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1.
Biomol Biomed ; 24(1): 51-60, 2024 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-37573539

RESUMO

The global practice of cryopreservation of human semen is commonplace in Assisted Reproductive Technology (ART) labs and sperm banks. However, information on the effects of long-term cryopreservation on semen is limited to clinical data summaries and descriptions. For this study, we prepared 4 semen specimens of fresh semen, 4 specimens cryostored for at least 1 year, 3 specimens cryostored for at least 5 years, 4 specimens cryostored for at least 10 years, and 3 specimens cryostored for at least 15 years. Total RNA was extracted from each sample, amplified, labeled, and mapped to the known primary microRNA (miRNA) in the miRBase database, enabling the prediction of novel miRNAs. We found that cryopreservation can lead to changes in miRNA expression, and with the increase in storage time, these changes became more pronounced. Meanwhile, the expression of let-7d-3p, let-7c-5p and let-7i-3p miRNAs changed dynamically over cryostorage time in frozen-thawed human sperm. Furthermore, we analyzed the time-dependent dynamics of cryostorage-expressed miRNAs and their target mRNAs and found that half of the target genes were expressed in oocytes. These intersection genes were mainly enriched in cancer and cytoskeletal signaling pathways. Our findings showed that the miRNA expression profile of cryopreserved human semen is modified by long-term storage. Furthermore, as the storage time increases, the impact on human sperm becomes more pronounced in terms of miRNAs, which may have an effect on subsequent fertilization and embryonic development.


Assuntos
MicroRNAs , Sêmen , Gravidez , Feminino , Humanos , Masculino , Espermatozoides , Criopreservação , Bancos de Esperma , MicroRNAs/genética
2.
Front Endocrinol (Lausanne) ; 14: 1230621, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37529594

RESUMO

Background: The National Health and Family Planning Commission of China (NHFPCC) issued the "Measures for the Management of Human Sperm Banks," which was revised in 2003 and is still in effect today. One of the standard guidelines is that potential donors undergo laboratory testing to exclude infectious and genetic diseases and karyotype analysis. However, patient demands for donor genetic testing have also increased, and only karyotype analysis to exclude genetic diseases is not sufficient to meet these demands. Objective: To examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks. Materials and methods: An electronic survey was distributed to twenty-seven sperm banks to examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks. Twenty-six human sperm banks responded to a 32-question survey about their current practices related to genetic testing of sperm donors. Results: The 26 sperm banks reported that all qualified sperm donors undergo karyotype analysis; 22 banks (84.6%) collected three generations of family history from each qualified sperm donor; 10 (38.5%) reported that they attempted to accommodate special requests from donor semen recipients for particular genetic tests. Only 2 of the 26 (7.7%) sperm banks reported that they performed whole-exome sequencing. At all the sperm banks, consent for genetic testing was obtained as part of the overall contract for sperm donors. Nineteen (73.1%) sperm banks had genetic counselors on their staff, while six (23.1%) had no genetic counselors on their staff but had access to genetic counselors at the hospital. Only one (3.8%) sperm bank had no genetic counselors on their staff or at the hospital. Conclusions: The need for larger scale genetic testing of donors and recipients and an extensive panel of genetic tests specific to the Chinese population. Additionally, professionally trained geneticists must be employed as genetic counsellors so that the results of genetic tests and their implications can be explained to donors.


Assuntos
Sêmen , Bancos de Esperma , Humanos , Masculino , Bancos de Esperma/métodos , Espermatozoides , Testes Genéticos/métodos , China
3.
J Clin Med ; 12(3)2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36769601

RESUMO

PURPOSE: To evaluate the effectiveness of donor in vitro fertilization (IVF-D) and donor artificial insemination (AI-D) in clinical outcomes, risks, and costs. METHODS: This study analyzed the cycle changes and clinical outcomes in 20,910 IVF-D and 16,850 AI-D cycles between 2013 and 2021 in the Reproductive and Genetic Hospital of CITIC-Xiangya. A cost-effectiveness analysis was performed to evaluate the costs per couple and per live birth cycle in the two treatment groups. RESULTS: IVF-D had higher pregnancy and live birth rates than AI-D (p < 0.001). The cumulative pregnancy and live birth rates for three AI-D cycles were 41.01% and 32.42%, respectively, higher than the rates for one or two AI-D cycles. The multiple birth and birth defect rate of AI-D was lower than that of IVF-D significantly. IVF-D mean cost per couple was higher than that of AI-D (CNY32,575 vs. CNY11,062, p < 0.001), with a mean cost difference of CNY21,513 (95% confidence interval, CNY20,517-22,508). The mean costs per live birth cycle for IVF-D and AI-D were CNY49,411 and CNY31,246, respectively. CONCLUSION: AI-D is more cost-effective and poses a lower risk for infertility couples than IVF-D, and patients should undergo three AI-D cycles to obtain the highest success rate.

