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PubMed1995

Does incest cause homosexuality?

A random sample of 5,182 adults from 6 U.S. metropolitan areas were questioned about incestuous sexual relationships during childhood. Incest was disproportionately reported by both male and female bisexuals and homosexuals. 148 gays (7.7% of the sample) reported 14 (50%) of same-sex, and 7 (22%) of opposite-sex incestuous experiences, and 20 (69%) of same-sex and 2 (3%) of opposite-sex sexual experiences with other relatives. 88 lesbians (3% of the sample) reported 2 (33%) of same-sex incest and 7 (9%) of opposite-sex incest and 1 (17%) of same-sex and 10 (13%) of opposite-sex sexual experiences with other relatives. 12% of 98 male homosexuals vs 0.8% of 1,224 male heterosexuals with a brother reported brother-brother incest. These findings are consonant with those of other studies in which disproportionately more incest by homosexuals was reported. As opposed to an evolutionary genetic hypothesis, these data support the alternative that homosexuality may be learned, since homosexuals do not produce children at sustainable levels and the incidence of homosexuality varies as a function of various social factors. Incest cannot be excluded as a significant basis for homosexuality.

Adolescent↗
PubMed2003

Pseudomonas aeruginosa lectin PA-IIL as a powerful probe for human and bovine milk analysis.

Milk composition exhibits species-specific differences depending on genetic, evolutionary, and environmental factors. In addition, commercial milk preparations are also changed by industrial manipulations, including severe heat processing. Cow milk, used as human food, provides important nutrients but lacks some essential components that are present in raw human milk. The present study, which was aimed at comparing infant breastfeeding to cow-based formula nourishment, shows major differences between the human and the commercial cow milk glycans detectable by the lectins PA-IL (galactose-binding) and PA-IIL (fucose and mannose-binding) isolated from the cells of human pathogen Pseudomonas aeruginosa. More than 40 human milk samples, several cow milks, and bovine milk-based infant formulas, were examined using these two lectins. For purposes of comparison, the plant lectins Concanavalin A (Con A), which binds mannose, and Ulex europaeus 1st lectin (UEA-I), which binds fucose, were also used. The most prominent difference was revealed using PA-IIL, which displayed a unique high sensitivity to the human milk fucosylated compounds. PA-IL and UEA-I also exhibited preferential sensitivity to the human milk but considerably lower than that of PA-IIL. Con A was inhibited by human and the other milk preparations examined to the same extent. These findings indicate the superb applicability of PA-IIL for rapid and reliable comparative investigation of milk glycans from human and cow, indicating which glycans could be added to infant formulas in order to enrich them, as well as for verification and quality control of otherwise improved bovine milk-based infant formulas.

Adhesins, Bacterial↗
PubMed2025

Genome-Wide Identification of the TIFY Family in Cannabis sativa L. and Its Potential Functional Analysis in Response to Alkaline Stress and in Cannabinoid Metabolism.

TIFY transcription factors play crucial regulatory roles in secondary metabolism and stress response. However, the expression patterns of the Cannabis sativa L. TIFY gene family under alkali stress, their involvement in cannabinoid metabolism, and their underlying genetic evolutionary mechanisms remain largely unexplored. In this study, we used bioinformatics approaches to conduct genome-wide identification and functional characterization of the C. sativa TIFY gene family. Fourteen TIFY genes were identified and mapped onto seven chromosomes. These genes were classified into four subfamilies: TIFY, JAZ, ZML, and PPD, with the JAZ subfamily further subdivided into five distinct branches. Collinearity analysis suggested that gene duplication events contributed to the expansion of the TIFY gene family in C. sativa. Weighted gene coexpression network analysis (WGCNA) revealed that CsJAZ2, CsJAZ3, and CsJAZ6 participated in the cannabinoid regulatory network. Cis-element analysis indicated that the promoter regions of TIFY genes were enriched in hormone- and stress-responsive elements. Furthermore, transcriptome and RT-qPCR analyses were conducted to examine gene expression patterns under alkaline stress (the RNA employed in RT-qPCR was extracted from the apical leaves of samples subjected to short-duration alkaline stress treatment). The results showed that CsJAZ5 and CsJAZ6 were downregulated, whereas CsPPD1, CsTIFY1, and CsZML1 were upregulated in response to alkali stress. In summary, CsJAZ5, CsPPD1, and CsTIFY1 may serve as candidate genes for the development of alkali-tolerant cultivars, while CsJAZ2 and CsJAZ3 may be valuable targets for enhancing cannabinoid production. This study provides important molecular insights and a theoretical basis for future research on the evolutionary dynamics and functional roles of TIFY transcription factors, particularly in stress adaptation and cannabinoid metabolism.

Cannabis↗
PubMed1999

A research programme for testing the biological homology concept.

