Actin protects mammalian eggs against chromosome segregation errors

Chromosome segregation is driven by a spindle that is made of microtubules but is generally thought to be independent of actin. Here, we report an unexpected actin-dependent mechanism that drives the accurate alignment and segregation of chromosomes in mammalian eggs. Prominent actin filaments permeated the microtubule spindle in eggs of several mammalian species, including humans. Disrupting actin in mouse eggs led to significantly increased numbers of misaligned chromosomes as well as lagging chromosomes during meiosis I and II. We found that actin drives accurate chromosome segregation by promoting the formation of functional kinetochore fibers, the microtubule bundles that align and segregate the chromosomes. Thus, actin is essential to prevent chromosome segregation errors in eggs, which are a leading cause of miscarriages, infertility, and Down syndrome.
Source: ScienceNOW - Category: Science Authors: Tags: Cell Biology, Molecular Biology, Online Only r-articles Source Type: news

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ABSTRACT Introduction: We evaluated the relationship between total testicular volume (TTV) and testicular volume differential (TVD) in adolescent males with varicocele. Both low TTV and high TVD have been independently associated with higher incidences of infertility later in life, but a predictive relationship between TTV and TVD directly has yet to be described. Materials and Methods: We retrospectively analyzed a database of Tanner 5 boys ages 16-21 who presented with varicocele at a single institution between 2009 and 2017. All patients had a scrotal sonogram prior to surgical intervention. TTV and TVD were calculated ...
Source: International Braz J Urol - Category: Urology & Nephrology Source Type: research
Conclusion Themeta-analysis suggests that ACE I/D polymorphism is associated with increased risk of RPL. The ACE I/D polymorphism may be a risk factor for RPL in Caucasian and West-Asian populations, but not in East-Asians.
Source: Revista Brasileira de Ginecologia e Obstetricia - Category: OBGYN Source Type: research
ConclusionEndometrial HOXA-10 gene expression in women with endometriosis is significantly down-regulated than in those without endometriosis. Endometriosis patients with infertility have significantly lower levels of endometrial HOXA-10 gene expression than endometriosis without infertility; thus decreased expression of this gene may, directly or indirectly, be related with the endometriosis-associated infertility. Severe endometriosis cases express, in their both endometrium and endometrioma tissues, significantly lower levels of HOXA-10 gene than moderate endometriosis cases.
Source: European Journal of Obstetrics and Gynecology and Reproductive Biology - Category: OBGYN Source Type: research
Abstract: Autoimmune progesterone dermatitis is an uncommon, poorly recognized and under-diagnosed catamenial dermatosis associated with hypersensitivity reactions to progestagens. Most cases manifest as urticaria, eczema or erythema multiforme-like. A 26-year-old woman developed violaceous plaques on the groin and abdomen, 4 days after a spontaneous abortion resolved with uterine curettage. The lesions recurred once monthly at the same sites, mimicking a fixed drug eruption. Although the histopathology was compatible with fixed drug eruption, positive intradermal testing and symptomatic improvement after using oral contra...
Source: Anais Brasileiros de Dermatologia - Category: Dermatology Source Type: research
Conditions:   Polycystic Ovary Syndrome;   Infertility Interventions:   Drug: sequential IVM system;   Procedure: intracytoplasmic sperm injection (ICSI);   Procedure: Thawed embryo transfer (TET);   Drug: traditional IVM system Sponsors:   Sun Yat-sen University;   Hospital for Reproductive Medicine Affiliated to Shandong University;   The First Affiliated Hospital with Nanjing Medical University;   First Affiliated Hospital of Wenzhou Medical University;   Shanghai 10th People's Hosp...
Source: ClinicalTrials.gov - Category: Research Source Type: clinical trials
(Natural News) The Canadian equivalent of CNN has shamelessly published a climate “infographic” that suggests the number one thing everyday people can do to help “mitigate” climate change is to stop having children. Pointing to a study published in the journal Environmental Research Letters, CBC News says there’s actually nothing more effective at combating climate...
Source: NaturalNews.com - Category: Consumer Health News Source Type: news
Authors: Wilch ES, Morton CC Abstract Chromosomal translocations, rearrangements involving the exchange of segments between chromosomes, were documented in humans in 1959. The first accurately reported clinical phenotype resulting from a translocation was that of Down syndrome. In a small percentage of Down syndrome cases, an extra 21q is provided by a Robertsonian translocation chromosome, either occurring de novo or inherited from a phenotypically normal parent with the translocation chromosome and a balanced genome of 45 chromosomes. Balanced translocations, including both Robertsonian and reciprocal translocati...
Source: Advances in Experimental Medicine and Biology - Category: Research Tags: Adv Exp Med Biol Source Type: research
This study shows that lifespan-extending conditions can slow molecular changes associated with an epigenetic clock in mice livers. Diverse interventions that extend mouse lifespan suppress shared age-associated epigenetic changes at critical gene regulatory regions Age-associated epigenetic changes are implicated in aging. Notably, age-associated DNA methylation changes comprise a so-called aging "clock", a robust biomarker of aging. However, while genetic, dietary and drug interventions can extend lifespan, their impact on the epigenome is uncharacterised. To fill this knowledge gap, we defined...
Source: Fight Aging! - Category: Research Authors: Tags: Newsletters Source Type: blogs
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Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs
Tanmoy Mukherjee, MD Associate Director, Division of Reproductive Endocrinology and Infertility, Mount Sinai Health System; Co-Director, Reproductive Medicine Associates of New York; Assistant Clinical Professor of Obstetrics, Gynecology and Reproductive Science, Icahn School of Medicine at Mount Sinai When prospective parents who are unable to conceive a child on their own consult me for assistance, I am excited to help them build their families. But for them, dealing with the challenges of infertility can be as stressful as having cancer. Fortunately, the latest advances in in vitro fertilization (IVF) are giving them a ...
Source: Healthy Living - The Huffington Post - Category: Consumer Health News Source Type: news
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