Differential and stage-related expression in embryonic tissues of a new human homoeobox gene

Abstract

The homoeobox is a 183 base-pair (bp) DNA sequence conserved in several Drosophila genes controlling segmentation and segment identity. Homoeobox sequences have been detected in the genome of species ranging from insects and anellids to vertebrates and homoeobox containing genes have been cloned from Xenopus, mouse and man. We recently isolated human homoeobox containing complementary DNA clones, that represent transcripts from four different human genes. One clone (HHO.c10) is selectively expressed in a 2.1 kilobase (kb) polyadenylated transcript in the spinal cord of human embryos and fetuses 5-10 weeks after fertilization. We report the characterization of a second cDNA clone, termed HHO.c13, that represents a new homoeobox gene. This clone encodes a protein of 255 amino-acid residues, which includes a pentapeptide, upstream of the homoeo domain, conserved in other Drosophila, Xenopus, murine and human homoeobox genes. By Northern analysis HHO.c13 detects multiple embryonic transcripts, which are differentially expressed in spinal cord, brain, backbone rudiments, limb buds and heart in 5-9-week-old human embryos and fetuses, in a striking organ- and stage-specific pattern. These observations suggest that in early mammalian development homoeobox genes may exert a wide spectrum of control functions in a variety of organs and body parts, in addition to the spinal cord.

HOM/HOX homeobox genes are present in hydra (Chlorohydra viridissima) and are differentially expressed during regeneration

“…Outside of the homeodomain we searched for the hexapeptide sequence (VYPWMK) that is usually located -15 amino acids in front of Drosophila or vertebrate homeodomains (Mavilio et al, 1986). In cnox2 and cnox3 sequences this motif is partially conserved (LYP) and located 43 and 42 amino acids upstream of their respective homeodomains.…”

A proline-rich transcriptional activation domain in murine HOXD-4 (HOX-4.2)

“…A pentapeptide motif (consensus VYPWM) (8,9) is located N-terminal to the homeodomain in Antp class homeoproteins and in the labial subfamily. It is not present in Abd-B, nor in Abd-B-like vertebrate proteins described to date (40).…”

“…1). Note that with S192 the sequence of the HOXD-4 homeodomain now shares 100% identity with that of human HOXD4 (9). The sequence of Hoxd-4 in the GenBank database has been revised appropriately (accession number J03770).…”

“…Apart from the homeodomain, other regions of the Hox and homeotic gene products are also conserved. Most notable is the so-called conserved pentapeptide (8,9), a domain found just N-terminal to the homeodomain of many Antp class homeoproteins. Regions of some conservation are also found immediately C-terminal to the homeodomain and at the extreme N-terminus (2).…”

Polymorphisms in the HOXD4 gene are not associated with peak bone mineral density in Chinese nuclear families

“…Oliver et al [13] found by in situ hybridization that HOXD4 was localized to 2q31-q32, with a peak number of gains at 2q32.3. Mavilio et al [14] reported that the HOXD4 gene may exert a wide spectrum of control functions in a variety of organs during early mammalian development. The HOXD4 gene maps to human chromosome 2 in the q31.1 region, and its total length is 1.839 kb [15] .…”