CRISPR technology is now laying a foundation in the agricultural world, trying to help corn growers improve the speed, versatility, and output of their crops. It has been difficult to implement CRISPR technology thus far, as the cells walls of plants, at a microscopic level, are particularly tough to penetrate. Fundamentally, CRISPR “…consists of enzymatic scissors called Cas9 that a guide made from RNA shuttles to an exact place in a genome.” The difficulty with plants cells is that, in comparison to animal cells, the extra-rigid cell walls make it immensely difficult for the guide RNA (gRNA) and the Cas9 to reach their destination on the genome. In response to this problem researchers have come up with what is described as an “inelegant” solution to this problem where they “…splice […] CRISPR genes into a bacterium that can breach the plant cell wall or put them on gold particles and shoot them with what’s known as a gene gun.” Unfortunately, this method doesn’t work in the crucial corn varieties where it is needed. However, a team of researchers in North Carolina, Timothy Kelliher and Quideng Que of Syngenta, in Durham, North Carolina have come up with an even more ingenious solution to deal with the stubborn plant cell walls. Haploid induction “…allows pollen to fertilize plants without permanently transferring ‘male’ genetic material to offspring. The newly created plants only have a female set of chromosomes – making them haploid instead of the traditional diploid. Haploid induction itself can lead to increased breeding efficiency and higher yielding plants.” This same method has been found to work in wheat and even Arabidopsis, “…a genus of plants related to cabbage, broccoli, kale, and cauliflower.” Yet again, sadly, CRISPR faces another drawback as scientist not that “…if it were done in the field, the changes wouldn’t spread because the male genome in the pollen – which carries the CRISPR apparatus – disappears shortly after fertilization.” However, there is still much hope for CRISPR technology, and it is without a doubt that we are making big strides into the future with gene editing technology.
A recent article, “Single gene separates queen from workers“, discusses a study published in Biology Letters carried out by scientists from Michigan State University and Wayne State University. They found a gene, which affects not only leg and wing development in bees but also the evolution of a bee’s ability to carry pollen. This gene, known as Ultrabithorax (UBX), gives worker bees the physical feature of their hind legs, which they need to carry pollen.
Thanks to Ubx, workers develop a smooth spot on their hind legs that is home to their pollen baskets. Elsewhere on their legs, the gene causes the formation of 11 bristles, known as the “pollen comb” and it synthesizes a pollen press, a “protrusion” that packs and transports pollen back to the hive. Queens don’t have these features that the Ubx gene is responsible for. The scientists isolated Ubx and silenced it. The results were the disappearance of the pollen baskets, the growth of pollen combs, and reduction in the size of pollen presses. The scientists also concluded that pollen baskets play a smaller role in bees that are “less socially complex”, and the main scientist, Huang states that: “We conclude that the evolution of pollen baskets is a major innovation among social insects and is tied directly to more-complex social behaviors.”
So why is this information important? Well, given the recent downhill trend of bee populations, this research can contribute towards future attempts to make bees better pollinators. Do you think scientists should pursue this?