4.
Front Endocrinol (Lausanne) ; 13: 942447, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36204111

RESUMO

Background: In China, numerous human sperm banks only perform three-generation family history evaluation to exclude genetic diseases with clinical symptoms; therefore, many inherited risks cannot be detected before donor qualification even when a thorough genetic family history evaluation has been performed. Hence, the risk of recessive disease inheritance persists with the current eligibility guidelines in China regarding the donor selection process. Methods: Retrospective study that reviewed the genetic test analyses and clinical outcomes of young adult men who were qualified sperm donors at the Hunan Province Human Sperm Bank of China from January 1, 2018, to May 1, 2021. We included a total of 3231 qualified sperm donors: all donors underwent primary screening for thalassemia and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Whereafter, 278 of donors underwent genetic testing for specific genes, and 43 donors underwent whole exome sequencing. Results: 2.4% of 3231 qualified sperm donors might have thalassemia and 1.4% might have G6PD deficiency. Sperm donors with thalassemia and G6PD deficiency would be eliminated. Specific gene testing identified 7 of the 278 donors (2.5%) as carriers of at least one pathogenic or likely pathogenic variant in a gene, including 1.9% of 154 donors (3/154) as carrier variants in α-Like or ß-Like globin genes, 17.6% of 17 donors (3/17) as carrier variants in GJB2, 12.5% of 8 donors (1/8) as carrier variants in SMN1. In addition, among the 43 sperm donors carrying the 111 pathogenic/likely pathogenic variants, eight (18.6%) were carriers of pathogenic variants of the GJB2 gene. The frequency, therefore, was approximately 1 in 5. Conclusions: The data suggest that used blood routine and RDT can make a preliminary screening of sperm donors, and special gene testing should be performed for sperm donors according to the regional incidence of specific genetic diseases. Meanwhile, whole exome sequencing can be used as a supplementary application in sperm donor genetic testing, and aid a successful and healthy pregnancy. However, industry guidelines must be modified to incorporate its use.


Assuntos
Deficiência de Glucosefosfato Desidrogenase , Talassemia , Feminino , Testes Genéticos , Globinas/genética , Glucosefosfato Desidrogenase , Deficiência de Glucosefosfato Desidrogenase/epidemiologia , Deficiência de Glucosefosfato Desidrogenase/genética , Humanos , Masculino , Gravidez , Estudos Retrospectivos , Sêmen , Bancos de Esperma , Espermatozoides , Talassemia/epidemiologia , Talassemia/genética , Adulto Jovem
5.
Front Pediatr ; 10: 1073711, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36683823

RESUMO

Background: Childhood obesity is a worldwide critical health concern. We aimed to clarify whether eating behaviours increased the risk of childhood obesity. Methods: We recruited 2,049 pre-school children aged 3-6 years between 1 December 2021 and 31 January 2022 in Taizhou, China. Children's weight status was classified according to the International Obesity Task Force criteria, and their eating behaviours were evaluated using the Children's Eating Behaviour Questionnaire. Correlation analyses, linear regressions, and one-way ANCOVA. were performed to analyse the association between children's eating behaviours and weight status. Results: In 'Food Avoidant' subscales, the scores of satiety responsiveness (P < 0.001) and slowness in eating (P = 0.001) were negatively associated with body mass index z score among pre-school children of both sexes. In 'Food Approach' subscales, the score of enjoyment of food was positively associated with body mass index z score in both boys (P = 0.007) and girls (P = 0.035), but the association of scores of food responsiveness with body mass index z score was found only in girls (P = 0.001). Conclusion: Our results supported that pre-school children with low scores in 'Food Avoidant' subscales and high scores in 'Food Approach' scales were more likely to become obese.

