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At least 55 records · Page 3Linked to original sources
PubMed2006

Peroxisome proliferator-activated receptor gamma coactivator-1alpha gene variations are not associated with gestational diabetes mellitus.

OBJECTIVE: Epidemiologic, pathophysiologic, and genetic data suggest a close link between gestational diabetes mellitus (GDM) and type 2 diabetes. Previous studies yielded controversial results on the impact of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1) gene variations on the development of type 2 diabetes mellitus. Therefore, we examined two common single nucleotide polymorphisms (SNP) of this gene in women with GDM. METHODS: We assessed a total of 875 women by oral glucose tolerance testing (OGTT). Two hundred women of this population, 100 patients with an abnormal OGTT and 100 normal controls, were randomly selected. DNA samples isolated from the blood of the control and study groups were analyzed with respect to the SNP Gly482Ser and Thr394Thr of the PGC-1 gene using polymerase chain reaction (PCR) amplification and restriction analysis. Furthermore, a potential interaction between the Gly482Ser and the Thr394Thr variant on the risk of GDM was investigated. RESULTS: Women with GDM were significantly older (32.2 +/-5.5 years vs 29.7 +/- 6.1 years; P = .005), had higher body mass indices (BMI; 28.0 +/- 7.1 kg/m2 vs 25.0 +/- 5.7 kg/m2; P = .002) and displayed higher hemoglobin A1c (HbA1c) values (5.6 +/- 0.9 vs 4.9 +/- 0.5; P <.001). There was no significant difference between the allele distribution of the two polymorphisms in women with and without GDM. No significant associations between the two polymorphisms and BMI or OGTT values were observed. When the different haplotype combinations of the two loci were analyzed for the risk of GDM, no significant association could be found. CONCLUSION: Based on our data, the Gly482Ser and the Thr394Thr polymorphisms of the PGC-1 gene are not associated with the development of GDM.

Adult↗
PubMed2006

An increased coronary risk is paradoxically associated with common cholesteryl ester transfer protein gene variations that relate to higher high-density lipoprotein cholesterol: a population-based study.

BACKGROUND: Several cholesteryl ester transfer protein (CETP) polymorphisms affect high-density lipoprotein (HDL) cholesterol, but the impact of CETP gene variants on incident coronary disease in the general population is uncertain after correction for their effect on HDL cholesterol. DESIGN: We determined relationships between the CETP -629C-->A promoter (n = 8141), the TaqIB (n = 8289), and the I405V (n = 8265) polymorphisms, serum lipids, C-reactive protein, and clinical factors with incident coronary heart disease (defined as death from or hospitalization for myocardial infarction, ischemic heart disease, or coronary intervention) during a median of 4.94 yr follow-up. SUBJECTS: A predominantly Caucasian general population was studied. RESULTS: HDL cholesterol was 0.08 mmol/liter higher in -629A carriers than in -629CC homozygotes (P < 0.001). The unadjusted coronary hazard was 1.26 [95% confidence interval (CI), 0.95-1.68; P = 0.11] in A carriers compared with CC homozygotes and increased to 1.46 (95% CI, 1.10-1.95; P = 0.01) after adjustment for HDL cholesterol. This effect remained after additional adjustment for apolipoprotein A-I, triglycerides, C-reactive protein, age, and gender. Likewise, the HDL-cholesterol-adjusted hazard ratio was also higher in AA than in CC homozygotes (hazard ratio, 1.72; 95% CI, 1.22-2.42; P < 0.01). Similar findings were obtained with the TaqIB polymorphism. The 405V allele was weakly associated with incident coronary heart disease after HDL cholesterol adjustment (P = 0.09). CONCLUSIONS: A common CETP promoter polymorphism, which beneficially contributes to higher HDL cholesterol, is paradoxically associated with increased incidence of coronary disease in the general population. Thus, CETP gene variation may affect coronary risk apart from the level of HDL cholesterol.

