Navigation Links
A new male-specific gene in algae unveils an origin of male and female

By studying the genetics of two closely related species of green algae that practice different forms of sexual reproduction, researchers have shed light on one route by which evolution gave rise to reproduction though the joining of distinct sperm and egg cells. The findings, which indicate that a gene underlying a more primitive system of reproduction was likely co-opted during evolution to participate in sex-specific sperm development, are reported by Hisayoshi Nozaki and colleagues at the University of Tokyo, Rikkyo (St. Paul’s) University, and Osaka University. The paper appears in the December 19th issue of the journal Current Biology, published by Cell Press.

The familiar notion of the separate male and female sexes exhibited by animal and plant species is based in part on the anatomically and genetically distinct gametes, sperm and egg, produced by members of each sex. But the evolutionary origin of oogamy—reproduction though joining of distinct sperm and egg cells—is in fact poorly understood. In particular, it has remained unclear how oogamy arose from isogamy, a more simple form of sex in which very similar reproductive cells take on different "mating types" but do not differentiate as distinct sperm and egg. The transition from isogamy to oogamy has apparently occurred multiple times during the evolution of animals, plants, and some algae, but how did such transitions occur"

In their new work, the researchers established a genetic connection between male sexuality of an oogamous multicellular green algae species, Pleodorina starrii, and one of the mating types of its isogamous ancestor, the unicellular alga Clamydomonas reinhardtii.

In C. reinhardtii, isogamous sexual reproduction occurs through "plus" (MT+) and "minus" (MT-) mating types. MT- represents a "dominant sex" because a particular gene, MID ("minus-dominance") of C. reinhardtii is both necessary and sufficient to cause the cells to differentiate as MT- isogametes. How ever, no sex-specific genes related to MID had been identified in closely related oogamous species. The researchers now report that they have successfully identified a version of the MID gene in Pleodorina starrii. This "PlestMID" gene is present only in the male genome, and it encodes a protein localized abundantly in the nuclei of mature sperm. The findings indicate that P. starrii maleness evolved from the dominant sex (MT-) of its isogamous ancestor. This breakthrough in understanding provides an opportunity to address any number of extremely interesting questions regarding evolution of oogamy and the origins of male-female dichotomy.

Source:Cell Press

Related biology news :

1. Evidence of 600-million-year old fungi-algae symbiosis discovered in marine fossils
2. Deep sea algae connect ancient climate, carbon dioxide and vegetation
3. The secret life of algae
4. Cellular antennae on algae give clues to how human cells receive signals
5. Detecting microalgae in coastal waters
6. Chemicals in brown algae may protect against skin cancer
7. Florida Tech explores microalgae for biofuel
8. Common algae helps illustrate mammalian brain electrical circuitry
9. Darkness unveils vital metabolic fuel switch between sugar and fat
10. UAB scientists discover the origin of a mysterious physical force
11. An (ecological) origin of species for tropical reef fish

Post Your Comments:

(Date:6/20/2016)... , June 20, 2016 Securus Technologies, ... technology solutions for public safety, investigation, corrections and ... prisons involved, it has secured the final acceptance ... facilities for Managed Access Systems (MAS) installed. Furthermore, ... facilities to be installed by October, 2016. MAS ...
(Date:6/9/2016)... Paris Police Prefecture and ... ensure the safety of people and operations in several locations ... Teleste, an international technology group specialised in broadband ... its video security solution will be utilised by ... across the country. The system roll-out is scheduled for the ...
(Date:6/2/2016)... , June 2, 2016   The Weather Company , ... Watson Ads, an industry-first capability in which consumers will be ... able to ask questions via voice or text and receive ... Marketers have long sought an advertising ... that can be personal, relevant and valuable; and can scale ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... June 23, 2016 Houston Methodist Willowbrook ... Cy-Fair Sports Association to serve as their official ... Houston Methodist Willowbrook will provide sponsorship support, athletic ... with association coaches, volunteers, athletes and families. ... Cy-Fair Sports Association and to bring Houston Methodist ...
(Date:6/23/2016)... SAN FRANCISCO , June 23, 2016   ... it has secured $1 million in debt financing from ... to ramp up automation and to advance its drug ... for its new facility. "SVB has been ... goes beyond the services a traditional bank would provide," ...
(Date:6/23/2016)... 23, 2016 Apellis Pharmaceuticals, Inc. today ... trials of its complement C3 inhibitor, APL-2. The ... ascending dose studies designed to assess the safety, ... injection in healthy adult volunteers. Forty ... a single dose (ranging from 45 to 1,440mg) ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... the Pennsylvania Convention Center and will showcase its product’s latest features from June ... be presenting a scientific poster on Disrupting Clinical Trials in The Cloud during ...
Breaking Biology Technology: