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Casellas J, Id-Lahoucine S, Cánovas A. Discriminating between allele- and genotype-specific transmission ratio distortion. Anim Genet 2020; 51:847-854. [PMID: 32996622 DOI: 10.1111/age.13007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2020] [Indexed: 11/30/2022]
Abstract
Transmission ratio distortion (TRD) is defined as the observed deviation from the expected Mendelian inheritance of alleles from heterozygous parents. This phenomenon is attributed to various biological mechanisms acting on germ cells, embryos or fetuses, or even in early postnatal life. Current statistical approaches typically use two independent parametrizations assuming that TRD relies on allele- or genotype-related mechanisms, although they have never been tested and compared. This study compared allele- and genotype-related TRD models on simulated datasets with 1000 genotyped offspring and real data from 168 sire-dam-offspring beef cattle trios. The analysis of simulated datasets favored the true model of analysis in most cases (>93%), and a low percentage of missidentification occurred under (almost) null dominance (genotype-related model) or similar and moderate-to-low sire- and dam-specific TRD parameters (allele-related model). Moreover, the correlation between simulated and predicted distortion parameters was high (>0.97) under the true model. The comparison of allele- and genotype-related TRD models is an appealing tool to infer the biological source of TRD (i.e. haploid vs. diploid cells) when screening the whole genome. The analysis of beef cattle data corroborated a TRD region previously reported in chromosome 4, although discarding allele-related mechanisms and favoring the genotype-related model as the more reliable one. The results of this study highlight the relevance of implementing and comparing different parametrizations to capture all kinds of TRD, and to compare them using appropriate statistical methods.
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Affiliation(s)
- J Casellas
- Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain
| | - S Id-Lahoucine
- Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.,Department of Animal Biosciences, Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - A Cánovas
- Department of Animal Biosciences, Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, N1G 2W1, Canada
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Shao YH, Zhang XY, Buckett W, Ao A. Impact of in vitro fertilization-preimplantation genetic testing (IVF-PGT) funding policy on clinical outcome: An issue that stems beyond effectiveness of treatment. Eur J Obstet Gynecol Reprod Biol 2019; 235:1-5. [PMID: 30743159 DOI: 10.1016/j.ejogrb.2019.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 12/10/2018] [Accepted: 01/01/2019] [Indexed: 01/02/2023]
Abstract
OBJECTIVE(S) The aim of this study was to compare the patient characteristics, type of genetic disease and inheritance, volume of activity, practice patterns and pregnancy outcomes, in private versus publically funded IVF pre-implantation genetic testing (PGT) for translocation (IVF-PGT-SR) and aneuploidy (PGT-A) periods. STUDY DESIGN This study retrospectively analyzed data during both privately funded period (PRP) and publically funded period (PUP) of assisted reproductive technology (ART) for a total of 275 patients. 83 patients underwent IVF-PGT-SR and 192 patients underwent IVF-PGT-A. Given that PGT-SR is a chromosomal abnormality hereditary in nature, whereas PGT-A is sporadic in addition to the contrasting funding policies, the two cohorts were analyzed separately. To achieve the proposed objective, the two groups under analysis were grouped in accordance with their respective coverage systems for infertility. RESULTS Among translocation patients, 94 normal/balanced embryos were obtained from 47 IVF-PGT cycles in PRP whereas 145 embryos were obtained from 92 IVF-PGT cycles in PUP. The average number of embryos transferred per embryo transfer cycle was significantly lower in PUP in comparison to PRP (1.13 vs. 1.74, p < 0.0001). 13 singletons and 2 sets of twins were conceived in PRP. 14 singletons were conceived in PUP. Regardless of funding period, there were more reciprocal translocation carriers (79.4% in PRP and 76.4% in PUP) and more male carriers (82.4% in PRP and 60% in PUP), of which the majority had abnormal sperm parameters. Among aneuploidy patients, on average 2.5 embryos in PRP and 1.4 embryos in PUP were transferred per ET cycle (p = 0.05). There was a 13.3% increase in number of IVF-PGT-A attempts per patient in PRP compared to PUP. Live birth rate per IVF-PGT-A was higher in PRP (29.7% vs. 15%, P = 0.02), which consisted of 48 singletons and 18 multiparous pregnancies in PRP and 9 singletons in PUP. CONCLUSION(S) Public coverage of ART is associated with a greater utilization ART, as well as a reduced number in embryo transfer (ET) per cycle, a lower proportion of cycles resulting in successful pregnancy and a lower multiple birth rate. Our study ultimately shines light on the effect of providers' and patients' monetary conscious on pregnancy outcome.
