UCR: Deceased male guppies store sperm for almost a year
Researchers from UC Riverside have found that female Trinidadian guppies are able to store sperm cells inside their bodies for at least 10 months until the optimal conditions to fertilize their eggs are met.
Since female guppies live on average six to eight times longer than their male counterparts — two years as compared to three to four months — this ability to ensure the growth and genetic diversity of the guppy population is vital and necessary from an evolutionary standpoint. Sperm storage allows short-lived males to expand their reproductive lifespan and pass on their genes even after they’re dead.
David Reznick, professor of biology and the principal investigator of the research project explained, “Populations that are too small can go extinct because close relatives end up breeding with each other and offspring suffer from inbreeding. [But] if there are stored sperm, then the real population size is bigger than the number of animals you see.”
Female guppies prefer to mate with male guppies with rare color patterns. And due to their ability to carry out selective fertilization, a color-pattern that has been lost for over two male guppy generations can suddenly reappear again inside the population.
“In addition to learning about sperm storage, this is the first time we are learning about the huge differences in lifespan between males and females,” said Reznick in a press release. “If we were to use males to estimate generation time, then these differences mean that lucky females live for three generations.”
The study is published in the journal Proceedings of the Royal Society B.
UCI: Herbal plant extends life span of fruit fly by 25 percent
The herbal extract of Rhodiola rosea, a yellow-flowered mountain plant commonly known as golden root or roseroot, is found to extend lifespan, according to researchers from UC Irvine.
The research team tested out the experiment by imposing a diet of Rhodiola rosea on fruit flies. The result revealed that the group of fruit flies that fed on the herbal extract lives exponentially longer — a 25 percent increase — than the group that fed on regular yeast or fruit produce.
“It demonstrates that Rhodiola can act even in individuals who are already long-lived and healthy,” said Associate Professor of Pharmaceutical Sciences Mahtab Jafari, who was also the lead researcher of this study.
Despite the recent study, the plant has long been used as traditional medicine in Russian and Scandinavian cultures, where it is widely circulated nowadays as treatment for a variety of illnesses and stresses.
The study was published in open access science journal PLOS One.
UCSD: Former doctoral student selected as NASA astronaut trainee
Jessica Mier, a Ph.D marine physiologist from UC San Diego, was selected out of a pool of 6,000 applicants to be one of the eight candidates to receive space training by the National Aeronautics and Space Administration (NASA).
The candidate selection process is highly selective, as qualified applicants must demonstrate perfect physical as well as mental health. Additionally, candidates must have obtained advanced degrees in engineering, biological science, physical science or mathematics, followed by at least three years of related fieldwork.
Mier, along with seven other selected candidates, will receive two years of intensive training in a variety of subjects including survival skills, Russian language and operating systems of space ships.
NASA notes that these trainings are to prepare the astronaut candidates “who will help the agency push the boundaries of exploration and travel to new destinations in the solar system, including an asteroid and Mars.”
“I’m incredibly excited about this opportunity to be a part of NASA’s human spaceflight program,” said Meir. “I’ve been very passionate about scientific outreach and education through my past research, and am thrilled to have another avenue to help inspire the next generation of scientists and explorers.”
Meir recalls that since she was five, she has always wanted to become an astronaut one day. Her childhood dream motivated her throughout the course of her career, inspiring her research in various geographical locations such as the sea ice of the Antarctic and the beaches of California, to reach this goal.