Antennapedia

Last updated
Homeotic protein antennapedia
Identifiers
Organism Drosophila melanogaster
Symbolantp
UniProt P02833
Search for
Structures Swiss-model
Domains InterPro
The mutation Antennapedia Antennapedia2.jpg
The mutation Antennapedia
The two Hox gene complexes in fruit flies Hoxgenesoffruitfly.svg
The two Hox gene complexes in fruit flies

Antennapedia (abbreviated Antp) is a Hox gene first discovered in Drosophila which controls the formation of legs during development. Loss-of-function mutations in the regulatory region of this gene result in the development of the second leg pair into ectopic antennae. By contrast gain-of-function alleles convert antennae into ectopic legs. [1]

Contents

This is just one illustration of the tendency of organisms to exhibit variations on a theme: modulated repetition. Legs and antennae are related to one another as much as molars are to incisors, fingers are to toes, and arms are to legs.

Antp also refers to a gene complex (ANT-C) in Drosophila ending with the Antp gene. It is responsible for formation and differentiation of the thoracic and head segments of the fly's body.

Origin of Antennapedia-class homeobox gene

The origin of the ancestor homeobox gene is an important aspect of the evolution of the Antp-class Hox genes. Early evolution of the Antp-class genes may have predated the divergence of cnidarians. However, the role that Antp plays in the spatial body development of cnidarians remains unclear. A widely accepted theory is that the ancestor Hox cluster containing three genes arose in the early metazoan era. It is suggested that Antennapedia arose from Evx, a non-Hox family of genes. This duplication event of Evx into the Antp-class probably occurred prior to cnidarian divergence, as there are Cnidarians with Evx and without Hox class genes and vice versa. [2]

Antennapedia in arachnids

Recent studies have observed that down-regulation of the Antp gene in Parasteatoda tepidariorum leads to the development of a pair of ectopic legs, resulting in 10-legged mutant spiders. DrosophilaAntp is thought to play an important role in the role of ectopic leg or antenna placement, but not in abdominal leg suppression. However, recent research supported that leg suppression was indeed performed by Antp in arachnids. [3] This suggests that spiders and insects may have separately developed strategies of the leg suppression via the evolutionary pressure of convergence. Arachnids' Antp gene is different from other AntpHox clusters, suggesting that it has evolved via a divergence event leading to the development on the leg suppression function. This example suggests how the functions of homeobox genes including Antp have evolved over time to account for different lineages' needs. [3]

HoxC6: an ortholog of Antp

Although it is known that Antp-class homeobox genes play some sort of role in transcriptional processes, not all of their actions and functions have been discovered. Recent studies observed Antp and the Hox ortholog HoxC6 in Xenopus in order to further distinguish the evolution of these orthologues. HoxC6 was found to play an important role in gastrulation in the vertebrate Xenopus. However, gastrulation was also a target in the DrosophilaAntp gene. The anterior–posterior pattern mechanism is highly conserved in these genes, as its function in Xenopus is clear, but it is unclear why it would be a target in Drosophila. The similarities continuously observed between Hox genes in vertebrates and Drosophila suggests a complex evolutionary history of the AntpHox gene cluster, as well as reaffirms the importance of the conservation of this gene cluster in the evolution of body morphology. [4]

Related Research Articles

<span class="mw-page-title-main">Homeobox</span> DNA pattern affecting anatomy development

A homeobox is a DNA sequence, around 180 base pairs long, that regulates large-scale anatomical features in the early stages of embryonic development. For instance, mutations in a homeobox may change large-scale anatomical features of the full-grown organism.

<span class="mw-page-title-main">Homeosis</span>

In evolutionary developmental biology, homeosis is the transformation of one organ into another, arising from mutation in or misexpression of certain developmentally critical genes, specifically homeotic genes. In animals, these developmental genes specifically control the development of organs on their anteroposterior axis. In plants, however, the developmental genes affected by homeosis may control anything from the development of a stamen or petals to the development of chlorophyll. Homeosis may be caused by mutations in Hox genes, found in animals, or others such as the MADS-box family in plants. Homeosis is a characteristic that has helped insects become as successful and diverse as they are.

