Tuesday, November 4, 2014

Delicious sex chromosomes.

Plants have sex? Yes, they totally do.

A brief overview: 
Plants have female reproductive organs (carpels) and male reproductive organs (stamens), but several different ways of determining sex. There are two main groups of seed-producing plants.

Gymnosperms are plants without covered seeds, and include those that produce cones. Gymnosperms and are split with about 75% exhibiting monoecy (having male and female sex organs on the same plant), and 25% exhibiting dioecy (having separate male plants and female plants).

Photo by Muhammad Mahdi Karim, via Wikimedia Commons
Alternatively,  Angiosperms, the flowering plants, have only a small subgroup that exhibit either separate male and female flowers or separate male and female plants, and instead most angiosperms are hermaphrodites, meaning all of their flowers contain both male and female sex organs.

Photo by Derek Ramsey, at Chanticleer Garden, via Wikimedia Commons
One thing that is fairly common among vertebrates (found in mammals, birds, frogs, reptiles, and fish), but rare among plants is sex chromosomes. But, as we look more and more, we are finding sex chromosomes in the most delicious places. All of the following plants have sex chromosomes:

Persimmon
A Y-chromosome–encoded small RNA acts as a sex determinant in persimmons
Takashi Akagi1,2,  Isabelle M. Henry1,  Ryutaro Tao2,*,  Luca Comai1,*

Photo by Σ64, via Wikimedia Commons
Asparagus
Identification of molecular markers for selection of supermale (YY) asparagus plants.
Gebler P, Wolko Ł, Knaflewski M.

Photo by Rasbak, via Wikimedia Commons
Wild strawberry
Sex-determining chromosomes and sexual dimorphism: insights from genetic mapping of sex expression in a natural hybrid Fragaria × ananassa subsp. cuneifolia.
Govindarajulu R, Liston A, Ashman TL.

Photo via Walter Siegmund, via Wikimedia Commons
Papaya
Accumulation of interspersed and sex-specific repeats in the non-recombining region of papaya sex chromosomes.
Na JK, Wang J, Ming R.

Photo by Sakurai Midori, via Wikimedia Commons
Wild grapes
A small XY chromosomal region explains sex determination in wild dioecious V. vinifera and the reversal to hermaphroditism in domesticated grapevines.
Picq S, Santoni S, Lacombe T, Latreille M, Weber A, Ardisson M, Ivorra S, Maghradze D, Arroyo-Garcia R, Chatelet P, This P, Terral JF, Bacilieri R.

Photo by Bangin, via Wikimedia Commons

So, yes, plants have sex, and some even have sex chromosomes. Just something to keep in mind as you work towards fulfilling your daily servings of fruits and veggies. 

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