Spermatozoal motility is the most frequently observed characteristic, however owing to acrosomal damage sperm cell
could be highly motile but not fertile.
must undergo capacitation, and those that do not go through the maturation stage do not have the capacity to fertilize oocytes (Chang, 1951).
On the basis of the dependence of the potential drop on both the shape and angle of a prolate spheroid to an electric field, the amplitude of undulation when a sperm cell
migrates through the aperture depends on both the deviation angle and shape (volume is also a factor but is consistent for all types).
The interaction of a sperm cell
with the egg at fertilization is the event that stimulates the second meiotic division in the egg and the completion of egg meiosis.
Soon after a sperm cell
makes contact with the oocyte membrane, the socalled cortical granules develop along the outer edge (cortex) of the oocyte.
within the germinal part the sperm cells
are groups of a few, probably four, mature sperm cells
each surrounded by thin extensions of somatic cells.
In addition, PEI-mediated transport of FAM-labeled 10 mer oligonucleotide into abalone sperm cells
resulted in almost 100% bright fluorescent nuclei.
Each egg and sperm cell
, therefore, ended with only half the usual number of chromosomes.
Given that it takes only one sperm cell
to fertilize an egg, is this really a crisis?
Once the sperm cells
meet the ovum, one boy representing a sperm cell
links arms with the girl representing the ovum.
ERGO increased sperm cell
viability by 15-20% in pre-clinical and clinical studies as measured by total and progressive motility, when added to known cell extender preservatives in general use in the fertility field.
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.
The researchers said that this is the first technique for collecting data on sperm cell
motility-a key predictor of IVF success-in three dimensions and over time.
Using his sperm, Quake and colleagues compiled the first-ever genetic blueprint for a single sperm cell
Already known by researchers, the powerful swimming of sperm is dependent on protons leaving the sperm cell
, lowering its acidity.