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PubMed1993

Chloroplast DNA diversity among trees, populations and species in the California closed-cone pines (Pinus radiata, Pinus muricata and Pinus attenuata).

The amount, distribution and mutational nature of chloroplast DNA polymorphisms were studied via analysis of restriction fragment length polymorphisms in three closely related species of conifers, the California closed-cone pines-knobcone pine: Pinus attenuata Lemm.; bishop pine: Pinus muricata D. Don; and Monterey pine: Pinus radiata D. Don. Genomic DNA from 384 trees representing 19 populations were digested with 9-20 restriction enzymes and probed with cloned cpDNA fragments from Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] that comprise 82% chloroplast genome. Up to 313 restriction sites were surveyed, and 25 of these were observed to be polymorphic among or within species. Differences among species accounted for the majority of genetic (haplotypic) diversity observed [Gst = 84(+/- 13)%]; nucleotide diversity among species was estimated to be 0.3(+/- 0.1)%. Knobcone pine and Monterey pine displayed almost no genetic variation within or among populations. Bishop pine also showed little variability within populations, but did display strong population differences [Gst = 87(+/- 8)%] that were a result of three distinct geographic groups. Mean nucleotide diversity within populations was 0.003(+/- 0.002)%; intrapopulation polymorphisms were found in only five populations. This pattern of genetic variation contrasts strongly with findings from study of nuclear genes (allozymes) in the group, where most genetic diversity resides within populations rather than among populations or species. Regions of the genome subject to frequent length mutations were identified; estimates of subdivision based on length variant frequencies in one region differed strikingly from those based on site mutations or allozymes. Two trees were identified with a major chloroplast DNA inversion that closely resembled one documented between Pinus and Pseudotsuga.

Chloroplasts↗

PubMed2004

Examination of NRCAM, LRRN3, KIAA0716, and LAMB1 as autism candidate genes.

BACKGROUND: A substantial body of research supports a genetic involvement in autism. Furthermore, results from various genomic screens implicate a region on chromosome 7q31 as harboring an autism susceptibility variant. We previously narrowed this 34 cM region to a 3 cM critical region (located between D7S496 and D7S2418) using the Collaborative Linkage Study of Autism (CLSA) chromosome 7 linked families. This interval encompasses about 4.5 Mb of genomic DNA and encodes over fifty known and predicted genes. Four candidate genes (NRCAM, LRRN3, KIAA0716, and LAMB1) in this region were chosen for examination based on their proximity to the marker most consistently cosegregating with autism in these families (D7S1817), their tissue expression patterns, and likely biological relevance to autism. METHODS: Thirty-six intronic and exonic single nucleotide polymorphisms (SNPs) and one microsatellite marker within and around these four candidate genes were genotyped in 30 chromosome 7q31 linked families. Multiple SNPs were used to provide as complete coverage as possible since linkage disequilibrium can vary dramatically across even very short distances within a gene. Analyses of these data used the Pedigree Disequilibrium Test for single markers and a multilocus likelihood ratio test. RESULTS: As expected, linkage disequilibrium occurred within each of these genes but we did not observe significant LD across genes. None of the polymorphisms in NRCAM, LRRN3, or KIAA0716 gave p < 0.05 suggesting that none of these genes is associated with autism susceptibility in this subset of chromosome 7-linked families. However, with LAMB1, the allelic association analysis revealed suggestive evidence for a positive association, including one individual SNP (p = 0.02) and three separate two-SNP haplotypes across the gene (p = 0.007, 0.012, and 0.012). CONCLUSIONS: NRCAM, LRRN3, KIAA0716 are unlikely to be involved in autism. There is some evidence that variation in or near the LAMB1 gene may be involved in autism.

Autistic Disorder↗

PubMed2006

The ATGL gene is associated with free fatty acids, triglycerides, and type 2 diabetes.

