scholarly journals Reduced heterozygosity impairs sperm quality in endangered mammals

2009 ◽  
Vol 5 (3) ◽  
pp. 320-323 ◽  
Author(s):  
John L. Fitzpatrick ◽  
Jonathan P. Evans
Keyword(s):  
Sperm Quality ◽  
Reproductive Function ◽  
Comparative Approach ◽  
Functional Explanation ◽  
Mammal Species ◽  
Sperm Abnormalities ◽  
Genome Wide ◽  
Outbred Populations ◽  
Inbred Populations ◽  
The Relationship

Inbreeding causes increases in homozygosity and is commonly associated with reductions in fertility and embryogenesis. Although the mechanisms underlying such effects are unknown, recent work has suggested that inbred males may suffer impaired ejaculate quality, thus providing a functional explanation for reductions in reproductive function in inbred populations. However, the relationship between inbreeding and sperm quality remains controversial, particularly in wild populations where the level of inbreeding is typically estimated using neutral molecular markers. Such markers are thought to reflect genome-wide levels of heterozygosity only under restricted conditions, and rarely in outbred populations. Here we employ a comparative approach that takes account of these criticisms and evaluates the evidence linking inbreeding to reductions in sperm quality in 20 mammal species. We focus on sperm abnormalities and sperm motility, which are key determinants of male fertility in many species. We show that species with reduced mean heterozygosity have impaired ejaculated quality, although subsequent analyses revealed that these effects were confined to endangered populations. Our findings therefore support the notion that inbreeding can severely impair sperm quality while concomitantly addressing criticisms surrounding the use of heterozygosity estimates to estimate the level of inbreeding.

The relation between obesity, kisspeptin, leptin, and male fertility

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Saber Ghaderpour ◽  
Rafighe Ghiasi ◽  
Hamed Heydari ◽  
Rana Keyhanmanesh
Keyword(s):  
Male Fertility ◽  
Sperm Quality ◽  
Reproductive Potential ◽  
Reproductive Function ◽  
Leptin Resistance ◽  
Resistance Development ◽  
Reproductive Axis ◽  
Gnrh Release ◽  
Hpt Axis ◽  
The Relationship

Abstract Over the past decades, obesity and infertility in men increased in parallel, and the association between both phenomena have been examined by several researchers. despite the fact that there is no agreement, obesity appears to affect the reproductive potential of men through various mechanisms, such as changes in the hypothalamic-pituitary-testicular (HPT) axis, spermatogenesis, sperm quality and/or alteration of sexual health. Leptin is a hormone produced by the adipose tissue, and its production elevates with increasing body fat. Many studies have supported the relationship between raised leptin production and reproductive function regulation. In fact, Leptin acts on the HPT axis in men at all levels. However, most obese men are insensitive to increased production of endogenous leptin and functional leptin resistance development. Recently, it has been recommended that Kisspeptin neurons mediate the leptin’s effects on the reproductive system. Kisspeptin binding to its receptor on gonadotropin-releasing hormone (GnRH) neurons, activates the mammal’s reproductive axis and stimulates GnRH release. Increasing infertility associated with obesity is probably mediated by the Kisspeptin-GnRH pathway. In this review, the link between obesity, kisspeptin, leptin, and male fertility will be discussed.

scholarly journals The genetic rescue of two bottlenecked South Island robin populations using translocations of inbred donors

2013 ◽  
Vol 280 (1752) ◽  
pp. 20122228 ◽  
Author(s):  
S. Heber ◽  
A. Varsani ◽  
S. Kuhn ◽  
A. Girg ◽  
B. Kempenaers ◽  
...  
Keyword(s):  
Endangered Species ◽  
Sperm Quality ◽  
Allelic Diversity ◽  
Juvenile Survival ◽  
Genetic Rescue ◽  
Reciprocal Translocations ◽  
Limited Application ◽  
Outbred Populations ◽  
Inbred Populations ◽  
Two Populations

