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1.
Sex Dev ; 13(3): 143-150, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31247625

RESUMO

The Indian garden lizard, Calotes versicolor, lacks cytologically recognizable sex chromosomes, and its mechanism of sex determination is unclear. We evaluated genotype-to-sex-phenotype association using RAD-seq in wild-caught males and females, 30 of each sex. Of 210,736 unique, 96-nt long RAD-tags, 48% contained polymorphisms, 23% of which were present in at least 40 of 60 individuals. Twenty one RAD-tags neared, but none achieved, the inclusion criteria for sex enrichment, as expected if C. versicolor lacks highly differentiated sex chromosomes. Three RAD-tags with alleles most strongly associated with sex tended to be heterozygous in females and to lack male-specific alleles, suggesting a ZW female/ZZ male system. Putative female alleles, however, were present in some males and lacking from some females, suggesting either recombination between these markers and the sex locus or sex reversal due to environmental or genetic factors. Paired-end, 250-nt reads from 1 male provided a fragmented draft genome assembly. Four sex-associated RAD-tags were identical to portions of 4 unique C. versicolor genomic contigs rather than linked to a single putative sex-linked region. The lack of strongly sex-linked loci coupled with weak evidence for temperature-associated sex determination intensifies the need for further investigation of the puzzling sex determination mechanism in C. versicolor.


Assuntos
Loci Gênicos , Lagartos/genética , Processos de Determinação Sexual/genética , Animais , Feminino , Biblioteca Gênica , Genoma , Masculino , Polimorfismo de Nucleotídeo Único/genética
2.
Cleft Palate Craniofac J ; 56(3): 363-372, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29738289

RESUMO

OBJECTIVE: To evaluate the association of transforming growth factor ß3 ( TGFß3), muscle segment homeobox 1 ( MSX1), Metalloproteinases 3 ( MMP3), and MMP9 genes as candidates for nonsyndromic cleft lip and/or palate in an Indian population. DESIGN: Case-control association study, mutational screening, and functional evaluation of obtained mutations. SETTING: Mutational screening of the developmental genes, TGFß3 and MSX1, along with functional evaluation and association of promoter region SNPs-one each in MMP3 and MMP9. PATIENTS, PARTICIPANTS: Two hundred forty five NSCL±P cases from G. S. Memorial Plastic Surgery Hospital and Trauma Center, Varanasi and 201 healthy controls without a family history of congenital malformations from nearby schools, primary health centers, and the university hospital. MAIN OUTCOME MEASURE(S): Sequencing, SSCP, and PCR-RFLP were used for candidate gene screening. MatInspector and electrophoretic mobility shift assay (EMSA) were used to check the differential transcription factor binding of the variants at promoter region. Luciferase assay was used to test the transcriptional potential of the variant, and evaluation of the alternative splice site was carried out using exon-trapping experiment. RESULTS: Metalloproteinases3 -1171 5A/6A was associated with NSCL±P, whereas MMP9 -1562 C/T did not show association. A rare variant in the promoter region of TGFß3 (rs117462711) creates a differential binding site, confirmed by EMSA. Luciferase assay showed 3.7-fold increased expression level in mutant construct. A synonymous change in MSX1 (rs34165410) showed association with NSCL±P, which may create an alternative splice site or lead to low codon usage. Exon-trapping experiment failed to confirm alternative splicing, indicating low codon usage frequency of the mutant affecting the gene function. CONCLUSIONS: TGFß3, MSX1, and MMP3 are candidates for NSCL±P.


Assuntos
Fenda Labial , Fissura Palatina , Fator de Transcrição MSX1/genética , Metaloproteinase 3 da Matriz/genética , Fator de Crescimento Transformador beta3/genética , Povo Asiático , Estudos de Casos e Controles , Humanos , Metaloproteases , Polimorfismo de Nucleotídeo Único
3.
Sex Dev ; 12(6): 295-307, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30227435

