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1.
Reproduction ; 163(2): 69-83, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-34904570

RESUMO

Defects in spermatogenesis are an important cause of male infertility. Multiple aspects of spermatogenesis are controlled by chromatin remodellers, including regulating transcription. We previously described mutations in chromatin remodelling gene Cecr2 that resulted in the lethal neural tube defect exencephaly in most mutant mice and subfertility in mice that were non-penetrant for exencephaly. Here, we show that the severity of male subfertility is dependent on age. Cecr2GT/Del males contain two mutant alleles, one of which is hypomorphic and therefore produces a small amount of protein. These males sire the fewest pups just after sexual maturity (88% fewer than Cecr2+/+ at P42-60) but improve with age (49% fewer than Cecr2+/+ at P81-100), although never completely recovering to Cecr2+/+(wild type) levels. When young, they also have defects in testis histology, in vivo fertilization frequency, sperm number and motility, and testis weight that show similar improvement with age. Immunostaining of staged seminiferous tubules showed CECR2 in type A, intermediate and B spermatogonia, and less in preleptotene and leptotene spermatocytes. Histological defects were first apparent in Cecr2GT/Del testes at P24, and RNA-seq analysis revealed 387 differentially expressed genes. This included 66 genes on the X chromosome (almost double the number on any other chromosome), all more highly expressed in Cecr2GT/Del testes. This inappropriate expression of X chromosome genes could be caused by a failure of effective meiotic sex chromosome inactivation. We identify several abnormally expressed genes that may contribute to defects in spermatogenesis at P24. Our results support a role for Cecr2 in juvenile spermatogenesis.


Assuntos
Cromatina , Infertilidade Masculina , Espermatogênese , Fatores de Transcrição , Animais , Montagem e Desmontagem da Cromatina , Infertilidade Masculina/genética , Infertilidade Masculina/metabolismo , Masculino , Camundongos , Espermatogênese/genética , Testículo/metabolismo , Fatores de Transcrição/metabolismo
2.
Biochem Cell Biol ; 99(6): 759-765, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34197713

RESUMO

Chromatin remodeling complexes alter chromatin structure to control access to DNA and therefore control cellular processes such as transcription, DNA replication, and DNA repair. CECR2 is a chromatin remodeling factor that plays an important role in neural tube closure and reproduction. Loss-of-function mutations in Cecr2 result primarily in perinatal lethal neural tube defect exencephaly, with non-penetrant mice that survive to adulthood exhibiting subfertility. CECR2 forms a complex with ISWI proteins SMARCA5 and (or) SMARCA1; however, further information on the structure and function of the complex is not known. Therefore, we identified candidate components of the CECR2-containing remodeling factor (CERF) complex in embryonic stem (ES) cells using mass spectroscopy. Both SMARCA5 and SMARCA1 were confirmed to be present in the CERF complexes in ES cells and testes. However, the novel proteins CCAR2 and LUZP1 are CERF components in ES cells, but not in the testis. This tissue specificity in mice suggests that these complexes may also have functional differences. Furthermore, LUZP1, the loss of which is also associated with exencephaly, appears to play a role in stabilizing the CERF complex in ES cells.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Montagem e Desmontagem da Cromatina , Proteínas de Ligação a DNA/metabolismo , Defeitos do Tubo Neural , Fatores de Transcrição/metabolismo , Animais , Cromatina , Reparo do DNA , Feminino , Masculino , Camundongos , Gravidez
3.
Biol Reprod ; 104(4): 835-849, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33354716

RESUMO

Defects in the maternal reproductive system that result in early pregnancy loss are important causes of human female infertility. A wide variety of biological processes are involved in implantation and establishment of a successful pregnancy. Although chromatin remodelers have been shown to play an important role in many biological processes, our understanding of the role of chromatin remodelers in female reproduction remains limited. Here, we demonstrate that female mice mutant for chromatin remodeler Cecr2 are subfertile, with defects detected at the peri-implantation stage or early pregnancy. Using both a less severe hypomorphic mutation (Cecr2GT) and a more severe presumptive null mutation (Cecr2Del), we demonstrate a clear difference in the severity of the phenotype depending on the mutation. Although neither strain shows detectable defects in folliculogenesis, both Cecr2GT/GT and Cecr2GT/Del dams show defects in pregnancy. Cecr2GT/GT females have a normal number of implantation sites at embryonic day 5.5 (E5.5), but significant embryo loss by E10.5 accompanied by the presence of vaginal blood. Cecr2GT/Del females show a more severe phenotype, with significantly fewer detectable implantation sites than wild type at E5.5. Some Cecr2GT/Del females also show premature loss of decidual tissue after artificial decidualization. Together, these results suggest a role for Cecr2 in the establishment of a successful pregnancy.


