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At least 685 records · Page 38Linked to original sources
PubMed1989

Restriction-map variation associated with the G6PD polymorphism in natural populations of Drosophila melanogaster.

Restriction-map variation was studied in 126 copies of the G6pd region in X chromosome lines of Drosophila melanogaster from North America, Europe, and Africa. Special attention was focused on the distribution of variation relative to the geographically variable polymorphism for two electrophoretic variants. Nucleotide heterozygosity as determined by eight six-cutter restriction enzymes for the 13-kb region is estimated, on the basis of the worldwide sample, to be 0.065%, which is the lowest value reported for any comparable region in the D. melanogaster genome. Significant linkage disequilibrium between electrophoretic alleles and restriction-site variation is observed for several sites. In contrast to published studies of other genetic regions, there are large insertions that reach significant frequencies and are found across considerable geographic distances. There is a clustering of this variation inside the first large intervening sequence of the G6PD gene.

Africa↗
PubMed2006

Hydrated Cs+-exchanged MFI zeolites: location and population of Cs+ cations and water molecules in hydrated Cs6.6MFI from in and ex situ powder X-ray diffraction data as a function of temperature and other experimental conditions.

Extending our previous investigation of dehydrated, Cs-exchanged MFI zeolites (J. Phys. Chem. B 2006, 110, 97-106) to hydrated analogues, we have determined the crystal structures of members of the Cs(6.6)H(0.3)MFI.xH(2)O series, for 0 < x < 28, from synchrotron-radiation powder diffraction data. In the fully hydrated phase, three independent Cs(+) cations and six water molecules are identified in difference Fourier maps. The populations of the cations amount to 2.79/3.40/0.41 Cs/unit cell (uc) for the Cs1/Cs2/Cs3 sites, respectively, and those of the water molecules to 4/4/4/4/8/4 H(2)O/uc for the Ow1/Ow2/Ow3/Ow4/Ow5/Ow6 sites, respectively. Close to water saturation, the Cs3 and Ow6 sites are near each other (approximately 1.44 A) and are not occupied simultaneously. At saturation, Cs cations and water molecules form three interconnected Cs(H(2)O)(n) clusters and one (H(2)O)(4) cluster in the MFI channel system: Cs2(H(2)O)(5) centered at x/y/z approximately -0.018/0.146/0.546 (midway between the intersection and the straight channels), Cs1(H(2)O)(4) centered at approximately 0.056/0.240/0.889 (the zigzag channel openings), Cs3(H(2)O)(2) centered at approximately 0.228/0.25/0.899 (in the zigzag channel), and the (H(2)O)(4) cluster (in the zigzag channel) bonded to Cs1 and Ow1. (H(2)O)(4) and Cs3(H(2)O)(2) exclude each other. The Cs2(H(2)O)(5) clusters are connected through weak Ow5...Ow5' hydrogen bonds (2.88 A) and form polymeric chains in the straight channel direction (010). During progressive hydration this Cs2 cation enlarges its hydration shell, stepwise, from Cs2(H(2)O)(2) to Cs2(H(2)O)(3), to Cs2(H(2)O)(4), and finally to a Cs2(H(2)O)(5) cluster. During the dehydration process, these extraframework species migrate, and it is shown that for varying total H(2)O/uc loadings the individual populations of the Cs(+) cations and H(2)O molecules strongly depend on experimental and measurement (in situ vs ex situ) conditions. The shapes of the channels change also; except for T > 150 degrees C, in all the Cs(6.6)H(0.3)MFI.xH(2)O phases, the straight channel D10R (double 10-ring) pore openings (1.16 < epsilon < 1.23) become strongly elliptical. The framework structure of all the investigated phases conforms to orthorhombic Pnma space group symmetry. Hydration and dehydration in Cs(6.6)MFI are fully reversible processes. From a knowledge of the Cs(+) locations, we are able to estimate, by computer simulations, the positions of H(2)O molecules in Cs(6.6)H(0.3)MFI.28H(2)O. The maximum theoretically possible water loading in an hypothetical and idealized cationless [Cs(6.6)H(0.3)]MFI structure amounts to 48 H(2)O/uc (nine independent water species), which is in fair agreement with existing high-pressure data (47 H(2)O/uc). This value is to be compared with the water saturation capacity obtained in a structural refinement of sealed-tube diffraction data of a proton-exchanged H(6.9)MFI.38H(2)O (seven independent water molecules). In the crystal structure of this H-ZSM-5 phase, the straight channel openings are almost circular (epsilon = 1.08). From this we conclude that the main factor responsible for the flexibility of the MFI framework is the presence of the Cs(H(2)O)(n)() clusters residing in, or close to, the straight channel double 10-rings.

