Estimation of nonpaternity in the Mexican population of Nuevo Leon: a validation study with blood group markers

Mediterranean Y-chromosome 2.0-why the Y in the Mediterranean is still relevant in the postgenomic era

CONTEXT

Due to its unique paternal inheritance, the Y-chromosome has been a highly popular marker among population geneticists for over two decades. Recently, the advent of cost-effective genome-wide methods has unlocked information-rich autosomal genomic data, paving the way to the postgenomic era. This seems to have announced the decreasing popularity of investigating Y-chromosome variation, which provides only the paternal perspective of human ancestries and is strongly influenced by genetic drift and social behaviour.

OBJECTIVE

For this special issue on population genetics of the Mediterranean, the aim was to demonstrate that the Y-chromosome still provides important insights in the postgenomic era and in a time when ancient genomes are becoming exponentially available.

METHODS

A systematic literature search on Y-chromosomal studies in the Mediterranean was performed.

RESULTS

Several applications of Y-chromosomal analysis with future opportunities are formulated and illustrated with studies on Mediterranean populations.

CONCLUSIONS

There will be no reduced interest in Y-chromosomal studies going from reconstruction of male-specific demographic events to ancient DNA applications, surname history and population-wide estimations of extra-pair paternity rates. Moreover, more initiatives are required to collect population genetic data of Y-chromosomal markers for forensic research, and to include Y-chromosomal data in GWAS investigations and studies on male infertility.

Paternity tests in Mexico: Results obtained in 3005 cases

National and international reports regarding the paternity testing activity scarcely include information from Mexico and other Latin American countries. Therefore, we report different results from the analysis of 3005 paternity cases analyzed during a period of five years in a Mexican paternity testing laboratory. Motherless tests were the most frequent (77.27%), followed by trio cases (20.70%); the remaining 2.04% included different cases of kinship reconstruction. The paternity exclusion rate was 29.58%, higher but into the range reported by the American Association of Blood Banks (average 24.12%). We detected 65 mutations, most of them involving one-step (93.8% and the remaining were two-step mutations (6.2%) thus, we were able to estimate the paternal mutation rate for 17 different STR loci: 0.0018 (95% CI 0.0005-0.0047). Five triallelic patterns and 12 suspected null alleles were detected during this period; however, re-amplification of these samples with a different Human Identification (HID) kit confirmed the homozygous genotypes, which suggests that most of these exclusions actually are one-step mutations. HID kits with ≥20 STRs detected more exclusions, diminishing the rate of inconclusive results with isolated exclusions (<3 loci), and leading to higher paternity indexes (PI). However, the Powerplex 21 kit (20 STRs) and Powerplex Fusion kit (22 STRs) offered similar PI (p = 0.379) and average number of exclusions (PE) (p = 0.339) when a daughter was involved in motherless tests. In brief, besides to report forensic parameters from paternity tests in Mexico, results describe improvements to solve motherless paternity tests using HID kits with ≥20 STRs instead of one including 15 STRs.

Genetic-genealogy approach reveals low rate of extrapair paternity in historical Dutch populations

OBJECTIVE

Evolutionary theory has shown that seeking out extrapair paternity (EPP) can be a viable reproductive strategy for both sexes in pair-bonded species, also in humans. As yet, estimates of the contemporary or historical EPP rate in human population are still rare. In the present study, we estimated the historical EPP rate in the Dutch population over the last 400 years and compared the rate with those obtained for other human populations to determine the evolutionary, cultural, and socio-demographic factors that influence human cuckoldry behavior.

METHODS

We estimated the historical EPP rate for the Dutch population via the "genealogical pair method", in which the EPP rate is derived from Y-chromosome mismatches between pairs of individuals that, based on genealogical evidence, share a common paternal ancestor.

RESULTS

Based on the analysis of 68 representative genealogical pairs, separated by a total of 1013 fertilization events, we estimated that the historical EPP rate for the Dutch population over the last 400 years was 0.96% per generation (95% confidence interval 0.46%-1.76%).