RESUMO

Foxl2,Rspo1, and Aromatase are genes important in the ovary developmental pathway in mammals and birds. Here, we show their presence in the lizard, Calotes versicolor, which is known to lack a chromosomal as well as a temperature-dependent mode of sex determination and has an indeterminate, bipotential gonad throughout embryonic development. The expression of the 3 genes, as well as that of CvSox9 and Wnt4 - the known testis and ovary pathway genes - was studied by RT-PCR and whole tissue RNA in situ hybridization (WRISH) on the developing mesonephros gonadal complex (MGC). The expression of all 3 genes was initiated in the gonad shortly after its evagination from the mesonephros (day 5 onwards). CvFoxl2 generally was expressed in those MGCs in which CvSox9 was either not expressed or lowly expressed and vice versa. On the other hand, CvArom was expressed rather sporadically and randomly, showing no association with CvFoxl2, CvRspo1, or CvSox9, though in later stages WRISH preparations showed its coincidence with CvWnt4. CvRspo1 was expressed in almost all embryos right from day 5. Immunofluorescence localization of Rspo1 and Foxl2 proteins showed their presence in the gonads from day 10 onwards, and by day 25 it was primarily confined to the cortex but away from the coelomic epithelium of the gonadal cortex. Apparently both proteins were localized in the pregranulosa cells, Rspo1 in the cytoplasm and Foxl2 in the nucleus. Thus, it is clear that both CvFoxl2 and CvRspo1 are active in ovary formation, but whether they are expressed in the same or different cells is unknown. Though the transcription pattern of CvArom remains circumspect for its role in differentiation of the ovary, earlier evidence on aromatase inhibitor-induced reversal to the male sex indicates its importance in ovary function.

4.
J Genet ; 97(1): 275-285, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29666346

RESUMO

Van der Woude syndrome (VWS) shows an autosomal dominant pattern of inheritance with two known candidate genes, IRF6 and GRHL3. In this study, by employing genome-wide linkage analyses on two VWS affected families, we report the cosegregation of an intronic rare variant in NOL4 in one family, and a haplotype consisting of three variants in the noncoding region of IRF6 (introns 1, 8 and 3'UTR) in the other family. Using mouse, as well as human embryos as a model, we demonstrate the expression of NOL4 in the lip and palate primordia during their development. Luciferase, as well as miRNA-transfection assays show decline in the expression of mutant NOL4 construct due to the creation of a binding site for hsa-miR-4796-5p. In family 2, the noncoding region IRF6 haplotype turns out to be the candidate possibly by diminishing its IRF6 expression to half of its normal activity. Thus, here we report a new candidate gene (NOL4) and a haplotype of IRF6 forVWS, and highlight the genetic heterogeneity of this disorder in the Indian population.


Assuntos
Anormalidades Múltiplas/genética , Fenda Labial/genética , Fissura Palatina/genética , Cistos/genética , DNA Intergênico/genética , Heterogeneidade Genética , Haplótipos/genética , Fatores Reguladores de Interferon/genética , Lábio/anormalidades , Proteínas Nucleares/genética , Processamento Alternativo/genética , Animais , Sítios de Ligação , Linhagem Celular , Criança , Pré-Escolar , Cromossomos Humanos/genética , Família , Feminino , Predisposição Genética para Doença , Humanos , Lactente , Fatores Reguladores de Interferon/metabolismo , Íntrons/genética , Lábio/embriologia , Masculino , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Mutação/genética , Proteínas Nucleares/metabolismo , Palato/embriologia , Linhagem , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras/metabolismo
5.
Gene ; 658: 123-128, 2018 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-29524576

RESUMO

BACKGROUND: Genome-wide linkage analysis and whole genome sequencing in a Van der Woude syndrome (VWS) family revealed that the SNP, rs539075, within intron 2 of the cadherin 2 gene (CDH2) co-segregated with the disease phenotype. RESULTS: A study with nonsyndromic cleft lip with or without cleft palate (NSCL ±â€¯P) cases (N = 292) and controls (N = 287) established association of this SNP with NSCL ±â€¯P as a risk factor. RT-PCR based expression analysis of the SNP-harbouring region of intron 2 of CDH2 in the clefted lip and/or palate tissues of 16 patients revealed that the mutant allele expressed in all those individuals having it (hetero-/homozygous), whereas the wild type allele expressed in <50% of the samples in which it was present. The intronic transcript was also present in the prospective lip and palate region of 13.5 dpc mouse embryo, detected by RNA in situ hybridization and RT-PCR. CONCLUSIONS: These results including the in silico, characterization of the ~200 nt-intronic transcript showed that conformationally it fits best with noncoding small RNA, possibly a precursor of miRNA. Its function in the orofacial organogenesis remains to be elucidated which will enable us to define the role of this mutant ncRNA in the clefting of lip and palate.