Apolipoprotein A-I↗
PubMed2005

No association between Angiotensin Converting Enzyme (ACE) gene variation and endurance athlete status in Kenyans.

East African runners are continually successful in international distance running. The extent to which genetic factors influence this phenomenon is unknown. The insertion (I) rather than deletion (D) of a 287 bp fragment in the human angiotensin converting enzyme (ACE) gene is associated with lower circulating and tissue ACE activity and with endurance performance amongst Caucasians. To assess the association between ACE gene variation and elite endurance athlete status in an African population successful in distance running, DNA samples were obtained from 221 national Kenyan athletes (N), 70 international Kenyan athletes (I), and 85 members of the general Kenyan population (C). Blood samples were obtained from C and assayed for circulating ACE activity. ACE I/D (rs????--from NCBI SNPdb first time poly mentioned) genotype was determined, as was genotype at A22982GD (rs????--from NCBI SNPdb first time poly mentioned) which has been shown to associate more closely with ACE levels in African subjects than the I/D polymorphism. ACE I/D and A22982G genotypes explained 13 and 24% of variation in circulating ACE activity levels (P = 0.034 and <0.001 respectively). I/D genotype was not associated with elite endurance athlete status (df = 4, chi(2) = 4.1, P=0.39). In addition, genotype at 22982 was not associated with elite endurance athlete status (df = 4, chi(2) = 5.7, P = 0.23). Nor was the A allele at 22982, which is associated with lower ACE activity, more prevalent in N (0.52) or I (0.41) relative to C (0.53). We conclude that ACE I/D and A22982G polymorphisms are not strongly associated with elite endurance athlete status amongst Kenyans.

Female↗
PubMed1973

Patterns of gene variation in central and marginal populations of Drosophila robusta.

The central and marginal populations of D. robusta differ greatly in the level of inversion polymorphism; the marginal populations are monomorphic or nearly so and the central populations are highly polymorphic. This paper presents the frequencies of alleles at forty gene loci in various populations of D. robusta, studied by electrophoresis of proteins and enzymes. Population samples were obtained from eight widely separated populations of D. robusta which included the central, the extreme marginal and the intervening populations between the center and the margins. We find that the proportion of polymorphic loci and average heterozygosity per individual is slightly higher in the marginal populations than the central populations. In D. robusta on an average, 39% of the loci are polymorphic and the average proportion of loci heterozygous per individual is 11%. A breakdown of loci in three categories, viz, hydrolytic enzymes and some other enzymes, larval proteins and glycolytic and Kreb's cycle enzymes, shows that in all populations the level of polymorphism is highest in the hydrolytic enzymes, intermediate in larval proteins and least in the glycolytic and Kreb's cycle enzymes. On the average, the proportion of loci heterozygous per individual for three groups of loci is: hydrolytic enzymes and others (.164), larval proteins (.115) and glycolytic and Kreb's cycle enzymes (.037). We also observe that in all populations the level of polymorphism on the X chromosome is far less than the expected 38%; in salivary gland cells the euchromatic length of the X chromosome is 38% of the entire genome. Lower levels of polymorphism for the X chromosome loci are explained due to low probability of balanced polymorphisms for the X-linked loci since the conditions for establishment of balanced polymorphism for X-linked loci are more restrictive than for the autosomal loci.-The polymorphic loci can be grouped according to pattern of allele frequencies in different populations as follows: (1) The allele frequencies are similar in all populations at the XDH, Pep-1 and Hex-1 loci. (2) The alleles at the Est-1, Est-2, Amy loci and the AP-4(1.0) and the LAP-1(.90) alleles show north south clinal change in frequency. (3) There is north south and east west differentiation at the Pt-5, Pt-8 and Pt-9 loci and the allele AP-4(.81). (4) Polymorphism at loci such as Fum, B.Ox, Hex-8, Pep-2 and Pep-3 are restricted to only one or two of the populations. (5) Allele frequencies at the MDH and ODH loci fluctuate between populations. (6) Allele frequencies at many polymorphic loci such as Est-1, Est-2, LAP-1, AP-4, Pt-5, Pt-8, Pt-9, Pt-16, MDH, Fum change clinally within a gene arrangement. The pattern of gene variation in D. robusta is very complex and cannot be easily explained due to migration of neutral alleles between once-isolated populations or to semi-isolation of neutral alleles. The observations of the pattern of allele variation in different populations, high levels of polymorphism in the marginal populations which have small population size and low levels of polymorphism of the X chromosome loci all support the argument in favor of balancing selection as the main mechanism for the maintenance of these polymorphisms. Environmental factors must play a role in the maintenance of a great deal of these polymorphisms, since we observe clinal allele frequency changes even within a given inversion type.