CONCLUSION

The Dutch EPP rate fits perfectly within the range reported for other contemporary and historical populations in Western Europe and was highly congruent with that estimated for neighboring Flanders, despite the socio-economic and religious differences between both populations. The estimated low EPP rate challenges the "dual mating strategy hypothesis" that states that women could obtain fitness benefits by securing investment from one man while cuckolding him to obtain good genes from an affair partner.

Familial Aggregation and Heritability of Wuchereria bancrofti Infection

BACKGROUND

The familial recurrence risk of lymphatic filariasis (LF) is unknown. This case study aimed to evaluate the familial susceptibility to infection with Wuchereria bancrofti and to microfilaremia in a village of the Republic of Congo.

METHODS

The heritability and intrafamilial correlation coefficients were assessed for both W. bancrofti infection and microfilaremia by controlling for individual risk factors, environmental influence, and household effects.

RESULTS

Pedigree charts were constructed for 829 individuals, including 143 individuals with a diagnosis of W. bancrofti circulating filarial antigens (CFAs) and 44 who also had microfilariae (MF). There was no intrafamilial correlation regarding CFA levels. However, the presence of MF (ρ = 0.45) and microfilarial density (ρ = 0.44) were significantly correlated among parent-offspring pairs. Heritability estimates for CFA positivity and intensity were 0.23 and 0.18, respectively. Heritability estimates were high for microfilarial positivity (h(2) = 0.74) and microfilarial density traits (h(2) = 0.81).

CONCLUSIONS

Our study suggests that the acquisition of LF is mainly driven by environmental factors and habits and that genetic factors are moderately involved in the regulation of infection. By contrast, genetic factors play a major role in both the presence and intensity of microfilaremia.

Sociosexual orientation and 2D:4D ratios in women: Relationship to men's desirability ratings as a long-term pair bond

The current study examined whether men's ratings of women's desirability as a long-term pairbond, based on static photographs, were related to the women's second-to-fourth digit (2D:4D) ratio and their sexual attitudes and behavior. The 2D:4D ratio was measured in 164 women and facial photographs were taken of 55 of these women. All women completed the Sociosexual Orientation Inventory (SOI). Male participants (n = 89), masked to this information, rated the 55 female participants on their desirability as a long-term sexual partner, specifically along dimensions of faithfulness, youthfulness, and attractiveness. Ten independent judges rated women's photographed faces on masculinity. Results indicated a significant negative relationship between women's SOI scores and men's faithfulness ratings (more unrestricted sociosexuality was associated with lower faithfulness ratings). There was also a significant positive relationship between right (but not left) 2D:4D ratio and faithfulness ratings (women with female-like ratios were rated as being more faithful). The SOI scores of the women were not related to 2D:4D ratios. These results suggest that the potential for sexual infidelity can be gleaned from static facial cues.

Low historical rates of cuckoldry in a Western European human population traced by Y-chromosome and genealogical data

Recent evidence suggests that seeking out extra-pair paternity (EPP) can be a viable alternative reproductive strategy for both males and females in many pair-bonded species, including humans. Accurate data on EPP rates in humans, however, are scant and mostly restricted to extant populations. Here, we provide the first large-scale, unbiased genetic study of historical EPP rates in a Western European human population based on combining Y-chromosomal data to infer genetic patrilineages with genealogical and surname data, which reflect known historical presumed paternity. Using two independent methods, we estimate that over the last few centuries, EPP rates in Flanders (Belgium) were only around 1–2% per generation. This figure is substantially lower than the 8–30% per generation reported in some behavioural studies on historical EPP rates, but comparable with the rates reported by other genetic studies of contemporary Western European populations. These results suggest that human EPP rates have not changed substantially during the last 400 years in Flanders and imply that legal genealogies rarely differ from the biological ones. This result has significant implications for a diverse set of fields, including human population genetics, historical demography, forensic science and human sociobiology.

