20 research outputs found
Sexually Selected Infanticide in a Polygynous Bat
Background: Adult individuals of many species kill unrelated conspecific infants for several adaptive reasons ranging from predation or resource competition to the prevention of misdirected parental care. Moreover, infanticide can increase the reproductive success of the aggressor by killing the offspring of competitors and thereafter mating with the victimized females. This sexually selected infanticide predominantly occurs in polygynous species, with convincing evidence for primates, carnivores, equids, and rodents. Evidence for bats was predicted but lacking. Methodology/Principal Findings: Here we report the first case, to our knowledge, of sexually selected infanticide in a bat, the polygynous white-throated round-eared bat, Lophostoma silvicolum. Behavioral studies in a free-living population revealed that an adult male repeatedly attacked and injured the pups of two females belonging to his harem, ultimately causing the death of one pup. The infanticidal male subsequently mated with the mother of the victimized pup and this copulation occurred earlier than any other in his harem. Conclusions/Significance: Our findings indicate that sexually selected infanticide is more widespread than previously thought, adding bats as a new taxon performing this strategy. Future work on other bats, especially polygynous species in the tropics, has great potential to investigate the selective pressures influencing the evolution of sexually selecte
New loci associated with birth weight identify genetic links between intrauterine growth and adult height and metabolism.
Birth weight within the normal range is associated with a variety of adult-onset diseases, but the mechanisms behind these associations are poorly understood. Previous genome-wide association studies of birth weight identified a variant in the ADCY5 gene associated both with birth weight and type 2 diabetes and a second variant, near CCNL1, with no obvious link to adult traits. In an expanded genome-wide association meta-analysis and follow-up study of birth weight (of up to 69,308 individuals of European descent from 43 studies), we have now extended the number of loci associated at genome-wide significance to 7, accounting for a similar proportion of variance as maternal smoking. Five of the loci are known to be associated with other phenotypes: ADCY5 and CDKAL1 with type 2 diabetes, ADRB1 with adult blood pressure and HMGA2 and LCORL with adult height. Our findings highlight genetic links between fetal growth and postnatal growth and metabolism
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The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study.
Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHRadjBMI in four strata (men â€50y, men >50y, women â€50y, women >50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR<5%) age-specific effects, of which 11 had larger effects in younger (<50y) than in older adults (â„50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape
Tumor angiogenesis as prognostic and predictive marker for chemotherapy dose-intensification efficacy in high-risk breast cancer patients within the WSG AM-01 trial
The goal of this analysis was to characterize the survival impact of angiogenesis in the patients with high-risk breast cancer, particularly the predictive impact on benefit from dose intensification of adjuvant chemotherapy. Formalin-fixed tissue sample of 152 patients treated as part of the WSG AM-01 trial by either high-dose or conventional dose-dense chemotherapy were analyzed. Angiogenic activity was measured using microvessel count and vascular surface area (VSA) determined by the expression of vascular markers CD31 (n = 128) and CD105/endoglin (n = 130). Protein molecular breast cancer subclasses were analyzed by k-means clustering (k = 5). The univariate impact of factors on event-free (EFS) and overall survival (OS) was tested by log-rank statistics and quantified by univariate Cox analysis. Multivariate survival analysis included factors significant in univariate analysis, as well as interactions was performed for EFS. Both VSA/CD31 (P = 0.004) and VSA/CD105 (P = 0.003) were significantly higher among cases with increased Ki-67. A significant association with molecular subtypes was also found for VSA/CD105: in patients with basal-like/Her-2 subtypes, mean was 1.72 versus 1.24 in patients with other subtypes (P < 0.001). Elevated VSA/CD105 was associated with both significantly decreased EFS (P = 0.01) and OS (P = 0.02). Increased tumor size and positive Her-2 status were also prognostic for poorer EFS. The benefit of dose intensification for EFS was seen in those low-VSA/CD105 patients. The result was evident both in univariate and in multivariate survival analysis including all factors that were significant at the univariate level. Expression of angiogenesis markers may mirror or confer resistance to chemotherapy in the patients with breast cancer, particularly within the context of dose intensified chemotherapy. Highly angiogenic tumors may not derive sufficient benefit from dose intensification of chemotherapy alone. Our findings may serve as a rationale for further exploring anti-angiogenic treatment options in the patients with such highly angiogenic tumor subtypes
New loci associated with birth weight identify genetic links between intrauterine growth and adult height and metabolism
Birth weight within the normal range is associated with a variety of
adult-onset diseases, but the mechanisms behind these associations are
poorly understood(1). Previous genome-wide association studies of birth
weight identified a variant in the ADCY5 gene associated both with birth
weight and type 2 diabetes and a second variant, near CCNL1, with no
obvious link to adult traits(2). In an expanded genome-wide association
metaanalysis and follow-up study of birth weight (of up to 69,308
individuals of European descent from 43 studies), we have now extended
the number of loci associated at genome-wide significance to 7,
accounting for a similar proportion of variance as maternal smoking.
Five of the loci are known to be associated with other phenotypes: ADCY5
and CDKAL1 with type 2 diabetes, ADRB1 with adult blood pressure and
HMGA2 and LCORL with adult height. Our findings highlight genetic links
between fetal growth and postnatal growth and metabolism
Evidence of a causal effect of genetic tendency to gain muscle mass on uterine leiomyomata
Uterine leiomyomata (UL) are the most common tumours of the female genital tract and the primary cause of surgical removal of the uterus. Genetic factors contribute to UL susceptibility. To add understanding to the heritable genetic risk factors, we conduct a genome-wide association study (GWAS) of UL in up to 426,558 European women from FinnGen and a previous UL meta-GWAS. In addition to the 50 known UL loci, we identify 22 loci that have not been associated with UL in prior studies. UL-associated loci harbour genes enriched for development, growth, and cellular senescence. Of particular interest are the smooth muscle cell differentiation and proliferation-regulating genes functioning on the myocardin-cyclin dependent kinase inhibitor 1A pathway. Our results further suggest that genetic predisposition to increased fat-free mass may be causally related to higher UL risk, underscoring the involvement of altered muscle tissue biology in UL pathophysiology. Overall, our findings add to the understanding of the genetic pathways underlying UL, which may aid in developing novel therapeutics.Peer reviewe