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Affiliation(s)
- Yi-Hong Shao
- Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Xiao Yun Zhang
- MUHC Reproductive Centre, Department of Obstetrics and Gynecology, McGill Univeristy, Montreal, Quebec, Canada
| | - William Buckett
- MUHC Reproductive Centre, Department of Obstetrics and Gynecology, McGill Univeristy, Montreal, Quebec, Canada
| | - Asangla Ao
- MUHC Reproductive Centre, Department of Obstetrics and Gynecology, McGill Univeristy, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada.
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Snyder EM, McCarty C, Mehalow A, Svenson KL, Murray SA, Korstanje R, Braun RE. APOBEC1 complementation factor (A1CF) is dispensable for C-to-U RNA editing in vivo. RNA (NEW YORK, N.Y.) 2017; 23:457-465. [PMID: 28069890 PMCID: PMC5340909 DOI: 10.1261/rna.058818.116] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 12/14/2016] [Indexed: 05/20/2023]
Abstract
Editing of the human and murine ApoB mRNA by APOBEC1, the catalytic enzyme of the protein complex that catalyzes C-to-U RNA editing, creates an internal stop codon within the APOB coding sequence, generating two protein isoforms. It has been long held that APOBEC1-mediated editing activity is dependent on the RNA binding protein A1CF. The function of A1CF in adult tissues has not been reported because a previously reported null allele displays embryonic lethality. This work aimed to address the function of A1CF in adult mouse tissues using a conditional A1cf allele. Unexpectedly, A1cf-null mice were viable and fertile with modest defects in hematopoietic, immune, and metabolic parameters. C-to-U RNA editing was quantified for multiple targets, including ApoB, in the small intestine and liver. In all cases, no changes in RNA editing efficiency were observed. Blood plasma analysis demonstrated a male-specific increase in solute concentration and increased cellularity in the glomeruli of male A1cf-null mice. Urine analysis showed a reduction in solute concentration, suggesting abnormal water homeostasis and possible kidney abnormalities exclusive to the male. Computational identification of kidney C-to-U editing sites from polyadenylated RNA-sequencing identified a number of editing sites exclusive to the kidney. However, molecular analysis of kidney C-to-U editing showed no changes in editing efficiency with A1CF loss. Taken together, these observations demonstrate that A1CF does not act as the APOBEC1 complementation factor in vivo under normal physiological conditions and suggests new roles for A1CF, specifically within the male adult kidney.
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Affiliation(s)
| | | | | | | | | | - Ron Korstanje
- The Jackson Laboratory, Bar Harbor, Maine 04609, USA
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Robertsonian translocations modify genomic distribution of γH2AFX and H3.3 in mouse germ cells. Mamm Genome 2016; 27:225-36. [PMID: 27090237 DOI: 10.1007/s00335-016-9630-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 04/04/2016] [Indexed: 12/28/2022]
Abstract
Heterozygosity for Robertsonian translocations hampers pairing and synapsis between the translocated chromosome and its normal homologs during meiotic prophase I. This causes meiotic silencing of unsynapsed chromatin in pericentromeric regions. Several lines of evidence suggest that autosomal asynapsis leads to meiotic arrest in males and two underlying mechanisms have been proposed: (1) reactivation of the X and Y chromosomes due to competition for silencing factors and (2) meiotic silencing of genes that are located in the unsynapsed regions and are essential for meiotic progression. The latter mechanism requires that asynapsis and meiotic silencing spread beyond the p-arms of the normal homologs into gene-rich regions. We used chromatin immunoprecipitation assays to determine whether histones γH2AFX and H3.3, both marks of asynapsis and meiotic silencing, are enriched in gene-rich regions of the translocated chromosomes and their homologs in the spermatocytes of heterozygous carriers of Robertsonian translocations. We also asked if γH2AFX and H3.3 enrichment was reduced at the X chromosome and if γH2AFX and H3.3 enrichment was higher on the normal homolog. Our data show that γH2AFX enrichment extends as far as 9-15 Mb of the annotated genomic sequence of the q-arms of the translocated chromosomal trivalents and that both γH2AFX and H3.3 levels are reduced over the X chromosome. Our data are also suggestive of an asymmetry in γH2AFX and H3.3 enrichment with a bias toward the non-translocated homolog.
