RESUMO
PWD/Ph and PWK/Ph (abbreviated PW*) are highly inbred mouse strains (F66 and F70) derived from wild mice of Mus musculus musculus subspecies. When compared with laboratory inbred strains, they display a plethora of differences in many complex phenotypes such as body weight, fat distribution pattern, blood levels of intermediary metabolites, sensitivity to type-1 diabetes or behaviour patterns. The PWD/Ph genes can rescue the lethal effect of lack of the Igf2 receptor. The male-limited hybrid sterility of (PWD/Ph x laboratory strain)F1 hybrids is a specific phenotype controlled by three or four unlinked loci. These complex phenotypic traits can be genetically dissected by QTL analysis using microsatellite markers of known genetic location. The PW strains are particularly useful for such genome-wide scans since 70-80% of randomly chosen microsatellite markers are polymorphic in (PW x laboratory strain) crosses compared to 35-45% in crosses between two laboratory strains. The list of polymorphic microsatellite loci is included in this report. The high degree of sequence polymorphism allows easier distinction between paternal and maternal mRNA transcripts in PW hybrids, which makes the PW* strains a useful tool also in molecular studies of genomic imprinting. The high frequency of phenotypic differences together with the high degree of sequence polymorphism and the relatively easy breeding of PW strains make them a valuable mammalian model organism for the functional genomics of the traits of biomedical importance.
Assuntos
Variação Genética , Camundongos Endogâmicos/genética , Polimorfismo Genético , Alelos , Animais , Mapeamento Cromossômico , Cruzamentos Genéticos , Feminino , Expressão Gênica , Infertilidade/genética , Masculino , Camundongos , Repetições de Microssatélites , Modelos Genéticos , Mutação , Fenótipo , Característica Quantitativa Herdável , Especificidade da EspécieRESUMO
Though DNA methylation is necessary to maintain monoallelic expression of imprinted genes, it is still unclear whether it represents the primary mark. Here we ask whether the imprinting mark is still present in terminally differentiated somatic cells in which the transcription of embryo-specific imprinted genes was shut off. For such analysis H19 and Igf2 genes were activated by inducing differentiation of (mouse embryonal carcinoma cell x mouse lymphocyte) hybrid cell clones. Although lymphocytes do not express H19 and Igf2, both genes are reactivated in a proper monoallelic manner in hybrid cells. Analysis of the upstream region of the H19 gene confirmed maintenance of differential methylation of the active and inactive H19 genes of lymphocyte origin, although a tendency toward in vitro induced hypermethylation was apparent. We conclude that the imprints of the H19, U2af1-rs1, and Igf2 genes are maintained in lymphocytes in adult mice.
Assuntos
Alelos , Impressão Genômica , Proteínas Musculares/genética , RNA não Traduzido , Animais , Carcinoma Embrionário/genética , Células Híbridas , Fator de Crescimento Insulin-Like II/genética , Linfócitos , Camundongos , RNA Longo não CodificanteRESUMO
Transcriptional regulation of the MHC class I genes leading to their developmental and tissue specific expression is still poorly understood in spite of the recovery of a large variety of cis-controlling sequences and trans-acting factors pertaining to the 5' enhancer and the downstream regulatory element. Here we produced a series transgenic lines of mice with a genomic subclone of the H2-Kb gene consisting of 367 bp of the 5' upstream region, the coding region and 1.5 kb of the 3' downstream region and carrying all hitherto known regulatory sequences. The comparison of nine transgenic lines carrying the same H2-Kb transgene made it possible to ask whether the cis-information present in the transgene was sufficient for the tissue- and developmental-specific expression and its copy number dependence. We found the proper developmental onset of expression of the transgene at day 13 p.c. and correct tissue specific mRNA levels in adult mice. While in lymphoid tissues and in lung the number of transgene copies still correlated with RNA levels, the copy number dependence was completely lost in liver, kidney and embryonic tissues. Comparison with previously published H2-Kb transgenes indicates that the H2-Kb locus-controlling region is composed of more than one element.
Assuntos
Regulação da Expressão Gênica/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Camundongos Transgênicos/imunologia , Animais , Técnicas de Transferência de Genes , Camundongos , RNA Mensageiro/imunologia , Transcrição GênicaRESUMO
The Hybrid sterility 1 (Hst1) gene causes male infertility in crosses between certain inbred strains of the laboratory and wild mouse, Mus musculus. To identify the causative gene, we have searched YAC clones encompassing the Hst1 region for testis-expressed sequences, using the cDNA selection method. We isolated 12 non-overlapping cDNA clones, sequenced them, and placed them on a physical map based on the analysis of YAC clones and total genomic DNA. The cDNA clones map to ten loci. Three cDNA sequences correspond to the proteasome subunit C5 (locus Psmb1), ornithine decarboxylase (Odc-rs15), and penta-zinc finger (Zfp91-rs1) transcripts. Three of the ten testis-expressed loci described in this report (D17Ph4e, Psmb1, and Zfp91-rs1) co-segregate with all Hst1 recombinants and, together with the Tbp gene, are therefore potential candidates for the Hst1 gene. The presented physical and genetic mapping data indicate there are no gross rearrangements distinguishing the Hst1(f) and Hst1(s) alleles.