Genetic Influences on Female Infidelity and Number of Sexual Partners in Humans: A Linkage and Association Study of the Role of the Vasopressin Receptor Gene (AVPR1A)

In humans, in contrast to animals, the genetic influences on infidelity are unclear. We report here a large study of over 1600 unselected United Kingdom female twin pairs who confidentially reported previous episodes of infidelity and total lifetime number of sexual partners, as well as attitudes towards infidelity. Our findings demonstrate that infidelity and number of sexual partners are both under moderate genetic influence (41% and 38% heritable, respectively) and the genetic correlation between these two traits is strong (47%). Conversely, attitudes towards infidelity are driven by shared and unique environmental, but not genetic, influences. A genome-wide linkage scan identified three suggestive but nonsignificant linkage areas associated with infidelity and number of sexual partners on chromosomes 3, 7 and 20 with a maximum LOD score of 2.46. We were unsuccessful in associating infidelity or number of sexual partners with a locus implicated in other mammals' sexual behavior, the vasopressin receptor gene. Nonetheless, our findings on the heritabil-ity of sexual infidelity and number of sexual partners provide support for certain evolutionary theories of human sexual behavior, as well as justifying further genetic and molecular research in this domain.

Detection of uniparental isodisomy in autosomal recessive mitochondrial DNA depletion syndrome by high-density SNP array analysis

Mitochondrial DNA (mtDNA) depletion syndrome encompasses a heterogeneous group of disorders characterized by a reduction in the mtDNA copy number. We identified two patients with clinical presentations consistent with mtDNA depletion syndrome (MDS), who were subsequently found to have apparently homozygous point mutations in TYMP and DGUOK, two of the nine nuclear genes commonly associated with these disorders. Further sequence analyses of parents indicated that in each case only one parent; the mother of the first and the father of the second, was a heterozygous carrier of the mutation identified in the affected child. The presence of underlying deletions was ruled out by use of a custom target array comparative genomic hybridization (CGH) platform. A high-density single-nucleotide polymorphism (SNP) array analysis revealed that the first patient had a region of copy-neutral absence of heterozygosity (AOH) consistent with segmental isodisomy for an 11.3 Mb region at the long-arm terminus of chromosome 22 (including the TYMP gene), and the second patient had results consistent with complete isodisomy of chromosome 2 (where the DGUOK gene is located). The combined sequencing, array CGH and SNP array approaches have demonstrated the first cases of MDS due to uniparental isodisomy. This diagnostic scenario also demonstrates the necessity of comprehensive examination of the underlying molecular defects of an apparently homozygous mutation in order to provide patients and their families with the most accurate molecular diagnosis and genetic counseling.

The evolved function of the oedipal conflict

Freud based his oedipal theory on three clinical observations of adult romantic relationships: (1) Adults tend to split love and lust; (2) There tend to be sex differences in the ways that men and women split love and lust; (3) Adult romantic relationships are unconsciously structured by the dynamics of love triangles in which dramas of seduction and betrayal unfold. Freud believed that these aspects of adult romantic relationships were derivative expressions of a childhood oedipal conflict that has been repressed. Recent research conducted by evolutionary psychologists supports many of Freud's original observations and suggests that Freud's oedipal conflict may have evolved as a sexually selected adaptation for reproductive advantage. The evolution of bi-parental care based on sexually exclusive romantic bonds made humans vulnerable to the costs of sexual infidelity, a situation of danger that seriously threatens monogamous bonds. A childhood oedipal conflict enables humans to better adapt to this longstanding evolutionary problem by providing the child with an opportunity to develop working models of love triangles. On the one hand, the oedipal conflict facilitates monogamous resolutions by creating intense anxiety about the dangers of sexual infidelity and mate poaching. On the other hand, the oedipal conflict in humans may facilitate successful cheating and mate poaching by cultivating a talent for hiding our true sexual intentions from others and even from ourselves. The oedipal conflict in humans may be disguised by evolutionary design in order to facilitate tactical deception in adult romantic relationships.