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Manieu C, González M, López-Fenner J, Page J, Ayarza E, Fernández-Donoso R, Berríos S. Aneuploidy in spermatids of Robertsonian (Rb) chromosome heterozygous mice. Chromosome Res 2014; 22:545-57. [PMID: 25385393 PMCID: PMC4544632 DOI: 10.1007/s10577-014-9443-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 09/27/2014] [Accepted: 10/14/2014] [Indexed: 11/30/2022]
Abstract
Rb translocations are chromosomal rearrangements frequently found in natural populations of the house mouse Mus musculus domesticus. The standard diploid karyotype of the house mouse consisting of 40 telocentric chromosomes may be reduced by the emergence of metacentric Rb chromosomes. Multiple simple Rb heterozygotes form trivalents exhibiting higher anaphase nondisjunction frequency and consequently higher number of unbalanced gametes than in normal males. This work will attempt to establish whether frequencies of aneuploidy observed in heterozygote spermatids of the house mouse M. musculus domesticus show differences in chromosomes derived from different trivalents. Towards this goal, the number and distribution frequency of aneuploidy was assessed via FISH staining of specific chromosomes of spermatids derived from 2n = 32 individuals. Our results showed that for a given set of target chromosomes, 90 % of the gametes were balanced, resulting from alternate segregation, and that there were no differences (approx. 10 %) in aneuploidy frequencies in chromosomes derived from different trivalents. These observations suggest that segregation effectiveness does not depend on the type of chromosomes involved in trivalents. As a consequence of the trivalent’s configuration, joint segregation of the telocentric chromosomes occurs thus favoring their appearance together in early spermatids. Our data suggest that Rb chromosomes and their telocentric homologs are subject to architectural constraints placing them close to each other. This proximity may ultimately facilitate fusion between them, hence contributing to a prevalence of Rb metacentric chromosomes.
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Affiliation(s)
- Catalina Manieu
- Programa Genética Humana, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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Abstract
Current statistical approaches to investigate the nature and magnitude of transmission ratio distortion (TRD) are scarce and restricted to the most common experimental designs such as F2 populations and backcrosses. In this article, we describe a new Bayesian approach to check TRD within a given biallelic genetic marker in a diploid species, providing a highly flexible framework that can accommodate any kind of population structure. This model relies on the genotype of each offspring and thus integrates all available information from either the parents' genotypes or population-specific allele frequencies and yields TRD estimates that can be corroborated by the calculation of a Bayes factor (BF). This approach has been evaluated on simulated data sets with appealing statistical performance. As a proof of concept, we have also tested TRD in a porcine population with five half-sib families and 352 offspring. All boars and piglets were genotyped with the Porcine SNP60 BeadChip, whereas genotypes from the sows were not available. The SNP-by-SNP screening of the pig genome revealed 84 SNPs with decisive evidences of TRD (BF > 100) after accounting for multiple testing. Many of these regions contained genes related to biological processes (e.g., nucleosome assembly and co-organization, DNA conformation and packaging, and DNA complex assembly) that are critically associated with embryonic viability. The implementation of this method, which overcomes many of the limitations of previous approaches, should contribute to fostering research on TRD in both model and nonmodel organisms.