Assuntos
Implantação do Embrião/genética , Perda do Embrião/genética , Infertilidade Feminina/genética , Fatores de Transcrição/genética , Animais , Embrião de Mamíferos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Mutação , Gravidez , Fatores de Transcrição/fisiologia
5.
Physiol Genomics ; 44(1): 35-46, 2012 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-22045912

RESUMO

Although neural tube defects (NTDs) are common in humans, little is known about their multifactorial genetic causes. While most mouse models involve NTDs caused by a single mutated gene, we have previously described a multigenic system involving susceptibility to NTDs. In mice with a mutation in Cecr2, the cranial NTD exencephaly shows strain-specific differences in penetrance, with 74% penetrance in BALB/cCrl and 0% penetrance in FVB/N. Whole genome linkage analysis showed that a region of chromosome 19 was partially responsible for this difference in penetrance. We now reveal by genetic analysis of three subinterval congenic lines that the chromosome 19 region contains more than one modifier gene. Analysis of embryos showed that although a Cecr2 mutation causes wider neural tubes in both strains, FVB/N embryos overcome this abnormality and close. A microarray analysis comparing neurulating female embryos from both strains identified differentially expressed genes within the chromosome 19 region, including Arhgap19, which is expressed at a lower level in BALB/cCrl due to a stop codon specific to that substrain. Modifier genes in this region are of particular interest because a large portion of this region is syntenic to human chromosome 10q25, the site of a human susceptibility locus.


Assuntos
Genes Modificadores/fisiologia , Estudos de Associação Genética , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Defeitos do Tubo Neural/genética , Animais , Mapeamento Cromossômico , Embrião de Mamíferos , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Defeitos do Tubo Neural/patologia , Especificidade da Espécie , Fatores de Transcrição
6.
Dev Dyn ; 240(2): 372-83, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21246654

RESUMO

The loss of Cecr2, which encodes a chromatin remodeling protein, has been associated with the neural tube defect (NTD) exencephaly and open eyelids in mice. Here, we show that two independent mutations of Cecr2 are also associated with specific inner ear defects. Homozygous mutant 18.5 days post coitus (dpc) fetuses exhibited smaller cochleae as well as rotational defects of sensory cells and extra cell rows in the inner ear reminiscent of planar cell polarity (PCP) mutants. Cecr2 was expressed in the neuroepithelium, head mesenchyme, and the cochlear floor. Although limited genetic interaction for NTDs was seen with Vangl2, a microarray analysis of PCP genes did not reveal a direct connection to this pathway. The mechanism of Cecr2 action in neurogenesis and inner ear development is likely complex.


Assuntos
Cromatina/metabolismo , Orelha Interna/anatomia & histologia , Orelha Interna/embriologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Neurulação/fisiologia , Organogênese/genética , Animais , Polaridade Celular/genética , Orelha Interna/metabolismo , Orelha Interna/fisiologia , Embrião de Mamíferos/anatomia & histologia , Embrião de Mamíferos/fisiologia , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Mesoderma/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Análise em Microsséries , Mutação , Proteínas do Tecido Nervoso/genética , Defeitos do Tubo Neural/genética , Células Neuroepiteliais/metabolismo , Fatores de Transcrição
7.
Sci Rep ; 11(1): 3111, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542446

RESUMO

Cat eye syndrome (CES), a human genetic disorder caused by the inverted duplication of a region on chromosome 22, has been known since the late 1890s. Despite the significant impact this disorder has on affected individuals, models for CES have not been produced due to the difficulty of effectively duplicating the corresponding chromosome region in an animal model. However, the study of phenotypes associated with individual genes in this region such as CECR2 may shed light on the etiology of CES. In this study we have shown that deleterious loss of function mutations in mouse Cecr2 effectively demonstrate many of the abnormal features present in human patients with CES, including coloboma and specific skeletal, kidney and heart defects. Beyond phenotypic analyses we have demonstrated the importance of utilizing multiple genetic backgrounds to study disease models, as we see major differences in penetrance of Cecr2-related abnormal phenotype between mouse strains, reminiscent of the variability in the human syndrome. These findings suggest that Cecr2 is involved in the abnormal features of CES and that Cecr2 mice can be used as a model system to study the wide range of phenotypes present in CES.


