美國國家標(biāo)準(zhǔn)技術(shù)研究院（NIST）和蓋提斯堡學(xué)院（Gettysburg College）的研究人員近日通過研究成功實(shí)現(xiàn)了單一細(xì)胞中線粒體的提取,。這項(xiàng)研究將有助于科學(xué)家更好地針對特定線粒體進(jìn)行深入研究,，從而了解各種遺傳疾病的產(chǎn)生機(jī)制。研究報(bào)告發(fā)表在近期《公共科學(xué)圖書館—綜合》（PLoS One）上,。
人體細(xì)胞中線粒體的提取是一段復(fù)雜的過程,。NIST的研究人員開發(fā)出的這套技術(shù)猶如外科手術(shù)般地可將細(xì)胞中的這種微小“引擎”剝離出來，為研究線粒體DNA與相應(yīng)疾病的關(guān)聯(lián)提供了潛在幫助,。（圖片來源：NIST）
在這項(xiàng)研究中,，研究小組采用了一種先前用于提取獨(dú)立稻米細(xì)胞中單一染色體的方法。他們利用激光將細(xì)胞外膜切開一個(gè)小口,，然后使用另一束激光,，像“鉗子”一般將線粒體與周圍的物質(zhì)分離開,，最后，他們用一種末端不足1微米大小的微小吸管將線粒體提取出來,。
這種提取方法讓研究小組能將單個(gè)線粒體置入小試管中,，并采用傳統(tǒng)方法對其遺傳構(gòu)成進(jìn)行仔細(xì)研究。他們發(fā)現(xiàn)整個(gè)細(xì)胞的變異過程都能在單一線粒體中得到體現(xiàn),，這意味著對線粒體疾病的廣泛性遺傳研究或?qū)⒆罱K成為可能,。
“用‘鉗子’獲取這樣微小的物質(zhì)并不是件容易的事”，參與研究的Koren Deckman說,，“但依賴于NIST十多年的研究工作,，我們現(xiàn)在已找到方法對線粒體進(jìn)行提取并觀察其整個(gè)轉(zhuǎn)錄過程，這也意味著我們能保證,，可從特定細(xì)胞中獲得（你想要的）線粒體樣本,。這對醫(yī)學(xué)研究人員了解遺傳疾病將有很大幫助”。（生物谷Bioon.com）
生物谷推薦原文出處：
PLoS ONE 5(12): e14359. doi:10.1371/journal.pone.0014359
Detection of Heteroplasmic Mitochondrial DNA in Single Mitochondria
Joseph E. Reiner1*, Rani B. Kishore1, Barbara C. Levin2, Thomas Albanetti3, Nicholas Boire3, Ashley Knipe3, Kristian Helmerson1, Koren Holland Deckman3
1 Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland, United States of America, 2 Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland, United States of America, 3 Department of Chemistry, Gettysburg College, Gettysburg, Pennsylvania, United States of America
Abstract
Background
Mitochondrial DNA (mtDNA) genome mutations can lead to energy and respiratory-related disorders like myoclonic epilepsy with ragged red fiber disease (MERRF), mitochondrial myopathy, encephalopathy, lactic acidosis and stroke (MELAS) syndrome, and Leber's hereditary optic neuropathy (LHON). It is not well understood what effect the distribution of mutated mtDNA throughout the mitochondrial matrix has on the development of mitochondrial-based disorders. Insight into this complex sub-cellular heterogeneity may further our understanding of the development of mitochondria-related diseases.
Methodology
This work describes a method for isolating individual mitochondria from single cells and performing molecular analysis on that single mitochondrion's DNA. An optical tweezer extracts a single mitochondrion from a lysed human HL-60 cell. Then a micron-sized femtopipette tip captures the mitochondrion for subsequent analysis. Multiple rounds of conventional DNA amplification and standard sequencing methods enable the detection of a heteroplasmic mixture in the mtDNA from a single mitochondrion.
Significance
Molecular analysis of mtDNA from the individually extracted mitochondrion demonstrates that a heteroplasmy is present in single mitochondria at various ratios consistent with the 50/50 heteroplasmy ratio found in single cells that contain multiple mitochondria.