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Bureš P, Zedek F. Holokinetic drive: centromere drive in chromosomes without centromeres. Evolution 2014; 68:2412-20. [PMID: 24758327 DOI: 10.1111/evo.12437] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 04/13/2014] [Indexed: 02/02/2023]
Abstract
Similar to how the model of centromere drive explains the size and complexity of centromeres in monocentrics (organisms with localized centromeres), our model of holokinetic drive is consistent with the divergent evolution of chromosomal size and number in holocentrics (organisms with nonlocalized centromeres) exhibiting holokinetic meiosis (holokinetics). Holokinetic drive is proposed to facilitate chromosomal fission and/or repetitive DNA removal (or any segmental deletion) when smaller homologous chromosomes are preferentially inherited or chromosomal fusion and/or repetitive DNA proliferation (or any segmental duplication) when larger homologs are preferred. The hypothesis of holokinetic drive is supported primarily by the negative correlation between chromosome number and genome size that is documented in holokinetic lineages. The supporting value of two older cross-experiments on holokinetic structural heterozygotes (the rush Luzula elegans and butterflies of the genus Antheraea) that indicate the presence of size-preferential homolog transmission via female meiosis for holokinetic drive is discussed, along with the further potential consequences of holokinetic drive in comparison with centromere drive.
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Affiliation(s)
- Petr Bureš
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic.
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Transmission ratio distortion: review of concept and implications for genetic association studies. Hum Genet 2012; 132:245-63. [PMID: 23242375 DOI: 10.1007/s00439-012-1257-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 12/04/2012] [Indexed: 12/31/2022]
Abstract
Transmission ratio distortion (TRD) occurs when one of the two alleles from either parent is preferentially transmitted to the offspring. This leads to a statistical departure from the Mendelian law of inheritance, which states that each of the two parental alleles is transmitted to offspring with a probability of 0.5. A number of mechanisms are thought to induce TRD such as meiotic drive, gametic competition, and embryo lethality. TRD has been extensively studied in animals, but the prevalence of TRD in humans remains largely unknown. Nevertheless, understanding the TRD phenomenon and taking it into consideration in many aspects of human genetics has potential benefits that have not been sufficiently emphasized in the current literature. In this review, we discuss the importance of TRD in three distinct but related fields of genetics: developmental genetics which studies the genetic abnormalities in zygotic and embryonic development, statistical genetics/genetic epidemiology which utilizes population study designs and statistical models to interpret the role of genes in human health, and population genetics which is concerned with genetic diversity in populations in an evolutionary context. From the perspective of developmental genetics, studying TRD leads to the identification of the processes and mechanisms for differential survival observed in embryos. As a result, it is a genetic force which affects allele frequency at the population, as well as, at the organismal level. Therefore, it has implications on genetic diversity of the population over time. From the perspective of genetic epidemiology, the TRD influence on a marker locus is a confounding factor which has to be adequately dealt with to correctly interpret linkage or association study results. These aspects are developed in this review. In addition to these theoretical notions, a brief summary of the empirical evidence of the TRD phenomenon in human and mouse studies is provided. The objective of our paper is to show the potentially important role of TRD in many areas of genetics, and to create an incentive for future research.
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9
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Abstract
Transmission ratio distortion (TRD) is the departure from the expected genotypic frequencies under Mendelian inheritance. This departure can be due to multiple physiological mechanisms during gametogenesis, fertilization, fetal and embryonic development, and early neonatal life. Although a few TRD loci have been reported in mouse, inheritance patterns have never been evaluated for TRD. In this article, we developed a Bayesian binomial model accounting for additive and dominant deviation TRD mechanisms. Moreover, this model was used to perform genome-wide scans for TRD quantitative trait loci (QTL) on six F2 mouse crosses involving between 296 and 541 mice and between 72 and 1854 genetic markers. Statistical significance of each model was checked at each genetic marker with Bayes factors. Genome scans revealed overdominance TRD QTL located in mouse chromosomes 1, 2, 12, 13, and 14 and additive TRD QTL in mouse chromosomes 2, 3, and 15, although these results did not replicate across mouse crosses. This research contributes new statistical tools for the analysis of specific genetic patterns involved in TRD in F2 populations, our results suggesting a relevant incidence of TRD phenomena in mouse with important implications for both statistical analyses and biological research.
