The mixed lineage leukemia gene (MLL) was originally identified through its involvement in reciprocal translocations in leukemias. MLL codes for a large multidomain protein and bears homology to the Drosophila developmental control gene trithorax in two small domains in the amino terminal region, the central zinc finger domain and the carboxy SET domain. Like the Drosophila trx, MLL has also been shown to be a positive regulator of Hox gene expression. We have targeted Mll (the murine homologue of MLL) in exon 5 causing expression of three truncated in-frame Mll transcripts. These transcripts retain all or some of the AT hook motifs and the DMT domain. This mutant allele causes early in vivo preimplantation lethality of homozygous embryos prior to the 2-cell stage. Embryos cultured in vitro progress to the 2-cell stage, but further development is arrested. The heterozygotes exhibit mild skeletal defects as well as defects in some neuroectodermal derivatives.

Download full-text PDF

Source
http://dx.doi.org/10.1002/gene.1066DOI Listing

Publication Analysis

Top Keywords

preimplantation lethality
8
lethality homozygous
8
homozygous embryos
8
2-cell stage
8
mll
6
gene
5
truncation mll
4
mll gene
4
gene exon
4
exon gene
4

Similar Publications

Human embryos with segmental aneuploidies display delayed early development: a multicenter morphokinetic analysis.

Fertil Steril

November 2024

Juno Genetics Italy, Reproductive Genetics, Rome, Italy; Unit of Molecular Genetics, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy; Department of Psychological Health and Territorial Sciences, School of Medicine and Health Sciences, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy. Electronic address:

Article Synopsis
  • The study aimed to determine if segmental aneuploid embryos exhibited distinct morphokinetic patterns compared to euploid and whole-chromosome aneuploid embryos during development.
  • Researchers analyzed data from over 7,000 embryos cultured in European IVF clinics and found that segmental aneuploids had significantly slower cleavage rates, particularly during the first three cell cycles.
  • A logistic regression model was developed to predict aneuploidy types based on morphokinetic data, but its overall predictive performance was modest when tested on new data.
View Article and Find Full Text PDF
Article Synopsis
  • CTCF motifs act as boundaries in chromatin domains, limiting enhancer activity and affecting gene regulation, but their disruption may only lead to mild dysregulation, making predictions about developmental impact difficult.
  • Researchers targeted a specific chromatin domain in the mouse genome with important developmental genes and found that deleting its boundary cluster caused abnormal interactions with enhancers, resulting in overexpression of FGF genes and severe developmental issues like perinatal lethality and physical malformations.
  • While some chromatin boundary changes led to significant phenotypic effects, not all CTCF clusters displayed the same sensitivity, highlighting the complexity of chromatin structure's influence on gene regulation and the need to consider small sequence variations as potential contributors to developmental and disease-related gene dysreg
View Article and Find Full Text PDF
Article Synopsis
  • ZNHIT1 and ZNHIT2 are essential proteins for early mammalian development, and their knockout leads to embryonic lethality during the peri-implantation stage.
  • Znhit1 and Znhit2 mutant embryos show overlapping defects, such as reduced SOX2-positive inner cell mass cells and altered expression of critical genes but are impacted by different mechanisms.
  • Specifically, ZNHIT1 deficiency disrupts the incorporation of H2A.Z, affecting gene expression for proper trophoblast cell invasion, while ZNHIT2 deficiency results in splicing dysfunction due to lack of EFTUD2.
View Article and Find Full Text PDF

Prior studies showed that mice deficient in the modifier subunit of glutamate cysteine ligase (Gclm), the rate-limiting enzyme in synthesis of the thiol antioxidant glutathione, have decreased ovarian glutathione concentrations, chronic ovarian oxidative stress, poor oocyte quality resulting in early preimplantation embryonic mortality and decreased litter size, and accelerated age-related decline in ovarian follicle numbers. Global deficiency of the catalytic subunit of this enzyme, Gclc, is embryonic lethal. We tested the hypothesis that granulosa cell- or oocyte-specific deletion of Gclc recapitulates the female reproductive phenotype of global Gclm deficiency.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!