Journal Article↗
PubMed2006

Genetic mapping of the bean golden yellow mosaic geminivirus resistance gene bgm-1 and linkage with potyvirus resistance in common bean (Phaseolus vulgaris L.).

Bean golden yellow mosaic virus (BGYMV) is a whitefly-transmitted geminivirus of the Begomovirus family that causes important yield losses to common beans grown in tropical and sub-tropical countries of Latin America and the Caribbean. A major resistance gene that has been widely deployed in this region is the recessive locus bgm-1 that prevents the development of severe yellowing typical of the disease. In this study, we developed a co-dominant sequence-characterized amplified region (SCAR) marker, SR2, based on a previously identified random amplified polymorphic DNA (RAPD) marker that is tightly linked to the bgm-1 resistance gene and identified the position of the locus in the common bean genome through comparative mapping using two genetic maps for the species. The SR2 marker was mapped relative to bgm-1 in a segregating population of recombinant inbred lines developed from the resistant x susceptible cross of DOR476 x SEL1309. Polymorphism was shown to be based on a 37 bp insertion event in the SR2 allele associated with susceptibility compared to the allele associated with resistance and the marker mapped at a distance of 7.8 cM from the resistance gene. The SR2 marker was significantly associated with overall disease symptoms and with three of the four symptoms associated with the disease (yellowing or chlorosis, flower abortion, foliar deformation) in a greenhouse trial in Colombia with the mechanically transmissible BGYMV-Guatemala strain. In both the DOR364 x G19833 and BAT93 x Jalo EEP558 mapping populations, SR2 was located near the end of linkage group b03 (chromosome 5) suggesting a sub-telomeric position. The position of the bgm-1 resistance gene was estimated to be close to that of bc-1, a strain-specific resistance gene for Bean common mosaic virus (BCMV), based on linkage of SR2 with the SCAR marker SBD5 in the DOR364 x G19833 mapping population. The implications of linkage between these two recessive resistance genes are discussed, as this is the first association between resistance genes against both a begomovirus and a potyvirus.

Base Sequence↗
PubMed1998

A mixture model approach to the mapping of quantitative trait loci in complex populations with an application to multiple cattle families.

A mixture model approach is presented for the mapping of one or more quantitative trait loci (QTLs) in complex populations. In order to exploit the full power of complete linkage maps the simultaneous likelihood of phenotype and a multilocus (all markers and putative QTLs) genotype is computed. Maximum likelihood estimation in our mixture models is implemented via an Expectation-Maximization algorithm: exact, stochastic or Monte Carlo EM by using a simple and flexible Gibbs sampler. Parameters include allele frequencies of markers and QTLs, discrete or normal effects of biallelic or multiallelic QTLs, and homogeneous or heterogeneous residual variances. As an illustration a dairy cattle data set consisting of twenty half-sib families has been reanalyzed. We discuss the potential which our and other approaches have for realistic multiple-QTL analyses in complex populations.

Animals↗
PubMed1991

The status of transmission of Trypanosoma cruzi in an endemic area of Argentina prior to control attempts, 1985.

A field survey of transmission of Trypanosoma cruzi was carried out in an area which had never been sprayed with insecticide. A population census, mapping and house classification, examination of insects in houses, and a human serological survey were performed. The entomological examination showed that 97% of the houses (433/445) were infested by Triatoma infestans and that 31% of the bugs examined were infected with T. cruzi. The level of infection, as well as the number of insects captured, had no apparent relationship with the type of house. Trypanosoma cruzi was found in 30% of the human population, and in 10% of children up to four years old. The rates of infection were significantly lower for inhabitants, especially children, living in 'urban' houses. The prevalence rate for the children did not correlate with the number of insects collected in the houses. The improvement of houses, outside the framework of an integrated control programme, had no obvious impact on the level of transmission. Nevertheless, the replacement of the original houses by houses with plastered walls and roofs of metal or cement resulted in a decrease in the prevalence of infection in children younger than four years of age. The community showed little confidence in sanitary precautions against Chagas' disease prior to the start of the survey.

