The Experts below are selected from a list of 120 Experts worldwide ranked by ideXlab platform
Come Ialyradio - One of the best experts on this subject based on the ideXlab platform.
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differential sperm motility mediates the sex ratio drive shaping mouse sex Chromosome evolution
Current Biology, 2019Co-Authors: Claudia Cattoni Rathje, Nabeel A Affara, Emma Elizabeth Philippa Johnson, Deborah Drage, Christina Patinioti, Giuseppe Silvestri, Come Ialyradio, Julie CocquetAbstract:Summary The mouse sex Chromosomes exhibit an extraordinary level of copy number amplification of postmeiotically expressed genes [ 1 , 2 ], driven by an “arms race” (genomic conflict) between the X and Y Chromosomes over the control of offspring sex ratio. The sex-linked ampliconic transcriptional regulators Slx and Sly [ 3 , 4 , 5 , 6 , 7 ] have opposing effects on global transcription levels of the sex Chromosomes in haploid spermatids via regulation of postmeiotic sex chromatin (PMSC) [ 8 , 9 , 10 , 11 ] and opposing effects on offspring sex ratio. Partial deletions of the Y Chromosome (Yq) that reduce Sly copy number lead to global overexpression of sex-linked genes in spermatids and either a distorted sex ratio in favor of females (smaller deletions) or sterility (larger deletions) [ 12 , 13 , 14 , 15 , 16 ]. Despite a large body of work studying the role of the sex Chromosomes in regulating spermatogenesis (recent reviews [ 17 , 18 , 19 , 20 ]), most studies do not address differential fertility effects on X- and Y-bearing cells. Hence, in this study, we concentrate on identifying physiological differences between X- and Y-bearing sperm from Yq-deleted males that affect their relative fertilizing ability and consequently lead to sex ratio skewing. We show that X- and Y-bearing sperm in these males have differential motility and morphology but are equally able to penetrate the cumulus and fertilize the egg once at the site of fertilization. The altered motility is thus deduced to be the proximate cause of the skew. This represents the first demonstration of a specific difference in sperm function associated with sex ratio skewing.
Nabeel A Affara - One of the best experts on this subject based on the ideXlab platform.
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differential sperm motility mediates the sex ratio drive shaping mouse sex Chromosome evolution
Current Biology, 2019Co-Authors: Claudia Cattoni Rathje, Nabeel A Affara, Emma Elizabeth Philippa Johnson, Deborah Drage, Christina Patinioti, Giuseppe Silvestri, Come Ialyradio, Julie CocquetAbstract:Summary The mouse sex Chromosomes exhibit an extraordinary level of copy number amplification of postmeiotically expressed genes [ 1 , 2 ], driven by an “arms race” (genomic conflict) between the X and Y Chromosomes over the control of offspring sex ratio. The sex-linked ampliconic transcriptional regulators Slx and Sly [ 3 , 4 , 5 , 6 , 7 ] have opposing effects on global transcription levels of the sex Chromosomes in haploid spermatids via regulation of postmeiotic sex chromatin (PMSC) [ 8 , 9 , 10 , 11 ] and opposing effects on offspring sex ratio. Partial deletions of the Y Chromosome (Yq) that reduce Sly copy number lead to global overexpression of sex-linked genes in spermatids and either a distorted sex ratio in favor of females (smaller deletions) or sterility (larger deletions) [ 12 , 13 , 14 , 15 , 16 ]. Despite a large body of work studying the role of the sex Chromosomes in regulating spermatogenesis (recent reviews [ 17 , 18 , 19 , 20 ]), most studies do not address differential fertility effects on X- and Y-bearing cells. Hence, in this study, we concentrate on identifying physiological differences between X- and Y-bearing sperm from Yq-deleted males that affect their relative fertilizing ability and consequently lead to sex ratio skewing. We show that X- and Y-bearing sperm in these males have differential motility and morphology but are equally able to penetrate the cumulus and fertilize the egg once at the site of fertilization. The altered motility is thus deduced to be the proximate cause of the skew. This represents the first demonstration of a specific difference in sperm function associated with sex ratio skewing.