Acid Phosphatase↗
PubMed2005

IL-6 gene variation is not associated with increased serum levels of IL-6, muscle, weakness, or frailty in older women.

Elevated levels of the inflammatory cytokine IL-6 are associated with the development of disability, frailty, and mortality in older adults. These outcomes are likely mediated through inflammatory activity that alters hormones, skeletal muscle, and the immune system. Polymorphic variants in the IL-6 gene influence IL-6 expression. We hypothesized that IL-6 alleles associate with increased serum of IL-6, decreased muscle strength, and frailty, and tested this in the Women's Health and Aging cohorts. We genotyped 463 participants age 70-79, and identified three common IL-6 haplotype blocks for the Caucasian (n=363) and African American (n=100) subsets. Using linear and logistic regression, and adjusting for age, BMI, race, and osteoarthritis, we identified no significant or clinically meaningful relationship between any single IL-6 single nucleotide polymorphism (SNP) or any IL-6 haplotype and serum IL-6 level, grip, knee, or hip strength, or frailty. Given that the promoter SNP (rs1800795) has been reported to influence IL-6 levels and health outcomes, we performed a similar association study in the In Chianti population (n=266) and confirmed lack of association. These results suggest that IL-6 gene variation may not be an important factor in the determination of elevated IL-6 levels and related phenotypes found in older women.

Aged↗
PubMed2005

Peroxisome proliferator-activated receptor alpha gene variation influences age of onset and progression of type 2 diabetes.

Dysregulation of fatty acid metabolism is important in the pathogenesis of type 2 diabetes. Peroxisome proliferator-activated receptor (PPAR)alpha is a master regulator of fatty acid catabolism, and PPARalpha activators delay the onset of type 2 diabetes. We examined association between three PPARalpha gene polymorphisms (an A-->C variant in intron 1, the L162V variant, and the intron 7 G-->C variant) and age at diagnosis of type 2 diabetes in 912 Caucasian type 2 diabetic subjects. Individually, PPARalpha gene variants did not influence age at diagnosis, but in combination, the rare alleles of both the intron 1 A-->C (P < 0.001) and intron 7 G-->C (P = 0.025) variants synergistically lowered age at diagnosis (interaction P < 0.001). Overall, the PPARalpha haplotype signficantly influenced age at diagnosis (P = 0.027), with the C-L-C and C-V-C haplotypes (intron 1-L162V-intron 7) accelerating onset of diabetes by 5.9 (P = 0.02) and 10 (P = 0.03) years, respectively, as compared with the common A-L-G haplotype, and was associated with an odds ratio for early-onset diabetes (age at diagnosis </=45 years) of 3.75 (95% CI 1.65-8.56, P = 0.002). Intron 1 C-allele carriers also progressed more rapidly to insulin monotherapy (AA 9.4 +/- 1.5 and AC + CC 5.3 +/- 1.1 years, P = 0.002). These data indicate that PPARalpha gene variation influences the onset and progression of type 2 diabetes.

Age of Onset↗
PubMed2006

Association between ghrelin gene variations and blood pressure in subjects with impaired glucose tolerance.