6.
J Exp Bot ; 72(6): 2114-2124, 2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33161430

RESUMO

Iron is an essential element for most organisms. As an indispensable co-factor of many enzymes, iron is involved in various crucial metabolic processes that are required for the survival of plants and pathogens. Conversely, excessive iron produces highly active reactive oxygen species, which are toxic to the cells of plants and pathogens. Therefore, plants and pathogens have evolved sophisticated mechanisms to modulate iron status at a moderate level for maintaining their fitness. Over the past decades, many efforts have been made to reveal these mechanisms, and some progress has been made. In this review, we describe recent advances in understanding the roles of iron in plant-pathogen interactions and propose prospects for future studies.


Assuntos
Ferro , Plantas , Interações Hospedeiro-Patógeno , Espécies Reativas de Oxigênio
7.
Fertil Steril ; 112(4): 663-669.e1, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31371041

RESUMO

OBJECTIVE: To evaluate the affect of the duration of donor sperm storage on pregnancy success among women undergoing assisted reproduction. DESIGN: Retrospective cross-sectional study. SETTING: Sperm bank. PATIENT(S): A total of 119,558 specimens retrieved using a clinical information database of young adult men who were qualified sperm donors at the Hunan Province Human Sperm Bank of China from 2001 to 2016. INTERVENTION(S): Analysis of semen samples and clinical outcomes after semen use. MAIN OUTCOME MEASURE(S): Clinical information included semen parameters before and after freezing, clinical pregnancy, abortion and live birth rates after semen use. RESULT(S): The sperm's frozen-thaw survival rate decreased from 85.72% to 73.98% after 15 years of cryopreservation (P<.01). The clinical pregnancy rate of women undergoing artificial insemination with donor sperm was 23.09%, 22.36% and 22.32%, the clinical abortion rate was 10.06%, 10.02% and 12.00% and the live birth rate was 82.17%, 80.21% and 80.00% in the groups with 0.5-5, 6-10 and 11-15 storage years, respectively. The clinical pregnancy rate of women undergoing in vitro fertilization was 64.29%, 64.94% and 53.48%, the clinical abortion rate was 12.26%, 11.38% and 17.39% and the live birth rate was 81.63%, 79.11% and 73.91%, in the groups with 0.5-5, 6-10 and 11-15 years, respectively. CONCLUSION(S): The long-term cryostorage of semen in a human sperm bank does not affect clinical outcomes. However, cryopreservation longer than 5 years negatively influenced the quality of frozen-thawed donor sperm samples.


Assuntos
Criopreservação , Fertilização In Vitro , Inseminação Artificial Heteróloga , Preservação do Sêmen , Bancos de Esperma , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Gravidez , Estudos Retrospectivos , Fatores de Tempo
8.
Mol Plant ; 11(9): 1166-1183, 2018 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-29960107

RESUMO

Plants have evolved sophisticated genetic networks to regulate iron (Fe) homeostasis for their survival. Several classes of plant hormones including jasmonic acid (JA) have been shown to be involved in regulating the expression of iron uptake and/or deficiency-responsive genes in plants. However, the molecular mechanisms by which JA regulates iron uptake remain unclear. In this study, we found that JA negatively modulates iron uptake by downregulating the expression of FIT (bHLH29), bHLH38, bHLH39, bHLH100, and bHLH101 and promoting the degradation of FIT protein, a key regulator of iron uptake in Arabidopsis. We further demonstrated that the subgroup IVa bHLH proteins, bHLH18, bHLH19, bHLH20, and bHLH25, are novel interactors of FIT, which promote JA-induced FIT protein degradation. These four IVa bHLHs function redundantly to antagonize the activity of the Ib bHLHs (such as bHLH38) in regulating FIT protein stability under iron deficiency. The four IVa bHLH genes are primarily expressed in roots, and are inducible by JA treatment. Moreover, we found that MYC2 and JAR1, two critical components of the JA signaling pathway, play critical roles in mediating JA suppression of the expression of FIT and Ib bHLH genes, whereas they differentially modulate the expression of bHLH18, bHLH19, bHLH20, and bHLH25 to regulate FIT accumulation under iron deficiency. Taken together, these results indicate that by transcriptionally regulating the expression of different sets of bHLH genes JA signaling promotes FIT degradation, resulting in reduced expression of iron-uptake genes, IRT1 and FRO2, and increased sensitivity to iron deficiency. Our data suggest that there is a multilayered inhibition of iron-deficiency response in the presence JA in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Ciclopentanos/metabolismo , Ferro/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Transporte Biológico/genética , Proteínas de Transporte/genética , Núcleo Celular/metabolismo , Ciclopentanos/farmacologia , FMN Redutase/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Homeostase , Peptídeos e Proteínas de Sinalização Intracelular , Deficiências de Ferro , Oxilipinas/farmacologia , Reguladores de Crescimento de Plantas/farmacologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Ligação Proteica , Estabilidade Proteica , Transdução de Sinais
9.
Plant Cell Environ ; 41(7): 1698-1714, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29677391