Assuntos
Antígenos CD/genética , Caderinas/genética , Fenda Labial/genética , Fissura Palatina/genética , RNA não Traduzido/genética , Animais , Estudos de Casos e Controles , Criança , Pré-Escolar , Fenda Labial/patologia , Fissura Palatina/patologia , Clonagem Molecular , Embrião de Mamíferos , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Lactente , Íntrons/genética , Masculino , Camundongos , Polimorfismo de Nucleotídeo Único , Gravidez , RNA não Traduzido/isolamento & purificação
6.
J Biosci ; 40(3): 539-47, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26333400

RESUMO

Incidence of sickle cell trait in India is high in peninsular south, south-eastern, central and south-western India, while in north and north-eastern India, it is absent. Unicentric origin of SCD in the tribals of nilgiri hills in southern India has been proposed. The present study on the frequency of HbS trait and beta-globin gene haplotypes was conducted in the tribal-rich states of Chhattisgarh and Jharkhand to get an insight into the uneven distribution of HbS in India. Jharkhand borders with the HbS-high Odisha and Chhattisgarh, and HbS-low UP, Bihar and Bengal. Cellulose acetate gel electrophoresis was performed on the collected blood samples, to detect sickle haemoglobin (HbS) followed by DNA analysis. HbS associated beta-gene haplotype was constructed for the samples positive for HbS and all the tribals by PCR-RFLP. Out of 805 (Chhattisgarh - 261, Jharkhand - 544; greater than 36 percent tribals) samples analysed HbS frequency was 13 percent in Chhattisgarh and 3.3 percent in Jharkhand. Within Jharkhand, frequencies varied considerably from 10 percent in Tatanagar to nil in Sahibganj. The Arab-India (AI) haplotype of beta-globin cluster occurred in low frequency, confined mainly to Chhattisgarh. The most abundant haplotype in all the populations was the East Asian, + - - - - - +, rare in HbS, mainly in Sahibganj in east Jharkhand, which lacked AI. Our results indicate that besides the heterozygote advantage againstmalaria, the uneven regional distribution of HbS trait is because of restricted movement of two different populations, Dravidian from the south and Tibeto-Burman from the east into the Indianmainland which failed tomeet, we conjecture, due to severe climatic conditions (deserts and heat) prevailing through parts of central India. Apparently, Jharkhand became a zone of contact between them in recent times.


Assuntos
Frequência do Gene/genética , Hemoglobina Falciforme/genética , Traço Falciforme/epidemiologia , Traço Falciforme/genética , Análise por Conglomerados , Etnicidade/genética , Geografia , Haplótipos/genética , Humanos , Índia/epidemiologia , Malária/epidemiologia , Globinas beta/genética
7.
Blood Cells Mol Dis ; 55(1): 10-4, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25976460

RESUMO

Heterogeneity in thalassemia is due to various modifying factors viz. coinheritance of α-gene defects, abnormal hemoglobin, XmnI polymorphism, variation in repeat sequences present in LCR, and silencer region of the gene. The present work on populations from eastern regions of India was undertaken to study the genetic profile of heterogeneity in thalassemia patients. Mutation analysis in 126 index families revealed the presence of 3 novel mutations: CD2 (-A) in the 1st exon, -42 (C-G), and -223 (T-C) in the promoter region of ß-globin gene. The modifying effect of coexisting α-gene defects, and abnormal Hb (HbS) was clearly observed in our study, however ameliorating effect of T allele of XmnI polymorphism was not found. Analysis of the regulatory regions (LCR) exhibited new combinations (CA(15)TA(5) and CA(13)TA(8)) in HS1 region and one (AT)(10)T(3) in (AT)(x)T(y )silencer region. Thus disparate factors, when considered together, were able to explain several of the thalassemic phenotypes, otherwise not explained by the ß globin mutations. However, there were still some cases in this group whose molecular origin could not be ascertained. Our findings confirm not only the extensive genotypic and clinical heterogeneity in ß thalassemia but also the need to look for more modulators and modifiers to better understand the genotype-phenotype correlation in thalassemia.


