| 翻訳と辞書 |
| homeotic gene ： ウィキペディア英語版 |
homeotic gene
Homeotic genes are genes which regulate the development of anatomical structures in various organisms such as insects, mammals, and plants. This regulation is done via the programming of various transcription factors by the homeotic genes, and these factors affect genes through regulatory genetic pathways.
Mutations in the homeotic genes can occur, leading to what are known as homeotic mutants. These mutants display ectopic placement of body parts (such as antennae growing at the posterior of the fly instead of at the head) or abnormal expression of the homeotic gene. Mutations that lead to these ectopic placements are usually lethal to the organism.
== Types of homeotic genes ==
There are several subsets of homeotic genes. They include many of the Hox and ParaHox genes which are important for segmentation, ''Hox genes'' (also known as homeobox genes) are found in countless organisms including ''Drosophila'' (in which they were first discovered), vertebrates, and mammals, including humans. The Hox genes are often preserved across species, so some of the Hox genes of ''Drosophila'' are homologous to those in humans. In general, Hox genes play a role of regulating expression of genes as well as aiding in development and assignment of specific structures during embryonic growth. This can range from segmentation in ''Drosophila'' to central nervous system (CNS) development in vertebrates.
They also include the MADS-box-containing genes involved in the ABC model of flower development. Besides flower-producing plants, the MADS-box motif is also present in other organisms such as insects, yeasts, and mammals. They have various functions depending on the organism including flower development, proto-oncogene transcription, and gene regulation in specific cells (such as muscle cells). Despite terms being commonly interchanged, not all homeotic genes are Hox genes; the MADS- box genes are homeotic but not Hox genes. Thus, the Hox genes are a proper subset of homeotic genes.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「homeotic gene」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|