Sex differences in subjective estimates of non-paternity rates in Austria

The determination of paternity is important due to the possibility of cuckoldry and the subsequent squandering of male reproductive effort. Men may be attuned to prevalence rates of cuckoldry in the local environment to assess risk. However, women may have an enhanced ability to assess paternity and may have superior insight into women's sexual infidelity. Accordingly, this study examined subjective estimates of human non-paternity (HNP), the discrepancy between social/legal versus genetic paternity. The hypothesis was that women would provide higher estimates of HNP than men. A sex difference in the hypothesized direction was observed across four community samples of Austrian adults (totalling 763 men and 795 women), with women overall providing higher HNP estimates than men (14.5% vs. 9.1%). Furthermore, key demographic variables impacted HNP estimates for both sexes: individuals who were unmarried, childless, currently unpartnered, or currently in a romantic relationship of a shorter duration provided higher HNP estimates than their counterparts, thus suggesting that such estimates might be attuned to mating effort and strategies, as well as relationship quality and investment.

Assessing genuine parents-offspring trios for genetic association studies

OBJECTIVES

Family-based association tests such as the transmission disequilibrium test (TDT) are dependent on the successful ascertainment of true nuclear family trios. Relationship misspecification inevitably occurs in a proportion of trios collected for genotyping which undetected can lead to a loss of power and increased Type I error due to biases in over-transmission of common alleles. Here, we introduce a method for evaluating the authenticity of nuclear family trios.

METHODS

Operating in a Bayesian framework, our approach assesses the extent of pedigree inconsistent genotype configurations in the presence of genotyping errors. Unlike other approaches, our method: (i) utilizes information from three individuals collectively (the whole trio) rather than consider two independent pairwise relationships; (ii) down-weighs SNPs with poor performance; (iii) does not require the user to pre-define a rate of genotyping error, which is often unknown to the user and seldom fixed across the different SNPs considered which available methods unrealistically assumed.

RESULTS

Simulation studies and comparisons with a real set of data showed that our approach is more likely to correctly identify the presence of true and misspecified trios compared to available software, accurately infers the extent of relationship misspecification in a trio and accurately estimates the genotyping error rates.

CONCLUSIONS

Assessing relationship misspecification depends on the fidelity of the genotype data used. Available algorithms are not optimised for genotyping technology with varying rates of errors across the markers. Through our comparison studies, our approach is shown to outperform available methods for assessing relationship misspecifications.

Paternal skeletal size predicts intrauterine bone mineral accrual

BACKGROUND

We have previously demonstrated that maternal body build and lifestyle factors predict neonatal bone mineral accrual. However, the paternal determinants of neonatal bone mass are not known. In this study we explored the relationship between a father's bone mass and that of his offspring.

METHODS

A total of 278 pregnancies (142 male and 136 female neonates) were recruited from the Southampton Women's Survey, a unique, well-established cohort of women, aged 20-34 yr, who had been assessed before and during pregnancy. The neonates and their fathers underwent whole body dual-x-ray absorptiometry (DXA) within 2 wk of birth using a Lunar DPX (General Electric Corp., Madison, WI) and Hologic Discovery instrument (Hologic Inc., Bedford, MA), respectively; correlation and regression methods were used to explore the parental determinants of neonatal bone mass.

RESULTS

After adjusting the paternal DXA indices for father's age and the neonatal for baby's gestational age and age at DXA scan, there were highly significant positive associations between baby's whole body bone area, bone mineral content, and bone mineral density and the corresponding indices in the father (P = 0.003, 0.0002, 0.046, respectively) among female infants. These relationships were independent of maternal height and fat stores. The associations for male infants with paternal DXA indices did not achieve statistical significance.

CONCLUSIONS

The father's skeletal size predicts skeletal size more strongly in female than male offspring, independently of the mother's body build. These data point toward the importance of considering paternal genotype in studies exploring the developmental origins of osteoporotic fracture and raise intriguing mechanistic questions about the gender specificity of influences on intrauterine bone mineral accrual.

