ドロソフィラの眼におけるニューロンパターン形成に関与する遺伝子であるセブンレス (sevenless) の分子特性と発現
Cell
|April 24, 1987
まとめ
ドロソフィラ・セブンレス (Drosophila sevenless) 変異は,目の特定のニューロン損失を引き起こす. 研究者は,seven遺伝子を特定し,そのトランスクリプトが光受容体の発達に不可欠であるが,その存在に必要なのは必ずしもそうではないことを発見した.
科学分野:
- 発達生物学 発達生物学とは
- 遺伝学 遺伝学とは
- 神経科学は神経科学である.
背景:
- ドロソフィラ・セブンレス (Drosophila sevenless (sev)) 変異は,オムマチディアにおける光受容体細胞R7の欠如につながります.
- この発達の欠陥は,幼虫の眼盤に由来する.
研究 の 目的:
- この発達障害の原因となる7less (sev) 遺伝子を分離し,特徴づけること.
- 目の発達中のセブ遺伝子産物の発現パターンと機能を理解する.
主な方法:
- P-要素誘発アレルの生成により,セブン遺伝子を隔離する.
- セブ遺伝子に関連した8.2kbのトランスクリプトの分析.
- 幼虫の眼盤のセブタンパク質に対する抗体を用いた局所化研究.
主要な成果:
- 8.2kbのトランスクリプトが眼盤に発現し,光受容体群の徴募と分化と一致する.
- トランスクリプトの局所化は,アピカル表面で起こり,プレパル段階を通して持続し,成人に再現します.
- あるアレルにはトランスクリプトが欠けていて,他のアレルには光受容体細胞R7が欠けていてもトランスクリプトが表れている.
結論:
- セブ遺伝子とその8.2kbのトランスクリプトは,光受容体細胞R7の発達において重要な役割を果たします.
- トランスクリプトの発現と局所化は,目の形態変異の間に遺伝子の機能についての洞察を提供します.
- この研究は,セブ遺伝子発現とR7細胞の存在との複雑な関係を強調しています.
関連する概念動画
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
03:18Non-LTR Retrotransposons
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
02:57piRNA - Piwi-interacting RNAs
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
01:41Signal Sequences and Sorting Receptors
Signal sequences are short amino acid sequences that guide newly synthesized proteins to their proper location within the cell. Classical signal sequences are fifteen to sixty amino acids long and present at the N-terminus of a polypeptide chain. Each signal sequence has a conserved segment of basic residues towards their N terminus, a hydrophobic core, and a C-terminus rich in polar residues. The C-terminus also contains a signal cleavage site and features a -3 -1 sequence motif. The -3-1...
02:46Genetic Screens
Genetic screens are tools used to identify genes and mutations responsible for phenotypes of interest. Genetic screens help identify individuals or a group of people at risk of developing genetic diseases and help them with early intervention, targeted therapy, and reproductive options.
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes...
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes...
01:20The Retinoblastoma Gene
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...