Assuntos
Transtornos Cromossômicos/genética , Coloboma/genética , Modelos Animais de Doenças , Anormalidades do Olho/genética , Cardiopatias/genética , Mutação com Perda de Função , Fatores de Transcrição/genética , Aneuploidia , Animais , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Transtornos Cromossômicos/metabolismo , Transtornos Cromossômicos/patologia , Duplicação Cromossômica , Cromossomos Humanos Par 22/química , Cromossomos Humanos Par 22/genética , Cromossomos Humanos Par 22/metabolismo , Coloboma/metabolismo , Coloboma/patologia , Embrião de Mamíferos , Anormalidades do Olho/metabolismo , Anormalidades do Olho/patologia , Feminino , Expressão Gênica , Cardiopatias/metabolismo , Cardiopatias/patologia , Humanos , Rim/metabolismo , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Penetrância , Especificidade da Espécie , Fatores de Transcrição/deficiência
9.
Birth Defects Res A Clin Mol Teratol ; 88(8): 619-25, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20589882

RESUMO

BACKGROUND: Over 200 mouse genes are associated with neural tube defects (NTDs), including Cecr2, the bromodomain-containing subunit of the CERF chromatin remodeling complex. METHODS: Gene-trap mutation Cecr2(Gt45Bic) results in 74% exencephaly (equivalent of human anencephaly) on the BALB/c strain. Gene expression altered during cranial neural tube closure by the Cecr2 mutation was identified through microarray analysis of 11-14 somites stage Cecr2(Gt45Bic)embryos. RESULTS: Analysis of Affymetrix Mouse 430 2.0 chips detected 60 transcripts up-regulated and 54 transcripts down-regulated in the Cecr2(Gt45Bic) embryos (fold > 1.5, p < 0.05). The Cecr2 transcript was reduced only approximately 7- to 14-fold from normal levels, suggesting the Cecr2(Gt45Bic) is a hypomorphic mutation. We therefore generated a novel Cecr2 null allele (Cecr2 (tm1.1Hemc)). Resulting mutants displayed a stronger penetrance of exencephaly than Cecr2(Gt45Bic) in both BALB/c and FVB/N strains, in addition to midline facial clefts and forebrain encephalocele in the FVB/N strain. The Cecr2 transcript is reduced 260-fold in the Cecr2(tm1.1Hemc) line. Subsequent qRT-PCR using Cecr2 (tm1.1Hemc) mutant heads confirmed downregulation of transcription factors Alx1/Cart1, Dlx5, Eya1, and Six1. CONCLUSIONS: As both Alx1/Cart1 and Dlx5 mouse mutations result in exencephaly, we hypothesize that changes in expression of these mesenchymal/ectodermal transcription factors may contribute to NTDs associated with Cecr2.


Assuntos
Ectoderma/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Mesoderma/metabolismo , Mutação , Defeitos do Tubo Neural/genética , Defeitos do Tubo Neural/metabolismo , Fatores de Transcrição/genética , Animais , Regulação para Baixo/genética , Ectoderma/fisiopatologia , Encefalocele/metabolismo , Ossos Faciais/anormalidades , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Mesoderma/fisiopatologia , Camundongos , Camundongos Endogâmicos BALB C , Defeitos do Tubo Neural/fisiopatologia , Gravidez , Prosencéfalo/anormalidades , Fatores de Transcrição/metabolismo , Transcrição Gênica , Regulação para Cima/genética
10.
Eur J Hum Genet ; 16(11): 1301-10, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18523453

