10 April 2018

Maughan, 2018

Maughan M. 2018. Cyclical parthenogenesis in crustaceans. Poster presentation, Utah State University, 12 April 2018. https://digitalcommons.usu.edu/researchweek/ResearchWeek2018/All2018/283/


Abstract


Apomixis is the replacement of sexual reproduction with asexual reproduction in plants. Some scientists hypothesize that apomixis is caused by genetics that evolved after sexual reproduction and apomixis mutated from sexual reproduction. However, we hypothesize that sexual reproduction and apomixis evolved simultaneously during eukaryogenesis, the evolution of eukaryotic life. We think that most organisms retain the capacity for apomixis and sexual reproduction in their genome. Many taxa, including plants and crustaceans, should have a single genome able to express both sexual and asexual reproduction as long as the correct metabolic signaling is provided to the germline cells. In Professor John Carman’s lab, researchers have successfully induced onset of apomixia in sexual plants. These successes support our hypothesis and suggest that some animals could also have the pathogenesis and sexual reproduction capabilities in their genome. The equivalent of plant apomixis in animals is apomictic parthenogenesis. We focus on cyclical parthenogenesis. In cyclical parthenogenesis animals alternate between sexual and asexual reproduction. Daphnia magna and Procambarus virginalis (marbled crayfish) are both cyclically parthenogenetic. The TOR (rapamycin complex 1) signaling pathway in plants and animals is a regulator of cell growth and it affects the pathway of reproduction. Oxidative stress turns off the TOR signaling pathway and turns SnRK1(SNF1-related kinase 1 in yeast and AMPK in animals) on. SnRK1 makes cells begin the process of sexual reproduction. To test this hypothesis, I will be researching how to switch asexual organisms to reproduce sexually. I will inject the ovaries of crayfish with chemicals designed to alter their glucose levels and place the Daphnia in a solution containing the appropriate chemicals. The presence of an egg sack from the Daphnia and the presence of male crayfish will show the success of the expirement (sic).

Keywords: None provided.

02 April 2018

Neff, 2018

Neff EP. 2018. The Marmorkrebs model. Lab Animal 47(4): 107-107. https://doi.org/10.1038/s41684-018-0030-y

Abstract

Without abstract. First paragraph:

In his lab at the German Cancer Research Center in Heidelberg, Frank Lyko studies epigenetics, how the environment can change an organism’s phenotype without altering its underlying DNA. About 15 years ago, a colleague introduced him to the marbled crayfish, a triploid, clonal, parthenogenic, and only very recently speciated invertebrate that’s proven to be quite the invasive pest across the globe. At the time, the Marmorkrebs (as it’s known in German) didn’t register in Lyko’s research plans. But recently, he began thinking about alternative models. Classical laboratory animals, like mice, worms, and fruit flies, “always have the same phenotype, and if you induce a genetic mutation you get one aberrant phenotype normally,” he explains. “This is super helpful if you do genetic research but it’s not necessarily good for describing what’s going on in epigenetics.” He tried honeybees, but found them challenging to keep in the laboratory. His lab wasn’t fond of another potential epigenetic model, the African desert locust, either. “These were really big animals and they were always escaping and flying around, so that was a mess,” he recalls. “Then I remembered my old conversation with G√ľnter Vogt.”

Keywords: None provided.