Adipose triglyceride lipase (ATGL) was recently described to predominantly perform the initial step in triglyceride hydrolysis and therefore seems to play a pivotal role in the lipolytic catabolism of stored fat in adipose tissue. In the first study investigating genetic variations within the ATGL gene in humans, 12 polymorphisms identified via sequencing and database search were studied in 2,434 individuals of European ancestry from Utah. These polymorphisms and their haplotypes were analyzed in subjects not taking diabetes medication for association with plasma free fatty acids (FFAs) as primary analysis, as well as triglycerides and glucose as a secondary analysis (n = 1,701, 2,193, or 2,190, respectively). Furthermore, type 2 diabetes (n = 342 of 2,434) was analyzed as an outcome. FFA concentrations were significantly associated with several single nucleotide polymorphisms (SNPs) of ATGL (P values from 0.015 to 0.00003), consistent with additive inheritance. The pattern was similar when considering triglyceride concentrations. Furthermore, two SNPs showed associations with glucose levels (P < 0.00001) and risk of type 2 diabetes (P < 0.05). Haplotype analysis supported and extended the shown SNP association analyses. These results complement previous findings of functional studies in mammals and elucidate a potential role of ATGL in pathways involved in components of the metabolic syndrome.

Adult↗

PubMed2006

Haplotype structures and large-scale association testing of the 5' AMP-activated protein kinase genes PRKAA2, PRKAB1, and PRKAB2 [corrected] with type 2 diabetes.

AMP-activated protein kinase (AMPK) is a key molecular regulator of cellular metabolism, and its activity is induced by both metformin and thiazolidinedione antidiabetic medications. It has therefore been proposed both as a putative agent in the pathophysiology of type 2 diabetes and as a valid target for therapeutic intervention. Thus, the genes that encode the various AMPK subunits are intriguing candidates for the inherited basis of type 2 diabetes. We therefore set out to test for the association of common variants in the genes that encode three selected AMPK subunits with type 2 diabetes and related phenotypes. Of the seven genes that encode AMPK isoforms, we initially chose PRKAA2, PRKAB1, and PRKAB2 because of their higher prior probability of association with type 2 diabetes, based on previous reports of genetic linkage, functional molecular studies, expression patterns, and pharmacological evidence. We determined their haplotype structure, selected a subset of tag single nucleotide polymorphisms that comprehensively capture the extent of common genetic variation in these genes, and genotyped them in family-based and case/control samples comprising 4,206 individuals. Analysis of single-marker and multi-marker tests revealed no association with type 2 diabetes, fasting plasma glucose, or insulin sensitivity. Several nominal associations of variants in PRKAA2 and PRKAB1 with BMI appear to be consistent with statistical noise.

AMP-Activated Protein Kinases↗

PubMed1999

ATP binding cassette transporter retina genotypes and age related macular degeneration: an analysis on exudative non-familial Japanese patients.

AIM: To determine whether mutations in the Stargardt's disease gene, ATP binding cassette transporter retina (ABCR) affect the occurrence of age related macular degeneration (AMD) in Japanese non-familial patients. METHODS: 80 unrelated Japanese patients with AMD (67 males and 13 females; mean age, 67.2 years) diagnosed by indocyanine green angiography and 100 age matched control subjects were studied. Among the AMD patients, 70 (87.5%) had choroidal neovascularisation of exudative type. Genomic DNA was purified from the total blood and 10 exons (exons 11, 23, 29, 32, 34, 37, 41, 43, 44, and 49) that have been reported to contain AMD associated mutations were amplified by polymerase chain reaction (PCR). The amplicons were analysed by the single strand conformation polymorphism (SSCP) method. The nucleotide sequencing of the amplicons was determined when necessary. RESULTS: Of the 10 exons, aberrant patterns of SSCP were detected in three exons-exons 29, 41, and 43. In exon 29, an aberrant pattern was found in seven of 80 patients (8.8%) and eight of 100 controls (8%). Sequencing of the PCR products revealed a heterozygous T1428M mutation which has been previously reported as one of the AMD associated mutations. Statistical analysis showed that there was no significant difference in the occurrence of this mutation between these AMD patients and the control groups (p = 0.86). In exons 23, 41, and 43, polymorphisms and sequence variations were found. CONCLUSION: No data to support the association between the ABCR gene mutations and AMD of Japanese patients, especially that of the exudative type, were obtained in this molecular genetic analysis.

ATP-Binding Cassette Transporters↗

PubMed2000

Molecular evolution and intratumor heterogeneity by topographic compartments in muscle-invasive transitional cell carcinoma of the urinary bladder.