BACKGROUND: Ghrelin is a gut-brain hormone, which stimulates food intake and controls energy balance. Recently, it has been shown that ghrelin may also play a role in the regulation of blood pressure (BP) by acting at the sympathetic nervous system. In the present study we genotyped six variants of the ghrelin gene and its promoter, and tested whether these single nucleotide polymorphisms (SNPs) were associated with BP levels in participants of the Finnish Diabetes Prevention Study. METHODS: The Finnish Diabetes Prevention Study was a longitudinal study where 522 subjects with impaired glucose tolerance were randomized into either an intervention or control group. DNA was available from 507 subjects (mean body mass index [BMI] 31.2+/-4.5 kg/m2, age 55+/-7 years). All six SNPs were screened by the restriction fragment length polymorphism method. RESULTS: Subjects with the most common genotype combination of the following four SNPs, -604G/A, -501A/C, Leu72Met, and Gln90Leu, had the lowest systolic (131+/-11 v 137+/-13 mm Hg, P=.003) and diastolic BP levels (79+/-7 v 83+/-7 mm Hg, P=.004) at the baseline of the study and during 3 years of follow-up compared to all other genotypes. Adjustments for age, gender, antihypertensive medication, BMI, waist circumference, and alcohol intake did not change this association. CONCLUSIONS: Several ghrelin gene variations were associated with BP levels in subjects with impaired glucose tolerance.

Adult↗
PubMed2004

Steroid sulfatase gene variation and DHEA responsiveness to resistance exercise in MERET.

Genetic influences and endurance exercise have been shown to alter circulating concentrations of dehydroepiandrosterone (DHEA) and its sulfated conjugate, DHEAS. We hypothesized that acute resistance exercise (RE) and training (RET) would increase DHEA steroids, and the magnitude of the increase would be influenced by a steroid sulfatase (STS) gene variation. Fasting blood samples were collected before and after the first (S1) and last (S30) session of a 10-wk RET program in 62 men and 58 women [age: 21.0 yr (2.4)]. Acute RE increased both DHEA [+2.8 (0.4), S1; +1.6 ng/ml (0.4), S30; P < 0.001] and DHEAS [+154 (24), S1; +166 ng/ml (15), S30; P < 0.001] and decreased DHEAS:DHEA [-27 (8), S1; -15 (7), S30; P < 0.01]. RET reduced resting DHEAS (-122 ng/ml, P < 0.01) and decreased DHEA response to RE (-50%, P < 0.05). Subjects with an STS "G" allele (n = 36) had greater acute changes in DHEA [+4.4 (0.7) vs. +2.0 ng/ml (0.5), S1; +3.2 (0.6) vs. +1.0 ng/ml (0.4), S30; P < 0.01] and DHEAS:DHEA [-37 (11) vs. 5 (7), S30, P < 0.05] than those subjects with only an "A" allele (n = 84). The observed increase in DHEA and DHEAS and decrease in DHEAS:DHEA suggest RE-induced STS activation which is influenced by the STS polymorphism.

Adult↗
PubMed2000

Gene variation of 5'-NCR and core region in serum samples collected from patients with HCV infection.

OBJECTIVE: To study the variation of HCV 5'-NCR and core gene in serial sera collected from patients with HCV infection. METHODS: Serial sera were collected from 4 plasma-donors with HCV infection. 5'-NCR and core gene were amplified, sequenced and analyzed using software. RESULTS: All the sequences obtained from the serial sera of patients with HCV infection were 1b and 2a subtypes. The variation of 5'-NCR only related to the genotype, and not associated with patients and time of serum collection. However, the sequences of core gene were not identical in HCV strains isolated from different patients. The sequences of those two regions of the same genotype isolated from the same patient did not change with time. CONCLUSION: 5'-NCR is more conserved than the core region and the genotype is the major cause of gene variation. No change in sequences of those two regions is found at the different points of time.

