Undead genes come alive days after life ends

first_img Sign up for our daily newsletter Get more great content like this delivered right to you! Country At first, the researchers assumed that genes would shut down shortly after death, like the parts of a car that has run out of gas. What they found instead was that hundreds of genes ramped up. Although most of these genes upped their activity in the first 24 hours after the animals expired and then tapered off, in the fish some genes remained active 4 days after death.The headline of this study is that we can probably get a lot of information about life by studying death.Peter NobleMany of these postmortem genes are beneficial in emergencies; they perform tasks such as spurring inflammation, firing up the immune system, and counteracting stress. Other genes were more surprising. “What’s jaw-dropping is that developmental genes are turned on after death,” Noble says. These genes normally help sculpt the embryo, but they aren’t needed after birth. One possible explanation for their postmortem reawakening, the researchers say, is that cellular conditions in newly dead corpses resemble those in embryos. The team also found that several genes that promote cancer became more active. That result could explain why people who receive transplants from the recently deceased have a higher risk of cancer, Noble says. He and his colleagues posted their results on the preprint server bioRxiv last week, and Noble says their paper is undergoing peer review at a journal.“This is a rare study,” says molecular pharmacologist Ashim Malhotra of Pacific University, Hillsboro, in Oregon, who wasn’t connected to the research. “It is important to understand what happens to organs after a person dies, especially if we are going to transplant them.” The team’s approach for measuring gene activity could be “used as a diagnostic tool for predicting the quality of a transplant.”In an accompanying paper on bioRxiv, Noble and two colleagues demonstrated another possible use for gene activity measurements, showing that they can provide accurate estimates of the time of death. Those results impress forensic scientist David Carter of Chaminade University of Honolulu. Although making a time of death estimate is crucial for many criminal investigations, “we are not very good at it,” he says. Such estimates often rely on evidence that isn’t directly connected to the body, such as the last calls or texts on the victim’s cellphone. Noble and his colleagues, Carter says, have “established a technique that has a great deal of potential to help death investigation.”A mouse or zebrafish doesn’t benefit, no matter which genes turn on after its death. The patterns of gene activity that the researchers observed may represent what happens when the complex network of interacting genes that normally keeps an organism functioning unwinds. Some genes may turn on, for example, because other genes that normally help kept them silent have shut off. By following these changes, researchers might be able to learn more about how these networks evolved, Noble says. “The headline of this study is that we can probably get a lot of information about life by studying death.” Click to view the privacy policy. Required fields are indicated by an asterisk (*) 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 Zimbabwecenter_img Does death really mean the end of our existence? Great thinkers from Plato to Blue Öyster Cult have weighed in on the question. Now, a study shows that at least one aspect of life continues: Genes remain turned on days after animals die. Researchers may be able to parlay this postmortem activity into better ways of preserving donated organs for transplantation and more accurate methods of determining when murder victims were killed.Before you ask, microbiologist Peter Noble of the University of Washington, Seattle, and colleagues were not trying to find out what allows zombies to stalk Earth and slurp the brains of the unwary. Instead, the scientists wanted to test a new method they had developed for calibrating gene activity measurements. Their research had already taken a morbid turn—2 years ago they published a paper on the abundance of microbes in different human organs after death—and they decided to apply their method to postmortem samples. “It’s an experiment of curiosity to see what happens when you die,” Noble says.Although scientists analyzing blood and liver tissue from human cadavers had previously noted the postmortem activity of a few genes, Noble and colleagues systematically evaluated more than 1000. The team measured which of these genes were functioning in tissues from recently deceased mice and zebrafish, tracking changes for 4 days in the fish and 2 days in the rodents. Emaillast_img

Leave a Reply

Your email address will not be published. Required fields are marked *