The ParaHox gene cluster is an array of homeobox genes from the Gsx, Xlox (Pdx) and Cdx gene families.

Hox genes, a subset of homeobox genes, are a group of related genes that specify regions of the body plan of an embryo along the head-tail axis of animals. Hox proteins encode and specify the characteristics of 'position', ensuring that the correct structures form in the correct places of the body. For example, Hox genes in insects specify which appendages form on a segment, and Hox genes in vertebrates specify the types and shape of vertebrae that will form. In segmented animals, Hox proteins thus confer segmental or positional identity, but do not form the actual segments themselves.

<span class="mw-page-title-main">Gene cluster</span>

A gene family is a set of homologous genes within one organism. A gene cluster is a group of two or more genes found within an organism's DNA that encode similar polypeptides, or proteins, which collectively share a generalized function and are often located within a few thousand base pairs of each other. The size of gene clusters can vary significantly, from a few genes to several hundred genes. Portions of the DNA sequence of each gene within a gene cluster are found to be identical; however, the resulting protein of each gene is distinctive from the resulting protein of another gene within the cluster. Genes found in a gene cluster may be observed near one another on the same chromosome or on different, but homologous chromosomes. An example of a gene cluster is the Hox gene, which is made up of eight genes and is part of the Homeobox gene family.

<span class="mw-page-title-main">HOXB7</span> Protein-coding gene in humans

Homeobox protein Hox-B7 is a protein that in humans is encoded by the HOXB7 gene.

<span class="mw-page-title-main">HOXB6</span> Protein-coding gene in the species Homo sapiens

Homeobox protein Hox-B6 is a protein that in humans is encoded by the HOXB6 gene.

<span class="mw-page-title-main">HOXB5</span> Protein-coding gene in humans

Homeobox protein Hox-B5 is a protein that in humans is encoded by the HOXB5 gene.

<span class="mw-page-title-main">HOXD13</span> Protein

Homeobox protein Hox-D13 is a protein that in humans is encoded by the HOXD13 gene. This gene belongs to the homeobox family of genes. The homeobox genes encode a highly conserved family of transcription factors that play an important role in morphogenesis in all multicellular organisms.

<span class="mw-page-title-main">HOXA7</span> Protein-coding gene in the species Homo sapiens

Homeobox protein Hox-A7 is a protein that in humans is encoded by the HOXA7 gene.

<span class="mw-page-title-main">Homeobox protein goosecoid</span> Protein-coding gene in the species Homo sapiens

Homeobox protein goosecoid(GSC) is a homeobox protein that is encoded in humans by the GSC gene. Like other homeobox proteins, goosecoid functions as a transcription factor involved in morphogenesis. In Xenopus, GSC is thought to play a crucial role in the phenomenon of the Spemann-Mangold organizer. Through lineage tracing and timelapse microscopy, the effects of GSC on neighboring cell fates could be observed. In an experiment that injected cells with GSC and observed the effects of uninjected cells, GSC recruited neighboring uninjected cells in the dorsal blastopore lip of the Xenopus gastrula to form a twinned dorsal axis, suggesting that the goosecoid protein plays a role in the regulation and migration of cells during gastrulation.

In evolutionary developmental biology, homeotic genes are genes which regulate the development of anatomical structures in various organisms such as echinoderms, insects, mammals, and plants. Homeotic genes often encode transcription factor proteins, and these proteins affect development by regulating downstream gene networks involved in body patterning.

Homeotic selector genes confer segment identity in Drosophila. They encode homeodomain proteins which interact with Hox and other homeotic genes to initiate segment-specific gene regulation. Homeodomain proteins are transcription factors that share a DNA-binding domain called the homeodomain. Changes in the expression and function of homeotic genes are responsible for the changes in the morphology of the limbs of arthropods as well as in the axial skeletons of vertebrates. Mutations in homeotic selector genes do not lead to elimination of a segment or pattern, but instead cause the segment to develop incorrectly.

