homeobox genes


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homeobox genes

A highly CONSERVED family of genes, found in a large range of different species, including insects. Homeobox genes are expressed early in embryonic development and are the determinants of body shape. These genes divide the early embryo into fields of cells each with the potentiality to develop into a particular part such as an arm, leg, tissue or organ. This is the key to the long-unexplained problem of how bodily configuration is determined by genetics. Mutations in homeobox genes cause severe bodily defects such as PHOCOMELIA.
References in periodicals archive ?
Hex homeobox gene controls the transition of the endoderm to a pseudostratified, cell emergent epithelium for liver bud development.
Genes of the NK2 class have a distinctive homeobox and encode proteins that have a tyrosine at homeodomain position 54, and the Tlx family of homeobox genes is distinguished by a Thr in position 47 of the homeodomain.
The fact that each of the fields expresses different combinations of patterning homeobox genes supports this theory
1) is a homeobox gene with mutations that effect second premolars and third molars with an association for cleft lip and/or palate and Witkop syndrome (Zhang et al.
Expression pattern of KN-1 type tobacco homeobox genes.
Members of the Antennapedia class of homeobox genes, known as Hox genes, are believed to be pivotal in regulating vertebrate craniofacial development and controlling morphogenesis and the growth of the proximal-distal axis.
Missense mutations in R31 have been found in the human homeobox genes PITX2, MSXI, MSX2, LMX1B, and HOXD13 and are associated with 5 different developmental diseases: iridogoniodysgenesis syndrome, tooth agenesis, enlarged parietal foramina, nail-patella syndrome, and several digital anomalies, respectively (18, 19).
Role of the Dlx homeobox genes in proximodistal patterning of the branchial arches: mutations of Dlx-1, Dlx-2, and Dlx-1 and -2 alter morphogenesis of proximal skeletal and soft tissue structures derived from the first and second arches.
Although researchers know that alcohol can affect the expression of some genes, it is uncertain whether these include homeobox genes.
Such products might be extracellular signaling molecules, such as growth factors or differentiation signals, but also transcriptional regulators, for example, a retinoic acid receptor acting on homeobox genes in a developing vertebrate limb.