scholarly journals Inactivation of ancV1R as a Predictive Signature for the Loss of Vomeronasal System in Mammals

2020 ◽  
Vol 12 (6) ◽  
pp. 766-778 ◽  
Author(s):  
Zicong Zhang ◽  
Masato Nikaido
Keyword(s):  
Marker Gene ◽  
Vomeronasal Organ ◽  
Purifying Selection ◽  
Predictive Marker ◽  
Specific Gene ◽  
Vomeronasal System ◽  
Reproductive Behaviors ◽  
Catarrhine Primates ◽  
Sensing Systems ◽  
Inactivating Mutations

Abstract The vomeronasal organ (VNO) plays a key role in sensing pheromonal cues, which elicits social and reproductive behaviors. Although the VNO is highly conserved across mammals, it has been lost in some species that have evolved alternate sensing systems during diversification. In this study, we investigate a newly identified VNO-specific gene, ancV1R, in the extant 261 species of mammals to examine the correlation between genotype (ancV1R) and phenotype (VNO). As a result, we found signatures for the relaxation of purifying selection (inactivating mutations and the elevation of dN/dS) on ancV1Rs in VNO-lacking mammals, such as catarrhine primates, cetaceans, the manatees, and several bat lineages, showing the distinct correlation between genotype and phenotype. Interestingly, we further revealed signatures for the relaxation of purifying selection on ancV1R in true seals, otters, the fossa, the owl monkey, and alcelaphine antelopes in which the existence of a functional VNO is still under debate. Our additional analyses on TRPC2, another predictive marker gene for the functional VNO, showed a relaxation of purifying selection, supporting the possibility of VNO loss in these species. The results of our present study invite more in-depth neuroanatomical investigation in mammals for which VNO function remains equivocal.

scholarly journals Expressed vomeronasal type-1 receptors (V1rs) in bats uncover conserved mechanisms of social chemical signaling

2018 ◽  
Author(s):  
Laurel R. Yohe ◽  
Kalina T. J. Davies ◽  
Stephen J. Rossiter ◽  
Liliana M. Dávalos
Keyword(s):  
Social Behavior ◽  
Chemical Cues ◽  
Vomeronasal Organ ◽  
Purifying Selection ◽  
Current Understanding ◽  
Chemical Signaling ◽  
Reproductive Behaviors ◽  
Conspecific Recognition ◽  
Receptor Number

AbstractIn mammals, social and reproductive behaviors are mediated by chemical cues encoded by hyperdiverse families of receptors expressed in the vomeronasal organ. Between species, the number of intact receptors can vary by orders of magnitude. However, the evolutionary processes behind variation in receptor number, and also its link to fitness-related behaviors are not well understood. From vomeronasal transcriptomes, we discovered the first evidence of intact vomeronasal type-1 receptor (V1r) genes in bats, and we tested whether putatively functional bat receptors were orthologous to those of related taxa, or whether bats have evolved novel receptors. We found that V1rs in bats and show high levels of orthology to those of their relatives, as opposed to lineage-specific duplications, and receptors are under purifying selection. Despite widespread vomeronasal organ loss in bats, V1r copies have been retained for >65 million years. The highly conserved nature of bat V1rs challenges our current understanding of mammalian V1r function and suggest roles other than conspecific recognition or mating initiation in social behavior.

scholarly journals Expressed Vomeronasal Type-1 Receptors (V1rs) in Bats Uncover Conserved Sequences Underlying Social Chemical Signaling

2019 ◽  
Vol 11 (10) ◽  
pp. 2741-2749 ◽  
Author(s):  
Laurel R Yohe ◽  
Kalina T J Davies ◽  
Stephen J Rossiter ◽  
Liliana M Dávalos
Keyword(s):  
Social Behavior ◽  
Chemical Cues ◽  
Vomeronasal Organ ◽  
Purifying Selection ◽  
Current Understanding ◽  
Chemical Signaling ◽  
Reproductive Behaviors ◽  
Conspecific Recognition ◽  
Receptor Number

