dc.contributor.author | MURPHY, PAULA | |
dc.date.accessioned | 2008-11-06T13:45:16Z | |
dc.date.available | 2008-11-06T13:45:16Z | |
dc.date.issued | 1991 | |
dc.date.submitted | 1991 | en |
dc.identifier.citation | Murphy, P. and Hill, R.E. `Expression of the mouse labial-like homeobox-containing genes, Hox 2.9 and Hox 1.6, during segementation of the hindbrain? in Development, 111, (1), 1991, pp 61 - 74 | en |
dc.identifier.issn | 1979 | |
dc.identifier.issn | 0950-1991 | |
dc.identifier.other | Y | |
dc.identifier.other | Y | en |
dc.identifier.uri | http://hdl.handle.net/2262/24020 | |
dc.description | PUBLISHED | en |
dc.description.abstract | The sequence of a mouse Hox 2.9 cDNA clone is
presented. The predicted homeodomain is similar to that
of the Drosophila gene labial showing 80 % identity. The
equivalent gene in the Hox 1 cluster is Hox 1.6 which
shows extensive similarity to Hox 2.9 both within and
outside the homeodomain. Hox 2.9 and Hox 1.6 are the
only two mouse members of the labial-like family of
homeobox-containing genes as yet identified.
Hox 2.9 has previously been shown to be expressed in
a single segmental unit of the developing hindbrain
(rhombomere) and has been predicted to be involved in
conferring rhombomere identity. To analyse further the
function of Hox 2.9 during development and to
determine if the other mouse labial-tike gene Hox 1.6,
displays similar properties, we have investigated the
expression patterns of these two genes and an additional
rhombomere-specific gene, Krox 20, on consecutive
embryonic sections at closely staged intervals. This
detailed analysis has enabled us to draw the following
conclusions:
(1) There are extensive similarities in the temporal
and spatial expression of Hox 2.9 and Hox 1.6,
throughout the period that both genes are expressed in
the embryo (7| to 10 days). At 8 days the genes occupy
identical domains in the neuroectoderm and mesoderm
with the same sharp anterior boundary in the presumptive
hindbrain. These similarities indicate a functional
relationship between the genes and further suggest that
the labial-tike genes are responding to similar signals in
the embryo.
(2) By 9 days the neuroectoderm expression of both
genes retreats posteriorly along the anteroposterior (AP)
axis. The difference at this stage between the expression
patterns is the persistence of Hox 2.9 in a specific region
of the hindbrain, illustrating the capacity of Hox 2.9 to
respond to additional positional regulatory signals and
indicating a unique function for this gene in the
hindbrain.
(3) The restriction of Hox 2.9 expression in the
hindbrain occurs at 8A days, approximately the same
time as Krox 20 is first detected in the posterior adjoining
domain. The mutually exclusive expression of Hox 2.9
and Krox 20 demarcated by sharp expression boundaries
suggest that compartmentalisation of cells within the
hindbrain has occurred up to 6 h before rhombomeres
(morphological segments) are clearly visible.
(4) Hox 2.9 expression is confined to the region of
rhombomere 4 that shows cell lineage restriction and,
unlike Krox 20, is expressed throughout the period that
rhombomeres are visible (to ll# days). These data
strengthen the evidence that Hox 2.9 participates in
conferring segment identity.
(5) Migrating neural crest cells that arise from
rhombomere 4 are uniquely identified by the expression
of Hox 2.9 supporting the idea that neural crest cells are
patterned according to their rhombomeric origin.
(6) The Hox 1.6 gene product is differentially
transcribed; only one of the two alternative transcripts
codes for a homeodomain-containing protein. A comparison
of the distribution patterns of the two transcripts
shows that the relative proportion of homeodomain-
producing message decreases as development
proceeds. | en |
dc.format.extent | 61 | en |
dc.format.extent | 74 | en |
dc.format.extent | 3855078 bytes | |
dc.format.mimetype | application/pdf | |
dc.language.iso | en | en |
dc.publisher | Company of Biologists | en |
dc.relation.ispartofseries | Development | en |
dc.relation.ispartofseries | 111 | en |
dc.relation.ispartofseries | 1 | en |
dc.rights | Y | en |
dc.subject | homeobox | en |
dc.subject | Hox 1.6 | en |
dc.subject | Hox 2.9 | en |
dc.subject | mouse development | en |
dc.title | Expression of the mouse labial-like homeobox-containing genes, Hox 2.9 and Hox 1.6, during segementation of the hindbrain | en |
dc.type | Journal Article | en |
dc.type.supercollection | scholarly_publications | en |
dc.type.supercollection | refereed_publications | en |
dc.identifier.peoplefinderurl | http://people.tcd.ie/pmurphy3 | |
dc.identifier.rssinternalid | 1979 | |
dc.identifier.rssuri | http://dev.biologists.org/cgi/reprint/111/1/61 | |