RESUMO

The severe mental retardation and speech deficits associated with 22q13 terminal deletions have been attributed in large part to haploinsufficiency of SHANK3, which maps to all 22q13 terminal deletions, although more proximal genes are assumed to have minor effects. We report two children with interstitial deletions of 22q13 and two copies of SHANK3, but clinical features similar to the terminal 22q13 deletion syndrome, including mental retardation and severe speech delay. Both these interstitial deletions are completely contained within the largest terminal deletion, but do not overlap with the nine smallest terminal deletions. These interstitial deletions indicate that haploinsufficiency for 22q13 genes other than SHANK3 can have major effects on cognitive and language development. However, the relatively mild speech problems and normal cognitive abilities of a parent who transmitted her identical interstitial deletion to her more severely affected son suggests that the phenotype associated with this region may be more variable than terminal deletions and therefore contribute to the relative lack of correlation between clinical severity and size of terminal deletions. The phenotypic similarity between the interstitial deletions and non-overlapping small terminal 22q13 deletions emphasizes the general nonspecificity of the clinical picture of the 22q13 deletion syndrome and the importance of molecular analysis for diagnosis.


Assuntos
Proteínas de Transporte , Cromossomos Humanos Par 22/genética , Deleção de Genes , Deficiência Intelectual/genética , Transtornos do Desenvolvimento da Linguagem/genética , Criança , Humanos , Lactente , Deficiência Intelectual/patologia , Transtornos do Desenvolvimento da Linguagem/patologia , Masculino , Proteínas do Tecido Nervoso , Síndrome
11.
Physiol Genomics ; 31(2): 244-51, 2007 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-17623803

RESUMO

Neural tube defects (NTDs), the second most common birth defect in humans, are multifactorial with complex genetic and environmental causes, although the genetic factors are almost completely unknown. In mice, >100 single gene mutations cause NTDs; however, the penetrance in many of these single gene mutant lines is highly dependent on the genetic background. We previously reported that a homozygous Cecr2 mutation on a BALB/c background causes exencephaly at a frequency of 74% compared with 0% on an FVB/N background. We now report that a major genetic modifier on chromosome 19, mapped using whole genome linkage analysis, increases the relative risk of exencephaly by 3.74 times in homozygous BALB embryos vs. BALB/FVB heterozygotes. Scanning electron microscopy revealed that the modifier does not affect the location of neural tube closure site 2, a known murine susceptibility factor for exencephaly. Crossing the Sp (Splotch) mutation in the Pax3 gene onto the FVB/N background for two generations indicated that this resistant strain also decreases the penetrance of spina bifida. The chromosome 19 modifier region corresponds to a linkage region on human chromosome 10q25.3 mapped in a whole genome scan of human NTD families. Since the FVB/N genetic background affects susceptibility to both exencephaly and spina bifida, the human homolog of the chromosome 19 modifier locus may be a better candidate for human NTD susceptibility factors than genes that when mutated actually cause NTDs in mice.


Assuntos
Epistasia Genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Defeitos do Tubo Neural/genética , Animais , Mapeamento Cromossômico , Cromossomos Humanos Par 10/genética , Cruzamentos Genéticos , Feminino , Predisposição Genética para Doença , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Escore Lod , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Mutantes , Proteínas dos Microfilamentos/genética , Defeitos do Tubo Neural/embriologia , Defeitos do Tubo Neural/patologia , Fator de Transcrição PAX3 , Fatores de Transcrição Box Pareados/genética , Penetrância , Locos de Características Quantitativas , Especificidade da Espécie , Fatores de Transcrição
12.
Birth Defects Res ; 109(2): 140-152, 2017 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-27768235

