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PubMed2005

How medical ethical principles are applied in treatment with artificial insemination by donors (AID) in Hunan, China: effective practice at the Reproductive and Genetic Hospital of CITIC-Xiangya.

This paper investigates the efficiency of application of medical ethics principles in the practice of artificial insemination by donors (AID) in China, in a culture characterised by traditional ethical values and disapproval of AID. The paper presents the ethical approach to AID treatment as established by the Reproduction and Genetics Hospital of CITIC-Xiangya (CITIC Hunan-Yale Approach) in the central southern area of China against the social ethical background of China and describes its general features. The CITIC-Xiangya Approach facilitates the implementation of ethical relations between clinicians and patients participating in AID treatment procedures in Hunan-Yale.

China↗
PubMed2006

Fast forward to new genes in mammalian reproduction.

The study of reproductive genetics in mammals has lagged behind that of simpler and more tractable model organisms, such as D. melanogaster, C. elegans and various yeast models. Although much valuable information has been generated using these organisms, they do not model the genetic and biological complexity of mammalian reproduction. Thus, the majority of genes required for gametogenesis in mammals remain unidentified. To expand on the existing knowledge of mammalian reproductive genetics, we have carried out forward genetic screens in mice to identify infertility mutants and the underlying mutant genes. Two different approaches were used: mutagenesis of the germline in whole mice, and mutagenesis of embryonic stem cells. This was followed by two- or three-generation breeding schemes to identify pedigrees segregating infertility mutations, which were then phenotypically characterized, genetically mapped, and in some cases, positionally cloned. This whole-genome approach has generated a wide collection of mutants with defects ranging from problems with germ cell development to abnormal sperm morphology. These models have allowed us to study the genetics, as well as the physiology, of reproduction in mammals. This review focuses on describing some of the genes identified in these screens and the ongoing effort to characterize additional mutants.

Animals↗
PubMed1999

Thinking theologically about reproductive and genetic enhancements: the challenge.

Current philosophical and legal bioethical reflections on reprogenetics provides little more than a rationalization of the interests of science. There are two reasons for this. First, bioethicists attempt to address ethical issues in a "language of precision" that characterizes science, and this works against analogical and narratological modes of discourse that have traditionally provided guidance for understanding human nature and purpose. Second, the current ethical and legal debate is framed by a public/private distinction that banishes robust norms to the private realm, and leaves a minimalist public discourse of harm avoidance that is insuffucient for regulating the science. In this essay, I argue that Mark Hanson's account of anxiety provides a valuable starting point for addressing deficiencies in the current philosophical and legal debate, and it highlights the need for a theological discourse on genetic enhancements. Through an assessment of Joel Shuman's criticism of the public/private distinction, I show how the needed theological discourse should be situated in the context of robust communities, and how such a communitarian inter-ethic is compatible with a variant of liberalism. Finally, I critically assess James Keenan's account of virtue and perfection, in order to outline what a sufficient discourse on reproductive and genetic enhancements requires.

Anthropology↗
PubMed2004

Autopoiesis and natural drift: genetic information, reproduction, and evolution revisited.

The contribution of the theory of autopoiesis to the definition of life and biological theory affirms biological autonomy as a central notion of scientific and philosophical inquiry, and opposes other biological approaches, based on the notion of genetic information, that consider reproduction and evolution to be the central aspects of life and living phenomenology. This article reviews the autopoietic criticisms of genetic information, reproduction, and evolution in the light of a biology that can solve the problem of living organization.

Animals↗
PubMed2002

Interactions between genetic and reproductive factors in breast cancer risk in a population-based sample of African-American families.

Incidence of breast cancer (BC) varies among ethnic groups, with higher rates in white than in African-American women. Until now, most epidemiological and genetic studies have been carried out in white women. To investigate whether interactions between genetic and reproductive risk factors may explain part of the ethnic disparity in BC incidence, a genetic epidemiology study was conducted, between 1989 and 1994, at the Howard University Cancer Center (Washington, DC), which led to the recruitment of 245 African-American families. Segregation analysis of BC was performed by use of the class D regressive logistic model that allows for censored data to account for a variable age of onset of disease, as implemented in the REGRESS program. Segregation analysis of BC was consistent with a putative dominant gene effect (P < 0.000001) and residual sister-dependence (P < 0.0001). This putative gene was found to interact significantly with age at menarche (P = 0.048), and an interaction with a history of spontaneous abortions was suggested (P = 0.08). A late age at menarche increased BC risk in gene carriers but had a protective effect in non-gene carriers. A history of spontaneous abortions had a protective effect in gene carriers and increased BC risk in non-gene carriers. Our findings agree partially with a similar analysis of French families showing a significant gene x parity interaction and a suggestive gene x age at menarche interaction. Investigating gene x risk factor interactions in different populations may have important implications for further biological investigations and for BC risk assessment.

