Genes in the DLX family encode
homeodomaintranscription factors related to the Drosophiladistal-less(Dll) gene.[1] The family has been related to a number of developmental features such as jaws and limbs. The family seems to be well preserved across species.[2] As DLX/Dll are involved in limb development in most of the major phyla, including vertebrates, it has been suggested that Dll was involved in appendage growth in
an early bilaterial ancestor.[3]
Six members of the family are found in human and mice, numbered DLX1 to DLX6. They form two-gene
clusters (bigene clusters) with each other. There are
DLX1-
DLX2,
DLX3-
DLX4,
DLX5-
DLX6 clusters in vertebrates, linked to
Hox gene clusters HOXD, HOXB, and HOXA respectively.[4]
In higher fishes like the
zebrafish, there are two additional DLX genes, dlx2b (dlx5) and dlx4a (dlx8).[5] These additional genes are not linked with each other, or any other DLX gene. All six other genes remain in bigene clusters.
DLX4, DLX7, DLX8 and DLX9 are the same gene in vertebrates.[6] They are named differently because every time the same gene was found, the researchers thought they had found a new gene.[7][8]
Function
DLX genes, like distal-less, are involved in limb development in most of the major phyla.[3]
DLX genes are involved in craniofacial morphogenesis[9][10] and the tangential migration of
interneurons from the subpallium to the
pallium during vertebrate
brain development.[11] It has been suggested that DLX promotes the migration of
interneurons by repressing a set of proteins that are normally expressed in terminally differentiated neurons and act to promote the outgrowth of
dendrites and
axons.[12] Mice lacking DLX1 exhibit electrophysiological and histological evidence consistent with delayed-onset
epilepsy.[13]
^Quinn LM, Johnson BV, Nicholl J,
Sutherland GR, Kalionis B (March 1997). "Isolation and identification of homeobox genes from the human placenta including a novel member of the Distal-less family, DLX4". Gene. 187 (1): 55–61.
doi:
10.1016/S0378-1119(96)00706-8.
PMID9073066. We originally submitted the cDNA sequence to the Genbank database as DLX8 (Accession number U31762) even though human DLX4 or DLX7 had not been identified. [...] This new Distal-less gene could not be considered the human homologue of murine Dlx4 or Dlx7 because the homeodomain sequences were too diverged.
^Vieux-Rochas M, Bouhali K, Baudry S, Fontaine A, Coen L, Levi G (December 2010). "Irreversible effects of retinoic acid pulse on Xenopus jaw morphogenesis: new insight into cranial neural crest specification". Birth Defects Research Part B: Developmental and Reproductive Toxicology. 89 (6): 493–503.
doi:
10.1002/bdrb.20269.
PMID21086490.
^Anderson SA, Eisenstat DD, Shi L, Rubenstein JL (October 1997). "Interneuron migration from basal forebrain to neocortex: dependence on Dlx genes". Science. 278 (5337): 474–6.
doi:
10.1126/science.278.5337.474.
PMID9334308.
^Beverdam A, Merlo GR, Paleari L, Mantero S, Genova F, Barbieri O, et al. (December 2002). "Jaw transformation with gain of symmetry after Dlx5/Dlx6 inactivation: mirror of the past?". Genesis. 34 (4): 221–7.
doi:
10.1002/gene.10156.
hdl:2318/87307.
PMID12434331.
S2CID19592597.