Abstract In mammals, social and reproductive behaviors are mediated by chemical cues encoded by hyperdiverse families of receptors expressed in the vomeronasal organ. Between species, the number of intact receptors can vary by orders of magnitude. However, the evolutionary processes behind variation in receptor number, and its link to fitness-related behaviors are not well understood. From vomeronasal transcriptomes, we discovered the first evidence of intact vomeronasal type-1 receptor (V1r) genes in bats, and we tested whether putatively functional bat receptors were orthologous to those of related taxa, or whether bats have evolved novel receptors. Instead of lineage-specific duplications, we found that bat V1rs show high levels of orthology to those of their relatives, and receptors are under comparative levels of purifying selection as non-bats. Despite widespread vomeronasal organ loss in bats, V1r copies have been retained for >65 million years. The highly conserved nature of bat V1rs challenges our current understanding of mammalian V1r function and suggests roles other than conspecific recognition or mating initiation in social behavior.

scholarly journals Differential Regulation of Gene Expression of Alveolar Epithelial Cell Markers in Human Lung Adenocarcinoma-Derived A549 Clones

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
Hiroshi Kondo ◽  
Keiko Miyoshi ◽  
Shoji Sakiyama ◽  
Akira Tangoku ◽  
Takafumi Noma
Keyword(s):  
Gene Expression ◽  
Epithelial Cell ◽  
Mapk Pathway ◽  
Alveolar Epithelial Cell ◽  
Marker Gene ◽  
Regulation Of Gene Expression ◽  
Surfactant Protein ◽  
Specific Gene ◽  
Expression Levels ◽  
Alveolar Epithelial

Stem cell therapy appears to be promising for restoring damaged or irreparable lung tissue. However, establishing a simple and reproducible protocol for preparing lung progenitor populations is difficult because the molecular basis for alveolar epithelial cell differentiation is not fully understood. We investigated anin vitrosystem to analyze the regulatory mechanisms of alveolus-specific gene expression using a human alveolar epithelial type II (ATII) cell line, A549. After cloning A549 subpopulations, each clone was classified into five groups according to cell morphology and marker gene expression. Two clones (B7 and H12) were further analyzed. Under serum-free culture conditions,surfactant protein C(SPC), an ATII marker, was upregulated in both H12 and B7.Aquaporin 5(AQP5), an ATI marker, was upregulated in H12 and significantly induced in B7. When the RAS/MAPK pathway was inhibited,SPCandthyroid transcription factor-1(TTF-1) expression levels were enhanced. After treatment with dexamethasone (DEX), 8-bromoadenosine 3′5′-cyclic monophosphate (8-Br-cAMP), 3-isobutyl-1-methylxanthine (IBMX), and keratinocyte growth factor (KGF),surfactant protein BandTTF-1expression levels were enhanced. We found that A549-derived clones have plasticity in gene expression of alveolar epithelial differentiation markers and could be useful in studying ATII maintenance and differentiation.

Evolutionary rewiring of the wheat transcriptional regulatory network by lineage-specific transposable elements

2021 ◽  
pp. gr.275658.121
Author(s):  
Yuyun Zhang ◽  
Zijuan Li ◽  
Yu'e Zhang ◽  
Kande Lin ◽  
Yuan Peng ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Genome Evolution ◽  
Regulatory Networks ◽  
Transcriptional Regulatory Network ◽  
Sequence Similarity ◽  
Purifying Selection ◽  
Wheat Genome ◽  
Specific Gene ◽  
High Sequence Similarity ◽  
Wheat Genome Evolution

More than 80% of the wheat genome consists of transposable elements (TEs), which act as one major driver of wheat genome evolution. However, their contributions to the regulatory evolution of wheat adaptations remain largely unclear. Here, we created genome-binding maps for 53 transcription factors (TFs) underlying environmental responses by leveraging DAP-seq in Triticum urartu, together with epigenomic profiles. Most TF-binding sites (TFBS) located distally from genes are embedded in TEs, whose functional relevance is supported by purifying selection and active epigenomic features. About 24% of the non-TE TFBS share significantly high sequence similarity with TE-embedded TFBS. These non-TE TFBS have almost no homologous sequences in non-Triticeae species and are potentially derived from Triticeae-specific TEs. The expansion of TE-derived TFBS linked to wheat-specific gene responses, suggesting TEs are an important driving force for regulatory innovations. Altogether, TEs have been significantly and continuously shaping regulatory networks related to wheat genome evolution and adaptation.

scholarly journals Sensitivity and transduction mechanisms of responses to general odorants in turtle vomeronasal system.