5' Untranslated Regions↗
PubMed2005

Rapid miocene-pliocene dispersal and evolution of Mediterranean rajid fauna as inferred by mitochondrial gene variation.

Rajidae (colloquially known as skates and rays) experienced multiple and parallel adaptive radiations allowing high species diversity and great differences of species composition between regional faunas. Nevertheless, they show considerable conservation of bio-ecological, morphological and reproductive traits. The evolutionary history and dispersal of North-east Atlantic and Mediterranean rajid fauna were investigated throughout the sequence analysis of the control region and 16S rDNA mitochondrial genes. Molecular estimates of divergence times indicated recent origin and rapid dispersal of the present species. Compared with the ancient origin of the family (Late Cretaceous), the present species diversity arose in a relatively narrow time-window (12 Myr) from Middle Miocene to Early Pleistocene, likely by speciation processes related to dramatic geological and climatic events in the Mediterranean. Nucleotide substitution rates and phylogenetic relationships indicated Mediterranean endemic skates derived from sister species with wider distribution during Late Pliocene-Pleistocene. Skate phylogeny and systematics obtained using mitochondrial gene variation were largely consistent with those based on morpho-anatomical data.

Animals↗
PubMed2002

Hypoglycaemia and elevated urine ethylmalonic acid in a child homozygous for the short-chain acyl-CoA dehydrogenase 625G > A gene variation.

UNLABELLED: The aim of this case report is to call attention to short-chain acyl-CoA dehydrogenase (SCAD) deficiency as a possible contributory factor to hypoglycaemia in childhood. We report on a previously healthy 14 mo-old Danish boy who presented with hypoglycaemia and metabolic acidosis after a few days of upper airway infection. After two days on a normal diet, he recovered clinically and biochemically. A thorough biochemical examination did not reveal the cause of the hypoglycaemia. However, the excretion of ethylmalonic acid in two morning urine samples was moderately increased, and hence the SCAD gene was screened for mutations. We found the child homozygous for the G > A SCAD gene variation at position 625. CONCLUSION: In this patient, reduced function of the SCAD protein is reflected in the excretion of ethylmalonic acid, a marker of intracellular accumulation of butyryl-CoA and the cytotoxic butyric acid. Furthermore, gluconeogenesis might be compromised owing to lack of reducing equivalents from the oxidation of short-chain fatty acids in the fasting or stressed state, thus contributing to the predisposition for fasting hypoglycaemia.

Acyl-CoA Dehydrogenase↗
PubMed2024

Analysis of human papillomavirus type 16 E4, E5 and L2 gene variations among women with cervical infection in Xinjiang, China.

BACKGROUND: There is a high incidence of cervical cancer in Xinjiang. Genetic variation in human papillomavirus may increase its ability to invade, spread, and escape host immune response. METHODS: HPV16 genome was sequenced for 90 positive samples of HPV16 infection. Sequences of the E4, E5 and L2 genes were analysed to reveal sequence variation of HPV16 in Xinjiang and the distribution of variation among the positive samples of HPV16 infection. RESULTS: Eighty-one of the 90 samples of HPV16 infection showed variation in HPV16 E4 gene with 18 nucleotide variation sites, of which 8 sites were synonymous variations and 11 missense variations. 90 samples of HPV16 infection showed variation in HPV16 E5 and L2 genes with 16 nucleotide variation sites (6 synonymous, 11 missense variations) in the E5 gene and 100 nucleotide variation sites in L2 gene (37 synonymous, 67 missense variations). The frequency of HPV16 L2 gene missense variations G3377A, G3599A, G3703A, and G3757A was higher in the case groups than in the control groups. CONCLUSIONS: Phylogenetic tree analysis showed that 87 samples were European strains, 3 cases were Asian strains, there were no other variations, and G4181A was related to Asian strains. HPV16 L2 gene missense variations G3377A, G3599A, G3703A, and G3757A were significantly more frequent in the case groups than in the control groups.