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Bidirectional transcription of a novel chimeric gene mapping to mouse Chromosome Yq
BMC Evolutionary Biology, 2007Co-Authors: Peter Ji Ellis, Lydia Ferguson, Emily J Clemente, Nabeel A AffaraAbstract:Background The male-specific region of the mouse Y Chromosome long arm (MSYq) contains three known highly multi-copy X-Y homologous gene families, Ssty1/2 , Sly and Asty . Deletions on MSYq lead to teratozoospermia and subfertility or infertility, with a sex ratio skew in the offspring of subfertile MSYqdel males Results We report the highly unusual genomic structure of a novel MSYq locus, Orly , and a diverse set of spermatid-specific transcripts arising from copies of this locus. Orly is composed of partial copies of Ssty1 , Asty and Sly arranged in sequence. The Ssty1- and Sly- derived segments are in antisense orientation relative to each other, leading to bi-directional transcription of Orly . Genome search and phylogenetic tree analysis is used to determine the order of events in mouse Yq evolution. We find that Orly is the most recent gene to arise on Yq, and that subsequently there was massive expansion in copy number of all Yq-linked genes. Conclusion Orly has an unprecedented chimeric structure, and generates both "forward" ( Orly ) and "reverse" ( Orlyos ) transcripts arising from the promoters at each end of the locus. The region of overlap of known Orly and Orlyos transcripts is homologous to Sly intron 2. We propose that Orly may be involved in an intragenomic conflict between mouse X and Y Chromosomes, and that this process underlies the massive expansion in copy number of the genes on MSYq and their X homologues.
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Bidirectional transcription of a novel chimeric gene mapping to mouse Chromosome Yq
BMC evolutionary biology, 2007Co-Authors: Peter Ji Ellis, Lydia Ferguson, Emily J Clemente, Nabeel A AffaraAbstract:Background The male-specific region of the mouse Y Chromosome long arm (MSYq) contains three known highly multi-copy X-Y homologous gene families, Ssty1/2, Sly and Asty. Deletions on MSYq lead to teratozoospermia and subfertility or infertility, with a sex ratio skew in the offspring of subfertile MSYqdel males
Julie Cocquet - One of the best experts on this subject based on the ideXlab platform.
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differential sperm motility mediates the sex ratio drive shaping mouse sex Chromosome evolution
Current Biology, 2019Co-Authors: Claudia Cattoni Rathje, Nabeel A Affara, Emma Elizabeth Philippa Johnson, Deborah Drage, Christina Patinioti, Giuseppe Silvestri, Come Ialyradio, Julie CocquetAbstract:Summary The mouse sex Chromosomes exhibit an extraordinary level of copy number amplification of postmeiotically expressed genes [ 1 , 2 ], driven by an “arms race” (genomic conflict) between the X and Y Chromosomes over the control of offspring sex ratio. The sex-linked ampliconic transcriptional regulators Slx and Sly [ 3 , 4 , 5 , 6 , 7 ] have opposing effects on global transcription levels of the sex Chromosomes in haploid spermatids via regulation of postmeiotic sex chromatin (PMSC) [ 8 , 9 , 10 , 11 ] and opposing effects on offspring sex ratio. Partial deletions of the Y Chromosome (Yq) that reduce Sly copy number lead to global overexpression of sex-linked genes in spermatids and either a distorted sex ratio in favor of females (smaller deletions) or sterility (larger deletions) [ 12 , 13 , 14 , 15 , 16 ]. Despite a large body of work studying the role of the sex Chromosomes in regulating spermatogenesis (recent reviews [ 17 , 18 , 19 , 20 ]), most studies do not address differential fertility effects on X- and Y-bearing cells. Hence, in this study, we concentrate on identifying physiological differences between X- and Y-bearing sperm from Yq-deleted males that affect their relative fertilizing ability and consequently lead to sex ratio skewing. We show that X- and Y-bearing sperm in these males have differential motility and morphology but are equally able to penetrate the cumulus and fertilize the egg once at the site of fertilization. The altered motility is thus deduced to be the proximate cause of the skew. This represents the first demonstration of a specific difference in sperm function associated with sex ratio skewing.
Liborio Stuppia - One of the best experts on this subject based on the ideXlab platform.
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Testis transcriptome analysis in male infertility: new insight on the pathogenesis of oligo-azoospermia in cases with and without AZFc microdeletion
BMC Genomics, 2010Co-Authors: Valentina Gatta, Florina Raicu, Alberto Ferlin, Ivana Antonucci, Anna Paola Scioletti, Andrea Garolla, Giandomenico Palka, Carlo Foresta, Liborio StuppiaAbstract:Background About 10% of cases of male infertility are due to the presence of microdeletions within the long arm of the Y Chromosome (Yq). Despite the large literature covering this critical issue, very little is known about the pathogenic mechanism leading to spermatogenesis disruption in patients carrying these microdeletions. In order to identify the presence of specific molecular pathways leading to spermatogenic damage, testicular gene expression profiling was carried out by employing a microarray assay in 16 patients carrying an AZFc microdeletion or affected by idiopathic infertility. Hierarchical clustering was performed pooling the data set from 26 experiments (16 patients, 10 replicates). Results An intriguing and unexpected finding is that all the samples showing the AZFc deletion cluster together irrespectively of their testicular phenotypes. This cluster, including also four patients affected by idiopathic infertility, showed a downregulation of several genes related to spermatogenesis that are mainly involved in testicular mRNA storage. Interestingly, the four idiopathic patients present in the cluster showed no testicular expression of DAZ despite the absence of AZFc deletion in the peripheral blood. Conclusions Our expression profiles analysis indicates that several forms of infertility can be triggered by a common pathogenic mechanism that is likely related to alterations in testicular mRNA storage. Our data suggest that a lack of testicular DAZ gene expression may be the trigger of such mechanism. Furthermore, the presence of AZFc deletions in mosaic or the loss of function of AZFc genes in absence of Yq deletion can perhaps explain these findings. Finally, based on our data, it is intriguing to hypothesize that DAZ gene dysfunctions can account for a larger number of previously thought "idiopathic" infertility cases and investigation of such testicular gene dysfunction can be important to reveal the molecular determinant of infertility than are undetected when only testing Yq deletions in peripheral blood.
