13 ( ANI ): Researchers have showed that when a bacterial cell divides into two
daughter cells there can be an uneven distribution of cellular organelles.
If MCM loading isn't completed successfully prior to cell division, there'll be a risk of major DNA mutations and death for the resulting
daughter cells.
It also determines which of two
daughter cells remains a stem cell and which will become a progenitor cell to replace or repair damaged tissue.
The protein seems to work by making sure the organelles are in the right locations so they can be divided between the
daughter cells.
But each time a stem cell divides, only one
daughter cell matures into a specific cell type.
The rarity of adult stem cells relative to their differentiated
daughter cells has, however, made them historically difficult to study.
Bioengineers at the UCLA Henry Samueli School of Engineering and Applied Science developed a platform to mechanically confine cells, simulating the in vivo three-dimensional environments in which they divide, and found that, upon confinement, cancer cells often split into three or more
daughter cells.
The researchers showed that a gene named SAPCD2 influences cell division orientation and controls
daughter cell fates in vivo.
Two types of stem cells exist in the fruit fly testis: One whose fate is to produce a
daughter cell that matures into a full-fledged sperm cell and a daughter that stays as a stem cell (otherwise, in each division the tissue would lose a stem cell and quickly exhaust its capacity for renewal), and a second stem cell type that is a somatic, or non-sex, stem cell that similarly produces a daughter that stays as a stem cell, and another daughter that matures into a protective cell that flanks the maturing sperm cell in an encysting process.
Thus, each
daughter cell would begin life no more or less worn out than the mother had been.
When a stem cell divides into two, one
daughter cell remains as an undifferentiated stem cell, thereby preserving that cell's potential for regeneration and repair.