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Xanthopoulou L, Mantzouratou A, Mania A, Cawood S, Doshi A, Ranieri DM, Delhanty JD. Male and female meiotic behaviour of an intrachromosomal insertion determined by preimplantation genetic diagnosis. Mol Cytogenet 2010; 3:2. [PMID: 20181117 PMCID: PMC2830219 DOI: 10.1186/1755-8166-3-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Accepted: 02/08/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Two related family members, a female and a male balanced carrier of an intrachromosomal insertion on chromosome 7 were referred to our centre for preimplantation genetic diagnosis. This presented a rare opportunity to investigate the behaviour of the insertion chromosome during meiosis in two related carriers. The aim of this study was to carry out a detailed genetic analysis of the preimplantation embryos that were generated from the three treatment cycles for the male and two for the female carrier.Patients underwent in vitro fertilization and on day 3, 22 embryos from the female carrier and 19 embryos from the male carrier were biopsied and cells analysed by fluorescent in situ hybridization. Follow up analysis of 29 untransferred embryos was also performed for confirmation of the diagnosis and to obtain information on meiotic and mitotic outcome. RESULTS In this study, the female carrier produced more than twice as many chromosomally balanced embryos as the male (76.5% vs. 36%), and two pregnancies were achieved for her. Follow up analysis showed that the male carrier had produced more highly abnormal embryos than the female (25% and 15% respectively) and no pregnancies occurred for the male carrier and his partner. CONCLUSION This study compares how an intrachromosomal insertion has behaved in the meiotic and preimplantation stages of development in sibling male and female carriers. It confirms that PGD is an appropriate treatment in such cases. Reasons for the differing outcome for the two carriers are discussed.
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Affiliation(s)
- Leoni Xanthopoulou
- UCL Centre for PGD, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK.
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Influence of sex on the meiotic segregation of a t(13;17) Robertsonian translocation: a case study in the pig. Hum Reprod 2009; 24:2034-43. [DOI: 10.1093/humrep/dep118] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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12
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Gonçalves Dos Santos Silva A, Sarkar R, Harizanova J, Guffei A, Mowat M, Garini Y, Mai S. Centromeres in cell division, evolution, nuclear organization and disease. J Cell Biochem 2008; 104:2040-58. [PMID: 18425771 DOI: 10.1002/jcb.21766] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
As the spindle fiber attachment region of the chromosome, the centromere has been investigated in a variety of contexts. Here, we will review current knowledge about this unique chromosomal region and its relevance for proper cell division, speciation, and disease. Understanding the three-dimensional organization of centromeres in normal and tumor cells is just beginning to emerge. Multidisciplinary research will allow for new insights into its normal and aberrant nuclear organization and may allow for new therapeutic interventions that target events linked to centromere function and cell division.
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13
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Vozdova M, Kubickova S, Cernohorska H, Rubes J. Detection of translocation rob(1;29) in bull sperm using a specific DNA probe. Cytogenet Genome Res 2008; 120:102-5. [PMID: 18467831 DOI: 10.1159/000118746] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2007] [Indexed: 12/17/2022] Open
Abstract
The Robertsonian translocation rob(1;29), connected with reduced fertility, is widespread in different cattle breeds all over the world. After laser microdissection, DOP-PCR, cloning and sequencing, a highly sensitive translocation-specific DNA probe, suitable for detection of rob(1;29) in cattle metaphase and interphase cells, including spermatozoa was designed. Sperm samples of five heterozygous translocation carriers were analyzed using this probe and a control probe for chromosome 6. One thousand decondensed spermatozoa from each bull were scored. Signals of the translocation-specific probe were detected in 48.8, 50.9, 50.1, 51.8, and 54.8% of spermatozoa, respectively. In contrast, semen samples from five chromosomally normal bulls showed only signals of the control probe for chromosome 6. Semen from a chimeric (XX/XY) bull, showing 57.5% of 59,XX,rob(1;29) and 42.5% of 60,XY cells in cultured peripheral lymphocytes, was also examined using this probe. No sperm head with signal of the translocation-specific probe was observed among 1,000 spermatozoa analyzed in this bull, demonstrating that female cells do not pass through the process of spermatogenesis.