Abortion, Spontaneous↗
PubMed2006

Genetic diversity, reproductive biology, and speciation in the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin.

Beauveria bassiana, a mitosporic fungus used for the biological control of many insect species, is recognized as a "species complex" comprising genetically diverse lineages. Being predominantly asexual, mating tests cannot be applied to delimit species in this species complex. Genetic tests offer an indirect means of identifying species among isolates. To this end, molecular genetic analysis of a sample of B. bassiana isolates with 2 subsamples, 1 representing a worldwide collection and another from a localized epizootic population was carried out. DNA markers generated through AFLPs (amplified fragment length polymorphisms) and SSCPs (single-strand conformation poly morphisms) and nucleotide sequence data of different allelic forms of 3 genes (large and small subunits of rRNA and beta-tubulin) were evaluated. The B. bassiana isolates from the worldwide sample showed 11% overall similarity and no closely clustered groups. Phylogenetic trees generated from the AFLP and SSCP data of this sample resolved the different isolates into distinct phylogenetic lineages. In the epizootic B. bassiana population, prevalence of recombination was evident from random association of alleles in multilocus tests and lack of phylogenetic concordance among 3 gene genealogies. Thus, the worldwide sample of B. bassiana exhibits a predominantly clonal structure, hinting at species divergence leading to cryptic speciation with recombination being customary among isolates sharing a close ecological niche.

Animals↗
PubMed1997

Interactions between genetic and reproductive factors in breast cancer risk in a French family sample.

Considerable progress has been made in the characterization of the genetic component of breast cancer (BC). However, BC still remains a complex disease involving a genetic component and many other risk factors essentially linked to reproductive-life factors. To search for interactions between genetic and reproductive-life factors in the etiology of BC, a systematic family study was performed in two French hospitals from December 1987 to January 1990 and led to recruitment of 288 families, the IGRC data ("IGRC" refers to the Institut Gustave Roussy and Institut Curie, where the data were obtained). Detailed information on reproductive factors was recorded for probands and female first-degree relatives. Segregation analysis of BC was conducted by taking into account a variable age at onset of disease, by use of the class D regressive logistic model, as implemented in the REGRESS computer program. Segregation analyses of BC in IGRC data showed evidence for the segregation of a dominant gene and additional sister-sister dependence, both when reproductive factors were ignored and when they were included. A significant interaction was detected between the dominant gene and age when reproductive factors were taken into account. Among the reproductive factors included in segregation analysis, parity was found to interact with the dominant-gene effect, and there was an indication of an interaction, albeit not significant, between the dominant gene and age at menarche. Whereas the usual protective effect conferred on breast-cancer risk by high parity remained in nonsusceptible women, it disappeared in susceptible women. The increased BC risk associated with a late age at menarche was higher in susceptible women than in nonsusceptible women. Interactions between inherited predisposition to BC and reproductive factors were detected here for the first time by segregation analysis. It would be of major interest to confirm these results by family studies in other populations.

Abortion, Spontaneous↗
PubMed1996

Are both genetic and reproductive associations with rheumatoid arthritis linked to prolactin?

The risk of rheumatoid arthritis (RA) seems to be associated with reduced fecundity and with breastfeeding; these apparently contradictory risk factors can be explained by their association with high prolactin concentrations. The only consistent genetic association with RA is for genes encoded in the HLA complex, particularly HLA DR4. We have identified some data indicating that the effects of breastfeeding and nulliparity are modified by HLA DR4 status, suggesting an interaction between genetic and reproductive risk factors in the aetiology of RA. The prolactin gene is in close proximity to the HLA region on the short arm of chromosome six. We therefore propose the hypothesis that the associations between DR4 and reproductive risk factors in RA are due to linkage disequilibrium between DR4 and an abnormally regulated prolactin gene polymorphism.

