Showing posts with label Gregor Mendel. Show all posts
Showing posts with label Gregor Mendel. Show all posts

Wednesday, April 23, 2025

Century-old genetics mystery of Mendel’s peas finally solved

 After More than 160 years after Gregor Mendel’s foundational experiments with pea plants, scientists have finally identified the genes responsible for the last three traits Mendel studied but never genetically explained. Mendel, considered the father of genetics, analyzed seven traits in pea plants, but the genes behind flower branching, pod color, and pod shape had remained elusive — until now.

In a landmark study published in Nature, an international team of researchers used advanced genome
sequencing and computational tools to solve this mystery. Building on the pea’s reference genome released in 2019, the team deep-sequenced nearly 700 pea genomes, uncovering around 155 million genetic variations. Through genome-wide association studies and selective breeding, they pinpointed the genes linked to the remaining traits. Pod color, they found, is influenced by a gene that affects chlorophyll production. Two genes tied to pod shape impact cell-wall development, and a gene deletion leads to fasciation — abnormal flower clustering.



The six-year effort highlights the power of interdisciplinary collaboration and modern genomics. According to co-author Noam Chayut of the John Innes Centre, the work not only closes a historical loop in genetics but also provides a treasure trove of data for crop improvement. The team also mapped 72 additional agriculturally significant traits, offering valuable insight for future pea breeding and sustainability research. With pea protein gaining popularity as a plant-based food source, the findings are expected to drive innovations in crop yield, disease resistance, and nutritional quality for years to come.

Friday, December 7, 2018

Why Do Some Finches Have Large Beaks While Others Have Small Ones?

Cameroonian finches have always had either a large beak size, or smaller beaks.  This had always been thought to be due to a difference in how hard the seeds they eat, much like the theory of Darwin's finches.  However, birder and biologist Tom Smith, investigated this further by establishing a breeding colony of these finches.  Based on the results, the trait seemed to be due to Mendelian genetics, and the larger beak was the dominant trait, with a 3:1 ratio of large to small beaks.  This was the stepping stone to figuring out which genes affected this trait, and with the help of Bridgett vonHoldt, Princeton biologist, the question was solved.  She found a stretch of DNA with 300,000 base pairs that always seemed to vary between the large and small-beaked finches, with the gene IFG-1 in the center.  This gene is a growth-factor gene. vonHoldt said that this is a gene she has studied in canines as well and that if it is changed how it is expressed, a normal-sized dog could be changed into a dwarf-sized dog.  This being said, not only can he gene affect the whole animal, but a specific trait as well, which is present in the case of the finches and their beak size.  This all depends on where the gene is located on the genome and where it gets expressed, says vonHoldt.
https://www.sciencedaily.com/releases/2018/11/181119064118.htm
https://www.princeton.edu/news/2018/11/19/princeton-geneticist-solves-long-standing-finch-beak-mystery

Saturday, October 27, 2018

What inspired Mendel?

Everyone knows Gregor Mendel as the father of genetics, but what to we really know about the man himself? There are not many letters that he wrote himself available for reading, and only a few of his letters to Charles Darwin have survived. Mendel's "intentions in studying plants" has been a long anticipated question. In a recent article in GENETICS, by Peter J. van Dijk et. al, two newspapers have been newly found that uncover Mendel's hidden motivations.
The popular opinion is that Mendel was trying to figure out "the rules of inheritance" but others argue that he was simply trying to figure out if he could create a new species from hybridization.

Van Dijk found these "overlooked" articles, one published in 1861 emphasizing Mendel's desire to produce new and improved crops and flowers in the region. He was "surprised" by the results of his crosses that produced "plentiful fruit".
The second article, published four days later, slightly criticized Mendel saying that the extent of his work was "exaggerated" and to not give him so much credit. Mendel may have thought he was doing a great work of the people of his region, but others thought it was highly over-glorified and was not that big of a deal.
Both newspaper articles found stress the fact that new science in its time is not exactly what everyone wants to automatically believe: it takes time for an idea to become part of everyone's thinking and to accept it as truth.

I believe that Mendel was a great scientist and did a great work for the work of science, genetics, and heredity. It is understandable that at his time his work was misunderstood because the science he was addressing was an uncharted water and at the time some people did not know what to think about this new world being discovered until more people started to study it as well.
http://genestogenomes.org/what-inspired-mendel/
http://www.biologyreference.com/Ho-La/Hybridization-Plant.html
http://www.genetics.org/content/210/2/347