1991 ◽  
Vol 98 (5) ◽  
pp. 909-919 ◽  
Author(s):  
T Shoji ◽  
K Kurihara
Keyword(s):  
Vomeronasal Organ ◽  
Na Channel ◽  
Channel Blockers ◽  
Ca Channel ◽  
Essential Difference ◽  
Free Solution ◽  
Vomeronasal System ◽  
Nacl Solution ◽  
Response Curves ◽  
Transduction Mechanisms

(a) The responses of the vomeronasal organ to general odorants in the turtle, Geoclemys reevesii, were measured by recording the accessory olfactory bulbar responses. The threshold concentrations of the vomeronasal responses to various odorants were similar to those in main olfactory bulbar responses, indicating that vomeronasal cells lacking cilia and olfactory cells having many cilia have similar sensitivities to general odorants. (b) The vomeronasal epithelium was perfused with 100 mM NaCl solution and the salt-free solution and the effects of NaCl on the vomeronasal responses to various odorants were examined. There was no essential difference between the concentration-response curves for n-amyl acetate and menthone dissolved in 100 mM NaCl solution and those dissolved in the salt-free solution in the whole concentration range examined. The ratios of the magnitudes of vomeronasal responses in the salt-free solution to those in 100 mM NaCl solution were between 1.01 and 1.10 for seven odorants tested. (c) The magnitudes of responses to the odorants were unchanged by changes in NaCl concentrations. The replacement of Na+ with organic cations such as choline+, Bis-Tris propane2+, and N-acetyl-D-glucosamine+ did not affect the magnitudes of the responses to the odorants. The Na channel blocker amiloride also did not affect the responses. (d) The vomeronasal responses were practically unchanged by changes in CaCl2 concentration. The Ca channel blockers diltiazem and verapamil did not affect the responses. (e) The replacement of Cl- with SO4(2-) did not affect the magnitudes of the vomeronasal responses. (f) The present results suggest that ion transport across the apical membranes of vomeronasal receptor cells does not contribute to the responses to odorants in the turtle.

scholarly journals The Cytoskeletal Network Controls c-Jun Expression and Glucocorticoid Receptor Transcriptional Activity in an Antagonistic and Cell-Type-Specific Manner

1999 ◽  
Vol 19 (3) ◽  
pp. 1742-1750 ◽  
Author(s):  
Anat Oren ◽  
Avia Herschkovitz ◽  
Iris Ben-Dror ◽  
Vered Holdengreber ◽  
Yehuda Ben-Shaul ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Glucocorticoid Receptor ◽  
Cell Separation ◽  
Transcriptional Activity ◽  
Marker Gene ◽  
Mitogen Activated Protein Kinase ◽  
Cell Contact ◽  
Specific Gene ◽  
Functional Link ◽  
Cytoskeletal Network

ABSTRACT The physical and functional link between adhesion molecules and the cytoskeletal network suggests that the cytoskeleton might mediate the transduction of cell-to-cell contact signals, which often regulate growth and differentiation in an antagonistic manner. Depolymerization of the cytoskeleton in confluent cell cultures is reportedly sufficient to initiate DNA synthesis. Here we show that depolymerization of the cytoskeleton is also sufficient to repress differentiation-specific gene expression. Glutamine synthetase is a glia-specific differentiation marker gene whose expression in the retinal tissue is regulated by glucocorticoids and is ultimately dependent on glia-neuron cell contacts. Depolymerization of the actin or microtubule network in cells of the intact retina mimics the effects of cell separation, repressing glutamine synthetase induction by a mechanism that involves induction of c-Jun and inhibition of glucocorticoid receptor transcriptional activity. Depolymerization of the cytoskeleton activates JNK and p38 mitogen-activated protein kinase and induces c-Jun expression by a signaling pathway that depends on tyrosine kinase activity. Induction of c-Jun expression is restricted to Müller glial cells, the only cells in the tissue that express glutamine synthetase and maintain the ability to proliferate upon cell separation. Our results suggest that the cytoskeletal network might play a part in the transduction of cell contact signals to the nucleus.

