遺傳重組

(重定向自基因重組

遺傳重組(genetic recombination;亦稱基因重組(genetic reshuffling))在遺傳學上的重組、是指DNA片段斷裂並且轉移位置的現象。发生在减数分裂时非姐妹染色单体上的基因结合。

A current model of meiotic recombination, initiated by a double-strand break or gap, followed by pairing with an homologous chromosome and strand invasion to initiate the recombinational repair process. Repair of the gap can lead to crossover (CO) or non-crossover (NCO) of the flanking regions. CO recombination is thought to occur by the Double Holliday Junction (DHJ) model, illustrated on the right, above. NCO recombinants are thought to occur primarily by the Synthesis Dependent Strand Annealing (SDSA) model, illustrated on the left, above. Most recombination events appear to be the SDSA type.

原核生物(例如細菌)來說,個體之間可以通過交接,或是經由病毒(例如噬菌體)的傳送,來交換彼此的基因,並且利用基因重組,將這些基因組合到本身原有的遺傳物質中。

對於較複雜的生物來說,重組通常是因為同源染色體配對時發生互換,使得同源染色體上的基因在遺傳到子代時,經常有不完全的連鎖。由於重組現象的存在,科學家可以利用重組率來定出基因之間的相對位置,描繪出基因圖譜

聯會编辑

減數分裂期間,聯會(同源染色體的配對)通常在遺傳重組之前發生。在一般減數分裂的步驟,先是聯會 、再進行遺傳重組及分離 (gene segregation)[1][2][3]

註釋编辑

  1. ^ Hawley RS, Arbel T.,"Yeast genetics and the fall of the classical view of meiosis"[1],PubMed - NCBI,1993 Feb 12;72(3):301-3.. PMID 8431941 DOI: 10.1016/0092-8674(93)90108-3
  2. ^ Peter B. Moens,"Molecular perspectives of chromosome pairing at meiosis"[2],BioEssays - Wiley Online Library,Volume16,Issue2,February 1994,Pages 101-106.
  3. ^ 趙紹惠[3] 和 大衛摩亞[4](Siu-Wai Chiu & David Moore),"解讀真菌的形態發育--第六章(Deciphering Fungal Morphogenesis--Chapter 6)"[5],香港中文大學生命科學學院,2003.

參考文獻编辑

  本条目引用的公有领域材料来自NCBI的文档《Science Primer》

  • Michael J. McDonald, Daniel P. Rice, Michael M. Desai: Sex speeds adaptation by altering the dynamics of molecular evolution. In: Nature. 2016, doi:10.1038/nature17143

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