What's Hiding in This Flower's Giant Y Chromosome

A recent article by Veronique Greenwood in The New York Times discusses how scientists have finally sequenced the Y chromosome of the white campion, a flower with a massive Y chromosome, even bigger than the entire genome of some organisms like puffer fish and fruit flies. Unlike most plants, which are hermaphrodites, white campion, on the other hand, has distinctive male and female sexes, thanks to sex chromosomes. Researchers have found that the Y chromosome is packed with genes controlling male traits and a lot of repetitive DNA that has been copying itself for millions of years. Scientists also discovered that, unlike in many other organisms where X and Y chromosomes swap DNA to remove excess material, the white campion lost this ability long ago, perhaps because swapping could have endangered the integrity of these genes, leading to its unusually massive Y chromosome.

         

            This discovery isn't just about curiosity, but understanding how sex chromosomes evolve could have a real-world impact, as many crops, like papaya and cannabis, rely on a similar system, so this research could help with breeding and agriculture. It could also help in understanding how sex-determining genes remain stable, or why some Y chromosomes remain stable, while some like this keep expanding. 

Genes That First Enabled Plants to Grow Leaves Identified by Scientists

       Over the course of the past half billion years plants have evolved from tiny little ground hugging organisms into a very large and diverse group essential to life on earth. An international research team consisting of researchers from the universities of Bristol, Lyon, and Palacky have now discovered the genes behind the formation of larger plants, such as the towering redwood tree. The team discovered that roughly 450 million years ago a switch caused plants to delay reproduction and displace cells downwards from the shoot tips, which consequently paved the way for plant diversification. The team studied swollen reproductive structures at the tips of the small stems of mosses. These small plants are raised upwards through cells generating in the middles of plant stems.
   
       Even though plants follow different growth patterns, very similar genes were found to be responsible for elongating the stems of mosses to form into larger and more elaborate shoots. The results obtained suggest that a mechanism for shoot development involving different timing and location of gene activity triggered the radiation of shoot forms. Dr. Jill Harrison says that, "By comparing our findings from moss with previous findings, we can see that a pre-existing genetic network was remodeled to allow shoot systems to arise in plant plant populations."

      I found this study interesting because plants are an essential part of life on earth as they maintain oxygen levels within the atmosphere. Also as research allows us to learn more about plan genetics to further our understanding of plant shape, we have the potential to engineer crops to increase future production.

https://www.sciencedaily.com/releases/2019/08/190802104539.htm

Studies of Domesticated Wheat Genome Reveal Information About Evolutionary Past

Grain and high carbohydrate diets have recieved a bad reputation today for being lacking in nutritional content.  Instead, many grain diets, pasta grains in particular, are regarded as 'empty calories'.  Recently, scientists have attempted to explain the lack of nutritional content in our grains.  A study by Romina Beleggia, Roberto Papa, et al.,  published in the journal of Molecular Biology and Evolution (Oxford University Press), examined study populations of wheat for metabolic content and population genomics.
Three populations were studied to identify two evolutionary changes between each stage.  These were representative of wild emmer, which was domesticated to the emmer grain.  And durum, which came about from emmer.  The domestication of this grain showed a trend of increaing yield by mass.  However, metabolic analyses show that the first domestation of wild type to emmer resulted in a lower production of unsaturated fats.  The change from emmer to durum was found to alter the protien content of the grain.  Co-author Roberto Papa is cited saying that, "not necessarily all of the metabolic variations that occured during domestication have proceeded towards an amelioration of the nutritional quality, probably because yield-related traits were given priority".
The methods of assessment for this study are interesting as they are very large in scale.   The population genomics survey that was performed is a wide-range assesment of the genetic diversity within the selected populations.  The test measures the frequency and variability of selected alleles to give a quantitative measurement of genatic divergence.  To view the free article, click here.

Tomato genetics study sheds light on plant evolution

Scientists have created a study in which tomatoes are genetically modified. This study so far has help shed light on plant evolution as a whole.

"The vast biodiversity we observed in tomato species was not the result of simply one evolutionary or environmental factor. It is the result of a complex set of genetic resources that we can distinguish with large-scale genomic data," said Pease, who joined the U-M Department of Ecology and Evolutionary Biology.

The research that was done may contribute to future studies and efforts to create better crops. These better crops could be more bug resistant and even more cold or hot resistant depending on the weather. These would be made by crossbreeding and not be genetically modifying them.

The tomato can adapt rapidly to ecological change, in which the scientists have found three major genetic strategies that support how it can adapt so quickly. These genetic strategies are: the recruitment of genes from a common ancestral pool, the trading of genes between species through a form of natural crossbreeding called intogression, and the rapid accumulation of new genetic mutations. Or, in other words, diversity from their ancestors, trading genes between species, and new evolutionary changes.