scholarly journals Behavior of homing endonuclease gene drives targeting genes required for viability or female fertility with multiplexed guide RNAs

2018 ◽  
Author(s):  
Georg Oberhofer ◽  
Tobin Ivy ◽  
Bruce A. Hay
Keyword(s):  
Gene Function ◽  
Homing Endonuclease ◽  
Marker Gene ◽  
Specific Gene ◽  
Gene Drive ◽  
Loss Of Function ◽  
Complex Activity ◽  
Guide Rnas ◽  
Carry Over ◽  
Population Suppression

AbstractA gene drive method of particular interest for population suppression utilizes homing endonuclease genes (HEGs), wherein a site-specific nuclease-encoding cassette is copied, in the germline, into a target gene whose loss of function results in loss of viability or fertility in homozygous, but not heterozygous progeny. Earlier work inDrosophilaand mosquitoes utilized HEGs consisting of Cas9 and a single gRNA that together target a specific gene for cleavage. Homing was observed, but resistant alleles, immune to cleavage, while retaining wildtype gene function, were also created through non-homologous end joining. Such alleles prevent drive and population suppression. Targeting a gene for cleavage at multiple positions has been suggested as a strategy to prevent the appearance of resistant alleles. To test this hypothesis, we generated two suppression HEGs, targeting genes required for embryonic viability or fertility, using a HEG consisting of CRISPR/Cas9 and guide RNAs (gRNAs) designed to cleave each gene at four positions. Rates of target locus cleavage were very high, and multiplexing of gRNAs prevented resistant allele formation. However, germline homing rates were modest, and the HEG cassette was unstable during homing events, resulting in frequent partial copying of HEGs that lacked gRNAs, a dominant marker gene, or Cas9. Finally, in drive experiments the HEGs failed to spread, due to the high fitness load induced in offspring as a result of maternal carry over of Cas9/gRNA complex activity. Alternative design principles are proposed that may mitigate these problems in future gene drive engineering.Significance statementHEG-based gene drive can bring about population suppression when genes required for viability or fertility are targeted. However, these strategies are vulnerable to failure through mechanisms that create alleles resistant to cleavage, but that retain wildtype gene function. We show that resistance allele creation can be prevented through the use of gRNAs designed to cleave a gene at four target sites. However, homing rates were modest, and the HEGs were unstable during homing. In addition, use of a promoter active in the female germline resulted in levels of HEG carryover that compromised the viability or fertility of HEG-bearing heterozygotes, thereby preventing drive. We propose strategies that can help to overcome these problems in next generation HEG systems.

scholarly journals Gene expression evolution in pattern-triggered immunity within Arabidopsis thaliana and across Brassicaceae species

2020 ◽  
Author(s):  
Thomas M. Winkelmüller ◽  
Frederickson Entila ◽  
Shajahan Anver ◽  
Anna Piasecka ◽  
Baoxing Song ◽  
...  
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Binding Sites ◽  
Microbial Control ◽  
Purifying Selection ◽  
Wrky Transcription Factor ◽  
Specific Gene ◽  
Specific Expression ◽  
Brassicaceae Species ◽  
Species Specific

AbstractPlants recognize surrounding microbes by sensing microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). Despite their significance for microbial control, the evolution of PTI responses remains largely uncharacterized. Employing comparative transcriptomics of six Arabidopsis thaliana accessions and three additional Brassicaceae species for PTI responses to the MAMP flg22, we identified a set of genes with expression changes under purifying selection in the Brassicaceae species and genes exhibiting species-specific expression signatures. Variation in flg22-triggered transcriptome and metabolome responses across Brassicaceae species was incongruent with their phylogeny while expression changes were strongly conserved within A. thaliana, suggesting directional selection for some species-specific gene expression. We found the enrichment of WRKY transcription factor binding sites in 5’-regulatory regions in conserved and species-specific responsive genes, linking the emergence of WRKY-binding sites with the evolution of gene responses in PTI. Our findings advance our understanding of transcriptome evolution during biotic stress.