Assuntos
Estudos de Associação Genética , Mutação , Talassemia/genética , alfa-Globinas/genética , Globinas beta/genética , Proteínas Adaptadoras de Transdução de Sinal , Adolescente , Adulto , Alelos , Sequência de Bases , Proteínas Sanguíneas/genética , Análise Mutacional de DNA , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Éxons , Feminino , Frequência do Gene , Genótipo , Humanos , Índia , Lactente , Masculino , Repetições de Microssatélites , Dados de Sequência Molecular , Fenótipo , Polimorfismo Genético , Regiões Promotoras Genéticas , Elementos Silenciadores Transcricionais , Talassemia/diagnóstico , Talassemia/patologia
8.
J Genet ; 94(4): 559-62, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27073819
9.
J Community Genet ; 6(1): 1-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25059538

RESUMO

Haemoglobinopathies are a leading cause of child mortality worldwide, although with a variable geographical incidence. A reliable estimate of prevalence of the disease is necessary for reducing its burden. However, most studies in India are either hospital based or from certain regions of the country and hence may not realistically reflect the disease burden. The eastern Indian states of Bihar, Chhattisgarh and Jharkhand and eastern region of Uttar Pradesh, which comprise ~25 % population of the country, are poorly studied with respect to haemoglobinopathies. The present study, conducted on 1,642 individuals from this region, shows a frequency of 3.4 % for ß-thalassaemia trait (BTT), 3.4 % for sickle cell haemoglobin trait (HbS)/haemoglobin E trait (HbE) and 18 % for α-globin defects. While BTT mutations are distributed rather uniformly across the region, HbS occurs only in Chhattisgarh and Jharkhand, the regions rich in tribal populations. The frequency of α-gene mutation is strikingly high, occurring even in individuals with normal blood count, in tribal as well as non-tribal groups. The mutation spectrum of BTT is also distinct since the common mutations, IVS1-1 (G-T) and 619 bp del, are absent while CD15 (G-A) is the second most frequent. The HbA2 level in the suspected cases is strikingly low. We demonstrate association of the low HbA2 level with vitamin B12 and folate deficiency in this cohort. Thus, the present report besides providing an estimate of the carrier frequency of ß-thalassaemia traits also confirms high prevalence of α-gene defects and regional heterogeneity in distribution of HbS in the eastern parts of India.

10.
PLoS One ; 8(8): e71587, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23936521

RESUMO

BACKGROUND & AIMS: Indian subcontinent has the highest child mortality rates along with a very high frequency of low birthweight (LBW). Folate and vitamin B12 (Vit-B12) are necessary during foetal development and their deficiency prevalence in Indians is very high. The objective of the present paper is to assess whether foetal homocysteine (Hcy)/folate metabolic pathway genes, their cofactors and homocysteine level independently (or collectively) predispose children to Low birth weight. METHODS: Cord blood was collected for the study. Frequency of 5 SNPs in 4-Hcy-pathway genes, and levels of Hcy, Vit-B12 and folate were evaluated. RESULTS: Of the 421 newborns recruited for the study, 38% showed low birth weight (<2.5 kg) and 16% were preterm babies. 101 neonates developed neonatal hyperbilirubinemia (NNH). High prevalence of Vit-B12 (65%) and folate (27%) deficiency was observed in newborns along with hyperhomocystinemia (hypHcy-25%). Preterm delivery, micronutrient deficiency, hypHcy and MTHFR 677T SNP are associated as risk factor while G allele of TCN2 C776G is protective against LBW. MTHFR 677T allele and folate deficiency are also independent risk factors for NNH. CONCLUSION: We record the highest incidence of Vit-B12, folate deficiency and elevated Hcy levels, of all the studies so far reported on neonates. These together with MTHFR 677T are potential risk factors for LBW. Association of impaired folate/Hcy metabolism with NNH is reported for the first time and the possible way of interaction is discussed. It appears that proper nutritional management during pregnancy would reduce the risk of complex clinical outcomes.