RESUMO

Fe and Zn are essential micronutrients for plant growth, and the interrelationship regarding their homeostasis is very complicated. In this study, we identified a FIT-binding protein (FBP) using the yeast two-hybrid system. The C-terminus of FBP binds to the bHLH domain of FIT, abolishing the DNA-binding capacity of FIT. Knockout of FBP results in an enhanced expression of NAS genes and a higher nicotianamine content, and the fbp mutant exhibits tolerance to excessive Zn. Physiological analyses reveal that the mutant fbp retains a larger amount of Zn in roots and transfers a greater proportion of Fe to shoots than that in wild type under Zn-excessive stress. As FBP is expressed in the root stele, the negative regulation caused by sequestration of FIT is restricted to this tissue, whereas other FIT-regulated genes, such as IRT1 and FRO2, which mainly expressed in root epidermis, do not show transcriptional upregulation in the fbp mutant. As an antagonistic partner, FBP offers a new approach to spatially fine-tune the expression of genes controlled by FIT. In conclusion, our findings provide a new insight to understand the interrelationship of Fe and Zn homeostasis in plants.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/metabolismo , Proteínas de Ligação a DNA/fisiologia , Homeostase , Ferro/metabolismo , Zinco/metabolismo , Proteínas de Arabidopsis/metabolismo , Clorofila/metabolismo , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA/metabolismo , Técnicas de Silenciamento de Genes , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Técnicas do Sistema de Duplo-Híbrido
10.
Zhonghua Nan Ke Xue ; 22(6): 525-529, 2016 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-28963842

RESUMO

OBJECTIVE: To investigate the pregnancy outcomes of assisted reproductive technology (ART) with cryopreserved donor sperm and the safety of the offspring thus conceived. METHODS: The Human Sperm Bank of CITIC Xiangya Hospital provided cryopreserved donor semen to 31 reproductive centers in China between January 2006 and December 2012, with which 50247 ART cycles were accomplished. We compared the rates of birth defects and spontaneous abortion of intracervical insemination (ICI), intrauterine insemination (IUI), in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI). RESULTS: A total of 39 047 ART cycles were performed by artificial insemination with cryopreserved donor sperm, including 36 674 cycles of ICI and 2 372 cycles of IUI. Among the 8 612 clinical pregnancies achieved by ICI, there were 917 cases of spontaneous abortion (at <28 gestational wk) (10.6%) and 6133 live births, with 43 cases of birth defect (0.70%). Of the 547 clinical pregnancies achieved by IUI, there were 41 cases of spontaneous abortion (7.5%) and 426 live births, with 2 cases of birth defect (0.47%). Totally, 11 200 cycles of IVF and ICSI were accomplished with cryopreserved donor sperm. Of the 5 860 clinical pregnancies achieved by IVF, there were 456 cases of spontaneous abortion (7.8%) and 5089 live births, with 55 cases of birth defect (1.08%). Among the 350 clinical pregnancies achieved by ICSI, there were 30 cases of spontaneous abortion (8.6%) and 229 live births, with 3 cases of birth defect (1.31%). The birth defect rate of ART with cryopreserved donor sperm was significantly lower than that published by the Chinese Ministry of Health (0.86% vs 1.53%,P<0.01). CONCLUSIONS: The safety of the offspring conceived by ART with cryopreserved donor sperm is controllable.