Zerknüllt is a gene in the Antennapedia complex of Drosophila and other insects, where it operates very differently from the canonical Hox genes in the same gene cluster. Comparison of Hox genes between species showed that the Zerknüllt gene evolved from one of the standard Hox genes in insects through accumulating many amino acid changes, changing expression pattern, losing ancestral function and gaining a new function.

The Cdx gene family, also called caudal genes, are a group of genes found in many animal genomes. Cdx genes contain a homeobox DNA sequence and code for proteins that act as transcription factors. The gene after which the gene family is named is the caudal or cad gene of the fruitfly Drosophila melanogaster. The human genome has three Cdx genes, called CDX1, CDX2 and CDX4. The zebrafish has no cdx2 gene, but two copies of cdx1 and one copy of cdx4. The Cdx gene in the nematode Caenorhabditis elegans is called pal-1.

<span class="mw-page-title-main">Hox genes in amphibians and reptiles</span>

Hox genes play a massive role in some amphibians and reptiles in their ability to regenerate lost limbs, especially HoxA and HoxD genes.

Proboscipedia (pb) is a protein coding gene in Drosophila melanogaster, the fruit fly.

Evx1 is a mammalian gene located downstream of the HoxA cluster, which encodes for a homeobox transcription factor. Evx1 is a homolog of even-skipped (eve), which is a pair-rule gene that regulates body segmentation in Drosophila. The expression of Evx1 is developmentally regulated, displaying a biphasic expression pattern with peak expression in the primitive streak during gastrulation and in interneurons during neural development. Evx1 has been shown to regulate anterior-posterior patterning during gastrulation by acting as a downstream effector of the Wnt and BMP signalling pathways. It is also a critical regulator of interneuron identity.

Brain-specific Homeobox is a protein that in humans is encoded by the BSX gene.

Robb Krumlauf is an American developmental biologist. He is best known for researching the Hox family of transcription factors. He is most interested in understanding the role of the Hox genes in the hindbrain and their role in areas of animal development, such as craniofacial development. Krumlauf worked with a variety of renowned scientists in the field of developmental biology throughout his time researching Hox genes.

References

  1. ↑ Schneuwly S, Klemenz R, Gehring WJ (1987). "Redesigning the body plan of Drosophila by ectopic expression of the homoeotic gene Antennapedia". Nature. 325 (6107): 816–8. Bibcode:1987Natur.325..816S. doi:10.1038/325816a0. PMID   3821869. S2CID   4320668.
  2. ↑ Gauchat D, Mazet F, Berney C, Schummer M, Kreger S, Pawlowski J, Galliot B (April 2000). "Evolution of Antp-class genes and differential expression of Hydra Hox/paraHox genes in anterior patterning" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 97 (9): 4493–8. doi: 10.1073/pnas.97.9.4493 . PMC   18262 . PMID   10781050.
  3. 1 2 Khadjeh S, Turetzek N, Pechmann M, Schwager EE, Wimmer EA, Damen WG, Prpic NM (March 2012). "Divergent role of the Hox gene Antennapedia in spiders is responsible for the convergent evolution of abdominal limb repression". Proceedings of the National Academy of Sciences of the United States of America. 109 (13): 4921–6. Bibcode:2012PNAS..109.4921K. doi: 10.1073/pnas.1116421109 . PMC   3323954 . PMID   22421434.
  4. ↑ Michaut L, Jansen HJ, Bardine N, Durston AJ, Gehring WJ (December 2011). "Analyzing the function of a hox gene: an evolutionary approach". Development, Growth & Differentiation. 53 (9): 982–93. doi: 10.1111/j.1440-169X.2011.01307.x . PMID   22150153. S2CID   10938031.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.