The Daughter-Guarding Hypothesis: Parental Influence on, and Emotional Reactions to, Offspring's Mating Behavior

Scant research has examined how individuals attempt to influence others' mating decisions. Parents are a special case because of their genetic relatedness to, and power over, their children. This paper tests the Daughter-Guarding Hypothesis: humans possess adaptations that motivate (1) protecting their daughter's sexual reputation, (2) preserving their daughter's mate value, and (3) preventing their daughters from being sexually exploited. Using two data sources, young adults and their parents, we found that parents were more likely to control their daughters' mating decisions. Parents were more likely to control their daughters' sexual behavior; parents reported more emotional upset over daughters' sexual activity; parents controlled their daughters' mate choice more than their sons'. The results support several hypothesized design features of the Daughter-Guarding hypothesis.

Attractive Women Want it All: Good Genes, Economic Investment, Parenting Proclivities, and Emotional Commitment

The current research tests the hypothesis that women have an evolved mate value calibration adaptation that functions to raise or lower their standards in a long-term mate according to their own mate value. A woman's physical attractiveness is a cardinal component of women's mate value. We correlated observer-assessed physical attractiveness (face, body, and overall) with expressed preferences for four clusters of mate characteristics ( N = 214): (1) hypothesized good-gene indicators (e.g., masculinity, sexiness); (2) hypothesized good investment indicators (e.g., potential income); (3) good parenting indicators (e.g., desire for home and children), and (4) good partner indicators (e.g., being a loving partner). Results supported the hypothesis that high mate value women, as indexed by observer-judged physical attractiveness, expressed elevated standards for all four clusters of mate characteristics. Discussion focuses on potential design features of the hypothesized mate-value calibration adaptation, and suggests an important modification of the trade-off model of women's mating. A minority of women—notably those low in mate value who are able to escape male mate guarding and the manifold costs of an exposed infidelity—will pursue a mixed mating strategy, obtaining investment from one man and good genes from an extra-pair copulation partner (as the trade-off model predicts). Since the vast majority of women secure genes and direct benefits from the same man, however, most women will attempt to secure the best combination of all desired qualities from the same man.

Sex Differences in Implicit Association and Attentional Demands for Information about Infidelity

Sex differences in reaction to a romantic partner's infidelity are well documented and are hypothesized to be attributable to sex-specific jealousy mechanisms that solve sex specific adaptive problems. There have been few cognitive-based investigations of jealousy, however. Here we investigated sex differences in implicit processing of jealousy-based information. In Experiment 1, we used the implicit association test (IAT) to investigate sex-differentiated biases in classifying sexual or emotional infidelity information as being positive or negative. Men made significantly more errors when asked to classify as pleasant, words indicating sexual infidelity. In Experiment 2, we modified the Stroop task to include words that depicted infidelity-related topics in three priming conditions: sexual infidelity priming, emotional infidelity priming, and a no priming control. Men were significantly slower to respond after being primed with sexual infidelity scenarios. The effect of sexual infidelity priming was not word-category specific, suggesting that cognition about a partner's sexual infidelity hijacks general cognitive and attentional processing. These findings suggest that men may automatically classify information about sexual infidelity as negative and that the automatic negative processing of sexual infidelity takes precedent over other types of immediate cognition.

Rats assess degree of relatedness from human odors

Despite widespread interest in the evolutionary implications of human olfactory communication, the mechanisms underlying human odor production are still poorly understood. Previous studies have demonstrated that human odor cues are related to variations in the major histocompatibility complex, but it is unclear whether odors are associated with overall genotypic variation. In this study, we investigated whether more closely related humans produce more similar odor cues. To assess objective odor qualities we tested odor similarity using rats in a habituation-discrimination paradigm. Rats were first habituated to a referent human odor and were then presented with two test odors obtained from individuals related in different degrees to the referent. Investigation times for each odor were compared. Because rats investigate novel odors longer than familiar odors, we were able to determine which test odor the rats perceived as more similar to the referent human odor. For six of ten odor donor families, rats investigated the odor of the less closely related individual significantly longer than that of the more closely related individual, and investigation durations were in the expected direction for all families. These results indicate that similarity of human odor cues is associated with degree of genetic relatedness, with more closely related humans producing more similar odor cues. This study supports the hypothesis that odor cues provide information regarding degree of relatedness and may thus affect a wide variety of human behaviors, including kin preferences, nepotism, and mate choice.

