Study on non-Mendel stain separation: the chances of chromosomes entering reproductive cells.

Two copies containing 23 chromosomes, one from the father and the other from the mother.
theory, when you produce a match, a sperm or egg, there is a 50% chance that each copy will pass on to your child, but is that really the case? In the study, scientists observed that chromosomes "cheat" and change their chances of getting into reproductive cells.
now, a team at the University of Pennsylvania has revealed how this imbalance occurs in female cells.
by carefully observing and experimenting with mouse oocytes (the precursor of egg cells), they found molecular signals that create asymmetries in the mechanism that drives subtractive division.
researchers found that specific chromosomes take advantage of this imbalance, moving themselves to the "right" of the cell as it divides and ending in the egg cell.
study on non-Mendel staining separation was published November 3 in Science.
these findings illustrate some common but unclear aspects of subtraction splits that can help people better understand the fragmentation of the number, such as why errors occur and how they occur.
during the division of the minus, the error segregated between chromosomes and the ligand is the root cause of miscarriage and certain diseases, such as Down's syndrome.
, an associate professor at The University of Pennsylvania College of Arts and Sciences and the author of the paper, said: "If we figure out how these 'selfish genes' use subtransciation mechanisms, we can better understand how this process works."
" for decades, scientists have realized that various genetic factors appear to be involved in a silent battle during the subtransdision split.
because some genetic factors are passed on to the matcher at a higher probability than chance, the term used to describe the phenomenon is called "minus split driver."
, "Usually we prioritize selfish genes at the level of natural selection, " says Lampson.
that means that genes that make you longer, more fertile, and able to kill enemies are easier to pass on.
but we can also consider its selfishness from the gene itself.
in this environment, genes need to compete with each other to get into the match.
Although we have evidence that this can happen, we don't really understand how it happens.
" bias in gene transmission, the team speculated, possibly related to the physical mechanisms of cell division.
for females, the final stage of a subtraction of division produces two cells, one as an egg and the other as an polar, which usually degrades.
the researchers chose to focus on cell division mechanisms and study subtranslating spindles, which consist of microtubules attached to chromosomes that pull cells to the other side of the cell before they divide.
by observing the microcells of ovaries, they found an unbalanced distribution of a change known as tyrosination: tyrosine near the side of the egg was less modified than near the cortex.
asymmetry occurs only when the spindle body moves from the middle of the cell to the cortation during the subtransfing period.
tells us that whatever the signal that causes the change in tyrosamine, it must come from the corttics," said Lampson, a researcher at the University of New China.
the next question is, what's the signal? "Researchers have obtained some information about increased molecular expression, including one called THE upper side of the cellular cortex called CDC42.
to test whether the molecule causes an imbalance in tyrosic acid, the researchers designed an experimental system in a polarizing selective LYCDC42.
their results showed that CDC42, at least in part, caused the tyrosic acid to change imbalance, which caused the spindle body to divide cells with bias.
determined that the imbalance exists and how it occurs, researchers began to study how it can make chromosomes learn to "cheat."
they do this by focusing on the grain, the area where the chromosomes attach to the spindle body.
they used two mice to interbreed, resulting in mice with two kinds of silk particles: one large and one small.
the team's early work, they knew that larger silk particles would be given higher priority in the match.
current work, they have confirmed that the larger the stronger the silk, the easier it is to enter the pole that forms the egg.
The signal regulation of micropig tyrosine (white) in the polarized cell cortical layer (green) of mouse ovaries leads to spindle asymmetry in subtransmetric division When researchers use mutation CDC42 and other targets to eliminate spindle asymmetry, the phenomenon of silk grain positioning bias disappears.
, "This links spindle asymmetry to cheating on chromosomes or silk particles," said Thompson.
" but the result raises the question of when the silk grains have become directional. When the spindle begins to move on both sides, which point is the turning point of the silk grain and unequal division with the direction preference? Using live imaging of mouse oocytes, the researchers found that the stronger the silk particles, the easier it is to detach from the spindle, and the easier they are to disengage if they are towed to the side of the cellular cortex.
this may be to flip it around so that you can turn yourself around and move toward the egg pole.
weaker sly slin rarely detaches, and there is no preference for the cell's two levels.
Lampson said: "If the selfish silk particles face the wrong path, it will give up, only in this way to find another way."
so they can win.
" in future work, the Lampson team will explore further which characteristics of silk particles make them "strong" or "weak."
study gives us an idea of the biased delivery of silk particles, but it also raises a lot of other questions," said Lampson, a researcher at the University of New China.
to see why silk particles do this and how they evolved to win competition.
these are basic biological problems that we haven't yet learned about.
"