Sentence examples for earliest cells are from inspiring English sources

These molecules were presumably rare on the early earth, present in trace amounts in the aqueous pools where the earliest cells are thought to have appeared.

Given the presumably dilute concentrations of macromolecules in the prebiotic pools where the earliest cells are thought to have appeared, how could the necessary components become concentrated and encapsulated within a semipermeable membrane?

Such hypothesis keep resurfacing from time to time, including recent proposals that the earliest cells were preceded by stages of evolution involving virus-like genetic polymers of abiotic origin synthesized within iron-sulfide mineral compartments in warm hydrothermal environments, which are assumed to be ancestral to extant RNA viruses, retroviruses, and later on DNA viruses.

These estimates reflect the timing of appearance of these markers as well as our expectation that early cells are not too far advanced in their cell cycle progression.

Simultaneously, the limited expression of TLRs on trophoblast cells at the early stages of pregnancy shows that these early cells are less able to deal with intrauterine infections than differentiated trophoblasts [ 38].

These early cells are also supported by the action of FL-ligand, that via the FLT-3 receptor [ 11, 12] stimulate lymphoid primed multipotent progenitors (LMPPs [ 13]) to proceed into the lymphoid lineages [ 14].

These early cells were also anaerobic (not requiring oxygen), deriving their energy from the fermentation of organic molecules that had previously accumulated on the Earth over long periods of time.

After the induction of C5b-9 formation (see earlier), cells were incubated with 100 µl/ml MTT (5 mg/ml thiazolyl blue) in sterile phosphate buffered saline (PBS) at 37 °C for 3 h until formazan crystals appeared.

On the other hand, subconfluent and early confluent cells are more susceptible to loss of cell-cell and cell-substrate interactions (S. Knoop, U. Rauen, unpublished results).

But early embryo cells are easier to clone than adult ones because they have not differentiated into muscle, heart or brain cells.

early apoptotic cells are Annexin-V-positive, PI-negative (lower right), whereas late apoptotic cells are Annexin-V positive and PI-positive (upper right).