Testing and Reporting ACMG Cystic Fibrosis Mutation Panel Results

Testing strategies and summary reports for pregnant patients and symptomatic patients being tested for cystic fibrosis (CF; MIM 219700) were developed based upon calculated after (posterior) test risk tables incorporating patient and family histories, ethnicities, and prior testing status. This manuscript defines the proportion of all mutations detected by the American College of Medical Genetics (ACMG)-recommended 23-mutation cystic fibrosis transmembrane conductance regulator (CFTR) gene core panel when testing all patient categories with severe symptoms, including pregnant couples with no family history as well as CF patients, their partners, and other family members. Reference tables incorporate prior and posterior test risks sufficient to complete >99% of all tested cases and to report the results according to HIPAA guidelines. These tables were calculated based on the assumption that all patient samples have been collected, labeled, analyzed, and reported correctly, including the patient's reported relationship to a known affected or carrier relative, even though the template letter states that the likelihood is about 99% that each reported result is accurate. Pedigrees and tables with the prior (before; a priori) test risks of patients offered CF screening with a family history of a CF patient and/or a known carrier patient are provided for ready reference with each risk frequency, dependent upon the assumption that the patient's pedigree reflects familial relationships correctly. Comparison of tables emphasizes the value of asking the tested partner to ask a relative known to have CF or who tested positive for a CF mutation to donate a sample as a DNA test control and/or to obtain a copy of a prior molecular test result and/or extracted DNA sample. These tables posterior test risks also indicate that when one partner with no family history tests negative for the 23 mutation panel, no further prenatal testing is indicated.

Facial Resemblance Exaggerates Sex-Specific Jealousy-Based Decisions

Sex differences in reaction to a romantic partner's infidelity are well documented and are hypothesized to be attributable to sex-specific jealousy mechanisms which are utilized to solve adaptive problems associated with risk of extra-pair copulation. Males, because of the risk of cuckoldry become more upset by sexual infidelity, while females, because of loss of resources and biparental investment tend to become more distressed by emotional infidelity. However, the degree to which these sex-specific reactions to jealousy interact with cues to kin are completely unknown. Here we investigated the interaction of facial resemblance with decisions about sex-specific jealousy scenarios. Fifty nine volunteers were asked to imagine that two different people (represented by facial composites) informed them about their romantic partner's sexual or emotional infidelity. Consistent with previous research, males ranked sexual infidelity scenarios as most upsetting and females ranked emotional infidelity scenarios most upsetting. However, when information about the infidelity was provided by a face that resembled the subject, sex-specific reactions to jealousy were exaggerated. This finding highlights the use of facial resemblance as a putative self-referent phenotypic matching cue that impacts trusting behavior in sexual contexts.

Women's sexual interests across the ovulatory cycle depend on primary partner developmental instability

Normally ovulating women have been found to report greater sexual attraction to men other than their own partners when near ovulation relative to the luteal phase. One interpretation is that women possess adaptations to be attracted to men possessing (ancestral) markers of genetic fitness when near ovulation, which implies that women's interests should depend on qualities of her partner. In a sample of 54 couples, we found that women whose partners had high developmental instability (high fluctuating asymmetry) had greater attraction to men other than their partners, and less attraction to their own partners, when fertile.

Measuring paternal discrepancy and its public health consequences

Paternal discrepancy (PD) occurs when a child is identified as being biologically fathered by someone other than the man who believes he is the father. This paper examines published evidence on levels of PD and its public health consequences. Rates vary between studies from 0.8% to 30% (median 3.7%, n = 17). Using information from genetic and behavioural studies, the article identifies those who conceive younger, live in deprivation, are in long term relationships (rather than marriages), or in certain cultural groups are at higher risk. Public health consequences of PD being exposed include family break up and violence. However, leaving PD undiagnosed means cases having incorrect information on their genetics and fathers continuing to suspect that children may not be theirs. Increasing paternity testing and use of DNA techniques in clinical and judicial procedures means more cases of PD will be identified. Given developing roles for individual's genetics in decisions made by health services, private services (for example, insurance), and even in personal lifestyle decisions, the dearth of intelligence on how and when PD should be exposed urgently needs addressing.