Assuntos
DNA Complementar/genética , Infertilidade Masculina/genética , Animais , Mapeamento Cromossômico , Clonagem Molecular , Cruzamentos Genéticos , Eletroforese em Gel de Campo Pulsado , Feminino , Expressão Gênica , Hibridização Genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , MuridaeRESUMO
We have generated a high-resolution genetic map, 0.071 cM per backcross animal, of the 13 cM T-H2 region of the mouse Chromosome (Chr) 17. The map contains two phenotypic loci, T and Hst1, 12 RFLP markers, and 24 microsatellite loci. The Hst1 gene was mapped to a chromosomal interval contained within a single 580-kb YAC clone. The FFEH11 YAC is 0.44 cM long and carries, besides the Hst1 gene, five polymorphic DNA markers and recombination breakpoints of six backcross animals. Two candidate genes for Hst1 were identified based on their location and testicular expression. These are Tbp and D17Ph4e. The submilliMorgan map of the T-H2 region revealed significant clustering of (CA)n loci. The clustering, if shown to be a common feature in the mouse genome, may cause gaps in the physical map of the mouse genome.
Assuntos
Mapeamento Cromossômico , Infertilidade Masculina/genética , Animais , Sequência de Bases , Primers do DNA , Feminino , Marcadores Genéticos , Genótipo , Antígenos H-2/genética , Hibridização Genética , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Família Multigênica , Polimorfismo de Fragmento de Restrição , Polimorfismo Conformacional de Fita Simples , Recombinação GenéticaRESUMO
The Thp deletion on mouse chromosome 17 is lethal when inherited from the mother, because it deletes the T-associated maternal effect (Tme) locus, the paternal copy of which is inactivated by genomic imprinting. We have found a paternally nonimprinted Tme variant in crosses of Thp females with Mus m. musculus males. The data are consistent with the existence of a single Tme-unlinked gene, Imprintor-1 (Imp-1), with two alleles, one of which only causes imprinting at the Tme locus. Imp-1 is unlinked to the gene for cation-dependent Man-6-P receptor and acts prezygotically. Although Tme and Igf2r were thought to be identical, they show different patterns of imprinting in interspecies hybrids. The apparent nonequivalence of the Igf2r gene and Tme results in occurrence of viable mice lacking an active Igf2r gene. These mice are bigger at birth than their normal littermates, in accord with the proposed function of the IGF-II/Man-6-P receptor.
Assuntos
Regulação da Expressão Gênica , Animais , Northern Blotting , Southern Blotting , Deleção Cromossômica , Feminino , Fertilização , Genes Dominantes , Genes Letais , Variação Genética , Hibridização Genética , Fator de Crescimento Insulin-Like II/genética , Fator de Crescimento Insulin-Like II/fisiologia , Masculino , Manosefosfatos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Modelos Genéticos , RNA Mensageiro/metabolismo , Receptor IGF Tipo 2 , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/fisiologiaRESUMO
The male-sterile reciprocal autosomal translocation T(16;17)43H displays a high frequency of adjacent-2 disjunction in meiosis of translocation heterozygotes. One haploid product of this abnormal chromosome segregation leads to viable partial trisomy of chromosome 17 after fertilization. The frequency of trisomics increases in the progeny of T43H/+ females when the wild-type allelic form of T-t complex is substituted for t12, tw32 or t6 recessive lethal haplotypes. Indirect evidence supports the idea that the suppression of crossing-over by t haplotypes is linked with the increase in adjacent-2 disjunction and subsequent Ts43H trisomy. The possible use of Ts43H trisomy for genetic dissection of the T-t complex is briefly discussed.
Assuntos
Camundongos Endogâmicos/genética , Animais , Cromossomos , Troca Genética , Feminino , Genes Letais , Genes Recessivos , Haploidia , Camundongos , Translocação Genética , TrissomiaRESUMO
A murine embryonal carcinoma (EC) cell line heterozygous for t0 recessive lethal mutation has been established from an embryo-derived transplantable teratocarcinoma TC1Ph of the genotype (129-T/t0 X C3H/Di)t0/+. The EC cell line, designated EC1Ph, and two cloned sublines, EC1Ph/a and EC1Ph/b, maintain the diploid karyotype (40, XY) and give rise to teratocarcinomas with differentiated derivatives of EC cells after inoculation into syngeneic recipients. The cloned sublines express low or zero amounts of SSEA-1 and ECMA-7 stage-specific antigens. At some passages, the EC1Ph line and the cloned subline EC1Ph/b express a significant quantity of class I H-2 antigens. This unusual EC phenotype resembles that of human teratocarcinoma cell lines.