Superficial transitional cell carcinomas (TCC) of the urinary bladder have been shown to be monoclonal. However, no combined study of clonality and tumor suppressor genes (TSG) is available to date for muscle-invasive TCC. Forty-four muscle-invasive TCC of the urinary bladder selected from women were included in this study. Tumor cells located above and below the muscularis mucosa zone were systematically microdissected and used for DNA extraction. Hha-I digested and undigested samples were used to study the methylation pattern of androgen receptor alleles and undigested samples were used for microsatellite analysis of TSG (TP53, RB1, WT1, and NF1). Both loss of heterozygosity (LOH) and single nucleotide polymorphism (SNP) analyses were performed using optimized denaturing gradient gel electrophoresis. The expression of p53, pRB, and p21WAF1 was assessed by immunohistochemistry. Appropriate controls were run in every case. All except two TCC showed a monoclonal pattern with the same allele inactivated in both compartments. Microsatellite analysis of TSG revealed the same LOH/SNP pattern in both tumor compartments in 30 cases (involving more than 1 TSG locus in 8) and genetic heterogeneity in 14 cases. From the latter group, 9 cases expressed more genetic changes in the deep compartment (involving TP53 gene in all cases, WT1 gene in 2, and NF1 in 1), whereas in 4 cases the superficial compartment showed more genetic changes (three involving NF1 and one involving both RB and TP53). No statistical difference in the immunoexpression was detected, although it tended to be higher in the superficial compartment than in the deep compartment. These concordant data in polymorphic DNA regions indicate that bladder-muscle-invasive TCC are monoclonal proliferations with homogeneous tumor cell selection. Heterogeneous tumor cell selection by topography defined two different genetic compartments: superficial, NF1-defective, and deep, TP53-defective. No differences in the immunohistochemical expression were observed, precluding a more extensive clinical application.

Base Sequence↗

PubMed2000

Loss-of-heterozygosity analysis of small-cell lung carcinomas using single-nucleotide polymorphism arrays.

Human cancers arise by a combination of discrete mutations and chromosomal alterations. Loss of heterozygosity (LOH) of chromosomal regions bearing mutated tumor suppressor genes is a key event in the evolution of epithelial and mesenchymal tumors. Global patterns of LOH can be understood through allelotyping of tumors with polymorphic genetic markers. Simple sequence length polymorphisms (SSLPs, or microsatellites) are reliable genetic markers for studying LOH, but only a modest number of SSLPs are used in LOH studies because the genotyping procedure is rather tedious. Here, we report the use of a highly parallel approach to genotype large numbers of single-nucleotide polymorphisms (SNPs) for LOH, in which samples are genotyped for nearly 1,500 loci by performing 24 polymerase chain reactions (PCR), pooling the resulting amplification products and hybridizing the mixture to a high-density oligonucleotide array. We characterize the results of LOH analyses on human small-cell lung cancer (SCLC) and control DNA samples by hybridization. We show that the patterns of LOH are consistent with those obtained by analysis with both SSLPs and comparative genomic hybridization (CGH), whereas amplifications rarely are detected by the SNP array. The results validate the use of SNP array hybridization for tumor studies.

Alleles↗

PubMed1993

Prospects for estimating nucleotide divergence with RAPDs.

The technique of random amplification of polymorphic DNA (RAPD), which is simply polymerase chain reaction (PCR) amplification of genomic DNA by a single short oligonucleotide primer, produces complex patterns of anonymous polymorphic DNA fragments. The information provided by these banding patterns has proved to be of great utility for mapping and for verification of identity of bacterial strains. Here we consider whether the degree of similarity of the banding patterns can be used to estimate nucleotide diversity and nucleotide divergence. With haploid data, fragments generated by RAPD-PCR can be treated in a fashion very similar to that for restriction-fragment data. Amplification of diploid samples, on the other hand, requires consideration of the fact that presence of a band is dominant to absence of the band. After describing a method for estimating nucleotide divergence on the basis of diploid samples, we summarize the restrictions and criteria that must be met when RAPD data are used for estimating population genetic parameters.

Computer Simulation↗

PubMed2000

Molecular variation at the In(2L)t proximal breakpoint site in natural populations of Drosophila melanogaster and D. simulans.