Sex differences in the neural correlates of child facial resemblance: an event-related fMRI study

Detection of genetic relatedness (i.e. kinship) impacts the social, parental, and sexual behavior of many species. In humans, self-referent phenotype matching based on facial resemblance may indicate kinship. For example, faces that resemble ours are perceived as more trustworthy and attractive. Sex differences in behavioral reactions to facial resemblance among children have also been demonstrated and are consistent with evolutionary theory suggesting that resemblance might serve as a paternity cue. Using event-related fMRI, we show that specific regions of the brain are implicated in processing facial resemblance and a sex difference in cortical response to facial resemblance expressed in children. We found a consistent activation in the fusiform gyrus across all face conditions, which is consistent with previous research on face processing. There were no sex differences in overall response to faces in the fusiform gyrus, and also to faces that did not resemble subjects. When resemblance was not modeled, females showed greater activation to child faces than males. Consistent with parental investment theory and theories of sexual selection, males showed greater cortical activity than females in response to children's faces that resembled them. These data suggest natural selection may have crafted a sexually differentiated neuro-sensory module implicated in detection of facial resemblance that may serve as a kin detection and paternity cue. This process may capitalize on neural substrates involved in self-referent processing and familiarity detection.

Patterns and universals of mate poaching across 53 nations: the effects of sex, culture, and personality on romantically attracting another person's partner

As part of the International Sexuality Description Project, 16,954 participants from 53 nations were administered an anonymous survey about experiences with romantic attraction. Mate poaching--romantically attracting someone who is already in a relationship--was most common in Southern Europe, South America, Western Europe, and Eastern Europe and was relatively infrequent in Africa, South/Southeast Asia, and East Asia. Evolutionary and social-role hypotheses received empirical support. Men were more likely than women to report having made and succumbed to short-term poaching across all regions, but differences between men and women were often smaller in more gender-egalitarian regions. People who try to steal another's mate possess similar personality traits across all regions, as do those who frequently receive and succumb to the poaching attempts by others. The authors conclude that human mate-poaching experiences are universally linked to sex, culture, and the robust influence of personal dispositions.

Electronic Data Base Systems Support the Evaluation of Male Infertility Factors, Example Cryptorchidism

BACKGROUND

A new data base system was applied to analyse our patient group with two aims: (a) to analyze the effects of former cryptorchidism on the fertility of OUR infertility patients in comparison with the data of the literature and (b) to evaluate this system in a clinical study.

MATERIALS AND METHODS

Using the electronic data base Winsperm 2000, 1,648 infertility patients, 79 patients with testicular cancer and 201 healthy semen donors were examined.

RESULTS

A history of cryptorchidism, treated at 6.8 +/- 3.3 years of life, was found in 10.1% of our infertility patient group. The routine spermiogram parameters, as well as basal hormone concentration of FSH, LH and testosterone, differed significantly from those of the healthy semen donor group. Comparison between patients with former unilateral and bilateral cryptorchidism differed significantly only in total sperm count. 27.7% of patients with a history of unilateral and 5.4% of patients with a history of bilateral cryptorchidism showed a sperm concentration within the normal range (p < 0.01). Azoospermia was detected in 13.1% of patients with unilateral cryptorchidism and in 29.7% of patients with former bilateral cryptorchidism (p < 0.05). The patients responding to our conception questionnaire realised a total conception rate of 46.1% in the 'non-cryptorchidism group' and of 20.6% in the 'cryptorchidism-group' (p < 0.05), whereas the conception rates did not differ between former unilateral and bilateral cryptorchidism (p > 0.05). Sixteen (20.3%) of the 79 patients with testicular neoplasm were previously treated for cryptorchidism.