RESUMO

Neurulation, the early embryonic process of forming the presumptive brain and spinal cord, is highly complex and involves hundreds of genes in multiple genetic pathways. Mice have long served as a genetic model for studying human neurulation, and the resulting neural tube defects (NTDs) that arise when neurulation is disrupted. Because mice appear to show mostly single gene inheritance for NTDs and humans show multifactorial inheritance, mice sometimes have been characterized as a simpler model for the identification and study of NTD genes. But are they a simple model? When viewed on different genetic backgrounds, many genes show significant variation in the penetrance and expressivity of NTD phenotypes, suggesting the presence of modifier loci that interact with the target gene to affect the phenotypic expression. Looking at mutations on different genetic backgrounds provides us with an opportunity to explore these complex genetic interactions, which are likely to better emulate similar processes in human neurulation. Here, we review NTD genes known to show strain-specific phenotypic variation. We focus particularly on the gene Cecr2, which is studied using both a hypomorphic and a presumptive null mutation on two different backgrounds: one susceptible (BALB/c) and one resistant (FVB/N) to NTDs. This strain difference has led to a search for genetic modifiers within a region on murine chromosome 19. Understanding how genetic variants alter the phenotypic outcome in NTD mouse models will help to direct future studies in humans, particularly now that more genome wide sequencing approaches are being used. Birth Defects Research 109:140-152, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Epistasia Genética , Genes Modificadores , Patrimônio Genético , Defeitos do Tubo Neural/genética , Neurulação/genética , Fatores de Transcrição/genética , Animais , Cromossomos de Mamíferos/química , Cromossomos de Mamíferos/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Mutação , Tubo Neural/anormalidades , Tubo Neural/crescimento & desenvolvimento , Tubo Neural/metabolismo , Defeitos do Tubo Neural/metabolismo , Defeitos do Tubo Neural/patologia , Penetrância , Fenótipo , Fatores de Transcrição/deficiência
13.
J Am Assoc Lab Anim Sci ; 56(2): 194-201, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28315651

RESUMO

Environmental enrichment items such as running wheels can promote the wellbeing of laboratory mice. Growing evidence suggests that wheel running simulates exercise effects in many mouse models of human conditions, but this activity also might change other aspects of mouse behavior. In this case study, we show that the presence of running wheels leads to pronounced and permanent circling behavior with route-tracing in a proportion of the male mice of a genetically distinct cohort. The genetic background of this cohort includes a mutation in Arhgap19, but genetic crosses showed that an unknown second-site mutation likely caused the induced circling behavior. Behavioral tests for inner-ear function indicated a normal sense of gravity in the circling mice. However, the levels of dopamine, serotonin, and some dopamine metabolites were lower in the brains of circling male mice than in mice of the same genetic background that were weaned without wheels. Circling was seen in both singly and socially housed male mice. The additional stress of fighting may have exacerbated the predisposition to circling in the socially housed animals. Singly and socially housed male mice without wheels did not circle. Our current findings highlight the importance and possibly confounding nature of the environmental and genetic background in mouse behavioral studies, given that the circling behavior and alterations in dopamine and serotonin levels in this mouse cohort occurred only when the male mice were housed with running wheels.


Assuntos
Comportamento Animal , Atividade Motora/fisiologia , Corrida , Animais , Encéfalo/metabolismo , Cruzamentos Genéticos , Meio Ambiente , Genótipo , Abrigo para Animais , Masculino , Camundongos , Mutação
14.
Genetics ; 170(1): 5-6, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15781711

RESUMO

Although mitosis and meiosis are fundamental to understanding genetics, students often find them difficult to learn. We suggest using common "pool noodles" as teaching aids to represent chromatids in classroom demonstrations. Students use these noodles to demonstrate the processes of synapsis, segregation, and recombination. Student feedback has been overwhelmingly positive.


Assuntos
Cromossomos/genética , Citogenética/educação , Meiose/genética , Mitose/genética , Modelos Genéticos
16.
Physiol Genomics ; 15(3): 191-8, 2003 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-14612589

RESUMO

The steady-state and kinetic properties of the KCNMB3 regulatory subunits associated with calcium-activated potassium channels (BK channels) are presented. BK channels containing four sequence variants (V1-V4) in the four different isoforms of the beta-subunit (beta3a, beta3b, beta3c, and beta3d) were expressed in Xenopus oocytes. Reconstituted BK channel inactivation ranged from none to around 90% inactivation. In particular, channels expressing the beta3b-V4 variant displayed a right shift in the potassium current voltage-dependence of activation and inactivated to about 30% of the maximum conductance, compared with wild-type beta3b channels that showed no inactivation. When the membrane potential was depolarized, BK channels inactivated with a very rapid time course (approximately 2-6 ms). This same variant was previously demonstrated to show subtly higher incidence in patients with idiopathic epilepsy (IE) compared with controls, especially when combined with variant V2 (combined heterozygotes). Furthermore, the gene maps to a region containing a susceptibility factor for this disorder. Taken together, these data suggest that neurons expressing BK channels composed of the beta3b-V4 variant subunit may experience reduced levels of inhibition and may therefore play permissive roles in high levels of neuronal activity that is characteristic of epilepsy.