A previous study of nucleotide polymorphism in a Costa Rican population of Drosophila melanogaster found evidence for a nonneutral deficiency in the number of haplotypes near the proximal breakpoint of In(2L)t, a common inversion polymorphism in this species. Another striking feature of the data was a window of unusually high nucleotide diversity spanning the breakpoint site. To distinguish between selective and neutral demographic explanations for the observed patterns in the data, we sample alleles from three additional populations of D. melanogaster and one population of D. simulans. We find that the strength of associations among sites found at the breakpoint varies between populations of D. melanogaster. In D. simulans, analysis of the homologous region reveals unusually elevated levels of nucleotide polymorphism spanning the breakpoint site. As with American populations of D. melanogaster, our D. simulans sample shows a marked reduction in the number of haplotypes but not in nucleotide diversity. Haplotype tests reveal a significant deficiency in the number of haplotypes relative to the neutral expectation in the D. simulans sample and some populations of D. melanogaster. At the breakpoint site, the level of divergence between haplotype classes is comparable to interspecific divergence. The observation of interspecific polymorphisms that differentiate major haplotype classes in both species suggests that haplotype classes at this locus are considerably old. When considered in the context of other studies on patterns of variation within and between populations of D. melanogaster and D. simulans, our data appear more consistent with the operation of selection than with simple demographic explanations.

Animals↗

PubMed2005

Loss of heterozygosity analyzed by single nucleotide polymorphism array in cancer.

Neoplastic progression is generally characterized by the accumulation of multiple genetic alterations including loss of tumor suppression gene function. Loss of heterozygosity (LOH) has been used to identify genomic regions that harbor tumor suppressor genes and to characterize different tumor types, pathological stages and progression. LOH pattern has been detected by allelotyping using restriction fragment length polymorphism, and later by simple sequence length polymorphisms (SSLPs or microsatellite) for 10 years. This paper reviews the detection of LOH by recently developed single nucleotide polymorphism (SNP) arrays (all analyzed by Affymetrix array); furthermore, its advantage and disadvantage were analyzed in several kinds of cancer.

Genes, Tumor Suppressor↗

PubMed2003

Genome-wide genetic characterization of bladder cancer: a comparison of high-density single-nucleotide polymorphism arrays and PCR-based microsatellite analysis.

Most human cancers are characterized by genomic instability, the accumulation of multiple genetic alterations, and allelic imbalance throughout the genome. Loss of heterozygosity (LOH) is a common form of allelic imbalance, and the detection of LOH has been used to identify genomic regions that harbor tumor suppressor genes and to characterize different tumor types, pathological stages and progression. Global patterns of LOH can be discerned by allelotyping of tumors with polymorphic genetic markers. Microsatellites are reliable genetic markers for studying LOH, but typically only a modest number of microsatellites are tested in LOH studies because the genotyping procedure can be laborious. Here we describe the use of a new alternative approach to comprehensive allelotyping in which samples are genotyped for nearly 1500 single-nucleotide polymorphism (SNP) loci distributed across all human autosomal arms. We examined the pattern of allelic imbalance in human transitional cell carcinomas of the urinary bladder including 36 primary tumors and 1 recurrent tumor with matched normal DNAs. The call rate for all SNPs was 78.5 +/- 1.87% overall samples. Overall, the median number of allelic imbalance was 47.5, ranging from 20 to 118. The mean number of allelic imbalances was 36.58, 51.30, and 67.78 for pT(a), pT(1), and > or =pT(2), respectively, and also increased by grade. The SNP microarray analysis result was validated by comparison with microsatellite allelotype analysis of 118 markers in the same tumors. Overall, the two methods produced consistent loss patterns at informative loci. The SNP assay discovered previously undiscovered allelic imbalances at chromosomal arms 12q, 16p, 1p, and 2q. The detection of LOH and other chromosomal changes using large numbers of SNP markers should enable rapid and accurate identification of allelic imbalance patterns that will facilitate the mapping and identification of important cancer genes. Moreover, SNP analysis raises the possibility of individual tumor genome-wide allelotyping with potential prognostic and diagnostic applications.

Carcinoma, Transitional Cell↗

PubMed2005

High level of conservation in Plasmodium vivax merozoite surface protein 4 (PvMSP4).