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Testis transcriptome analysis in male infertility: new insight on the pathogenesis of oligo-azoospermia in cases with and without AZFc microdeletion
BMC genomics, 2010Co-Authors: Valentina Gatta, Florina Raicu, Alberto Ferlin, Ivana Antonucci, Anna Paola Scioletti, Andrea Garolla, Giandomenico Palka, Carlo Foresta, Liborio StuppiaAbstract:About 10% of cases of male infertility are due to the presence of microdeletions within the long arm of the Y Chromosome (Yq). Despite the large literature covering this critical issue, very little is known about the pathogenic mechanism leading to spermatogenesis disruption in patients carrying these microdeletions. In order to identify the presence of specific molecular pathways leading to spermatogenic damage, testicular gene expression profiling was carried out by employing a microarray assay in 16 patients carrying an AZFc microdeletion or affected by idiopathic infertility. Hierarchical clustering was performed pooling the data set from 26 experiments (16 patients, 10 replicates). An intriguing and unexpected finding is that all the samples showing the AZFc deletion cluster together irrespectively of their testicular phenotypes. This cluster, including also four patients affected by idiopathic infertility, showed a downregulation of several genes related to spermatogenesis that are mainly involved in testicular mRNA storage. Interestingly, the four idiopathic patients present in the cluster showed no testicular expression of DAZ despite the absence of AZFc deletion in the peripheral blood. Our expression profiles analysis indicates that several forms of infertility can be triggered by a common pathogenic mechanism that is likely related to alterations in testicular mRNA storage. Our data suggest that a lack of testicular DAZ gene expression may be the trigger of such mechanism. Furthermore, the presence of AZFc deletions in mosaic or the loss of function of AZFc genes in absence of Yq deletion can perhaps explain these findings. Finally, based on our data, it is intriguing to hypothesize that DAZ gene dysfunctions can account for a larger number of previously thought "idiopathic" infertility cases and investigation of such testicular gene dysfunction can be important to reveal the molecular determinant of infertility than are undetected when only testing Yq deletions in peripheral blood.
Claudia Cattoni Rathje - One of the best experts on this subject based on the ideXlab platform.
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differential sperm motility mediates the sex ratio drive shaping mouse sex Chromosome evolution
Current Biology, 2019Co-Authors: Claudia Cattoni Rathje, Nabeel A Affara, Emma Elizabeth Philippa Johnson, Deborah Drage, Christina Patinioti, Giuseppe Silvestri, Come Ialyradio, Julie CocquetAbstract:Summary The mouse sex Chromosomes exhibit an extraordinary level of copy number amplification of postmeiotically expressed genes [ 1 , 2 ], driven by an “arms race” (genomic conflict) between the X and Y Chromosomes over the control of offspring sex ratio. The sex-linked ampliconic transcriptional regulators Slx and Sly [ 3 , 4 , 5 , 6 , 7 ] have opposing effects on global transcription levels of the sex Chromosomes in haploid spermatids via regulation of postmeiotic sex chromatin (PMSC) [ 8 , 9 , 10 , 11 ] and opposing effects on offspring sex ratio. Partial deletions of the Y Chromosome (Yq) that reduce Sly copy number lead to global overexpression of sex-linked genes in spermatids and either a distorted sex ratio in favor of females (smaller deletions) or sterility (larger deletions) [ 12 , 13 , 14 , 15 , 16 ]. Despite a large body of work studying the role of the sex Chromosomes in regulating spermatogenesis (recent reviews [ 17 , 18 , 19 , 20 ]), most studies do not address differential fertility effects on X- and Y-bearing cells. Hence, in this study, we concentrate on identifying physiological differences between X- and Y-bearing sperm from Yq-deleted males that affect their relative fertilizing ability and consequently lead to sex ratio skewing. We show that X- and Y-bearing sperm in these males have differential motility and morphology but are equally able to penetrate the cumulus and fertilize the egg once at the site of fertilization. The altered motility is thus deduced to be the proximate cause of the skew. This represents the first demonstration of a specific difference in sperm function associated with sex ratio skewing.