were therefore to determine how chin and symphysis size and shape vary with sex, and to discuss “sexual selection” theory as a reason for its formation. Head and neck computed tomography (CT) scans of 419 adults were utilized to measure chin and symphysis sizes and shapes. The chin and symphysis measures were compared between the sexes using an independent-samples t-test, a Mann–Whitney test, and the F-statistic. The chin width was significantly greater in males than in females (p < 0.001), whereas the chin height, area, and size index were significantly greater in females (p < 0.001). Symphysis measures did not differ significantly between the sexes. Size accounted for 2–14% of the chin variance and between 24–33% of the symphysis variance. Overall, the chin was found to be a more heterogeneous anatomical structure than the symphysis, as well as more sexually dimorphic.

scholarly journals miR-185 and SEPT5 Genes May Contribute to Parkinson’s Disease Pathophysiology

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Arman Rahimmi ◽  
Ilaria Peluso ◽  
Aref Rajabi ◽  
Kambiz Hassanzadeh
Keyword(s):  
Gene Expression ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Chromosomal Location ◽  
Gene Expression Pattern ◽  
Control Group ◽  
Significant Difference

There are still unknown mechanisms involved in the development of Parkinson’s disease (PD), which elucidating them can assist in developing efficient therapies. Recently, studies showed that genes located on the human chromosomal location 22q11.2 might be involved in the development of PD. Therefore, the present study was designed to evaluate the role of two genes located on the chromosomal location (miR-185 and SEPT5), which were the most probable candidates based on our bibliography. In vivo and in vitro models of PD were developed using male Wistar rats and SHSY-5Y cell line, respectively. The expression levels of miR-185, SEPT5, LRRK2, and PARK2 genes were measured at a mRNA level in dopaminergic areas of rats’ brains and SHSY-5Y cells using the SYBR Green Real-Time PCR Method. Additionally, the effect of inhibition on the genes or their products on cell viability and gene expression pattern in SHSY-5Y cells was investigated. The level of miR-185 gene expression was significantly decreased in the substantia nigra (SN) and striatum (ST) of the rotenone-treated group (control group) compared to the healthy normal group (P<0.05). In addition, there was a significant difference in the expression of SEPT5 gene (P<0.05) in the substantia nigra between two studied groups. The results of an in vitro study showed no significant change in the expression of the genes; however, the inhibition on miR-185 gene expression led to the increase in LRRK2 gene expression in SHSY-5Y cells. The inhibition on LRRK2 protein also decreased the cellular toxicity effect of rotenone on SHSY-5Y cells. The results suggested the protective role of miR-185 gene in preventing the development of PD.

scholarly journals Sexual selection is a form of social selection

2012 ◽  
Vol 367 (1600) ◽  
pp. 2266-2273 ◽  
Author(s):  
Bruce E. Lyon ◽  
Robert Montgomerie
Keyword(s):  
Sexual Selection ◽  
Social Interactions ◽  
Social Selection ◽  
Reproductive Competition ◽  
Selection Theory ◽  
Males And Females ◽  
Female Roles ◽  
Comprehensive Framework ◽  
Natural And Sexual Selection ◽  
Lines Of Evidence

Social selection influences the evolution of weapons, ornaments and behaviour in both males and females. Thus, social interactions in both sexual and non-sexual contexts can have a powerful influence on the evolution of traits that would otherwise appear to be detrimental to survival. Although clearly outlined by West-Eberhard in the early 1980s, the idea that social selection is a comprehensive framework for the study of ornaments and weapons has largely been ignored. In West-Eberhard's view, sexual selection is a form of social selection—a concept supported by several lines of evidence. Darwin's distinction between natural and sexual selection has been useful, but recent confusion about the limits of sexual selection suggests that some traits are not easily categorized as naturally or sexually selected. Because social selection theory has much to offer the current debates about both sexual selection and reproductive competition in females, it is sometimes viewed, narrowly, to be most useful when considering female roles. However, social selection theory encompasses much more than female reproductive competition. Our goal here was to provide that broader perspective.

scholarly journals Inter- and Intraspecific Variation in Drosophila Genes with Sex-Biased Expression

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Lena Müller ◽  
Sonja Grath ◽  
Korbinian von Heckel ◽  
John Parsch
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
Molecular Evolution ◽  
Protein Sequence ◽  
Sequence Variation ◽  
Purifying Selection ◽  
Sexually Dimorphic ◽  
Expression Divergence ◽  
Sexually Dimorphic Expression ◽  
Dimorphic Expression

Genes with sexually dimorphic expression (sex-biased genes) often evolve rapidly and are thought to make an important contribution to reproductive isolation between species. We examined the molecular evolution of sex-biased genes in Drosophila melanogaster and D. ananassae, which represent two independent lineages within the melanogaster group. We find that strong purifying selection limits protein sequence variation within species, but that a considerable fraction of divergence between species can be attributed to positive selection. In D. melanogaster, the proportion of adaptive substitutions between species is greatest for male-biased genes and is especially high for those on the X chromosome. In contrast, male-biased genes do not show unusually high variation within or between populations. A similar pattern is seen at the level of gene expression, where sex-biased genes show high expression divergence between species, but low divergence between populations. In D. ananassae, there is no increased rate of adaptation of male-biased genes, suggesting that the type or strength of selection acting on sex-biased genes differs between lineages.