Plasmodium vivax merozoite surface protein 4 (PvMSP4) has been considered to be a promising malarial vaccine candidate. The antigenic diversity displayed by parasite populations is one of the main factors limiting the efficacy of asexual-stage anti-malarial vaccine candidates. The present study is the first characterising PvMSP4 polymorphism. P. vivax isolates were collected from endemic areas in Colombia and diversity and selection pattern studies were carried out. Overall conservation in this protein was remarkable. Changes were only found in exons I and II, the former only having single nucleotide polymorphisms (SNPs) whilst the latter showed variations in tandem repeat number caused by exon II slippage. The remaining regions (EGF-like domain, GPI anchor and intron) were completely conserved. Selection and neutrality tests carried out over variant exons indicated negative selective forces acting on them. No evidence of intragenic recombination was found. The strong conservation displayed in this molecule by isolates from geographically different regions (Colombia, Salvador and Thailand) stresses its potential importance as a candidate for a vaccine against P. vivax malaria.

Amino Acid Sequence↗

PubMed2003

Simultaneous detection of ACP1 and GC genotypes using PCR/SSCP.

The classical enzyme and protein markers ACP1 and GC have gained new importance because of the biological functions of their gene products. ACP1 encodes a low molecular weight enzyme which is now recognized as a phosphotyrosine phosphatase with a role in the regulation of signal transduction pathways, and GC-globulin acts both as a transporter of vitamin D and as a plasma actin scavenger and plays a role in macrophage activation. These two polymorphisms were phenotyped for decades on the basis of electrophoretic isozyme or protein patterns; the gene structures are now known. Nucleotide substitutions determining the common alleles are close enough at each locus to be contained in one short PCR product. We have developed a simple, rapid and reliable multiplex method based on PCR and SSCP which allows the simultaneous determination of the common ACP1 and GC genotypes.

Alleles↗

PubMed2000

Heterogeneity of the prtC gene of Porphyromonas gingivalis.

In this study, the nucleotide sequences of the prtC genes of six clinical Porphyromonas gingivalis isolates obtained from patients with periodontitis and from reference strain 53977 were determined. All analyzed genes were heterogeneous in their nucleotide composition and differed in up to 13 nucleotides. Moreover, substantial differences were found in comparison to prtC of reference strain 53977. The prtC genes of 45 Porphyromonas gingivalis isolates were amplified by polymerase chain reaction (PCR) and the PCR products were also digested with restriction endonucleases Tsp509I, NlaIII and DraII (PCR-restriction fragment-length polymorphism). Nine different restriction pattern combinations were observed, with four being most frequent (28.9%, 26.7%, 17.8% and 11.1%). The data presented here demonstrates that prtC genes are heterogeneous in their nucleotide sequence and therefore may be used as a target for molecular epidemiological studies. The observed heterogeneity of prtC genes may be a result of microevolution processes.

Bacterial Proteins↗

PubMed2004

Genetic variability and evolution of two pharmacologically important classes of genes.

We have studied the human genetic variability of single nucleotide polymorphisms (SNPs) and haplotypes in two pharmaceutically important classes of genes that might be expected to experience different evolutionary pressures: antigen presentation and processing (APP) and nuclear hormone receptor (NHR) genes. We compared the variation pattern in these two classes of genes with 5119 reference (REF) genes. We assessed this variability by sequencing and discovering SNPs in 5'-upstream, 5'-untranslated region (5'UTR), exon, intron, 3'UTR and 3'-downstream regions of all these genes in 79 unrelated humans from diverse ethnic backgrounds, one chimpanzee (Pan troglodytes) and a gorilla (Gorilla gorilla). SNP density and nucleotide diversity were higher in the APP genes than the REF genes. Relative to the REF genes, APP SNP density was significantly higher in the coding and 3'UTR regions. Higher variation in the coding region of the APP genes was due specifically to having more non-synonymous changes, which suggests that natural selection may be acting to promote change or diversity in these proteins. In contrast, the NHR genes showed lower SNP density and diversity relative to REF genes. The NHR genes consistently showed lower nucleotide diversity in all the genomic regions except in the 3'downstream region. SNP frequency data on the non-synonymous SNPs also suggested that the coding region in the NHR genes is conserved to a higher degree than the coding region in the REF genes. Significantly lower SNP density was observed in the 5'-upstream and 5'UTR regions of the NHR genes, perhaps reflecting selective conservation of these regions. Heterozygosity in the APP genes was significantly higher than in the NHR genes in each of the three species tested. Moreover, between species there were more fixed differences in the APP genes than in the NHR genes. Substantial variability exists in these two classes of genes. It is important to consider this interindividual variability pattern while developing drugs that act on such targets.