Populations forced through bottlenecks typically lose genetic variation and exhibit inbreeding depression. ‘Genetic rescue’ techniques that introduce individuals from outbred populations can be highly effective in reversing the deleterious effects of inbreeding, but have limited application for the majority of endangered species, which survive only in a few bottlenecked populations. We tested the effectiveness of using highly inbred populations as donors to rescue two isolated and bottlenecked populations of the South Island robin ( Petroica australis ). Reciprocal translocations significantly increased heterozygosity and allelic diversity. Increased genetic diversity was accompanied by increased juvenile survival and recruitment, sperm quality, and immunocompetence of hybrid individuals (crosses between the two populations) compared with inbred control individuals (crosses within each population). Our results confirm that the implementation of ‘genetic rescue’ using bottlenecked populations as donors provides a way of preserving endangered species and restoring their viability when outbred donor populations no longer exist.

scholarly journals Discovery of runs-of-homozygosity diplotype clusters and their associations with diseases in UK Biobank

2020 ◽  
Author(s):  
Ardalan Naseri ◽  
Degui Zhi ◽  
Shaojie Zhang
Keyword(s):  
Demographic History ◽  
Hfe Gene ◽  
Uk Biobank ◽  
Runs Of Homozygosity ◽  
Genome Wide ◽  
A Genome ◽  
Large Populations ◽  
History Of ◽  
Outbred Populations ◽  
Inbred Populations

AbstractRuns of homozygosity (ROH) segments, contiguous homozygous regions in a genome were traditionally linked to families and inbred populations. However, a growing literature suggests that ROHs are ubiquitous in outbred populations. Still, most existing genetic studies of ROH in populations are limited to aggregated ROH content across the genome, which does not offer the resolution for mapping causal loci. This limitation is mainly due to a lack of methods for efficient identification of shared ROH diplotypes. Here, we present a new method, ROH-DICE, to find large ROH diplotype clusters, sufficiently long ROHs shared by a sufficient number of individuals, in large cohorts. ROH-DICE identified over 1 million ROH diplotypes that span over 100 SNPs and shared by more than 100 UK Biobank participants. Moreover, we found significant associations of clustered ROH diplotypes across the genome with various self-reported diseases, with the strongest associations found between the extended HLA region and autoimmune disorders. We found an association between a diplotype covering the HFE gene and haemochromatosis, even though the well-known causal SNP was not directly genotyped nor imputed. Using genome-wide scan, we identified a putative association between carriers of an ROH diplotype in chromosome 4 and an increase of mortality among COVID-19 patients. In summary, our ROH-DICE method, by calling out large ROH diplotypes in a large outbred population, enables further population genetics into the demographic history of large populations. More importantly, our method enables a new genome-wide mapping approach for finding disease-causing loci with multi-marker recessive effects at population scale.

Colonialism and the Highland Clearances

2017 ◽  
Vol 8 (1) ◽  
pp. 22-48 ◽  
Author(s):  
Iain Mackinnon
Keyword(s):  
Industrial Development ◽  
Comparative Approach ◽  
Indigenous Research ◽  
Internal Colonialism ◽  
New Approach ◽  
A Site ◽  
Relationship Of ◽  
The Relationship ◽  
Imperial State ◽  
Late Modern

This article employs a new approach to studying internal colonialism in northern Scotland during the 18th and 19th centuries. A common approach to examining internal colonial situations within modern state territories is to compare characteristics of the internal colonial situation with attested attributes of external colonial relations. Although this article does not reject the comparative approach, it seeks to avoid criticisms that this approach can be misleading by demonstrating that promoters and managers of projects involving land use change, territorial dispossession and industrial development in the late modern Gàidhealtachd consistently conceived of their work as projects of colonization. It further argues that the new social, cultural and political structures these projects imposed on the area's indigenous population correspond to those found in other colonial situations, and that racist and racialist attitudes towards Gaels of the time are typical of those in colonial situations during the period. The article concludes that the late modern Gàidhealtachd has been a site of internal colonization where the relationship of domination between colonizer and colonized is complex, longstanding and occurring within the imperial state. In doing so it demonstrates that the history and present of the Gaels of Scotland belongs within the ambit of an emerging indigenous research paradigm.