Arthritis, Rheumatoid↗
PubMed2005

An analysis of genetic toxicity, reproductive and developmental toxicity, and carcinogenicity data: II. Identification of genotoxicants, reprotoxicants, and carcinogens using in silico methods.

This study examined a novel method to identify carcinogens that employed expanded data sets composed of in silico data pooled with actual experimental genetic toxicity (genetox) and reproductive and developmental toxicity (reprotox) data. We constructed 21 modules using the MC4PC program including 13 of 14 (11 genetox and 3 reprotox) tests that we found correlated with results of rodent carcinogenicity bioassays (rcbioassays) [Matthews, E.J., Kruhlak, N.L., Cimino, M.C., Benz, R.D., Contrera, J.F., 2005b. An analysis of genetic toxicity, reproductive and developmental toxicity, and carcinogenicity data: I. Identification of carcinogens using surrogate endpoints. Regul. Toxicol. Pharmacol.]. Each of the 21 modules was evaluated by cross-validation experiments and those with high specificity (SP) and positive predictivity (PPV) were used to predict activities of the 1442 chemicals tested for carcinogenicity for which actual genetox or reprotox data were missing. The expanded data sets had approximately 70% in silico data pooled with approximately 30% experimental data. Based upon SP and PPV, the expanded data sets showed good correlation with carcinogenicity testing results and had correlation indicator (CI, the average of SP and PPV) values of 75.5-88.7%. Conversely, expanded data sets for 9 non-correlated test endpoints were shown not to correlate with carcinogenicity results (CI values <75%). Results also showed that when Salmonella mutagenic carcinogens were removed from the 12 correlated, expanded data sets, only 7 endpoints showed added value by detecting significantly more additional carcinogens than non-carcinogens.

Animals↗
PubMed1996

The genetics of reproductive isolation in the Drosophila simulans clade: X vs. autosomal effects and male vs. female effects.

A strong effect of homozygous autosomal regions on reproductive isolation was found for crosses between the species in the Drosophila simulans clade. Second chromosome regions were introgressed from D. mauritiana and D. sechellia into D. simulans and tested for their homozygous effects on hybrid male and hybrid female sterility and inviability. Most introgressions are fertile as heterozygotes, yet produce sterile male offspring when made homozygous. The density of homozygous autosomal factors contributing to hybrid male sterility is comparable to the density of X chromosome factors for this level of resolution. Female sterility was also revealed, yet the disparity between male and female levels of sterility was great, with male sterility being up to 23 times greater than female sterility. Complete hybrid inviability was also associated with some regions of the second chromosome, yet there were no strong sex differences. In conclusion, we find no evidence to support a strong X chromosome bias in the evolution of hybrid sterility or inviability but do find a very strong sex bias in the evolution of hybrid sterility. In light of these findings, we reevaluate the current models proposed to explain the genetic pattern of reproductive isolation.

Alleles↗
PubMed1999

The morality of assisted reproduction and genetic manipulation.

The author analyzes the pros and cons of various forms of assisted reproduction, including the use of so-called 'genetic manipulation'. He shows how in ethics the only arguments with any chance of reaching a consensus (or at least an agreement) are those of the rational type, based on universally acceptable ethical principles or corroborated by empirical facts and real life experience (as the starting point for identifying problems requiring analysis). After an analysis in which he identifies the incoherence and inconsistency of arguments against assisted reproduction, the author defends the right of human beings to decide autonomously about the most healthy forms of procreation, including those involving genetic manipulation. His starting point is the moral principle by which it is morally preferable to intervene in natural processes (as opposed to not intervening) whenever this implies preventing and reducing disease and suffering.

Bioethics↗
PubMed2005

An analysis of genetic toxicity, reproductive and developmental toxicity, and carcinogenicity data: I. Identification of carcinogens using surrogate endpoints.