Humans↗
PubMed2005

Adiponectin gene variation associates with the increasing risk of type 2 diabetes in non-diabetic Japanese subjects.

Adiponectin is an adipocyte-secreted protein that is known to modulate insulin sensitivity and glucose homeostasis. A number of genetic variations have been studied. Among them, two single-nucleotide polymorphisms (SNP45T>G, SNP276G>T) showed an association with type 2 diabetes in the Japanese population. In this study, we examined the association between these SNPs and risk factors of type 2 diabetes in 194 non-diabetic Japanese subjects. SNP45 was associated with insulin sensitivity (determined by HOMA-IR, p=0.046) and obesity (body mass index; BMI, p=0.043). SNP276 showed a stronger association with HOMA-IR (p=0.018) and BMI (p=0.017). However, neither SNP had an association with insulin secretion (insulinogenic index) and plasma lipid levels. Moreover, a linkage dis-equilibrium was observed between SNP45 and SNP276. Carriers with SNP45G-SNP276G haplotype had higher BMI (p=0.034) and carriers with SNP45T-SNP276T haplotype had lower BMI (p=0.005) and HOMA-IR (p=0.037). Adiponectin gene variations showed an association with obesity and insulin sensitivity, and adiponectin genotypes may predict the increasing risk for type 2 diabetes in non-diabetic subjects.

Adiponectin↗
PubMed2026

Exploring precision risk in pediatric vesicoureteral reflux: Innate immune gene variations and reflux outcomes in the RIVUR cohort.

INTRODUCTION: Children with vesicoureteral reflux (VUR) are at increased risk for morbidity from recurrent urinary tract infections (UTIs), yet the factors influencing spontaneous VUR resolution remain poorly defined. This study evaluates whether genetic variations in key urinary innate immune effectors (DEFA1A3, DMBT1, and RNASE7) influences VUR resolution and interacts with prophylaxis to alter clinical response. METHODS: We conducted a secondary analysis of 303 RIVUR participants with available DEFA1A3 and DMBT1 copy number variation (CNV) data and RNASE7 rs1263872 genotype. Primary outcomes were (1) VUR improvement (decrease in grade) and (2) VUR resolution at study exit. Multivariable logistic regression models included genotype, treatment, and their interactions, adjusting for age, sex, baseline grade (high vs low), laterality, bowel/bladder dysfunction, and any UTI. Internal validation used 2000-sample bootstrap with bias-corrected and accelerated confidence intervals and influence diagnostics. RESULTS: Clinical covariates did not significantly predict VUR improvement. Children with DEFA1A3 CNV >5 had higher odds of improvement (OR 2.36, 95% CI 1.12-4.96, p = 0.023), an effect that remained significant in bootstrap analyses. High-grade VUR was associated with lower odds of resolution (OR 0.34, 95% CI 0.12-0.94, p = 0.038). A significant interaction was observed between prophylaxis and high DMBT1 copy number for VUR resolution (interaction OR 2.99, 95% CI 1.11-8.04, p = 0.031); no interaction was seen for improvement. RNASE7 rs1263872 was not associated with either outcome. CONCLUSION: Innate immune gene variation may contribute to heterogeneity in VUR outcomes. High DEFA1A3 copy number was associated with reflux improvement and a DMBT1-prophylaxis interaction was associated with reflux resolution. The results of this study is hypothesis-generating and prompt further evaluation to assess whether a subset of children may experience structural benefit from prophylaxis or have a more favorable natural history based on their innate immune genotype.

Humans↗
PubMed2000

Lipoprotein lipase gene variation is associated with adipose tissue lipoprotein lipase activity, and lipoprotein lipid and glucose concentrations in overweight postmenopausal women.