Assuntos
Variação Genética , Proteínas do Tecido Nervoso/fisiologia , Canais de Potássio Cálcio-Ativados/fisiologia , Canais de Potássio/fisiologia , Subunidades Proteicas/fisiologia , Sequência de Aminoácidos , Animais , Eletrofisiologia/métodos , Feminino , Regulação da Expressão Gênica/fisiologia , Subunidades beta do Canal de Potássio Ativado por Cálcio de Condutância Alta , Canais de Potássio Ativados por Cálcio de Condutância Alta , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Neurônios/química , Neurônios/metabolismo , Oócitos/química , Oócitos/metabolismo , Técnicas de Patch-Clamp , Potássio/metabolismo , Canais de Potássio/biossíntese , Canais de Potássio/genética , Canais de Potássio Cálcio-Ativados/antagonistas & inibidores , Canais de Potássio Cálcio-Ativados/genética , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/fisiologia , Subunidades Proteicas/genética , RNA Mensageiro/biossíntese , Xenopus laevis
17.
J Mol Biol ; 415(5): 793-806, 2012 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-22154806

RESUMO

The regulation of nucleosome positioning and composition by ATP-dependent chromatin remodeling enzymes and their associated binding partners plays important biological roles in mammals. CECR2 is a binding partner to the ISWI (imitation switch) ATPase SNF2L/SMARCA1 and is involved in neural tube closure and inner ear development; however, its functions in adult tissues have not been examined. Here, we report that CECR2 contributes to spermatogenesis and forms a complex that includes the other ISWI ATPase SNF2H/SMARCA5 in the testis. Cecr2 mutant males non-penetrant for neural tube defects sired smaller litters than wild-type males. Strikingly, while we found that Cecr2 mutants have normal seminiferous epithelium morphology, sperm count, motility, and morphology, the mutant spermatozoa were compromised in their ability to fertilize oocytes. Investigation of CECR2/ISWI complexes in the testis showed that SNF2H interacted with CECR2, and this interaction was also observed in embryonic stem cells, suggesting that CECR2 may interact with SNF2H or SNF2L depending on the cell type. Finally, we found that Cecr2 mutants exhibit misregulation of the homeobox transcription factor Dlx5 in the testis, suggesting that CECR2 complexes may regulate gene expression during spermatogenesis. Taken together, our results demonstrate a novel role of CECR2-containing complexes in spermatogenesis and show that CECR2 interacts predominantly with SNF2H instead of SNF2L in the testis.


Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Espermatogênese , Testículo/metabolismo , Adenosina Trifosfatases/genética , Animais , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/metabolismo , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Infertilidade Masculina/metabolismo , Infertilidade Masculina/patologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Mutantes , Epitélio Seminífero/citologia , Epitélio Seminífero/metabolismo , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Espermatozoides/citologia , Espermatozoides/metabolismo , Testículo/citologia , Fatores de Transcrição/metabolismo
18.
Genome ; 50(8): 767-77, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17893736

RESUMO

The mammalian CECR2 protein contains a highly conserved bromodomain and forms a chromatin-remodelling complex with the ISWI homologue SNF2L. Mutation of the mouse CECR2 homologue results in a neural tube defect. Here we describe the characterization of the Drosophila melanogaster homologue of CECR2. Originally annotated as 2 genes, dikar and CG32394 now appear to encode both a long dikar/CG32394 transcript homologous to CECR2 and a truncated transcript missing the bromodomain. This truncated transcript may be specific to Diptera, as it is predicted from the genomic sequences of several other dipteran species but it is not predicted in the honey bee, Apis mellifera, and it is not found in mammals. Five different P element-mediated 5' deletions of the Drosophila dikar gene were generated. All mutants were homozygous-viable and the 3 mutants examined further displayed continued, albeit aberrant, transcription of dikar/CG32394. In a previous study, a dikar insertion mutation was associated with long-term memory deficits. However, the 2 deletion mutants tested here showed normal long-term memory, suggesting that the memory deficit associated with the dikar P element insertion is not due to disruption of dikar. No genetic interaction was seen between Iswi and dikar mutations. This study therefore suggests that the lack of a visible phenotype in dikar mutants is due to compensation by a second gene, possibly acf1.