A retrospective analysis of standard genetic toxicity (genetox) tests, reproductive and developmental toxicity (reprotox) studies, and rodent carcinogenicity bioassays (rcbioassay) was performed to identify the genetox and reprotox endpoints whose results best correlate with rcbioassay observations. A database of 7205 chemicals with genetox (n = 4961), reprotox (n = 2173), and rcbioassay (n = 1442) toxicity data was constructed; 1112 of the chemicals have both genetox and rcbioassay data and 721 chemicals have both reprotox and rcbioassay data. This study differed from previous studies by using conservative weight of evidence criteria to classify chemical carcinogens, data from 63 genetox and reprotox toxicological endpoints, and a new statistical parameter of correlation indicator (CI, the average of specificity and positive predictivity) to identify good surrogate endpoints for predicting carcinogenicity. Among 63 endpoints, results revealed that carcinogenicity was well correlated with certain tests for gene mutation (n = 8), in vivo clastogenicity (n = 2), unscheduled DNA synthesis assay (n = 1), and reprotox (n = 3). The current FDA regulatory battery of four genetox tests used to predict carcinogenicity includes two tests with good correlation (gene mutation in Salmonella and in vivo micronucleus) and two tests with poor correlation (mouse lymphoma gene mutation and in vitro chromosome aberrations) by our criteria.

Animals↗
PubMed1999

Reproductive and genetic evidence for a reticulate evolutionary history of mass-spawning corals.

Reef-building corals, which reproduce through simultaneous multispecies spawning, are thought to hybridize frequently, and it is hypothesized that they have evolved in repeated rounds of species separation and fusion. We conducted cross-fertilization experiments and molecular analyses with a number of mass-spawning coral species in the genus Acropora. A high rate of interspecific fertilization occurred between some species despite very different morphologies. The hybrid larvae developed normally and contained an allelic sequence transmitted from each parent, suggesting common diploid hybridization. Molecular phylogenetic analyses provided strong evidence for a gene pool shared between the hybridizing species. These reproductive and genetic characteristics are consistent with a species complex formed under the separation/fusion processes predicted for a reticulate evolutionary history.

Animals↗
PubMed1993

Genetics of reproductive isolation in the Drosophila simulans clade: DNA marker-assisted mapping and characterization of a hybrid-male sterility gene, Odysseus (Ods).

In this study, we address the question of whether there exist major genes that cause complete male sterility in the interspecific hybrids of Drosophila and, if they do, how these genes may be characterized at the molecular level. Our approach is to introgress small segments of the X chromosome from Drosophila mauritiana (or Drosophila sechellia) into Drosophila simulans by repeated backcrosses for more than 20 generations. The introgressions are monitored by both visible mutations and a series of DNA markers. We compare the extent of introgressions that cause male sterility with those that do not. If a major sterility factor exists, there should be a sharp boundary between these two classes of introgressions and their breakpoints should demarcate such a gene. Furthermore, if male sterility is the only major fitness effect associated with the introgression, recombination analysis should yield a pattern predicted by the classical three-point cross. Both the genetic and molecular analyses suggest the presence of a major sterility factor from D. mauritiana, which we named Odysseus (Ods), in the cytological interval of 16D. We thus formalize three criteria for inferring the existence of a major gene within an introgression: (1) complete penetrance of sterility, (2) complementarity in recombination analysis, and (3) physical demarcation. Introgressions of Ods from D. sechellia do not cause sterility. Twenty-two introgressions in our collection have breakpoints in this interval of about 500 kb, making it possible to delineate Ods more precisely for molecular identification. The recombination analysis also reveals the complexity of the introgressed segments--even relatively short ones may contain a second male sterility factor and partial viability genes and may also interfere with crossovers. The spermatogenic defects associated with Ods and/or a second factor were characterized by phase-contrast microscopy.

Animals↗
PubMed2007

Uncovering the biodiversity of genetic and reproductive systems: time for a more open approach. American Society of Naturalists E. O. Wilson Award winner address.

Important scientific findings frequently arise from serendipitous findings. Unfortunately, many scientists are not prepared to take advantage of unexpected results and to question established paradigms, and this prevents them from capitalizing on their good fortune. In this essay, I first explain how pure serendipity led us to discover unusual modes of reproduction such as clonal reproduction by males and a green-beard gene. Next, I argue that the reproductive systems of ants and other organisms are probably much more diverse than is generally appreciated. This leads me to advocate for a new "molecular naturalist" approach to reproductive systems and a more "naturalistic" approach in population and evolutionary genetics. Finally, I make two further points. The first is that our current funding and education systems tend to hinder originality and curiosity. The other is that the field of ecology and evolution, and more generally all of science, would benefit from a shift in values from scientific productivity to scientific creativity. A few suggestions are made to this effect.

Animals↗