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The proximodistal trend is the tendency for more general functions of limbs to develop before more specific or fine motor skills. It comes from the Latin words proxim- which means "close" [ 1 ] and "-dis-" meaning "away from", [ 2 ] because the trend essentially describes a path from the center outward.
Limb development in vertebrates is an area of active research in both developmental and evolutionary biology, with much of the latter work focused on the transition from fin to limb. [ 1 ] Limb formation begins in the morphogenetic limb field , as mesenchymal cells from the lateral plate mesoderm proliferate to the point that they cause the ...
The proximodistal trend, on the other hand, is the prenatal growth from 5 months to birth when the fetus grows from the inside of the body outwards. When referring to motor development, the proximodistal trend refers to the development of motor skills from the center of the body outwards.
The limb bud is a structure formed early in vertebrate limb development. As a result of interactions between the ectoderm and underlying mesoderm, formation occurs roughly around the fourth week of development. [1] In the development of the human embryo the upper limb bud appears in the third week and the lower limb bud appears four days later. [2]
[Ref 1] However, some recent evidence using microinjected embryos suggests that the cells are prespecified early in limb bud development. [Ref 2] The progress zone acts as positional information to tell which cells to develop into the limb. If cells spend a very short time in this area as they receive signals from the apical ectodermal ridge ...
Activation of these genes results in a new limb axis that ultimately results in digit development, possibly interpreting gene expression to assign digit identity. Overall, the molecular ZPA requires input for several signaling centers, but acts as an organizer itself, inducing anterior-posterior pattering of the chick limb bud.
Plant development is the process by which structures originate and mature as a plant grows. It is studied in plant anatomy and plant physiology as well as plant morphology. Plants constantly produce new tissues and structures throughout their life from meristems [ 35 ] located at the tips of organs, or between mature tissues.
This type of specification results from cell-intrinsic properties; it gives rise to mosaic development. The cell-intrinsic properties arise from a cleavage of a cell with asymmetrically expressed maternal cytoplasmic determinants (proteins, small regulatory RNAs and mRNA). Thus, the fate of the cell depends on factors secreted into its ...