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Affiliation(s)
- M Vozdova
- Veterinary Research Institute, Brno, Czech Republic
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Abstract
Robertsonian (Rb) translocation is the largest source of chromosomal diversity in the western European house mouse (Mus musculus domesticus). Recently, the fusion Rb(7.17) was found in the chromosomal polymorphic zone of this subspecies in the north-east of the Iberian Peninsula. This fusion has not been reported in any other European population. Here we give data on the distribution and frequency of this mutation in this region. Results revealed that Rb(7.17) is restricted to a small geographic area, and that, in comparison with other fusions in this polymorphic zone, it occurs at low frequencies. We suggest some possible explanations for the distribution of this translocation.
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Schulz R, Underkoffler LA, Collins JN, Oakey RJ. Nondisjunction and transmission ratio distortion ofChromosome 2 in a (2.8) Robertsonian translocation mouse strain. Mamm Genome 2006; 17:239-47. [PMID: 16518691 PMCID: PMC1403820 DOI: 10.1007/s00335-005-0126-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2005] [Accepted: 11/25/2005] [Indexed: 12/21/2022]
Abstract
Aneuploidy results from nondisjunction of chromosomes in meiosis and is the leading cause of developmental disabilities and mental retardation in humans. Therefore, understanding aspects of chromosome segregation in a genetic model is of value. Mice heterozygous for a (2.8) Robertsonian translocation were intercrossed with chromosomally normal mice and Chromosome 2 was genotyped for number and parental origin in 836 individuals at 8.5 dpc. The frequency of nondisjunction of this Robertsonian chromosome is 1.58%. Trisomy of Chromosome 2 with two maternally derived chromosomes is the most developmentally successful aneuploid karyotype at 8.5 dpc. Trisomy of Chromosome 2 with two paternally derived chromosomes is developmentally delayed and less frequent than the converse. Individuals with maternal or paternal uniparental disomy of Chromosome 2 were not detected at 8.5 dpc. Nondisjunction events were distributed randomly across litters, i.e., no evidence for clustering was found. Transmission ratio distortion is frequently observed in Robertsonian chromosomes and a bias against the transmission of the (2.8) Chromosome was detected. Interestingly, this was observed for female and male transmitting parents.
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Affiliation(s)
- Reiner Schulz
- Department of Medical and Molecular Genetics, King’s College London, 8th Floor Guy’s Tower, London, SE1 9RT United Kingdom
| | - Lara A. Underkoffler
- Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Joelle N. Collins
- Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Rebecca J. Oakey
- Department of Medical and Molecular Genetics, King’s College London, 8th Floor Guy’s Tower, London, SE1 9RT United Kingdom
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Eichenlaub-Ritter U. Mouse genetic models for aneuploidy induction in germ cells. Cytogenet Genome Res 2005; 111:392-400. [PMID: 16192722 DOI: 10.1159/000086917] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Accepted: 03/04/2005] [Indexed: 12/16/2022] Open
Abstract
Rodents have been successfully used as models to identify risks of chemical exposures or age to aneuploidy induction in germ cells, which may be transmitted to the progeny. For this administration in vivo as well as exposures to in vitro maturing germ cells have been useful. Genetic models involving mice with structural chromosomal rearrangements and transgenic animals have the potential to model conditions predisposing to aneuploidy in one or both sexes, and in this way to identify potential targets for aneugens and gender-effects. The review provides an overview of mouse genetic models for aneuploidy induction in mammalian germ cells and discusses perspectives for combining genetic with experimental approaches in aneuploidy research.
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Affiliation(s)
- U Eichenlaub-Ritter
- Institute of Gentechnology/Microbiology, Faculty of Biology, University of Bielefeld, Bielefeld, Germany.
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