Age Factors↗
PubMed2005

Genetic mapping of new cotton fiber loci using EST-derived microsatellites in an interspecific recombinant inbred line cotton population.

There is an immediate need for a high-density genetic map of cotton anchored with fiber genes to facilitate marker-assisted selection (MAS) for improved fiber traits. With this goal in mind, genetic mapping with a new set of microsatellite markers [comprising both simple (SSR) and complex (CSR) sequence repeat markers] was performed on 183 recombinant inbred lines (RILs) developed from the progeny of the interspecific cross Gossypium hirsutum L. cv. TM1 x Gossypium barbadense L. Pima 3-79. Microsatellite markers were developed using 1557 ESTs-containing SSRs (> or = 10 bp) and 5794 EST-containing CSRs (> or = 12 bp) obtained from approximately 14,000 consensus sequences derived from fiber ESTs generated from the cultivated diploid species Gossypium arboreum L. cv AKA8401. From a total of 1232 EST-derived SSR (MUSS) and CSR (MUCS) primer-pairs, 1019 (83%) successfully amplified PCR products from a survey panel of six Gossypium species; 202 (19.8%) were polymorphic between the G. hirsutum L. and G. barbadense L. parents of the interspecific mapping population. Among these polymorphic markers, only 86 (42.6%) showed significant sequence homology to annotated genes with known function. The chromosomal locations of 36 microsatellites were associated with 14 chromosomes and/or 13 chromosome arms of the cotton genome by hypoaneuploid deficiency analysis, enabling us to assign genetic linkage groups (LG) to specific chromosomes. The resulting genetic map consists of 193 loci, including 121 new fiber loci not previously mapped. These fiber loci were mapped to 19 chromosomes and 11 LG spanning 1277 cM, providing approximately 27% genome coverage. Preliminary quantitative trait loci analysis suggested that chromosomes 2, 3, 15, and 18 may harbor genes for traits related to fiber quality. These new PCR-based microsatellite markers derived from cotton fiber ESTs will facilitate the development of a high-resolution integrated genetic map of cotton for structural and functional study of fiber genes and MAS of genes that enhance fiber quality.

Aneuploidy↗
PubMed1989

Restriction-map variation at the zeste-tko region in natural populations of Drosophila melanogaster.

Restriction-map variation in 64 X chromosome lines extracted from three different natural populations of Drosophila melanogaster was investigated with seven six-nucleotide-recognizing enzymes for a 20-kb region including the zeste and tko genes. Ten restriction-site and four length polymorphisms (two insertions and two deletions) were detected. Contrary to the predicted lower level of variation for genes on the X chromosome, the level of variation attributable to nucleotide substitution (estimated heterozygosity/nucleotide = 0.004) was similar to that previously reported for autosomal loci. The amount of insertion/deletion variation in the studied region was within the range observed in autosomal regions and thus not explainable by a simple selection model against the effects of insertional mutations. A general lack of linkage disequilibrium between polymorphic sites was observed.

Animals↗
PubMed2002

Genomewide linkage disequilibrium mapping of severe bipolar disorder in a population isolate.

Genomewide association studies may offer the best promise for genetic mapping of complex traits. Such studies in outbred populations require very densely spaced single-nucleotide polymorphisms. In recently founded population isolates, however, extensive linkage disequilibrium (LD) may make these studies feasible with currently available sets of short tandem repeat markers, spaced at intervals as large as a few centimorgans. We report the results of a genomewide association study of severe bipolar disorder (BP-I), using patients from the isolated population of the central valley of Costa Rica. We observed LD with BP-I on several chromosomes; the most striking results were in proximal 8p, a region that has previously shown linkage to schizophrenia. This region could be important for severe psychiatric disorders, rather than for a specific phenotype.

Bipolar Disorder↗
PubMed1988

A cladistic analysis of phenotype associations with haplotypes inferred from restriction endonuclease mapping. II. The analysis of natural populations.