Assuntos
Antígenos de Neoplasias/genética , Técnicas Citológicas , Glicolipídeos/genética , Teratoma/genética , Animais , Antígenos de Neoplasias/análise , Antígenos de Superfície/análise , Linhagem Celular , Separação Celular , Transformação Celular Neoplásica , Células Clonais , Glicolipídeos/análise , Antígenos CD15 , Camundongos , Camundongos Endogâmicos , Mutação , Transplante de Neoplasias , Fenótipo , Radioimunoensaio , Teratoma/patologiaRESUMO
The hybrid cell line H422 was constructed by fusing embryonal carcinoma (EC) cells of the PCC4AzaRCapR cell line with lymphocytes from a 129-tw32 mouse inbred strain female. An apparently complete extinction of stage-specific gene products of the lymphocyte parent was inferred from comparison of protein maps in two-dimensional PAGE of parental and hybrid cells, and from the reactivity patterns of monoclonal antibodies in radioimmunobinding assays. Furthermore, the hybrid cells display a true EC phenotype and EC functions, tumorigenicity and pluripotency. Taken together, the available evidence suggests either that the lymphocyte genome is a 'silent passenger' as far as the differentiated functions of hybrid cells are concerned, or that the developmentally restricted lymphocyte genome is reprogrammed in the hybrid cells back to a non-determined stage and both genomes thus act in a concerted manner.
Assuntos
Diferenciação Celular , Regulação da Expressão Gênica , Hibridização Genética , Linfócitos/fisiologia , Teratoma/genética , Animais , Linhagem Celular , Eletroforese em Gel de Poliacrilamida , Feminino , Genes Dominantes , Linfonodos/citologia , Linfócitos/citologia , Mesentério , Camundongos , Fenótipo , Teratoma/patologiaRESUMO
The embryo-derived teratocarcinoma TC1Ph of the genotype (129 t0/T X C3H)t0/+ and embryonal carcinoma (EC) cell line EC1Ph, established from the TC1Ph, were used as grafts for mice differing only at the T-H-2 interval of chromosome 17. Using exceptional recombinants in this chromosome region a two-gene model of genetic control of EC histocompatibility was proposed. The Cech-1 gene situated at the T end of the T-H-2 interval would control expression of the EC histocompatibility gene located near the H-2 complex.
Assuntos
Mapeamento Cromossômico , Genes , Rejeição de Enxerto , Teratoma/patologia , Animais , Histocompatibilidade , Camundongos , Modelos Genéticos , Transplante de NeoplasiasRESUMO
Male mice heterozygous for double translocations, involving chromosome 17, T(16, 17)43H (reciprocal) and Rb (16, 17)7 Bnr (Robertsonian), as well as mice with partial trisomy for centromeric region of chromosome 17(Ts17(16)T43H) are fertile but demonstrate a high rate of sterile matings. On the 3rd day of gestation in the progeny of males heterozygous for double translocations chromosomal aberrations were shown in 9,5% of all cleaving embryos. The number of blastomeres in embryos with partial trisomy or monosomy of chromosome 17 or 16 corresponds well to that in embryos with normal karyotype. Partial trisomy Ts17(16)T43H does not affect cleavage and early postimplantation development but may cause growth retardation during major organogenesis. Some of these embryos are probably eliminated by the end of gestation or soon after birth. Mice with translocation T43H are useful tools for studying the action of different parts of chromosome 17 at different stages of ontogenesis.
Assuntos
Aberrações Cromossômicas , Transtornos Cromossômicos , Embrião de Mamíferos/ultraestrutura , Fertilidade , Translocação Genética , Trissomia , Animais , Aberrações Cromossômicas/genética , Cruzamentos Genéticos , Feminino , Heterozigoto , Humanos , Cariotipagem , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , GravidezRESUMO
The animals with partial trisomy of chromosome 17, Ts(17A1-17B) 43H, were recovered among progeny of females heterozygous for T(16;17)43H "male-sterile" translocation. The trisomics as well as Rb7Bnr/T43H hybrids of both sexes were fertile, although the male fertility was significantly reduced in comparison with T43H/T43H homozygotes and males without chromosomal rearrangements. Ts43H trisomy acts as a semilethal aneuploidy since a significant deficiency of Ts43H animals was observed in progeny of Ts43H parent, while the expected proportion of trisomic embryos was found up to the 18th day of embryonic development.