Assuntos
Homocisteína/sangue , Homocisteína/metabolismo , Hiperbilirrubinemia Neonatal/sangue , Hiperbilirrubinemia Neonatal/epidemiologia , Recém-Nascido de Baixo Peso/sangue , Recém-Nascido de Baixo Peso/metabolismo , Micronutrientes/sangue , Estudos de Coortes , Feminino , Ácido Fólico/sangue , Genótipo , Humanos , Hiperbilirrubinemia Neonatal/genética , Hiperbilirrubinemia Neonatal/metabolismo , Incidência , Índia/epidemiologia , Recém-Nascido , Masculino , Gravidez , Fatores de Risco , Vitamina B 12/sangue
11.
Eur J Pediatr ; 172(12): 1627-32, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23877636

RESUMO

Heme oxygenase-1 (HO-1) is a rate-limiting enzyme in bilirubin metabolism, and its genetic variant may modulate hyperbilirubinemia risk in neonates. The aim of the present study was to assess the association between heme oxygenase-1 gene variants and hyperbilirubinemia risk in Indian newborns. In a prospective case-control study, we analyzed (GT)n repeats and g.-413A>T variant of HO-1 gene and UGT1A1 gene variants in 100 case newborns with total serum bilirubin (TSB) levels exceeding 95th percentile and 100 control newborns with TSB levels below 75th percentile on the hour-specific bilirubin nomogram of the American Academy of Pediatrics. Study population consisted of term (37-41 weeks) and late preterm (34-36 weeks) newborns during the first 2 weeks of age. In our analysis, the (GT)n allele was highly polymorphic, ranging in number from 15 to 40. The incidence of short (GT)n allele (≤ 20) was significantly higher in neonates with hyperbilirubinemia than in controls. Although g.-413A>T variant was widely prevalent in the study population, no difference was noted in its prevalence between cases and controls. Short (GT)n repeats of HO-1 gene, c.211G>A variant of UGT1A1 gene, and excessive weight loss were independent risk factors for neonatal hyperbilirubinemia. In the presence of two or more risk factors, the odds of developing neonatal hyperbilirubinemia were high. Shorter (GT)n genotype in the promoter region of HO-1 gene is significantly associated with hyperbilirubinemia risk in Indian newborns. This genotype may interact with other genetic and clinical risk factors to further potentiate hyperbilirubinemia risk in newborns.


Assuntos
Bilirrubina/análise , Frequência do Gene , Glucuronosiltransferase/genética , Heme Oxigenase-1/genética , Hiperbilirrubinemia Neonatal/genética , Polimorfismo Genético , Análise de Variância , Estudos de Casos e Controles , Feminino , Humanos , Índia , Recém-Nascido , Icterícia/genética , Masculino , Análise Multivariada , Razão de Chances , Reação em Cadeia da Polimerase , Estudos Prospectivos , Fatores de Risco
12.
J Biosci ; 38(1): 21-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23385809

RESUMO

In India, as in other parts of the world, nonsyndromic cleft lip with or without cleft palate (NSCL +/- P) is a highly prevalent birth defect, its incidence in males being twice that in females. A case-control association study has been carried out with respect to homocysteine level and MTHFR C677T, A1298C and SLC19A1 (RFC1) G80A genotypes from an eastern Indian cohort to investigate whether Hcy and other Hcy-pathway genes also contribute to the risk level. While MTHFR 677T and SLC19A1 80G are individually and cumulatively risk factors, SLC19A1 80A appears to be protective against MTHFR 677T risk allele. Elevated Hcy associates with NSCL +/- P both in case mothers and cases. Significantly, this difference shows a gender bias: the level of elevation of Hcy in female cases is distinctly higher than in males, and more case females are hyperhomocyteinemic than the case males. It implies that compared with the males, higher level of Hcy is needed for NSCL +/- P to manifest in the females. We consider this as one of the possible factors why the incidence of this disorder in females is much lower than in males.


Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Homocisteína/sangue , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo Genético , Proteína Carregadora de Folato Reduzido/genética , Adolescente , Adulto , Alelos , Estudos de Casos e Controles , Criança , Pré-Escolar , Fenda Labial/sangue , Fenda Labial/epidemiologia , Fissura Palatina/sangue , Fissura Palatina/epidemiologia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Incidência , Índia/epidemiologia , Lactente , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/sangue , Proteína Carregadora de Folato Reduzido/sangue , Fatores de Risco , Fatores Sexuais
13.
J Pediatr Endocrinol Metab ; 23(4): 379-85, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20583543

RESUMO

Phenotypic presentation of 46,XY DSD depends on the underlying defects. Defect in androgen action on the target tissues or production of active metabolite share common morphological features. Molecular study may help differentiating these abnormalities with precision. Mutational analysis of androgen receptor (AR) and SRD5A2 genes was performed in 29 patients with 46,XY DSD, by PCR-SSCP. The amplicons that showed an aberrant migration in SSCP were subjected to sequencing. Interestingly, six patients from 4 unrelated families (a pair of sibs, uncle/nephew and other two isolated) were identified with mutations in SRD5A2 gene. In five patients p.R246Q missense mutation was detected, of which four were homozygous and one was compound heterozygous: g.80_87delT CGCGAAG (p.A27fsX132) and p.R246Q. Another patient with isolated micropenis harbored a heterozygous p.G196S missense mutation. No AR gene mutation was detected. In conclusion, our study suggests that p.R246Q mutation is common amongst patients with SRD5A2 gene defect from the Northern states of India. Also, it records a novel deletion in exon 1 of SRD5A2 gene in a patient with severe hypospadias.


Assuntos
3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Disgenesia Gonadal 46 XY/genética , Proteínas de Membrana/genética , Adolescente , Adulto , Criança , Pré-Escolar , Éxons/genética , Disgenesia Gonadal 46 XY/diagnóstico , Humanos , Masculino , Mutação de Sentido Incorreto/genética , Nucleotídeos/genética , Reação em Cadeia da Polimerase , Deleção de Sequência
14.
Sex Dev ; 4(3): 162-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20453477

RESUMO

The Indian garden lizard, Calotes versicolor, an apparently non-chromosomal sex determination (CSD), non-temperature-dependent sex determination (TSD) species, represents a unique category of reptiles where male hormone-treated embryos emerge as males. The present paper traces the modulation of gene activity in the embryonic gonad following dihydrotestosterone (DHT) administration on day 8 of embryonic development. Expression of CvAR, CvWnt4, CvDmrt1 and CvSox9 genes has been studied in the mesonephros gonadal complex (MGC) 2 and 6 days after the treatment by RT-PCR and real-time qPCR. In the treated (30 microg/egg) embryos (sacrificed 48 h after treatment), CvAR was expressed in almost all the MGCs in contrast to its dimorphic expression in controls. CvWnt4, the autosomal ovary-specific gene, which has only basal level of expression in controls, was further down-regulated in the treated embryos. The dimorphic expression pattern of the male-specific CvSox9 and CvDmrt1 does not deviate from that seen in controls, suggesting that it acts upstream of CvAR. It appears that in C. versicolor, the primary sex determining switch for testis is essentially genetic (CvSox9 and CvDmrt1), but the genetic pathway of ovary differentiation, which is initiated later in development, is flexible enough to be modulated by hormones, as in other TSD and genetic sex determination (GSD) reptiles. One of the mechanisms of this flexibility, it appears, could be silencing of the ovary-inducing genes by the male hormones.