Genes that code for products involved in the physiology of a phenotype are logical candidates for explaining interindividual variation in that phenotype. We present a methodology for discovering associations between genetic variation at such candidate loci (assayed through restriction endonuclease mapping) with phenotypic variation at the population level. We confine our analyses to DNA regions in which recombination is very rare. In this case, the genetic variation at the candidate locus can be organized into a cladogram that represents the evolutionary relationships between the observed haplotypes. Any mutation causing a significant phenotypic effect should be imbedded within the same historical structure defined by the cladogram. We showed, in the first paper of this series, how to use the cladogram to define a nested analysis of variance (NANOVA) that was very efficient at detecting and localizing phenotypically important mutations. However, the NANOVA of haplotype effects could only be applied to populations of homozygous genotypes. In this paper, we apply the quantitative genetic concept of average excess to evaluate the phenotypic effect of a haplotype or group of haplotypes stratified and contrasted according to the nested design defined by the cladogram. We also show how a permutational procedure can be used to make statistical inferences about the nested average excess values in populations containing heterozygous as well as homozygous genotypes. We provide two worked examples that investigate associations between genetic variation at or near the Alcohol dehydrogenase (Adh) locus and Adh activity in Drosophila melanogaster, and associations between genetic variation at or near some apolipoprotein loci and various lipid phenotypes in a human population.

Alcohol Dehydrogenase↗
PubMed2005

Wheat genome structure: translocations during the course of polyploidization.

The genomic organization of Triticum timopheevii (2n=28, AtAtGG) was compared with hexaploid wheat T. aestivum (2n=42, AABBDD) by comparative mapping using microsatellites derived from bread wheat. Genetic maps for the two crosses T. timopheevii var. timopheevii x T. timopheevii var. typica and T. timopheevii K-38555xT. militinae were constructed. On the first population, 121 loci were mapped, and on the second population 103 loci. The transferability of the wheat markers to T. timopheevii was generally better for the A genome-specific markers (76-78% produced amplification products; 26 and 29% were polymorphic) than for B genome-specific markers (54% produced amplification products; 14 and 16% were polymorphic). Of the D genome-specific markers, one third produced amplification products in T. timopheevii, but only 5 and 2% were polymorphic in the corresponding mapping populations. The maps constructed confirmed the previously described translocation between chromosome arms 6AtS and 1GS and revealed at least two yet unknown rearrangements on chromosomes 4At and 6At09. The presence of other translocations and rearrangements between T. timopheevii and T. aestivum was demonstrated by a variety of markers mapping to nonhomoeologous positions.

Chromosome Mapping↗
PubMed2005

A comparison of linkage disequilibrium patterns and estimated population recombination rates across multiple populations.

Large-scale studies of linkage disequilibrium (LD) have shown considerable variation in the extent and distribution of pairwise LD within and between populations. Taken at face value, these results suggest that genomewide LD maps for one population may not be generalizable to other populations. However, at least part of this diversity is due to some undesirable features of pairwise LD measures, which are well documented for the D' and r2 measures. In this report, we compare patterns of LD derived from pairwise measures with statistical estimates of population recombination rates ( rho ) along a 10-Mb stretch of chromosome 20 in four population samples, comprising East Asians, African Americans, and U.K. and U.S. individuals of western European descent. The results reveal the expected variability of D' within and between populations but show better concordance in estimates of r2 for the same markers across the population samples. Estimates of rho correlate well across populations, but there is still evidence of population-specific spikes and troughs in rho values. We conclude that it is unlikely that a single haplotype map will provide a definitive guide for association studies of many populations; rather, multiple maps will need to be constructed to provide the best-possible guides for gene mapping.

Black or African American↗
PubMed1996

Adherence of Helicobacter pylori to areas of incomplete intestinal metaplasia in the gastric mucosa.

BACKGROUND & AIMS: Helicobacter pylori is not usually found in areas of intestinal metaplasia. Thus, the development of intestinal metaplasia has been viewed as a mechanism by which the stomach eliminates H. pylori. The aim of this study was to evaluate the frequency of H. pylori adherence to intestinal metaplasia in different populations. METHODS: Mapped gastric biopsy specimens from 378 H. pylori-positive subjects from various geographical regions were examined. Intestinal metaplasia was typed by staining with periodic acid-Schiff/alcian blue and high-iron diamine/alcian blue. RESULTS: In 32 patients, H. pylori was found in intimate contact with intestinal metaplasia. This was documented by electron microscopy. All areas of intestinal metaplasia showing adherence contained sulfomucins and had no brush border. Posttreatment biopsy specimens from 4 patients whose infection was not cured showed persistence of H. pylori in intestinal metaplasia. CONCLUSIONS: These patients may have a strain of H. pylori with unusual adhesion characteristics, or their type of intestinal metaplasia may have biochemical properties that make it hospitable for H. pylori. The exclusive association of H. pylori adherence with incomplete intestinal metaplasia (a putative precursor of carcinoma) and its greater frequency in Koreans (a population at risk for gastric cancer) suggest that this phenomenon may play a role in the hypothetical sequence metaplasia > dysplasia > carcinoma.