Assuntos
Fertilidade , Genes , Trissomia , Animais , Heterozigoto , Masculino , CamundongosRESUMO
Analysis of the chromosome behaviour at pachytene has been performed by means of the silver staining technique visualizing the synaptonemal complexes (SCs) in male mice heterozygous for the male-sterile translocations T(5;12)31Hm T(16;17)43H and T(7;19)145H, respectively. the T(9;17)138Ca male heterozygotes and T43H/T43H homozygous males were used as fertile controls. The sterile mice displayed a high frequency (about 60%) of pachytene spermatocytes with autosomal translocation configuration located in close vicinity of the XY pair. The dense round body (XAB), normally located near the X-chromosome axis in fertile males, exhibited abnormal affinity to translocation configuration in the sterile translocation heterozygotes. The incomplete synapsis of autosomes involved in translocation configuration was observed in more than 70% of the pachytene spermatocytes with the male-sterile translocations but less than 20% of the cells from T138Ca fertile male.s. A hypothesis relating the spermatogenic arrest of carriers of male-sterile rearrangements to the presumed interference with X chromosome inactivation in male meiosis is discussed.
Assuntos
Infertilidade Masculina/genética , Meiose , Cromossomos Sexuais/ultraestrutura , Cromossomo X/ultraestrutura , Cromossomo Y/ultraestrutura , Animais , Feminino , Masculino , Camundongos , Prata , Espermatócitos/ultraestrutura , Coloração e Rotulagem , Translocação GenéticaAssuntos
Camundongos Endogâmicos/genética , Translocação Genética , Animais , Troca Genética , Feminino , Ligação Genética , Infertilidade Masculina/genética , Cariotipagem , Complexo Principal de Histocompatibilidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL/genética , EspermatogêneseRESUMO
A new meiotic phenomenon is described in male heterozygous for the male-sterile translocations T(10;13)199H, T(16;17)43H, and T(7;19)145H. The phenomenon consists of a nonrandom contact between the C bands of the X chromosome and the translocation configuration in diakinesis/metaphase I plates. Translocation configurations with positively heteropycnotic regions, oftern associated with the allocyclic X chromosome, are found in some early diakineses that have not been overtreated with alkali. Such heteropycnosis of a part of translocated autosome, apparently in phase with the allocyclic X, is typical for all three male-sterile translocations. In contrast to these findings, neither nonrandom contacts nor positive heteropycnosis of the translocation configuration can be found in males heterozygous for the translocation T(9;17)138Ca, which does not impair spermatogenesis. Dissociation of the X and Y at diakinesis is significantly enhanced in sterile males, though the occurrence of dissociation is evidently not related to the presence of the C-band contact between translocated chromosomes and the X. A working hypothesis is proposed, relating the observed nonrandom C-band contact and heteropycnosis of translocated chromosomes to a presumed impairment of X inactivation in primary spermatocytes and to consequent failure of spermatogenesis. An alternative explanation cannot be excluded, however, which would account for the hitherto available data wihtout postulating any causal relationship between the meiotic findings and male sterility. Both alternatives are amenable to experimental verification.
Assuntos
Infertilidade Masculina/genética , Translocação Genética , Animais , Feminino , Masculino , Meiose , Camundongos , Espermatócitos/ultraestrutura , Espermatogênese , Cromossomo X , Cromossomo YRESUMO
We have followed the possible influence of H-2 system on the differences in the relative weights of testes, vesicular gland and thymus in animals of a segregating (B10 X AKR) F2 generation. H-2b/H-2b male mice had significantly higher values of relative vesicular gland weight and significantly lower values of relative testes weight than H-2k/H-2k males. No differences in the relative thymus weight were found between these two groups of animals. The differences are caused by a complex effect of the H.2 associated genetic factor(s) because they influence simultaneously the body weight and the organ weights, the two indicators being mutually dependent to some extent.
Assuntos
Androgênios/metabolismo , Histocompatibilidade , Animais , Formação de Anticorpos , Peso Corporal , Genótipo , Antígenos de Histocompatibilidade/análise , Masculino , Camundongos , Camundongos Endogâmicos AKR , Camundongos Endogâmicos C57BL , Tamanho do Órgão , Glândulas Seminais/imunologia , Glândulas Seminais/metabolismo , Testículo/imunologia , Testículo/metabolismo , Timo/imunologia , Timo/metabolismoRESUMO
Significant differences in relative weight of the levator ani muscle (LAW) between inbred and congenic mouse strains, differing genetically only by the major histocompatibility H-2 complex were found. It is assumed that a genetic factor (Hom-1), identical or closely associated wi th the H-2 complex, is one of the genes which influence LAW. These experiments suggest that for assay methods for myotropic activity of androgens groups of animals may be used with a homogenous genotype.