Adipose tissue lipoprotein lipase (LPL) activity is under strong genetic control in both mice and humans. This study determines whether common DNA variation in the LPL gene (PvuII and HindIII polymorphisms) is associated with adipose tissue LPL activity and metabolic risk factors in a homogeneous population of 75 overweight postmenopausal women (body mass index >25 kg/m2; age: 51-69 years old). The allele frequencies for the presence of the cut-sites for LPL HindIII and PvuII were 0.71 and 0.49, respectively. There were no associations between the HindIII polymorphism and any of the measured variables. Age, body mass index, percent body fat, waist-hip ratio, visceral and subcutaneous fat area, and gluteal (GLT) and abdominal (ABD) adipocyte size did not differ by LPL PvuII genotype. However, adipose tissue LPL activity at both GLT and ABD sites was higher in women without the LPL PvuII cut-site (-/-) compared with women who were heterozygous (+/-) or homozygous (+/+) for the cut-site (P<0.05). Total and LDL cholesterol were lower in women without the LPL PvuII cut-site (-/-) compared with women who were heterozygous or homozygous for the cut-site (P<0.05), whereas triglyceride and HDL levels were similar between LPL PvuII genotypes. Fasting glucose, but not insulin, was lower in women without the LPL PvuII cut-site (-/-). These data suggest that the LPL PvuII polymorphism is a possible marker for a functional mutation that is found in the LPL gene and that alters LPL activity in older overweight women.

Adipocytes↗
PubMed1987

Genomic and gene variation in Mycoplasma hominis strains.

DNAs from 14 strains of Mycoplasma hominis isolated from various habitats, including strain PG21, were analyzed for genomic heterogeneity. DNA-DNA filter hybridization values were from 51 to 91%. Restriction endonuclease digestion patterns, analyzed by agarose gel electrophoresis, revealed no identity or cluster formation between strains. Variation within M. hominis rRNA genes was analyzed by Southern hybridization of EcoRI-cleaved DNA hybridized with a cloned fragment of the rRNA gene from the mycoplasma strain PG50. Five of the M. hominis strains showed identical hybridization patterns. These hybridization patterns were compared with those of 12 other mycoplasma species, which showed a much more complex band pattern. Cloned nonribosomal RNA gene fragments of M. hominis PG21 DNA were analyzed, and the fragments were used to demonstrate heterogeneity among the strains. A monoclonal antibody against strain PG21 was produced. The possible presence of the corresponding antigenic epitope in the other 13 M. hominis strains was analyzed by immunoblotting and compared with results of immunoblotting using polyclonal antibodies against PG21.

Antibodies, Bacterial↗
PubMed1992

Phenotype-associated env gene variation among eight related human immunodeficiency virus type 1 clones: evidence for in vivo recombination and determinants of cytotropism outside the V3 domain.

The nucleotide sequences of the env genes of eight phenotypically heterogeneous human immunodeficiency virus type 1 (HIV-1) clones recovered from a single individual within a 3-week period were compared. In addition, the accessory gene sequences for four of these clones were obtained. Variation among most accessory genes was limited. In contrast, pronounced phenotype-associated sequence variation was observed in the env gene. At least three of these clones most likely resulted from genetic recombination events in vivo, indicating that this phenomenon may account for the emergence of proviruses with novel phenotypic properties. Within the env genes of the eight clones, four domains could be defined, the sequence of each of which clustered in two groups with high internal homology but 11 to 30% cluster variation. The extensive env gene variation among these eight clones could largely be explained by the unique manner in which the alleles of these four domains were combined in each clone. Experiments with chimeric proviruses demonstrated that the HIV-1 env gene determined the capacity to induce syncytia and tropism for T-cell lines. Amino acids previously shown to be involved in gp120-CD4 and gp120-gp41 interaction were completely conserved among these eight clones. The finding of identical V3 sequences in clones differing in tropism for primary monocytes and T-cell lines demonstrated the existence of determinants of tropism outside the env V3 region.

Amino Acid Sequence↗