Bacterial Adhesion↗
PubMed2000

A simple sequence repeat-based linkage map of barley.

A total of 568 new simple sequence repeat (SSR)-based markers for barley have been developed from a combination of database sequences and small insert genomic libraries enriched for a range of short simple sequence repeats. Analysis of the SSRs on 16 barley cultivars revealed variable levels of informativeness but no obvious correlation was found with SSR repeat length, motif type, or map position. Of the 568 SSRs developed, 242 were genetically mapped, 216 with 37 previously published SSRs in a single doubled-haploid population derived from the F(1) of an interspecific cross between the cultivar Lina and Hordeum spontaneum Canada Park and 26 SSRs in two other mapping populations. A total of 27 SSRs amplified multiple loci. Centromeric clustering of markers was observed in the main mapping population; however, the clustering severity was reduced in intraspecific crosses, supporting the notion that the observed marker distribution was largely a genetical effect. The mapped SSRs provide a framework for rapidly assigning chromosomal designations and polarity in future mapping programs in barley and a convenient alternative to RFLP for aligning information derived from different populations. A list of the 242 primer pairs that amplify mapped SSRs from total barley genomic DNA is presented.

Chromosome Mapping↗
PubMed1979

The molecular basis of alpha-thalassemias: frequent occurrence of dysfunctional alpha loci among non-Asians with Hb H disease.

Study of Asians has previously indicated that deletion of alpha-globin structural genes is the predominant lesion in alpha-thalassemias and that Hb H disease occurs when three of four normal alpha loci per cell are deleted. To test the generality of this model, Hb H disease DNAs of both Asian and non-Asian origin were analyzed by restriction endonuclease mapping using the technique of Southern (1975). Whereas in normal DNA, alpha sequences are present in a single Eco Rl fragment of cellular DNA approximately 22.5 kb long, fragments of 22.5, 20 and 2.6 kb were found in various Hb H disease DNAs. The 20 kb Eco Rl fragment alone, in which a single alpha-globin structural locus resides, was found in Asian Hb H disease DNA. This finding is consistent with the deletion model of alpha-thalassemia. In contrast, seven of eight non-Asian Hb H disease DNAs displayed a more complex molecular composition. The fragment patterns observed were 22.5 kb alone, 22.5 plus 2.6 kb, 20 plus 2.6 kb and 20 kb alone. Non-Asian Hb H disease DNAs contained one, two or three alpha loci per cell in contrast to the one locus predicted by the simple deletion model of alpha-thalassemia. The data are best explained by the existence of defective alpha loci in certain individuals with alpha-thalassemia, particularly outside the Asian population. Restriction mapping of the 20 kb Eco Rl fragment found in Asian and some non-Asian Hb H disease DNAs demonstrated a striking similarity in the placement of restriction sites about the single alpha gene compared with sites about the two genes in the 22.5 kb Eco Rl fragment seen in normal DNA. These data are consistent with origin of the 20 kb fragment from the 22.5 kb normal Eco Rl fragment by either unequal crossing-over or a deletion event. The molecular heterogeneity and frequent occurrence of defective alpha loci in non-Asian Hb H disease DNAs described here may explain, in part, the clinical heterogeneity of alpha-thalassemias and the absence of the homozygous deletion state (hydrops fetalis) in non-Asians. Further study of cellular DNA fragments containing the defective alpha loci identified in this work may indicate the types of specific mutations responsible for abnormal globin gene expression and complement similar studies on abnormal beta genes in beta-thalassemias.

Asia↗
PubMed2002

Application of non-parametric bootstrap methods to estimate confidence intervals for QTL location in a beef cattle QTL experimental population.

Empirical confidence intervals (CIs) for the estimated quantitative trait locus (QTL) location from selective and non-selective non-parametric bootstrap resampling methods were compared for a genome scan involving an Angus x Brahman reciprocal fullsib backcross population. Genetic maps, based on 357 microsatellite markers, were constructed for 29 chromosomes using CRI-MAP V2.4. Twelve growth, carcass composition and beef quality traits (n = 527-602) were analysed to detect QTLs utilizing (composite) interval mapping approaches. CIs were investigated for 28 likelihood ratio test statistic (LRT) profiles for the one QTL per chromosome model. The CIs from the non-selective bootstrap method were largest (87 7 cM average or 79-2% coverage of test chromosomes). The Selective II procedure produced the smallest CI size (42.3 cM average). However, CI sizes from the Selective II procedure were more variable than those produced by the two LOD drop method. CI ranges from the Selective II procedure were also asymmetrical (relative to the most likely QTL position) due to the bias caused by the tendency for the estimated QTL position to be at a marker position in the bootstrap samples and due to monotonicity and asymmetry of the LRT curve in the original sample.

Animals↗
PubMed2005

Towards an expanded linkage map and exploration on co-dominant scoring of AFLPs in maize.

Simple sequence repeats (SSRs) and amplified fragment length polymorphisms (AFLPs) have become the most important markers for molecular mapping. Primarily based on restriction fragment length polymorphism (RFLP) markers, extensive linkage maps of maize had been developed. To construct a near-saturated genetic linkage map, an expanded maize genetic linkage map was constructed using a population of 234 F2 individuals derived from a cross of X178 and B73 base on an essential SSR framework map of maize. The level of polymorphisms and genetic properties of SSR and AFLP markers were characterized. A total of 249 markers consisting of 130 SSRs and 119 AFLPs have been landed on 10 chromosomes of maize. The 249-locus map spanned 1 659.3 centi-morgans (cM) and had a mean density of 6.66 cM. This mapping population and related information should connect further research involving analysis of quantitative trait loci, comparative genomics, and heterosis. Moreover, in many studies, AFLPs were analyzed on the basis of the presence or absence of a band on the electrophoresis gels. A new method based on double polymorphic bands of co-dominant scoring of AFLPs was explored according to the similarity of loci amplified from AFLP enzyme combination.

Amplified Fragment Length Polymorphism Analysis↗
PubMed2002

[Analysis of gene loci and epistasis for drought tolerance in seedling stage of rice (Oryza sativa L.)].

Drought tolerance of rice is important because a considerable proportion of the world rice area is not irrigated and is prone to water deficit. In this study, an indica variety, Zhai Ye Qing 8 (ZYQ8), and a japonica variety, Jing Xi 17 (JX17), and their double haploid (DH) population were used for genetic study of drought tolerance. Water supply was stopped in seedling period for 15 days and then drought tolerance of the DH population and their parents were investigated. Mapping quantitative trait loci (QTLs) was undertaken base on the constructed molecular linkage map of this population. Two QTLs (qDR-5 and qDR-12) for drought tolerance were identified, they were in the region of GA41-GA257 on chromosome 5 and RG457-Y12817R on chromosome 12, respectively. The tolerance alleles of both QTLs were from the indica parent, ZYQ8. In the meantime two genes for drought tolerance near GA257 and Y12817R were detected too by using Epistat software, that is in accordance with the result by using Mapmaker/QTL. In addition, three loci (RG541, G318 and G192 on chromosome 1, 4 and 8, respectively) were found interacting with GA257 by Epistat software, while one locus (CT234 on chromosome 3) found interacting with Y12817R were also detected by Epistat software.

Chromosome Mapping↗
PubMed1999

Computing probabilities of homozygosity by descent.

A person is autozygous at a locus if the person inherits the same allele twice identical by descent along two distinct paths from the same ancestor. Autozygosity is a common cause of recessive diseases in inbred populations. Homozygosity mapping uses this fact to locate the genes that cause recessive diseases. The probability of autozygosity can be used to estimate the probability of a true positive and of a false positive in homozygosity mapping. Thompson [1994] and Guo [1997] therefore studied the problem of computing the prior, unconditional (multilocus) probability of autozygosity (MPA). I consider a different quantity: the interval probability of autozygosity (IPA). The two measures are identical in the single-locus case. IPA has two notable advantages over MPA: 1. IPA does not include the possibility of heterozygous regions between the homozygous markers. 2. IPA can be computed in time that is polynomial in the pedigree size. My polynomial-time algorithm for the single-locus case solves a problem mentioned by Guo. I implemented a program to compute the IPA. The contribution of this work is the application of basic, abstract methods from computer science to address a problem in genetics.

Algorithms↗