Alleles↗

PubMed2001

Analysis of Korean strains of infectious laryngotracheitis virus by nucleotide sequences and restriction fragment length polymorphism.

Korean field strains of infectious laryngotracheitis virus (ILTV) were analyzed by comparison of nucleotide sequences of thymidine kinase (TK) and glycoprotein G (gG) genes and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) patterns. Main differences among TK gene sequence were found in both amino acid at 252 and mRNA polyadenylation signals. In virulent strains, amino acid 252 of TK gene was methionine but was threonine in low virulence and vaccine strains. The mRNA polyadenylation signals of TK gene were identified at 24bp downstream from the stop codon in virulent strains, but not in low virulence and vaccine strains. The gG gene of all virulent strains showed the same nucleotide sequence except for N87278 which had a gG gene sequence identical to that of vaccine strains. The virulent ILTV strains differed from low virulence and vaccine strains in PCR-RFLP patterns of TK and gG genes. The RFLP patterns of TK and gG genes of low virulence ILTV strains were identical to those of vaccine strains. In the case of N87278, the PCR-RFLP patterns of TK and gG genes were identical to those of virulent and vaccine strains of ILTV, respectively. From these results, ILTV field strains were classified into three groups according to sequences of TK and gG genes and PCR-RFLP, and the virulent ILTV strains could be discriminated from low virulence and vaccine strains by PCR-RFLP of TK gene. And it was suspected that N87278 might be produced by in vivo recombination between virulent and vaccine strains of ILTV.

Amino Acid Sequence↗

PubMed2001

DNA variation in the 5' upstream region of the Adh locus of the wild plants Arabidopsis thaliana and Arabis gemmifera.

To investigate the level and pattern of DNA polymorphism in the noncoding regulatory region in the plant nuclear genome, 2.4 kb of nucleotide sequence of the 5' upstream region of ADH: was determined for 14 ecotypes of Arabidopsis thaliana and five accessions of Arabis gemmifera. Using this data set and previously determined ADH: sequence data, DNA variation was analyzed in a 4.4-kb region of the locus. Two divergent sequence types detected in the transcriptional unit of ADH: were not present in the 5' region of the ADH: gene in A. thaliana. Nucleotide diversity of the entire 5' region was estimated to be 0.0040, which is lower than that in the transcriptional unit. The level of variation was not uniform. There were peaks of variations in a approximately 400-bp region where cis-regulatory elements for ADH: expression were clustered and in exon 4. In interspecific comparison with A. gemmifera, lower divergence was observed in the 5' flanking region than in the exons. High peaks of divergence in the 400-bp regulatory region and exon 4 were also detected, although there were many other peaks. These results indicate that regions of functional importance have a high level of polymorphism and divergence in the ADH: locus of these genera. The possibility of balancing selection in the ADH: gene of these plants is discussed.

5' Untranslated Regions↗

PubMed1997

Nucleotide polymorphism in the acidic chitinase locus (ChiA) region of the wild plant Arabidopsis thaliana.

To investigate DNA variation in natural plant populations, a 1.8-kb region of the acidic chitinase locus (ChiA)was analyzed for 17 ecotypes of Arabidopsis thaliana sampled worldwide and 3 Arabis species in Japan. As in the Adh region, dimorphism was detected throughout the investigated ChiA region, suggesting the possibility that dimorphic DNA variation exists in the entire nuclear genome of A. thaliana. The ChiA region was divided into two blocks by an intragenic recombination between two parental sequence types, which diverged 7.4 MYA under the assumption that nucleotide mutation rate per site per year is mu = 10(-9). Nucleotide diversity in the entire ChiA region was 0.0104. Tajima's test was significantly negative for both nucleotide and indel variations, which was manifested as an excess of unique polymorphisms. However, the level and pattern of polymorphism in the ChiA region were inconsistent with simple theoretical explanations. The HKA test detected no difference in the levels of intra- and interspecific variations between the ChiA and Adh regions. In the ChiA coding region, no difference in the patterns of synonymous and replacement variation was found in intra- and interspecific comparisons by the MK test. Although it was difficult to determine the exact genetic mechanism acting on the ChA locus, these results suggested that the ChA locus region was under the same genetic mechanism before and after the establishment of A. thaliana as a species.

Alcohol Dehydrogenase↗