Assuntos
Criopreservação , Técnicas de Reprodução Assistida , Espermatozoides/citologia , Aborto Espontâneo/epidemiologia , China , Anormalidades Congênitas/epidemiologia , Feminino , Fertilização In Vitro , Humanos , Inseminação Artificial , Masculino , Gravidez , Resultado da Gravidez , Técnicas de Reprodução Assistida/efeitos adversos , Injeções de Esperma Intracitoplásmicas , Doadores de Tecidos
11.
Trop Anim Health Prod ; 48(3): 659-62, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26712362

RESUMO

Wenyonella philiplevinei is one of the pathogens causing coccidiasis in ducks. The prevalence of W. philiplevinei infection in Linwu ducks (a Chinese local domesticated duck) was investigated in Linwu county (an area of Hunan province) of Hunan province, subtropical China from March 2014 to February 2015. Two hundred fifty-eight of 1800 (14.3 %) Linwu ducks were found to be infected with W. philiplevinei. To identify the species identity of the collected samples, a portion of the 18S rDNA was amplified from W. philiplevinei by polymerase chain reaction (PCR) and cloned and then sequenced. The sequences of 18S rDNA of all samples were 422 bp in size. The A + T content of the 18S rDNA sequences is 58-59 %. Sequence comparison revealed that the similarity in 18S rDNA sequences among Hunan isolates with that of the W. philiplevinei available (Guangdong isolate) were more than 98 %. The intra-specific sequence variations within each of the Hunan isolates were 0-1.7 %. Phylogenetic analysis using maximum likelihood (ML) method indicated that the genus Wenyonella is more closely related to Eimeria + Cyclospora than to that of the Isospora. These new data provide a genetic marker for the differentiation of W. philiplevinei or other closely related coccidian. This is the first report of W. philiplevinei prevalence in ducks in Hunan province, subtropical China.


Assuntos
Coccidiose/veterinária , Patos , Eimeria/isolamento & purificação , Doenças das Aves Domésticas/epidemiologia , Animais , China/epidemiologia , Coccidiose/epidemiologia , Eimeria/genética , Fezes/parasitologia , Variação Genética , Filogenia , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/parasitologia , Prevalência
12.
PLoS One ; 8(1): e54262, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23342113

RESUMO

Akt1 is well known for its role in regulating cell proliferation, differentiation, and apoptosis and is implicated in tumors and several neurological disorders. However, the role of Akt1 in neural development has not been well defined. We have isolated zebrafish akt1 and shown that this gene is primarily transcribed in the developing nervous system, and its spatiotemporal expression pattern suggests a role in neural differentiation. Injection of akt1 morpholinos resulted in loss of neuronal precursors with a concomitant increase in post-mitotic neurons, indicating that knockdown of Akt1 is sufficient to cause premature differentiation of neurons. A similar phenotype was observed in embryos deficient for Notch signaling. Both the ligand (deltaA) and the downstream target of Notch (her8a) were downregulated in akt1 morphants, indicating that Akt1 is required for Delta-Notch signaling. Furthermore, akt1 expression was downregulated in Delta-Notch signaling-deficient embryos and could be induced by constitutive activation of Notch signaling. In addition, knockdown of Akt1 was able to nullify the inhibition of neuronal differentiation caused by constitutive activation of Notch signaling. Taken together, these results provide in vivo evidence that Akt1 interacts with Notch signaling reciprocally and provide an explanation of why Akt1 is essential for the inhibition of neuronal differentiation.


Assuntos
Neurônios/citologia , Neurônios/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Notch/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Animais , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas Proto-Oncogênicas c-akt/genética , Receptores Notch/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Peixe-Zebra , Proteínas de Peixe-Zebra/genética
13.
Cell Mol Life Sci ; 70(5): 935-50, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23052218

RESUMO

The schizophrenia susceptibility gene, Rgs4, is one of the most intensively studied regulators of G-protein signaling members, well known to be fundamental in regulating neurotransmission. However, little is known about its role in the developing nervous system. We have isolated zebrafish rgs4 and shown that it is transcribed in the developing nervous system. Rgs4 knockdown did not affect neuron number and patterning but resulted in locomotion defects and aberrant development of axons. This was confirmed using a selective Rgs4 inhibitor, CCG-4986. Rgs4 knockdown also attenuated the level of phosphorylated-Akt1, and injection of constitutively-activated AKT1 rescued the motility defects and axonal phenotypes in the spinal cord but not in the hindbrain and trigeminal neurons. Our in vivo analysis reveals a novel role for Rgs4 in regulating axonogenesis during embryogenesis, which is mediated by another schizophrenia-associated gene, Akt1, in a region-specific manner.


