Sex differential in methylation patterns of selected genes in Singapore Chinese

To date there have been few reports of a gender difference in methylation levels of genes. When examining the methylation levels of four autosomal genes (ESR1, MTHFR, CALCA and MGMT) in the white blood cells of a random sample of Singapore Chinese Health Study cohort participants (n=291), we encountered an unexpected gender differential. Using MethyLight technology, we calculated a gene-specific percentage of methylated reference (PMR) value, which quantified the relative level of gene methylation for each study subject (134 males and 157 females). Two summary methylation indices were constructed by assigning gene-specific rank scores. We then used ANCOVA to compare logarithmically transformed individual PMR values and summary methylation indices by age and gender simultaneously. Adjustment was made for plasma homocysteine. For ESR1, for which a large proportion of subjects were negative for methylation, we also used polytomous regression to compare methylation across age and gender. Increasing age and the male gender independently predicted increasing PMR values for CALCA and MGMT. For the MTHFR gene, male gender was associated with higher PMR values (P=0.002), while age was not (P=0.75). Neither age nor gender had any statistically significant influence on the PMR values for ESR1 (P=0.13 and 0.96, respectively). Our data suggest that gender is at least as strong a predictor of methylation level in the four genes under study as age, with males showing higher PMRs.     

Sex differentials in perinatal mortality in china and Finland

Abstract

This study describes patterns of sex differentials in perinatal mortality in China and Finland. The analysis is based on three population‐based one‐year birth cohorts, one from Qingdao, China, in 1992 and two from Northern Finland in 1966 and 1985–86, comprised of 9,219, 11,422 and 9,207 singletons with at least 28 gestational weeks and 1000 g in birthweight, respectively. Both Finnish cohorts had an excess of male over female perinatal deaths, but in the Chinese cohort girls were more likely to die than boys. The adjusted odds ratio (OR) of perinatal mortality for boys was 1.31 (95 per cent confidence interval [CI] 0.98,1.78) and 1.57 (95 per cent CI 0.89, 2.78) in the Finnish 1966 and 1985–86 cohorts, respectively, and 0.82 (95 per cent CI 0.55,1.20) in the Chinese cohort. The corresponding figure for stillbirths in the Chinese was 0.57 (95 per cent CI 0.33, 0.98), which could explain the total excess of female deaths during the perinatal period. Our results suggest that the role of different social and cultural environments on the existing sex differentials in perinatal mortality between the countries needs further evaluation.     

Sex differences in mouse urination patterns

When tested in circular open fields male and female mice (Mus musculus) produced strongly centrifugal urination patterns, which showed a clear ‘edge-dependency’ in all the field sizes used. However, striking sex differences in the pattern of deposition were shown in terms of both the number and distribution of the urine spots. Male mice produce large numbers of spots which are regularly dispersed, while females produce relatively fewer spots with a more clumped distribution. It is suggested that a hitherto unsuspected level of intersexual communication may explain these differences.     

Asian mothers' risk factors for perinatal death--the same or different? A 10 year review of Leicestershire perinatal deaths.

A case-control study of all perinatal deaths in Leicestershire was established in 1976. By 1985 some 1342 singleton perinatal deaths had occurred. Perinatal mortality among patients of Asian origin was consistently higher than that among European women. Many of the sociomedical risk factors for perinatal death known at booking were common to both population groups. In this population of Asian women, however, low social class was not associated with perinatal risk and illegitimacy hardly ever occurred. In contrast, previous infertility among the Asian women was associated with risk of perinatal death, while no such association was found with European women. In 19% of perinatal deaths care was either inadequately provided or taken up. The case-control design in these circumstances provides a practicable way to evaluate causal factors and at the same time to provide information of value to educators and health service planners.     

Evaluation of the association of zoonotic Ljungan virus with perinatal deaths and fetal malformation

More and more epidemiologic and experimental data support the notion that Ljungan virus (LV), originally isolated from some rodent populations in Sweden, Denmark, and the United States, plays an important role in stillbirth and fetal malformation. Mouse dams infected with LV may result in uterine resorption and perinatal deaths that may cross generations, and their offspring may suffer high rates of malformations including cranial, brain, and limb malformations. In humans, researches founded that LV infection is related to malformation, intrauterine fetal death, and even central nervous system malformation. Although molecularly characterized, little is known about the biophysical nature of LV. Consequently, the role of LV infections in sudden infant death syndrome is still confusing, and the mechanism of how LV infections cause diseases is not clear. More research is clearly necessary to explore the mechanisms of LV infection in human and animal diseases to bring improvement to the clinical outcomes. Birth Defects Research (Part C) 105:81–85, 2015. © 2015 Wiley Periodicals, Inc.     

