Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Meiosis I01:49

Meiosis I

Meiosis is a carefully orchestrated set of cell divisions, the goal of which—in humans—is to produce haploid sperm or eggs, each containing half the number of chromosomes present in somatic cells elsewhere in the body. Meiosis I is the first such division, and involves several key steps, among them: condensation of replicated chromosomes in diploid cells; the pairing of homologous chromosomes and their exchange of information; and finally, the separation of homologous chromosomes by a...
Sex-linked Disorders01:43

Sex-linked Disorders

Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked.
Nondisjunction01:29

Nondisjunction

During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
Sex Linked Disorders01:43

Sex Linked Disorders

Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked.
Nondisjunction01:29

Nondisjunction

During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
Nondisjunction01:21

Nondisjunction

Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers.  Nondisjunction is common during anaphase I or anaphase II of meiosis.  Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold sister...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Lessons from KEEPS: the Kronos Early Estrogen Prevention Study.

Climacteric : the journal of the International Menopause Society·2020
Same author

Bioinformatic analysis of benzo-α-pyrene-induced damage to the human placental insulin-like growth factor-1 gene.

Reproductive sciences (Thousand Oaks, Calif.)·2013
Same author

The PBRN initiative: transforming new technologies to improve patient care.

Journal of dental research·2012
Same author

Progestin receptor-containing cells in guinea pig hypothalamus: Afferent connections, morphological characteristics, and neurotransmitter content.

Molecular and cellular neurosciences·2009
Same author

Using basic science to design a clinical trial: baseline characteristics of women enrolled in the Kronos Early Estrogen Prevention Study (KEEPS).

Journal of cardiovascular translational research·2009
Same author

HRT in the early menopause: scientific evidence and common perceptions.

Climacteric : the journal of the International Menopause Society·2008
Same journal

Likelihood ratios enhance clinical interpretation of metagenomic prediction of early-onset neonatal sepsis in preterm premature rupture of membranes (Letter-to-the-Editor).

American journal of obstetrics and gynecology·2026
Same journal

Taking risk stratification in preterm premature rupture of membranes to the bedside (Reply to Letter-to-the-Editor).

American journal of obstetrics and gynecology·2026
Same journal

Gestational Age at Full-Term Delivery and Long-Term Offspring Morbidity in Low-Risk Pregnancies: A Population-Based Cohort Study.

American journal of obstetrics and gynecology·2026
Same journal

Trajectories of childbirth-related posttraumatic stress symptoms after a vaginal delivery: a multicenter prospective study.

American journal of obstetrics and gynecology·2026
Same journal

Early life adversity and polycystic ovary syndrome among North American pregnancy planners.

American journal of obstetrics and gynecology·2026
Same journal

Survival assessment of adjuvant chemotherapy for cytology-negative, non-myoinvasive stage IC clear cell endometrial cancer.

American journal of obstetrics and gynecology·2026
See all related articles

Related Experiment Video

Updated: Jun 28, 2026

Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas
09:04

Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas

Published on: September 5, 2011

Discordant severe cranial defects in monozygous twins.

R Osathanodh, S G Driscoll, F Naftolin

    American Journal of Obstetrics and Gynecology
    |June 1, 1975
    PubMed
    Summary
    This summary is machine-generated.

    This study reports three cases of monozygous male twins where one twin had severe developmental abnormalities like exencephaly, while the other was normal. Findings suggest environmental factors may contribute to these rare twin conditions.

    More Related Videos

    Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye
    09:52

    Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye

    Published on: September 5, 2011

    Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model
    08:03

    Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model

    Published on: November 4, 2025

    Related Experiment Videos

    Last Updated: Jun 28, 2026

    Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas
    09:04

    Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas

    Published on: September 5, 2011

    Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye
    09:52

    Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye

    Published on: September 5, 2011

    Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model
    08:03

    Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model

    Published on: November 4, 2025

    Area of Science:

    • Developmental biology
    • Human genetics
    • Teratology

    Background:

    • Monozygous twins can exhibit discordant phenotypes.
    • Congenital abnormalities in twins present unique diagnostic and etiological challenges.
    • Exencephaly, anencephaly, and acephaly are severe neural tube defects.

    Purpose of the Study:

    • To report and analyze three cases of monozygous male twins with discordant severe congenital abnormalities.
    • To investigate potential etiological factors, including environmental influences, in these rare twin presentations.

    Main Methods:

    • Pathologic examination to confirm monozygosity.
    • Blood group antigen testing in one case for corroboration.
    • Clinical and pathological review of the affected twin pairs.

    Main Results:

    • Three cases of monozygous male twins were identified, with one twin exhibiting exencephaly/anencephaly/acephaly and the cotwin being normal.
    • Pathologic examination confirmed monozygosity in all cases.
    • One case showed adrenal hypoplasia and chorionic vascular anastomoses, suggesting potential environmental influences.

    Conclusions:

    • Monozygosity with severe discordant congenital malformations can occur.
    • Environmental factors, possibly acting through mechanisms like vascular anastomoses, may play a role in the etiology of these conditions.
    • Further research is warranted to elucidate the interplay of genetic and environmental factors in twin developmental discordance.