THE ONTOLOGICAL ROOTEDNESS OF COGNITIVE PRACTICES LINGUISTIC FORMS IN RELIGIOUS SOCIO-CULTURAL TRADITIONS: A COMPARATIVE APPROACH

Communicology ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 138-148
Author(s):  
NATALIA MALSHINA ◽  
Keyword(s):  
Traditional Approach ◽  
Philosophical Tradition ◽  
Psychological State ◽  
Comparative Approach ◽  
Cultural Traditions ◽  
Fundamental Ontology ◽  
Ontology Language ◽  
The World ◽  
True Knowledge ◽  
The Relationship

This study examines the ontological problems in the aspect of the ratio of different cognitive practices and their mutual conditionality in the context of communication and their socio-cultural prerequisites, which is possible only if the traditional approach to the distinction between epistemology and faith is revised. Based on the idea of identity of common grounds of cognitive practices “belief” is included in the understanding of interpretation in the communicative situation for true knowledge in each of the modes of being. Belief in the philosophical tradition reveals the ontological foundations of hermeneutics. Three reflections are synthesised: the hermeneutic concept of understanding, the structuralist concept of language, and the psychoanalytic concept of personality. It is necessary to apply the method of phenomenological reduction to the ontological substantiation of hermeneutics in the Christian Orthodox tradition. Hence, the very natural seems the meeting of semantics, linguistics, and onomatodoxy, with the ontology language of Heidegger, the origins of which resides in in Husserl phenomenology. Fundamental ontology and linguistics, cult philosophy - both in different ways open the horizons of substantiation of hermeneutics. The beginning of this justification is the hermeneutic problem in Christianity, which has appeared as a sequence of the question of the relationship between the two Covenants, or two Unions. In the paper, the author attempts to identify the stages of constructing the philosophical concept of Pavel Florensky. As a result, the substantiation of the birth of the world in consciousness by the cult is revealed. Ontological tradenote words can be seen in Florensky through symbols. The symbol makes the transition from a small energy to a larger one, from a small information saturation to a greater one, acting as a lumen of being - when by the name we hear the reality. The word comes into contact with the world that is on the other side of our own psychological state. The word, the symbol shifts all the time from subjective to objective. The communicative model acts as a common point uniting these traditions. The religious approach as part of semiotic approach reveals the horizons of ontological conditionality of language and words, and among the words - the name, as the name plays a central role in the accumulation and transmission of information, understanding of the commonality of this conditionality in the concepts of phenomenology and Christian, Orthodox tradition.

Migraine: Genetic Variants and Clinical Phenotypes

2019 ◽  
Vol 26 (34) ◽  
pp. 6207-6221 ◽  
Author(s):  
Innocenzo Rainero ◽  
Alessandro Vacca ◽  
Flora Govone ◽  
Annalisa Gai ◽  
Lorenzo Pinessi ◽  
...  
Keyword(s):  
Genetic Variants ◽  
Association Studies ◽  
Mthfr Gene ◽  
Genome Wide Association Studies ◽  
Clinical Phenotypes ◽  
Network Analyses ◽  
Genome Wide ◽  
Genomic Studies ◽  
The Common ◽  
The Relationship

Migraine is a common, chronic neurovascular disorder caused by a complex interaction between genetic and environmental risk factors. In the last two decades, molecular genetics of migraine have been intensively investigated. In a few cases, migraine is transmitted as a monogenic disorder, and the disease phenotype cosegregates with mutations in different genes like CACNA1A, ATP1A2, SCN1A, KCNK18, and NOTCH3. In the common forms of migraine, candidate genes as well as genome-wide association studies have shown that a large number of genetic variants may increase the risk of developing migraine. At present, few studies investigated the genotype-phenotype correlation in patients with migraine. The purpose of this review was to discuss recent studies investigating the relationship between different genetic variants and the clinical characteristics of migraine. Analysis of genotype-phenotype correlations in migraineurs is complicated by several confounding factors and, to date, only polymorphisms of the MTHFR gene have been shown to have an effect on migraine phenotype. Additional genomic studies and network analyses are needed to clarify the complex pathways underlying migraine and its clinical phenotypes.