Mediterranean climate patterns and wine quality in North and Central Italy

Results show that the year-to-year quality variation of wines produced in North and Central Italy depends on the large-scale climate variability, and that the wine quality improvement in the last four decades is partially due to an increase of temperature and to a decrease of precipitation in West and Central Mediterranean Europe (WME; CME). In addition, wine quality is positively correlated with air temperature throughout the entire active period of the grapevine, weakly negatively correlated with precipitation in spring, and well negatively correlated in summer and fall. The month-to-month composites of the NAO anomaly show that, in years of good quality wine, this anomaly is negative in late spring, oscillates around zero in summer, and is positive in early fall; while, in years of bad quality wine, it is positive in late spring and summer, and negative in early fall, i.e. its polarity has an opposite sign in spring and fall in good versus bad years. The composite seasonal maps show that good wines are produced when the spring jet stream over the Atlantic diverts most of the weather perturbations towards North Europe, still providing a sufficient amount of rainwater to CME; when summer warming induced by southerly winds is balanced by the cooling induced by westerly winds; and when a positive geopotential anomaly over WME shelters CME from fall Atlantic storms. Bad quality wines are produced when the jet stream favors the intrusion of the Atlantic weather perturbations into the Mediterranean. Results suggest that atmospheric pattern persistencies can be used as precursors for wine quality forecast.     

Spatial landscape patterns and trends of declining reed-beds in peninsular Italy

Patterns and trends of declining reed-beds in four freshwater ecosystems in central Italy are investigated through an aerial orthoimagery-based diachronic analysis over a period of 24 years. Extent variations and retreat from the waterfront are detected in all sites, compensated only in few cases by backwards enlargements. These shape and size modifications suggest that reed die-back is associated with retreat and with a notable fragmentation process. Long-term analysis performed in one of the sites, compared to water levels, shows a drastic extent decrease co-occurring with an artificial rise of the water level, confirming the regulation of freshwater bodies as a driver of biodiversity loss. Results also suggest that reed-dominated ecosystems may reach a threshold of tolerance towards stressing conditions beyond which they cannot regenerate. The carried out study testifies for a valuable role of landscape metrics in analysing the spatial processes related to declining reed-beds. Spatial metrics prove to be a suitable tool in monitoring processes, working as early warning signals of ongoing decline and helping to model future changes.     

Sex chromosome pairing patterns in male mice of novel Sxr genotypes

The influence of the sex-reversal factor (Sxr) on X and Y chromosome pairing was examined by comparing males with novel and standard Sxr genotypes. The novel Sxr males were exceptional in carrying Sxr on their X rather than their Y chromosome, or homozygously on both their X and Y chromosomes, or on a Y chromosome of different origin to that on which the factor arose. Regardless of its chromosomal location, Sxr was found to elevate the frequency of X-Y separation. Univalent X and Y chromosomes were observed to undergo self-association in a variable proportion of spermatocytes of all Sxr-carrying males. There was a suggestion that chromosomal location of the factor could influence the frequency of univalent self-association. Our observations do not support the published hypothesis of Y self-pairing as the cause of the elevated rate of X-Y separation at pachytene in Sxr-carrying males. Rather, they suggest that heterozygosity due to the presence of Sxr in the XY pairing region may be sufficient to disrupt pairing and cause univalence, or alternatively, that Sxr is an inefficient promoter of X-Y pairing initiation.     

Sex and diel period influence patterns of resource selection in elk

Resource selection and space use are important aspects of an animal's ecology and understanding these behaviors is necessary for proper wildlife management. We used mixed-effect integrated step-selection models to evaluate seasonal variation in resource selection between male and female elk (Cervus canadensis) and diel periods in central Pennsylvania, USA. Resource selection varied seasonally, between sexes, and across diel periods. These results demonstrate strong seasonal sexual segregation in resource use, and movements between habitats throughout the day, highlighting the dynamic nature of resource selection by elk and underscoring the importance of considering sexual variation at multiple temporal scales when designing ungulate management strategies. Finally, we developed habitat suitability maps for male and female elk in the Pennsylvania Elk Management Area. Wildlife ecologists and managers must consider multiple sources of variation in habitat use and resource selection, particularly for large mobile species such as elk.     