Assuntos
Montagem e Desmontagem da Cromatina/genética , Cromatina/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Deleção de Genes , Peptídeos e Proteínas de Sinalização Intercelular/genética , Animais , Cromatina/metabolismo , Cruzamentos Genéticos , DNA/genética , DNA/isolamento & purificação , DNA Complementar , Proteínas de Drosophila/metabolismo , Homozigoto , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Transcrição Gênica
19.
J Mol Evol ; 61(6): 776-94, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16245011

RESUMO

Adenosine deaminase (ADA) is a well-characterized enzyme involved in the depletion of adenosine levels. A group of proteins with similarity to ADA, the adenosine deaminase-related growth factors (ADGF; known as CECR1 in vertebrates), has been described recently in various organisms. We have determined the phylogenetic relationships of various gene products with significant amino acid similarity to ADA using parsimony and Bayesian methods, and discovered a novel paralogue, termed ADA-like (ADAL). The ADGF proteins share a novel amino acid motif, "MPKG," within which the proline and lysine residues are also conserved in the ADAL and ADA subfamilies. The significance of this new domain is unknown, but it is located just upstream of two ADA catalytic residues, of which all eight are conserved among the ADGF and ADAL proteins. This conservation suggests that ADGF and ADAL may share the same catalytic function as ADA, which has been proven for some ADGF members. These analyses also revealed that some genes previously thought to be classic ADAs are instead ADAL or ADGFs. We here define the ADGF, ADAL, ADA, adenine deaminase (ADE), and AMP deaminase (AMPD) groups as subfamilies of the adenyl-deaminase family. The availability of genomic data for the members of this family allowed us to reconstruct the intron evolution within the phylogeny and strengthen the introns-late hypothesis of the synthetic introns theory. This study shows that ADA activity is clearly more complex than once thought, perhaps involving a delicately balanced pattern of temporal and spatial expression of a number of paralogous proteins.


Assuntos
Adenosina Desaminase/genética , Proteínas de Drosophila/genética , Filogenia , Motivos de Aminoácidos/genética , Sequência de Aminoácidos , Animais , Sítios de Ligação , Drosophila melanogaster/genética , Íntrons , Dados de Sequência Molecular , Isoformas de Proteínas/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
20.
Hum Mol Genet ; 14(4): 513-24, 2005 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-15640247

RESUMO

Chromatin remodeling complexes play critical roles in development. Here we describe a transcription factor, CECR2, which is involved in neurulation and chromatin remodeling. CECR2 shows complex alternative splicing, but all variants contain DDT and bromodomain motifs. A mutant mouse line was generated from an embryonic stem cell line containing a genetrap within Cecr2. Reporter gene expression demonstrated Cecr2 expression to be predominantly neural in the embryo. Mice homozygous for the Cecr2 genetrap-induced mutation show a high penetrance of the neural tube defect exencephaly, the human equivalent of anencephaly, in a strain-dependent fashion. Biochemical isolation of CECR2 revealed the presence of this protein as a component of a novel heterodimeric complex termed CECR2-containing remodeling factor (CERF). CERF comprises CECR2 and the ATP-dependent chromatin remodeler SNF2L, a mammalian ISWI ortholog expressed predominantly in the central nervous system. CERF is capable of remodeling chromatin in vitro and displays an ATP hydrolyzing activity that is stimulated by nucleosomes. Together, these data identify a novel chromatin remodeling complex with a critical role in neurulation.


Assuntos
Sistema Nervoso Central/embriologia , Montagem e Desmontagem da Cromatina , Cromatina , Proteínas de Ligação a DNA/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Fatores de Transcrição/metabolismo , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Processamento Alternativo , Animais , Células Cultivadas , Sistema Nervoso Central/metabolismo , Proteínas de Ligação a DNA/genética , Feminino , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Defeitos do Tubo Neural , Nucleossomos/metabolismo , Fatores de Transcrição/genética
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