Good news!
Notice again how the elite university calls women "people" and tries very hard to avoid mention "female", "woman" or "women" in this article that is about a woman's health topic. The elite university uses "individual" or omit entirely to refer to women or females. Plus, the abstract of the research paper also avoids mentioning females or women! Very appalling, if not disgusting!
"As many as 1 in 6 adults [adult females/women] face fertility difficulties worldwide, research has shown, and the challenge become harder as they age. ...
A new Yale study offers new insights that could improve outcomes for these individuals females/women and families. ...
According to their findings, the structures that help eggs reduce chromosome numbers accurately before fertilization become weaker as people [females/women] age. This is problematic because eggs must halve their chromosome number to assure that fusion with a sperm restores the correct number needed for health embryo development.
The researchers also identified how three proteins cooperate to maintain these critical structures. Restoring one of these components to the structures that anchor chromosomes improved chromosome positioning in aged eggs, they found, revealing a contributor to declining egg quality and a potential direction for research into preserving reproductive health. ...
For the study, the researchers investigated whether weakening centromeres could be an additional cause of chromosome errors in aging eggs. They focused on three proteins — CENP-A, CENP-B, and CENP-C — that are components of centromeres.
They combined studies of naturally aged eggs from [female] mice with experiments that recreate specific features of aging in young eggs within hours. First, they measured centromere proteins in young and aged eggs.
Then they used targeted protein degradation, a technique that directs the cell to remove a selected protein, to reduce CENP-A in the young eggs. With quantitative, high-resolution live microscopy, they tracked how chromosomes moved, lined up, and separated during division. ...
The researchers found that naturally aged eggs have lower levels of CENP-A and CENP-C proteins at their centromeres. Reducing CENP-A in young eggs by the same amount lost during natural aging caused chromosomes to become incorrectly positioned and lag behind during division. ..."
From the abstract:
"Maternal age is the primary risk factor for aneuploidy in mammalian oocytes, but the molecular mechanisms that preserve meiotic chromosome segregation fidelity during aging remain incompletely understood.
Using ultrastructural analysis, we observe that spindle microtubules in aged [female] mouse oocytes tend to exhibit increased misorientation and shorter interaction lengths, whereas microtubule number and density remain largely unchanged.
We demonstrate that the levels of the key centromeric components CENP-A and CENP-C are reduced in oocytes from aged [female] mice. Acute degradation of CENP-A during meiosis I affects CENP-C stability at centromeres and causes chromosome segregation errors in young oocytes, a phenotype not observed in mitosis.
The expression of exogenous CENP-C rescues these defects via CENP-B–dependent centromere binding, supporting a link between centromere weakening and meiotic errors.
This intervention also partially improves chromosome alignment in oocytes from older [female] animals. Together, these findings implicate centromere weakening, alongside cytoskeletal disorganization, in the age-related decline in chromosome segregation fidelity in oocytes."
Declining centromere strength compromises meiotic chromosome segregation in aging oocytes (open access)
Super-resolution image of the intricate chromosome division machinery in a young mouse oocyte. At metaphase I, homologous chromosomes (green) are positioned within the spindle’s network of microtubules (orange). Centromeres (magenta) mark the sites where chromosomes connect to this machinery, helping ensure that the egg receives the correct number of chromosomes.
Fig. 1 Ultrastructural analysis identifies age-associated differences in microtubule organization in mammalian eggs. ...
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