Biology 3338A Lecture Notes - Lecture 14: Lateral Plate Mesoderm, Hox Gene, Limb Bud
16 Jun 2016
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Vertebrate limb development: complex but highly conserved patterns. 3 axes: proximal-distal (shoulder-fingertip, anterior-posterior (thumb-pinky, dorsal-ventral (knuckles-palm) Limbs (limb buds) only grow at limb fields. Limb buds grow out from body axis and take body axis with them. 4 limbs in vertebrates (2 pairs opposite eachother, forelimbs, hindlimbs) Position constant due to hox gene expression a lot of things are going to migrate into limb fields and cause limbs to grow: Sclerotomes, dermatomes, mytomes (muscle) migrating away from somites after it undergoes its met. Many hox paralogue groups in drosphila, hox genes are very important. Give identity of specific segments from anterior posterior. Order of genes going 3" to 5" on dna is the same order as genes are seen in the embryo (5"=anterior, 3"=posterior) Hox genes also give identities to segments from anterior posterior in vertebrates. But mutating hox genes in vertebrates doesn"t have the same powerful effect as it does in drosphila (ex.
