first_img By Elizabeth PennisiMar. 15, 2018 , 2:00 PM DNA mutations cause tumor cells to grow out of control, but they also generate variety that enables organisms to adapt to their environments and evolve. Until now, biologists have only had crude methods for estimating the average rates and effects of mutations. But in a new study, biophysicists have documented individual mutations as they happen in bacterial cells.These changes occur at about the same rate over time—as opposed to in bursts—and only about 1% are deadly, the researchers report today in Science. Moreover, all bacteria in a given strain seem to have about the same mutation rate—about one mutation per 600 hours in normal bacteria, and about 200 mutations per 600 hours in bacteria engineered to mutate at a faster rate—they note.To see the mutations, the team built 1000 microscopic channels into a computerlike chip and placed a single bacterial cell at the closed end of each the channel, along with plenty of nutrients to survive. The bacteria carried a modified DNA repair protein that caused any mutations to glow yellow. Then, for 8 hours up to 3 days, the researchers took a picture every few minutes as new bacterial cells were formed, pushed down the channel, and then swept away by fluid flowing across the ends of these channels. Automated image processing let them count the number of mutations and assess how well the cells were doing. Dead cells signaled a deadly mutation; slower growing cells signaled a detrimental change. Mutating DNA caught on film Country * Afghanistan Aland Islands Albania Algeria Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia, Plurinational State of Bonaire, Sint Eustatius and Saba Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory Brunei Darussalam Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Congo, the Democratic Republic of the Cook Islands Costa Rica Cote d’Ivoire Croatia Cuba Curaçao Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and McDonald Islands Holy See (Vatican City State) Honduras Hungary Iceland India Indonesia Iran, Islamic Republic of Iraq Ireland Isle of Man Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Korea, Democratic People’s Republic of Korea, Republic of Kuwait Kyrgyzstan Lao People’s Democratic Republic Latvia Lebanon Lesotho Liberia Libyan Arab Jamahiriya Liechtenstein Lithuania Luxembourg Macao Macedonia, the former Yugoslav Republic of Madagascar Malawi Malaysia Maldives Mali Malta Martinique Mauritania Mauritius Mayotte Mexico Moldova, Republic of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island Norway Oman Pakistan Palestine Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Qatar Reunion Romania Russian Federation Rwanda Saint Barthélemy Saint Helena, Ascension and Tristan da Cunha Saint Kitts and Nevis Saint Lucia Saint Martin (French part) Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Sint Maarten (Dutch part) Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Islands South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syrian Arab Republic Taiwan Tajikistan Tanzania, United Republic of Thailand Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu Uganda Ukraine United Arab Emirates United Kingdom United States Uruguay Uzbekistan Vanuatu Venezuela, Bolivarian Republic of Vietnam Virgin Islands, British Wallis and Futuna Western Sahara Yemen Zambia Zimbabwe Click to view the privacy policy. Required fields are indicated by an asterisk (*)center_img Email Sign up for our daily newsletter Get more great content like this delivered right to you! Country According to its developers, the technique can be applied to assess mutation dynamics in other types of cells, even human cancer cells. And the researchers eventually hope to be able to monitor mutation rates real time in entire organisms, such as zebra fish, to see whether different tissues have different mutation rates.last_img read more