The Prevalence of Bacteriospermia in Infertile Men and Association with Semen Quality in Southwestern Iran

2020 ◽  
Vol 20 (2) ◽  
pp. 198-202 ◽  
Author(s):  
Mohammad Motamedifar ◽  
Yalda Malekzadegan ◽  
Parisa Namdari ◽  
Behzad Dehghani ◽  
Bahia Namavar Jahromi ◽  
...  
Keyword(s):  
Semen Quality ◽  
Sperm Quality ◽  
Reproductive Function ◽  
World Health ◽  
Public Health Issue ◽  
Control Group ◽  
Microbiological Analysis ◽  
Male Reproductive Function ◽  
Infertile Men ◽  
Southwestern Iran

Introduction: Infertility considered as a social and public health issue and estimated that most of these infertile couples are residents of developing countries. Infectious diseases including the history of Sexually Transmitted Infections (STIs) may impact on male reproductive function. Therefore, the present study aimed to investigate the prevalence of bacterial contaminants of semen and probable association with sperm quality of infertile men in Iranian population. Methods: The study population consisted of 200 infertile men and 150 fertile men attending an infertility Center in southwestern Iran during the study period in 2015. The assessment of sperm parameters was according to the World Health Organization (WHO) guidelines. The presumptive pathogens were identified using standard microbiology tests and confirmed by specific PCR primers. Results: The prevalence of bacteriospermia in the semen of the infertile group was significantly higher than that in the fertile group (48% vs. 26.7%, P <0.001). The microbiological analysis of samples showed that the most abundant species of bacteria in semen of infertile men were Chlamydia trachomatis (12.5%) followed by Neisseria gonorrhoeae (11%). On the other hand, in the control group, Lactobacillus spp. (17.3%) was the most isolated pathogen. Results showed that the presence of N. gonorrhoeae, C. trachomatis, Mycoplasma genitalium, Haemophilus, and Klebsiella was significantly associated with sperm abnormality. Conclusion: Based on our findings, it seems that bacteriospermia is associated with alterations in the properties of semen which may lead to a decrease in the fertilization potential of sperm. Therefore, immediate and appropriate treatment is necessary before investigating every other possible cause of infertility.

scholarly journals CagA-PositiveHelicobacter pyloriInfection and Reduced Sperm Motility, Vitality, and Normal Morphology

2013 ◽  
Vol 35 ◽  
pp. 229-234 ◽  
Author(s):  
E. Moretti ◽  
G. Collodel ◽  
L. Mazzi ◽  
M. S. Campagna ◽  
N. Figura
Keyword(s):  
Sperm Motility ◽  
Normal Forms ◽  
Molecular Mimicry ◽  
Sperm Quality ◽  
Semen Analysis ◽  
Normal Morphology ◽  
Partial Linear ◽  
Caga Status ◽  
The Relationship ◽  
Autoimmune Phenomena

Helicobacter pylori(HP) infection, particularly when caused by strains expressing CagA, may be considered a concomitant cause of male and female reduced fertility. This study explored, in 87 HP-infected males, the relationship between infection by CagA-positive HP strains and sperm parameters. HP infection and CagA status were determined by ELISA and Western blotting; semen analysis was performed following WHO guidelines. The amino acid sequence of human enzymes involved in glycolysis and oxidative metabolism were “blasted” with peptides expressed by HP J99. Thirty-seven patients (42.5%) were seropositive for CagA. Sperm motility (18% versus 32%; ), sperm vitality (35% versus 48%; ) and the percentage of sperm with normal forms (18% versus 22%; ) in the CagA-positive group were significantly reduced versus those in the CagA-negative group. All the considered enzymes showed partial linear homology with HP peptides, but four enzymes aligned with four different segments of the samecagisland protein. We hypothesize a relationship between infection by strains expressing CagA and decreased sperm quality. Potentially increased systemic levels of inflammatory cytokines that occur in infection by CagA-positive strains and autoimmune phenomena that involve molecular mimicry could explain the pathogenetic mechanism of alterations observed.

