Genes in theDLX family encodehomeodomaintranscription factors related to theDrosophiladistal-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] AsDLX/Dll are involved in limb development in most of the major phyla, including vertebrates, it has been suggested thatDll was involved in appendage growth inan early bilaterial ancestor.[3]
Six members of the family are found in human and mice, numbered DLX1 to DLX6. They form two-geneclusters (bigene clusters) with each other. There areDLX1-DLX2,DLX3-DLX4,DLX5-DLX6 clusters in vertebrates, linked toHox gene clusters HOXD, HOXB, and HOXA respectively.[4]
In higher fishes like thezebrafish, there are two additionalDLX genes,dlx2b (dlx5) anddlx4a (dlx8).[5] These additional genes are not linked with each other, or any otherDLX gene. All six other genes remain in bigene clusters.
DLX4, DLX7, DLX8 andDLX9 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]
DLX genes, likedistal-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 ofinterneurons from the subpallium to thepallium during vertebratebrain development.[11] It has been suggested thatDLX promotes the migration ofinterneurons by repressing a set of proteins that are normally expressed in terminally differentiated neurons and act to promote the outgrowth ofdendrites andaxons.[12] Mice lacking DLX1 exhibit electrophysiological and histological evidence consistent with delayed-onsetepilepsy.[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.