Assuntos
Axônios/metabolismo , Axônios/patologia , Neurônios/citologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas RGS/metabolismo , Peixe-Zebra/metabolismo , Sequência de Aminoácidos , Animais , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Humanos , Dados de Sequência Molecular , Sistema Nervoso/embriologia , Sistema Nervoso/metabolismo , Sistema Nervoso/patologia , Neurogênese , Neurônios/metabolismo , Neurônios/patologia , Filogenia , Proteínas RGS/química , Proteínas RGS/genética , Alinhamento de Sequência , Transdução de Sinais , Peixe-Zebra/embriologia , Peixe-Zebra/genética
14.
PLoS One ; 6(4): e19394, 2011 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-21541299

RESUMO

Understanding how diversity of neural cells is generated is one of the main tasks of developmental biology. The Hairy/E(spl) family members are potential targets of Notch signaling, which has been shown to be fundamental to neural cell maintenance, cell fate decisions, and compartment boundary formation. However, their response to Notch signaling and their roles in neurogenesis are still not fully understood. In the present study, we isolated a zebrafish homologue of hairy/E(spl), her8a, and showed this gene is specifically expressed in the developing nervous system. her8a is positively regulated by Su(H)-dependent Notch signaling as revealed by a Notch-defective mutant and injection of variants of the Notch intracellular regulator, Su(H). Morpholino knockdown of Her8a resulted in upregulation of proneural and post-mitotic neuronal markers, indicating that Her8a is essential for the inhibition of neurogenesis. In addition, markers for glial precursors and mature glial cells were down-regulated in Her8a morphants, suggesting Her8a is required for gliogenesis. The role of Her8a and its response to Notch signaling is thus similar to mammalian HES1, however this is the converse of what is seen for the more closely related mammalian family member, HES6. This study not only provides further understanding of how the fundamental signaling pathway, Notch signaling, and its downstream genes mediate neural development and differentiation, but also reveals evolutionary diversity in the role of H/E(spl) genes.


Assuntos
Proteínas de Homeodomínio/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurogênese , Receptor Notch1/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Sequência de Aminoácidos , Animais , Embrião não Mamífero/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Embrião não Mamífero/patologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/genética , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Sistema Nervoso/efeitos dos fármacos , Sistema Nervoso/embriologia , Sistema Nervoso/metabolismo , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Neurogênese/efeitos dos fármacos , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neuroglia/patologia , Oligonucleotídeos Antissenso/farmacologia , Fenótipo , Filogenia , Receptor Notch1/química , Receptor Notch1/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/química , Fatores de Transcrição/genética , Regulação para Cima/efeitos dos fármacos , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/química , Proteínas de Peixe-Zebra/genética
15.
New Phytol ; 191(1): 49-56, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21517874

RESUMO

• Biotransformation of arsenic includes oxidation, reduction, methylation, and conversion to more complex organic arsenicals. Members of the class of arsenite (As(III)) S-adenosylmethyltransferase enzymes catalyze As(III) methylation to a variety of mono-, di-, and trimethylated species, some of which are less toxic than As(III) itself. However, no methyltransferase gene has been identified in plants. • Here, an arsM gene from the soil bacterium Rhodopseudomonas palustris was expressed in Japonica rice (Oryza sativa) cv Nipponbare, and the transgenic rice produced methylated arsenic species, which were measured by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). • Both monomethylarsenate (MAs(V)) and dimethylarsenate (DMAs(V)) were detected in the roots and shoots of transgenic rice. After 12 d exposure to As(III), the transgenic rice gave off 10-fold greater volatile arsenicals. • The present study demonstrates that expression of an arsM gene in rice induces arsenic methylation and volatilization, theoretically providing a potential stratagem for phytoremediation.


Assuntos
Arsênio/metabolismo , Oryza/genética , Plantas Geneticamente Modificadas/metabolismo , Biodegradação Ambiental , Biotransformação , Genes Bacterianos , Metilação , Oryza/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Rodopseudomonas/genética , Volatilização
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