The classical homology concept has served as a heuristic principle for organizing the enormous wealth of information on comparative anatomical patterns across a wide range of organisms. However, the classical homology concept reaches its limit as knowledge of the evolutionary, genetic and developmental processes that underlie these anatomical patterns increases. The biological homology concept places the known anatomical patterns into a mechanistic context and asserts that character identity is based on common variational properties in this chapter a research programme for testing the biological homology concept that involves the following steps is outlined: (1) identifying of two or more putative homologues is a clade; (2) determining the phylogenetic distribution of the putative homologues; (3) describing the intra- and interspecific variation patterns of each putative homologue; (4) describing the development of each putative homologue, and determining if modes of development and distribution of homologues are phylogenetically congruent; and (5) providing and testing a model of how differences in modes of development between putative homologues effect differences in variational tendencies. The goal is to demonstrate a link between developmental and variational differences of two homologues.

Animals↗
PubMed2003

PyPop: a software framework for population genomics: analyzing large-scale multi-locus genotype data.

Software to analyze multi-locus genotype data for entire populations is useful for estimating haplotype frequencies, deviation from Hardy-Weinberg equilibrium and patterns of linkage disequilibrium. These statistical results are important to both those interested in human genome variation and disease predisposition as well as evolutionary genetics. As part of the 13th International Histocompatibility and Immunogenetics Working Group (IHWG), we have developed a software framework (PyPop). The primary novelty of this package is that it allows integration of statistics across large numbers of data-sets by heavily utilizing the XML file format and the R statistical package to view graphical output, while retaining the ability to inter-operate with existing software. Largely developed to address human population data, it can, however, be used for population based data for any organism. We tested our software on the data from the 13th IHWG which involved data sets from at least 50 laboratories each of up to 1000 individuals with 9 MHC loci (both class I and class II) and found that it scales to large numbers of data sets well.

Computational Biology↗
PubMedDate not supplied

[Alu repeats in the human genome].

Highly repetitive DNA sequences account for more than 50% of the human genome. The L1 and Alu families harbor the most common mammalian long (LINEs) and short (SINEs) interspersed elements. Alu elements are each a dimer of similar, but not identical, fragments of total size about 300 bp, and originate from the 7SL RNA gene. Each element contains a bipartite promoter for RNA polymerase III, a poly(A) tract located between the monomers, a 3'-terminal poly(A) tract, and numerous CpG islands, and is flanked by short direct repeats. Alu repeats comprise more than 10% of the human genome and are capable of retroposition. Possibly, these elements played an important part in genome evolution. Insertion of an Alu element into a functionally important genome region or other Alu-dependent alterations of gene functions cause various hereditary disorders and are probably associated with carcinogenesis. In total, 14 Alu families differing in diagnostic mutations are known. Some of these, which are present in the human genome, are polymorphic and relatively recently inserted into new loci. Alu copies transposed during ethnic divergence of the human population are useful markers for evolutionary genetic studies.

Alu Elements↗
PubMed2003

Genome-wide prediction of disease-relevant genes and variants.

To decipher the semantics of the human genome, insights from classical, molecular and evolutionary genetics have to be integrated. For this purpose, bioinformatics methods need to be combined with genetic analyses. From the point of view of human genetics, this article reviews recent approaches to dissecting recombination patterns of the human genome, mining biomedical knowledge from large-scale datasets and analyzing intra- and interspecies diversity. Advancements are illustrated by biomedical examples that are likely to stimulate further investigations.

Animals↗
PubMed2003

[Polymorphism of the HFE gene associated with hereditary hemochromatosis in populations of Russia].

Expression of hereditary hemochromatosis as well as predisposition to iron overload syndrome and sporadic porphyria cutanea tarda are currently believed to be associated with the inheritance of certain allelic variants of the HFE gene. Allele frequencies of the C282Y (845A) and H63D (187G) mutations in the HFE gene in human populations of different races are remarkably different, and the prevalence of the S65C (193T) mutation is still poorly studied. In the present study we estimated allele frequencies of HFE mutations in Russians and in a number of Siberian ethnic indigenous populations. In Russians, allele frequencies of the C282Y, H63D and S65C mutations were 3.7, 13.3 and 1.7%, respectively. These values were similar to those observed in populations of Europe. The C282Y mutation was not detected in the population samples of Siberian ethnic groups, including Mansis, Khantys (Finno-Ugric group), Altaians, and Nivkhs (Mongoloids), suggesting that the frequency of this allele in the populations examined was lower than 1%. The frequency of the C282Y allele in the Tuvinian and Chukchi samples (Mongoloids) constituted 0.45 and 0.8%, respectively. Furthermore, pedigree analysis of both Chukchi carriers discovered showed that some of their ancestors were from other ethnic groups. Low frequencies of this allelic variant is typical of many Eastern Asian populations, which are also characterized by rather low frequencies of the H63D variant. In contrast, in some ethnic groups of Western Siberia allelic frequency of the H63D mutation is rather high, constituting 8.7% in Altaians, 15.5% in Mansis, and 11.3% in Khantys. The frequency of this allele in Tuvinians, Nivkhs, and Chukchis constituted 5, 4.7, and 0.8%, respectively. These findings make it possible to estimate the proportion of individuals predisposed to iron overload syndrome in different Russian ethnic groups. The HFE allele frequency distribution patterns observed in the populations examined pointed to pre-Celtic appearance of the CY82 allele. It also provides elucidation of the evolutionary genetic relationships between Siberian ethnic groups and the contemporary populations of Eastern and Western Europe.