Assuntos
Androgênios/farmacologia , Transtornos do Desenvolvimento Sexual , Lagartos/fisiologia , Animais , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Lagartos/genética , Masculino , Receptores Androgênicos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOX9/genética , Proteínas Wnt/genética
15.
Gene ; 449(1-2): 77-84, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19751810

RESUMO

Sex determination in the Indian garden lizard, Calotes versicolor, which lacks sex chromosomes and temperature-dependent sex determination, appears to be genically controlled, and previous studies have identified orthologues of Sox9, Dmrt1 and Androgen receptor (AR) as genes involved in testis differentiation in genetic males. In the pursuit of female pathway genes in this species, the present paper deals with the identification of Wnt4 and Dax1 genes in C. versicolor and their expression in embryonic gonad. CvDax1 is expressed throughout the development in certain embryos from day 5 onwards but shows no clear association with either testis or ovary. However, its preferred association with CvSox9 in early development and with CvWnt4 during later development suggests a role in the structuring of the gonads. CvWnt4 shows little expression in early development. It expresses prominently from day 20 onwards, and almost exclusively in those embryos that do not express CvSox9, demonstrating that CvWnt4 is the ovary differentiation gene in this species. This evidence leads us to suggest that temporal distinction of expression of ovary-specific (day 20 onwards) and testis-specific (day 5 onwards) genes could be an important part of the process of sex determination in C. versicolor. Taken together, the mechanism of sex determination in C. versicolor appears closer to the CSD in mammals than that in the ESD reptiles and birds.


Assuntos
Lagartos/genética , Ovário/metabolismo , Testículo/metabolismo , Proteínas Wnt/genética , Animais , Feminino , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Diferenciação Sexual
16.
Cleft Palate Craniofac J ; 46(5): 541-4, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19929101

RESUMO

OBJECTIVE: Evaluation of the IRF6 gene in Van der Woude syndrome cases from an Indian population. SUBJECTS: Nine affected and four unaffected individuals from seven families with Van der Woude syndrome as well as five normal controls (with no history of Van der Woude or any other congenital malformation and belonging to the same geographical area as the families with Van der Woude syndrome). METHOD: Direct sequencing of all coding regions and exon-intron boundaries of the IRF6 gene. RESULTS: Five novel variants: IVS1+3900 A>G, 191 T>C, IVS4+775 C>T, IVS8+218 C>T, 1511 T>A (Ser 416 Arg) and two known variants: IVS6+27 C>G, 1083 G>A (V274I) were detected. Except for one, all were in noncoding regions either in 3'UTR or in introns. There was only one mutation in the coding region, detected in a normal control. CONCLUSION: The present report indicates that point mutations in the coding region of the IRF6 gene may not be a major cause of Van der Woude syndrome in Indian populations.


Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Fatores Reguladores de Interferon/genética , Fases de Leitura Aberta/genética , Regiões 3' não Traduzidas/genética , Anormalidades Múltiplas/genética , Adenina , Arginina/genética , Estudos de Coortes , Citosina , Éxons/genética , Feminino , Variação Genética/genética , Genótipo , Guanina , Heterozigoto , Homozigoto , Humanos , Índia , Íntrons/genética , Masculino , Mutação Puntual/genética , Análise de Sequência de DNA , Serina/genética , Síndrome , Timina
17.
J Hum Reprod Sci ; 2(2): 54-6, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19881148

RESUMO

BACKGROUND: Male infertility is a multifactorial disorder which affects approximately 10% of couples at childbearing age with substantial clinical and social impact. Genetic variation and environmental factors contribute to susceptibility to spermatogenic impairment in humans. The A386G (T54A) polymorphism of the autosomal gene, DAZL, has shown susceptibility to spermatogenic failure in Taiwanese population. However, no such association has been seen in infertile patients from Italy and South India. AIM: This study aims to find out the possible association between A386G (T54A) polymorphism of the autosomal gene, DAZL and idiopathic male infertility in patients from North India. DESIGN: Case-control study. MATERIALS AND METHODS: The prevalence of A386G (T54A) polymorphism was determined in 165 idiopathic infertile azoo-/oligospermic patients and 200 fertile healthy control men. PCR-RFLP analysis was employed to determine the genotypes. PCR amplicons were subjected to restriction digestion with AluI as this mutation created a restriction site (AGCT), and separated on a 12% polyacrylamide gel. RESULTS: Analysis of 165 idiopathic infertile azoo-/oligospermic and 200 fertile control men revealed only one case of the variant as a heterozygote in the control population. Single Nucleotide Polymorphism (SNP) was absent in the infertile patients. CONCLUSION: As in the report from Italy and South India, our results illustrate the rarity of this mutation. Apparently, this mutation is of recent origin and/or has poor selective value. Its preponderance in infertile patients from Taiwan (all heterozygotes) suggests a founder effect and also that its low selective value could be due to impaired spermatogenesis.