scholarly journals Sex differences in gene expression and proliferation are dependent on the epigenetic modifier HP1γ

2019 ◽  
Author(s):  
Pui-Pik Law ◽  
Ping-Kei Chan ◽  
Kirsten McEwen ◽  
Huihan Zhi ◽  
Bing Liang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sex Differences ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Autosomal Gene ◽  
Sexually Dimorphic ◽  
Heterochromatin Protein 1 ◽  
Epigenetic Modifier ◽  
Early Embryos ◽  
Males And Females

SummarySex differences in growth rate in very early embryos have been recognized in a variety of mammals and attributed to sex-chromosome complement effects as they occur before overt sexual differentiation. We previously found that sex-chromosome complement, rather than sex hormones regulates heterochromatin-mediated silencing of a transgene and autosomal gene expression in mice. Here, sex dimorphism in proliferation was investigated. We confirm that male embryonic fibroblasts proliferate faster than female fibroblasts and show that this proliferation advantage is completely dependent upon heterochromatin protein 1 gamma (HP1γ). To determine whether this sex-regulatory effect of HP1γ was a more general phenomenon, we performed RNA sequencing on MEFs derived from males and females, with or without HP1γ. Strikingly, HP1γ was found to be crucial for regulating nearly all sexually dimorphic autosomal gene expression because deletion of the HP1γ gene in males abolished sex differences in autosomal gene expression. The identification of a key epigenetic modifier as central in defining gene expression differences between males and females has important implications for understanding physiological sex differences and sex bias in disease.

scholarly journals Phylogenetic Shifts in Gene Body Methylation Correlate with Gene Expression and Reflect Trait Conservation

2019 ◽  
Vol 37 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Danelle K Seymour ◽  
Brandon S Gaut
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Molecular Evolution ◽  
Methylation Status ◽  
Evolutionary Constraint ◽  
Gene Body ◽  
Gene Body Methylation ◽  
Plant Genomes ◽  
Genome Wide ◽  
Rates Of Molecular Evolution

Abstract A subset of genes in plant genomes are labeled with DNA methylation specifically at CG residues. These genes, known as gene-body methylated (gbM), have a number of associated characteristics. They tend to have longer sequences, to be enriched for intermediate expression levels, and to be associated with slower rates of molecular evolution. Most importantly, gbM genes tend to maintain their level of DNA methylation between species, suggesting that this trait is under evolutionary constraint. Given the degree of conservation in gbM, we still know surprisingly little about its function in plant genomes or whether gbM is itself a target of selection. To address these questions, we surveyed DNA methylation across eight grass (Poaceae) species that span a gradient of genome sizes. We first established that genome size correlates with genome-wide DNA methylation levels, but less so for genic levels. We then leveraged genomic data to identify a set of 2,982 putative orthologs among the eight species and examined shifts of methylation status for each ortholog in a phylogenetic context. A total of 55% of orthologs exhibited a shift in gbM, but these shifts occurred predominantly on terminal branches, indicating that shifts in gbM are rarely conveyed over time. Finally, we found that the degree of conservation of gbM across species is associated with increased gene length, reduced rates of molecular evolution, and increased gene expression level, but reduced gene expression variation across species. Overall, these observations suggest a basis for evolutionary pressure to maintain gbM status over evolutionary time.

scholarly journals Role of Histone-Like Proteins H-NS and StpA in Expression of Virulence Determinants of Uropathogenic Escherichia coli

2006 ◽  
Vol 188 (15) ◽  
pp. 5428-5438 ◽  
Author(s):  
Claudia M. Müller ◽  
Ulrich Dobrindt ◽  
Gábor Nagy ◽  
Levente Emödy ◽  
Bernt Eric Uhlin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Gene Expression Pattern ◽  
Direct Interaction ◽  
Virulence Determinants ◽  
Dna Arrays ◽  
Infectious Dose ◽  
E Coli ◽  
Huge Impact

ABSTRACT The histone-like protein H-NS is a global regulator in Escherichia coli that has been intensively studied in nonpathogenic strains. However, no comprehensive study on the role of H-NS and its paralogue, StpA, in gene expression in pathogenic E. coli has been carried out so far. Here, we monitored the global effects of H-NS and StpA in a uropathogenic E. coli isolate by using DNA arrays. Expression profiling revealed that more than 500 genes were affected by an hns mutation, whereas no effect of StpA alone was observed. An hns stpA double mutant showed a distinct gene expression pattern that differed in large part from that of the hns single mutant. This suggests a direct interaction between the two paralogues and the existence of distinct regulons of H-NS and an H-NS/StpA heteromeric complex. hns mutation resulted in increased expression of alpha-hemolysin, fimbriae, and iron uptake systems as well as genes involved in stress adaptation. Furthermore, several other putative virulence genes were found to be part of the H-NS regulon. Although the lack of H-NS, either alone or in combination with StpA, has a huge impact on gene expression in pathogenic E. coli strains, its effect on virulence is ambiguous. At a high infection dose, hns mutants trigger more sudden lethality due to their increased acute toxicity in murine urinary tract infection and sepsis models. At a lower infectious dose, however, mutants lacking H-NS are attenuated through their impaired growth rate, which can only partially be compensated for by the higher expression of numerous virulence factors.

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