Geographic homogeneity and non-equilibrium patterns of mtDNA sequences in Tuscany,Italy

The geographical distribution of 49 mtDNA sequences from 22 localities in Southern Tuscany, Italy, was studied by molecular analysis of variance, by a new spatial autocorrelation statistic specifically designed for sequence data and by reconstructing genealogies of haplotypes. All these methods indicated a high homogeneity of populations. Nevertheless, genetic variability showed significant departure from equilibrium expectations, in agreement with the predicted effects of a population expansion. We suggest that a past population expansion that was probably associated with a migrational wave and with local gene flow between localities prevented spatial structuring in Southern Tuscany. Received: 30 November 1995 / Revised: 5 March 1996     

Value and quality of perinatal and infant postmortem examinations: cohort analysis of 400 consecutive deaths.

OBJECTIVES--To evaluate the contribution that perinatal and infant necropsy makes to clinical practice and to see how this might be influenced by the quality of the investigation. DESIGN--Cohort analysis, with data from the all Wales perinatal survey, of perinatal and infant deaths during 1993 of babies born to mothers usually resident in Wales. The clinicopathological classification of death based on clinical details was compared with the classification after necropsy. Similarly, cases in which necropsy yielded new information were identified. The quality of the necropsy was assessed by scoring six aspects of the examination. SUBJECTS--400 consecutive deaths at 20 weeks of gestation to 1 year of age. MAIN OUTCOME MEASURES--Necropsy rate, effect of necropsy on clinicopathological classification, new information disclosed by necropsy, quality of necropsies, and the link between new information and quality of the necropsy. RESULTS--Necropsy was performed in 232 cases (58%). The clinicopathological classification was altered by necropsy in 29 cases (13%). New information was obtained in 60 cases (26%), and in 42 (18%) it disclosed the cause of death. The quality of necropsy was substantially higher when the main cause of death was detected than when nothing new was found. CONCLUSION--Necropsy is underused. Clinicians should be more positive about necropsies and realise how much clinically relevant information can be obtained from a good quality examination.     

Characterization of genes with tissue-specific differential expression patterns in Populus

Like many plants, Populus has an evolutionary history in which several, both recent and more ancient, genome duplication events have occurred and, therefore, constitutes an excellent model system for studying the functional evolution of genes. In the present study, we have focused on the properties of genes with tissue-specific differential expression patterns in poplar. We identified the genes by analyzing digital expression profiles derived by mapping 90,000+ expressed sequence tags (ESTs) from 18 sources to the predicted genes of Populus. Our sequence analysis suggests that tissue-specific differentially expressed genes have less diverged paralogs than average, indicating that gene duplication events is an important event in the pathway leading to this type of expression pattern. The functional analysis showed that genes coding for proteins involved in processes of functional importance for the specific tissue(s) in which they are expressed and genes coding for regulatory or responsive proteins are most common among the differentially expressed genes, demonstrating that the expression differentiation process is under strong selective pressure. Thus, our data supports a model where gene duplication followed by gene specialization or expansion of the regulatory and responsive networks leads to tissue-specific differential expression patterns. We have also searched for clustering of genes with similar expression pattern into gene-expression neighborhoods within the Populus genome. However, we could not detect any major clustering among the analyzed genes with highly specific expression patterns. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Sex differences in dogfish behaviour: alternative activity patterns and habitat choice

Guppies are highly sexually dimorphic and females have been shown to mate preferentially with males with various visible traits. Guppies, however, have been shown to respond behaviourally to odour cues from conspecifics. Using a specially designed olfactory choice tank, we tested whether females (1) could detect other guppies on the basis of their olfactory cues alone, (2) preferred to associate with males or with females and (3) could distinguish between different males. Female guppies were found to associate preferentially with other guppies when given a choice between water containing cues from another fish and water containing no cues. When females were presented with olfactory cues from a male or a female, they preferred the female initially but most then reversed their decision and swam to the male. Females associated preferentially with certain males based upon olfactory cues alone. Males, however, preferred on the basis of olfactory cues were the least preferred for visual cues.