scholarly journals Multimodal Learning of Pheromone Locations

2019 ◽  
Author(s):  
Meenakshi Pardasani ◽  
Shruti D. Marathe ◽  
Urvashi Dalvi ◽  
Nixon M. Abraham
Keyword(s):  
Mammalian Species ◽  
Vomeronasal Organ ◽  
Long Term Memory ◽  
Multimodal Learning ◽  
Reproductive Behaviors ◽  
Male Urine ◽  
Female Mice ◽  
Main Olfactory Epithelium ◽  
Opposite Sex

AbstractMemorizing pheromonal locations is critical for many mammalian species as it involves finding mates and avoiding competitors. In rodents, pheromonal sensing happens through both vomeronasal organ (VNO) and main olfactory epithelium (MOE). It remains unclear as to which modalities and cues are used by rodents to form these long-term memories efficiently. Here, we addressed this problem by training female mice on a multimodal task to locate pheromones by sampling volatiles emanating from male urine and associating with the dimensions of certain shapes sensed by their vibrissae. In this novel pheromone location assay, female mice’ preference towards male urine scent decayed over time while permitting them to explore pheromones versus neutral stimuli, water. On training the animals for associations involving olfactory and whisker systems, they were able to memorize the location of opposite sex pheromones, when tested 15 days later. This memory was not formed either when the somatosensory inputs through whisker pad were blocked or pheromonal cues were replaced by that of same sex. On investigating the neural correlates of volatile pheromone information processing, we observed increased neurogenesis in the main olfactory bulb (MOB) after two weeks of learning. However, the pheromonal exposure induced Whitten effect, the estrous cycle synchronization, did not cause any differences in the MOB mediated discrimination learning pace for various non-pheromonal volatiles. Our study thus provides the evidence for associations formed between different sensory modalities facilitating the long-term memory formation in social and reproductive behaviors.

scholarly journals Sexually dimorphic gene expression and transcriptome evolution provides mixed evidence for a fast-Z effect in Heliconius

2018 ◽  
Author(s):  
A Pinharanda ◽  
M Rousselle ◽  
SH Martin ◽  
JJ Hanly ◽  
JW Davey ◽  
...  
Keyword(s):  
Gene Expression ◽  
Molecular Evolution ◽  
Adaptive Evolution ◽  
Sex Chromosomes ◽  
Expression Profiles ◽  
Sequence Divergence ◽  
Gene Expression Profiles ◽  
Purifying Selection ◽  
Specific Gene ◽  
Sex Determination System

AbstractSex chromosomes have different evolutionary properties as compared to the autosomes due to their hemizygous nature. In particular, recessive mutations are more readily exposed to selection, which can lead to faster rates of molecular evolution. Here, we report patterns of gene expression and molecular evolution in the sex chromosomes of a group of tropical butterflies. We first improved the completeness of the Heliconius melpomene reference annotation, a neotropical butterfly with a ZW sex determination system. Then we sequenced RNA from male and female whole abdomens and female ovary and gut tissue to identify sex and tissue specific gene expression profiles in H. melpomene. Using these expression profiles we compare sequence divergence and polymorphism, the strength of positive and negative selection and rates of adaptive evolution for Z and autosomal genes between two species of Heliconius butterflies, H. melpomene and H. erato.We show that the rate of adaptive substitutions is higher for Z as compared to autosomal genes, but contrary to expectation it is also higher for male as compared to female biased genes. There is therefore mixed evidence that hemizygosity influences the rate of adaptive substitutions. Additionally, we find no significant increase in the rate of adaptive evolution or purifying selection on genes expressed in ovary tissue, a heterogametic specific tissue. Together our results provide limited support for fast-Z evolution. This contributes to a growing body of literature from other ZW systems that also provide mixed evidence for a fast-Z effect.

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