Simplest known animals engage in sex

Oct 10, 2005

A Yale University study suggests even the most simple of animals engage in sex. Ana Signorovitch and colleagues have demonstrated placozoans, the simplest known free-living animals, undergo a sexual phase in their life cycle.

Placozoans possess the smallest genome of any known animal and are composed of only four different cell types. While asexual reproduction has been observed in placozoans, no evidence of sexual reproduction has been documented. The biology of the organisms remains largely unknown.

Signorovitch and colleagues utilized molecular genetics to investigate if placozoans reproduce sexually. Because asexual and sexual animals have distinct patterns of gene variation, the researchers studied the DNA sequences of several genes from a sample placozoan population of 10 individuals.

Genetic signatures consistent with a sexual mode of reproduction were observed. Within-individual and overall DNA diversity were found to be consistent with levels seen in sexually reproducing organisms. Also, genetic recombination and sharing of gene variants were observed, supporting the presence of a sexual phase in the placozoan life cycle.

Signorovitch said the findings indicate placozoans have or had the ability to reproduce sexually.

The research appears in the online early edition of the Proceedings of the National Academy of Sciences.

Copyright 2005 by United Press International

Explore further: How were fossil tracks made by Early Triassic swimming reptiles so well preserved?

add to favorites email to friend print save as pdf

Related Stories

What factors motivate people to text while driving?

16 minutes ago

Nearly a third of adult drivers text while driving, despite the increased risk of accidents, stricter laws against it, and many awareness-raising efforts. What motivates this behavior and why it is so difficult to discourage ...

Korean tech start-ups offer life beyond Samsung

10 hours ago

As an engineering major at Seoul's Yonsei University, Yoon Ja-Young was perfectly poised to follow the secure, lucrative and socially prized career path long-favoured by South Korea's elite graduates.

Fresh nuclear leak detected at Fukushima plant

22 hours ago

Sensors at the Fukushima nuclear plant have detected a fresh leak of highly radioactive water to the sea, the plant's operator announced Sunday, highlighting difficulties in decommissioning the crippled plant.

Spacewalking astronauts route cable in 1st of 3 jobs

22 hours ago

(AP)—Spacewalking astronauts routed more than 300 feet (90 meters) of cable outside the International Space Station on Saturday, tricky and tiring advance work for the arrival of new American-made crew ...

Recommended for you

Predicting human crowds with statistical physics

Feb 27, 2015

For the first time researchers have directly measured a general law of how pedestrians interact in a crowd. This law can be used to create realistic crowds in virtual reality games and to make public spaces safer.

Bribery 'hits 1.6 billion people a year'

Feb 27, 2015

A total of 1.6 billion people worldwide – nearly a quarter of the global population – are forced to pay bribes to gain access to everyday public services, according to a new book by academics at the Universities of Birmingham ...

Broken windows thesis springs a leak

Feb 27, 2015

The broken windows theory posits that minor misdemeanors, like littering or graffiti spraying, stimulate more serious anti-social behavior. LMU sociologists now argue that the idea is flawed and does not ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.