Asian People↗
PubMed2004

Chromosome Karyotypes of Echinacea angustifolia var. angustifolia and E. purpurea.

Chromosome karyotypes of the most commonly cultivated and medicinally used Echinacea taxa, E. angustifolia DC. var. angustifolia and E. purpurea (L.) Moench., were analyzed. The chromosomes of both taxa are medium in length, ranging from 4.12 to 5.83 μm in E. angustifolia var. angustifolia and 3.99 to 6.08 μm in E. purpurea. No abrupt length changes in the chromosomes were noted. The karyotypes of the two species are generally similar, but a distinguishable feature exists in one pair of chromosomes. The centromere of chromosome pair 10 is subterminally located in E. purpurea, but terminally located in E. angustifolia var. angustifolia, which can be readily recognized in mitotic metaphase cell plates. This finding may provide useful information for Echinacea evolutionary, genetic, and breeding studies.

Journal Article↗
PubMed2006

A general multivariate extension of Fisher's geometrical model and the distribution of mutation fitness effects across species.

The evolution of complex organisms is a puzzle for evolutionary theory because beneficial mutations should be less frequent in complex organisms, an effect termed "cost of complexity." However, little is known about how the distribution of mutation fitness effects (f(s)) varies across genomes. The main theoretical framework to address this issue is Fisher's geometric model and related phenotypic landscape models. However, it suffers from several restrictive assumptions. In this paper, we intend to show how several of these limitations may be overcome. We then propose a model of f(s) that extends Fisher's model to account for arbitrary mutational and selective interactions among n traits. We show that these interactions result in f(s) that would be predicted by a much smaller number of independent traits. We test our predictions by comparing empirical f(s) across species of various gene numbers as a surrogate to complexity. This survey reveals, as predicted, that mutations tend to be more deleterious, less variable, and less skewed in higher organisms. However, only limited difference in the shape of f(s) is observed from Escherichia coli to nematodes or fruit flies, a pattern consistent with a model of random phenotypic interactions across many traits. Overall, these results suggest that there may be a cost to phenotypic complexity although much weaker than previously suggested by earlier theoretical works. More generally, the model seems to qualitatively capture and possibly explain the variation of f(s) from lower to higher organisms, which opens a large array of potential applications in evolutionary genetics.

Animals↗
PubMed1982

The microevolutionary process--a view from South America.

After a short review on opinions about human evolutionary genetics and the prospects for understanding the biological variation present in our species, descriptions are made for studies performed in Brazil concerning: (a) C-band variability in chromosomes 1, 9, 16 and Y in Indian populations, with a Caucasoid sample used for comparison; (b) The paradox of the restricted number of HLA haplotypes observed in Indian groups, coupled with a finding of significantly less homozygotes than those expected assuming Hardy-Weinberg equilibrium; (c) The distribution of Gc and Tf isoelectric focusing subtypes in Indians and its anthropological significance; (d) Racial admixture quantitative estimations in samples from two Indian tribes and two cities.

Biological Evolution↗
PubMed1981

[Discordance and variability in the clinical picture of schizophrenia in hereditarily loaded families].

On the basis of comparing the clinical forms of schizophrenia in 132 "parents--children" pairs and 104 pairs of sibs (of 200 families with aggravated heredity) the authors have shown that the discordance phenomenon is associated with the characteristics of the catatonic and simple forms of schizophrenia and the periodic and paroxysmal course of the process, the facts, that prove the phylogenetic connection of the forms and types of the schizophrenia course. The discordance data are in agreement with a chronological random analysis of the schizophrenia diagnoses (with regard to the forms of the disease and the type of its course) made in 1961 to 1976 The diminution of the number of patients with the paroxysmal course of the process and with the catatonic form observed in the last years can be understood from the standpoint of the evolutionary-genetic hypothesis of schizophrenia.

Adolescent↗
PubMed1995

[Allelic isozymes].