CONCLUSION

The results of our patient group underline the significance of former cryptorchidism for infertility and testicular neoplasm. The new data base system facilitates rapid data retrieval and examination.

Evolution of human mate choice

This article provides a review of evolutionary theory and empirical research on mate choices in nonhuman species and uses it as a frame for understanding the how and why of human mate choices. The basic principle is that the preferred mate choices and attendant social cognitions and behaviors of both women and men, and those of other species, have evolved to focus on and exploit the reproductive potential and reproductive investment of members of the opposite sex. Reproductive potential is defined as the genetic, material, and/or social resources an individual can invest in offspring, and reproductive investment is the actual use of these resources to enhance the physical and social well- being of offspring. Similarities and differences in the mate preferences and choices of women and men are reviewed and can be understood in terms of similarities and differences in the form of reproductive potential that women and men have to offer and their tendency to use this potential for the well-being of children.

ACP best practice no 170. Investigation of infertility with the emphasis on laboratory testing and with reference to radiological imaging

This review will discuss the investigation of infertility, with emphasis on laboratory testing and reference to the value of other investigations, including clinical and radiological. The role of laboratory investigations is viewed within an appropriate clinically directed pathway that includes medical, surgical, and social history together with environmental factors. Because embryology and assisted reproduction techniques are developing rapidly and produce continuous changes in everyday practice, this article gives a critical review of the plethora of tests that are currently used.

Uniparental disomy of chromosome 2 resulting in lethal trifunctional protein deficiency due to homozygous alpha-subunit mutations

The mitochondrial trifunctional protein (TFP) is an enzyme complex of the fatty acid beta-oxidation cycle composed of an alpha- and a beta-subunit. The two encoding genes are located in the same region on chromosome 2 (2p23). TFP deficiency due to either alpha- or beta-subunit mutations is characterized by mutational and phenotypic heterogeneity with severe, early-onset, cardiac forms and milder, later-onset, myopathic phenotypes. In two unrelated patients with lethal TFP deficiency, we delineated apparently homozygous alpha-subunit mutations that were present in heterozygous form in both mothers, but not in either biological father. We performed a microsatellite repeat analysis of both patients and their parents using seven chromosome 2-specific polymorphic DNA markers and four nonchromosome 2 markers. In both patients, two chromosome 2-specific markers demonstrated maternal isodisomy of chromosome 2. The other five chromosome 2-specific markers were noninformative in each patient. Inheritance of alleles from chromosomes 4, 5, and 7 was consistent with paternity. These results explain the apparently anomalous pattern of transmission. Six of our 12 known TFP-deficient patients with alpha-subunit mutations have disease due to homozygous changes and two of them via the mechanism of uniparental disomy (UPD) (16.7%). For very rare autosomal recessive diseases, UPD may represent a common mechanism. This study emphasizes the need to confirm mutations in parents whenever possible. TFP deficiency is another disorder that has become manifest due to isodisomy of chromosome 2. This information will impact genetic counseling for these families, reducing greatly the 25% risk normally used for recessive disorders.

Changes in women's sexual interests and their partners' mate-retention tactics across the menstrual cycle: evidence for shifting conflicts of interest

Because ancestral women could have obtained genetic benefits through extra-pair sex only near ovulation, but paid costs of extra-pair sex throughout the cycle, one might expect selection to have shaped female interest in partners, other than primary partners, to be greater near ovulation than during the luteal phase. Because men would have paid heavier costs if their partners had extra-pair sex near ovulation, one might also expect selection to have shaped males' efforts to track their primary partners' whereabouts to be increased near ovulation, relative to the luteal phase. Women filled out questionnaires about their sexual interests and their partners' mate-retention tactics twice: once within 5 days before a lutenizing hormone surge and once during the luteal phase. Results showed that: (i) women reported greater sexual interest in, and fantasy about, non-primary partners near ovulation than during the luteal phase; (ii) women did not report significantly greater sexual interest in, and fantasy about, primary partners near ovulation; (iii) women reported that their primary partners were both more attentive and more proprietary near ovulation.