Genetic Proof for Origin of the Genders Identified in Green Algae

The foundation of how we became males and females – how species developed to have physically distinct men and women – may be demystified, say plant biologists, following they determined a master gene in control of sex and propagation among green algae.

The gene identified in the Volvox carteri algae was identified to be liable for the specific physical variances between the men and women in the multicellular organisms.

This could also “offer a feasible outline for how genders in other multicellular species such as plants and animals may have began,” say the scientists.

The comparisons between the two kinds of reproductive cells (known by biologists as the gametes, which join while in fertilization) are obvious: it is the distinction between sperm and eggs.

“However,” say the scientists, “the evolutionary origins of men and women sexes are not clear simply because the distant unicellular relatives of plants, animals and other multicellular organisms usually don’t have distinct sexes, but rather have propagation types – a system in which gametes of one mating kind can only join with those with a various mating type, but the cells of each propagation type are indistinguishable from each other in dimension and morphology.”

Gene developed from single-celled species

The researchers have presented the outcomes of their study on Volvox in the open-access journal PLOS Biology.

The sexes of that multicellular alga were identified to be produced from the mating types of its single celled relative, a species recognized as Chlamydomonas reinhardtii.

A gene was fundamental to the determination of sperm Vs egg – the lab work resolved earlier theoretical work to discover that “a single ancestral mating locus gene, MID, progressed from its role in identifying mating kind in C. reinhardtii to identify either spermatogenesis(the production or development of mature spermatozoa) or oogenesis(the production or development of an ovum.)in V. carteri.”

How do the results associate to more complex beings? The authors states that the algae offer an “outstanding model for examining the progress of sexual dimorphism” due to the fact of the way they demonstrate “development from unicellular species to multicellular types with growing size and cell-type specialization.”

Gender reassignment

The biologists’ results are extremely scientific and engaged meticulous lab work, but basically they gender-swapped the algae via genetic manipulation.

The team – lead by Dr. James Umen, was capable to convert what would have been egg cells into packets of useful sperm cells in the genetically female Volvox.

On the other hand, the team also pushed the genetic males “to grow with functional eggs in area of their sperm packets.”

This was all obtained by means of the manipulation of a single gene known as MID, which the team recognizes as the “master regulatory gene for genders and propagation types” in this class of green algae.

The outcomes of the work “hint that an identical evolutionary situation may underlie the foundation of genders in animals, plants and other multicellular species,” say the plant researchers.

Additionally to the contribution to evolutionary concept, the results could give realistic help to researchers working on the development of biofuels and other biotechnological programs, where, states that Dr. Umen, “sexual reproduction in most algal species is improperly recognized.”

‘Remarkable’ discoveries

In an editorial presented in the same issue of the journal, molecular and medical geneticist G. Roberts states that the scientists were able not only capable to show that the genetic change was a male-versus-female one, but also one that could figure out hermaphrodites.

With some genetic information, he writes: “Incredibly, the authors were capable to display that this male/female change is tunable – when they used a sluggish version of the Volvox carteri MID RNAi hairpin, the partial reduction of Volvox carteri MID resulted in hermaphrodites that comprised the two pseudo-male sperm packets and pseudo-female eggs.”

The two species of algae examined, which are “divided by 200 million years of evolution,” adds Dr. Roberts, “could not be more different in their physical appearance or sexual proclivities.” Yet, he publishes, a single gene not merely identified the sexes in both species, but drove the dimorphism among the sexes, and the “significant divergence” in the way the two species grow sexually.