Allelic isozymes or allozymes, are the products of allelic genes of paternal and maternal origin at the same locus. They can be identified by electrophoresis. From the technical easiness of electrophoretic detection, allozymes are used for the identification of individuals in population study. Amino acid and nucleotide sequence analyses of allozymes and their genes have provided a powerful tool for molecular evolutionary genetics and molecular systematics.

Alleles↗
PubMed1994

New applications of the nuclear microprobe for biological samples.

The continuing development of the Nuclear Microprobe (NMP) has opened up new fields of applications in biology and medicine. Quantitative multielemental analysis in small sections of samples can be performed routinely. The use of techniques such as scanning transmission ion microscopy makes imaging as well as mass normalization possible at submicron resolution. Recent medical applications include studies on thin cryosections prepared from autopsies and biopsies, as well as single cells grown directly on the backing foil used in the NMP analyses. The purpose of the single cell analysis is often pharmacological, e.g., testing of new drugs, their uptake and distribution. New applications, for instance, in food chemistry, ecology and evolutionary genetics, are also taking advantage of the high analytical sensitivity of the NMP in combination with its imaging capability.

Alzheimer Disease↗
PubMed1997

HLA class II allele frequencies in northern Thais (Kamphaeng Phet).

The polymorphism of HLA class II genes (HLA-DRB1, -DQA1, -DQB1 and -DPB1) was investigated in 97 normal Northern Thais (NT) from Kamphaeng Phet province using PCR-SSO typing. Allele frequencies (AF) have been determined. DRB1*1202 (17.5%), DRB1*1502 (16.5%), DQA1*0101 (25.8%), DQA1*0102 (21.7%), DQB1*0502 (22.7%), DPB1*0501 (23.2%) and DPB1*1301 (22.7%) showed the highest frequencies in each locus. These results were more similar to those observed in Present-day Thais (PDT) and Central Thais (CT) than Northern Thais from Chiang Mai (CM) and Dai Lue (DL). However, the data presented in this population study should be useful in many fields, such as anthropology, organ transplantation, disease susceptibility and evolutionary genetics.

Alleles↗
PubMed1997

An efficient DNA extraction method for small metazoans.

The isolation of total nucleic acids from small metazoan taxa is difficult and often leads to an unacceptably large percentage of unsuccessful polymerase chain reaction (PCR) amplifications. Our work with the evolutionary genetics of harpacticoid copepods was an incentive to refine techniques such that consistent amplifications from minute marine organisms were feasible. We describe these modifications and demonstrate their utility for the amplification of multiple loci from single harpacticoid copepods.

Animals↗
PubMed1998

Inferring the major genomic mode of dominance and overdominance.

The mode of within-locus gene action in most genomic regions is termed as the major genomic mode, i.e., it is the within-locus allelic effects in most regions of the genome. Determining whether dominance or overdominance is the major genomic mode is important for two long-standing evolutionary genetics issues: 1. How is the genetic variation in most genomic regions maintained? 2. What is the major mechanism for heterosis? Many efforts have been made, but almost all of them suffer some explanational difficulties. Here we propose an alternative inference approach. It is based on the existent theoretical results on the correlation of the recombination rate and the level of neutral variation in different genomic regions. Positive and negative correlation suggest dominance and overdominance, respectively, as the major genomic mode. Zero correlations imply either few selected sites or about equal composition and distribution of dominant and overdominant regions in the genome, depending on the data distribution. This approach not only avoids all the problems associated with earlier approaches, but it is also particularly useful in organisms where controlled breeding is difficult. Well-corroborated data in Drosophila and recently emerging data in mice and humans all suggest dominance as the major genomic mode.

Animals↗
PubMed2001

Identifying main evolutionary mechanisms shaping genetic variation of Leuciscus cephalus L. 1758 (Cyprinidae) in western Greece: discordance between methods.

Numerous methods can be used in intraspecific phylogeographic studies to infer the evolutionary mechanisms that shaped observed genetic variation in populations. However, these methods are scarcely used jointly, and the evolutionary outcomes they could propose are not fully compared. In this study, using a chub (Leuciscus cephalus; Cyprinidae) mitochondrial DNA data set (13 populations in Western Greece, 14 haplotypes), we compare three distinct 'historical' methods that could possibly infer relative importance of basic evolutionary mechanisms (isolation vs migration) shaping genetic variation: the nested clade analysis, the psi-test and the 'mismatch distributions'. Taking together, interpretations of these analyses allow to draw a picture of the evolutionary history of chub in Western Greece based on isolation and genetic drift for higher clades. However, results issued each method can differ for low differentiated clades. We discuss such differences and suggest that methods should be used jointly in phylogeographic studies for a better evaluation of the evolutionary mechanisms that shaped genetic variation.

Animals↗