scholarly journals Inheritable testicular metabolic memory of high-fat diet causes transgenerational sperm defects in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luís Crisóstomo ◽  
Ivana Jarak ◽  
Luís P. Rato ◽  
João F. Raposo ◽  
Rachel L. Batterham ◽  
...  
Keyword(s):  
Sperm Quality ◽  
Feeding Habits ◽  
Reproductive Function ◽  
Principal Component ◽  
Testicular Tissue ◽  
Sperm Parameters ◽  
Metabolic Memory ◽  
High Fat ◽  
And Function ◽  
The Impact

AbstractThe consumption of energy-dense diets has contributed to an increase in the prevalence of obesity and its comorbidities worldwide. The adoption of unhealthy feeding habits often occurs at early age, prompting the early onset of metabolic disease with unknown consequences for reproductive function later in life. Recently, evidence has emerged regarding the intergenerational and transgenerational effects of high-fat diets (HFD) on sperm parameters and testicular metabolism. Hereby, we study the impact of high-fat feeding male mice (F0) on the testicular metabolome and function of their sons (F1) and grandsons (F2). Testicular content of metabolites related to insulin resistance, cell membrane remodeling, nutritional support and antioxidative stress (leucine, acetate, glycine, glutamine, inosine) were altered in sons and grandsons of mice fed with HFD, comparing to descendants of chow-fed mice. Sperm counts were lower in the grandsons of mice fed with HFD, even if transient. Sperm quality was correlated to testicular metabolite content in all generations. Principal Component Analysis of sperm parameters and testicular metabolites revealed an HFD-related phenotype, especially in the diet-challenged generation and their grandsons. Ancestral HFD, even if transient, causes transgenerational “inherited metabolic memory” in the testicular tissue, characterized by changes in testicular metabolome and function.

scholarly journals Variation in VKORC1 Is Associated with Vascular Dementia

2021 ◽  
Vol 80 (3) ◽  
pp. 1329-1337
Author(s):  
Jure Mur ◽  
Daniel L. McCartney ◽  
Daniel I. Chasman ◽  
Peter M. Visscher ◽  
Graciela Muniz-Terrera ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Vascular Dementia ◽  
Genetic Variant ◽  
Warfarin Dose ◽  
Uk Biobank ◽  
Parental History ◽  
Genome Wide ◽  
History Of ◽  
First Time ◽  
The Relationship

Background: The genetic variant rs9923231 (VKORC1) is associated with differences in the coagulation of blood and consequentially with sensitivity to the drug warfarin. Variation in VKORC1 has been linked in a gene-based test to dementia/Alzheimer’s disease in the parents of participants, with suggestive evidence for an association for rs9923231 (p = 1.8×10–7), which was included in the genome-wide significant KAT8 locus. Objective: Our study aimed to investigate whether the relationship between rs9923231 and dementia persists only for certain dementia sub-types, and if those taking warfarin are at greater risk. Methods: We used logistic regression and data from 238,195 participants from UK Biobank to examine the relationship between VKORC1, risk of dementia, and the interplay with warfarin use. Results: Parental history of dementia, APOE variant, atrial fibrillation, diabetes, hypertension, and hypercholesterolemia all had strong associations with vascular dementia (p < 4.6×10–6). The T-allele in rs9923231 was linked to a lower warfarin dose (βperT - allele = –0.29, p < 2×10–16) and risk of vascular dementia (OR = 1.17, p = 0.010), but not other dementia sub-types. However, the risk of vascular dementia was not affected by warfarin use in carriers of the T-allele. Conclusion: Our study reports for the first time an association between rs9923231 and vascular dementia, but further research is warranted to explore potential mechanisms and specify the relationship between rs9923231 and features of vascular dementia.

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