18.
Genet Test Mol Biomarkers ; 13(3): 355-60, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19419265

RESUMO

AIM: To determine the association of three SNPs, IRF6 G820A, MTHFR C677T, and MTHFR A1298C, with nonsyndromic cleft lip with or without cleft palate (NSCL/P) in an Indian population. METHOD: A total of 323 NSCL/P patients, 116 of their mothers, 108 of their fathers, and 214 normal controls have been examined for the above three SNPs. RESULT: Frequency of IRF6 GG was 65% in controls, 78% in cases, 84% in case-fathers, and 80% in case-mothers. MTHFR 677T homozygosity was lower than 1% in controls and unaffected parents, while in the group of probands it was much higher (3.4%; OR 4.30). The frequency of CT genotype was also high in the cases and case-mothers (OR 1.89 and 2.2, respectively). MTHFR A1298C did not reveal a statistically significant deviation in allele and genotype frequencies. CONCLUSION: While MTHFR 677T homozygotes show a significant association with NSCL/P, heterozygotes 677CT are minor risk factors. MTHFR A1298C does not show a risk in any combination of alleles. IRF6 820GG too forms a minor risk. However, combined genotypes IRF6 GG/MTHFR 677CT together form greater risk for NSCL/P.


Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Fatores Reguladores de Interferon/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Grupos Populacionais/genética , Alelos , Estudos de Casos e Controles , Pai , Feminino , Frequência do Gene , Genótipo , Heterozigoto , Homozigoto , Humanos , Índia , Masculino , Mães , Núcleo Familiar , Polimorfismo de Nucleotídeo Único , Fatores de Risco
19.
Mol Cell Endocrinol ; 303(1-2): 100-6, 2009 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-19428997

RESUMO

The Indian garden lizard, Calotes versicolor, shows neither cytologically distinguishable sex chromosomes nor temperature dependent sex determination. However, previous studies on the administration of androgens to embryos during early development have shown reversal towards male sex. We have cloned and sequenced a cDNA fragment of the androgen receptor (AR) gene (CvAR) and characterized its expression. CvAR shares much homology with AR gene of other vertebrates at the nucleotide and amino acid levels indicating their evolutionary conservation. Whole mount RNA in situ hybridization (WRISH) and semi-quantitative RT-PCR analyses of its expression in the genital ridge of individual embryos from different stages of development, demonstrate its initiation by day 10 which is later than CvSox9 but occurs dimorphically only in those embryonic gonads which express CvSox9, a male specific marker. It suggests that AR expression may be crucial in the male sex determination pathway in C. versicolor.


Assuntos
Gônadas , Lagartos/fisiologia , Receptores Androgênicos/genética , Processos de Determinação Sexual , Animais , Clonagem Molecular , DNA Complementar , Embrião não Mamífero , Lagartos/genética , Masculino , RNA Mensageiro/análise , Fatores de Transcrição SOX9/análise
20.
Indian J Hum Genet ; 15(1): 19-22, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20407645

RESUMO

Infertility being a multifactorial disorder, both genetic and environmental factors contribute to the etiology of infertile phenotype. Chromosomal anomalies and Y-microdeletion are the established genetic risk factors of male infertility. Y-haplotypes has been found as risk factor for male infertility in certain populations, though in certain others no association has been reported, suggesting a population-specific association of these variations with male infertility. In a case-control study, 165 azoo-/oligospermic patients and 200 controls were haplotyped for certain Y-haplogroups for a possible association with idiopathic male infertility in an Indian population. Analysed Y-haplogroups showed no association with infertile phenotype. Thus this genetic factor is not a risk for infertility in the studied Indian population but that does not rule out the possibility of any of them, to be a risk in other populations.

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