This article contains the process that can lead to restoration of fertility in sterile hybrid.
The process of restoring fertility in sterile hybrids is called hybrid rejuvenation or backcrossing. It involves crossing the sterile hybrid with one of its parent species to produce offspring with hybrid characteristics and improved fertility. This process can be repeated several times until a sufficient level of fertility is restored in the hybrid population.
Another method is cytoplasmic hybridization, where the cytoplasm (but not the nuclear genome) of one parent is replaced with that of the other parent, potentially restoring fertility. Additionally, gene editing techniques such as CRISPR can be used to introduce or remove specific genes that contribute to hybrid sterility. In some cases, chemical or hormonal treatments can also reverse hybrid sterility. However, the effectiveness of these methods varies and depends on the specific cause of infertility in the hybrid population.
It is important to note that restoring fertility in hybrids is not always possible and may be limited by complex genetic and physiological factors. In some cases, hybrid infertility may be the result of multiple genes or interactions between genes and the environment, making it difficult to reverse.
Moreover, restoring fertility in hybrids may have unintended consequences, such as affecting the survival or adaptation of the hybrid population to its environment, altering the balance of the ecosystem, and potentially hybridizing with other species, leading to a loss of genetic diversity.
Therefore, any attempt to restore fertility in hybrids should be carefully evaluated and planned with consideration of potential ecological and evolutionary implications.
Restoring fertility in sterile hybrids is a complex process that requires a thorough understanding of the underlying causes of infertility and the potential ecological and evolutionary consequences. There are various methods that can be used, including backcrossing, cytoplasmic hybridization, gene editing, and chemical and hormonal treatments.
However, success is not guaranteed, and restoring fertility may have unintended consequences. It is important to approach hybrid fertility restoration with caution and careful planning to ensure that the outcomes are positive and sustainable.
In summary, there are several processes that can lead to the restoration of fertility in a sterile hybrid. One of the most commonly used processes is whole-genome duplication (WGD). WGD involves duplicating the entire genome of the hybrid, which helps to restore fertility by making the hybrid polyploid, or having multiple copies of each chromosome.
Another process is the use of hybrid-sterility genes, such as Prdm9, which can cause failure of the pairing of a chromosome and potentially restore fertility in the hybrids. Additionally, hybrid production in autogamous plants can be facilitated by using a method to block certain genes that cause male sterility.
Finally, the two-line hybrid-resistance technology can be used to create sterile-rice lines, with fertility being restored by linking glufosinate resistance (LibertyLink) to the barnase transgene.
Process That Could Lead to Restoration of Fertility in Sterile Hybrid
1. Chromosome doubling, also known as polyploidization, is a process in which an organism’s number of chromosomes is increased. This can sometimes lead to restoration of fertility in hybrid plants that are sterile due to problems with chromosome pairing during meiosis, the process of cell division that leads to the formation of gametes (sperm and eggs).
In some cases, when a hybrid plant has an odd number of chromosomes, they can have difficulty pairing the chromosomes correctly during meiosis, leading to infertility. However, if the number of chromosomes is increased through chromosome doubling, it can sometimes lead to restoration of fertility because the extra chromosomes can assist with proper chromosome pairing during meiosis.
It’s worth noting that this process does not always result in the restoration of fertility and can sometimes lead to other genetic issues. Additionally, the consequences of chromosome doubling can vary greatly depending on the species and the specific hybrid involved.
Therefore, while chromosome doubling can be a potential avenue for restoring fertility in sterile hybrids, it is not a guaranteed solution and must be approached with caution, taking into account the specific biology of the organism and the potential consequences of the process.
2. Backcrossing is a breeding method that involves crossing a hybrid plant with one of its parental species or a closely related species in order to transfer specific desirable traits from the hybrid to the parental line. This process can be used to restore fertility in a sterile hybrid if the infertility is due to problems with chromosome pairing during meiosis.
If the hybrid has difficulty pairing its chromosomes correctly during meiosis, resulting in infertility, backcrossing with a parent or related species that has a compatible chromosome complement can lead to the transfer of genes that regulate proper chromosome pairing, leading to the restoration of fertility.
However, it’s important to note that backcrossing is not a guaranteed solution for restoring fertility in all sterile hybrids, as the infertility may be due to other factors such as mutations or structural changes in the chromosomes. Additionally, backcrossing can lead to the introduction of other undesirable traits from the parental or related species, so the process must be approached with caution and a thorough understanding of the biology of the hybrid and the species involved.
While backcrossing has the potential to restore fertility in some sterile hybrids, it is not a guaranteed solution and must be approached with caution, taking into account the specific biology of the hybrid and the species involved.
3. Autopolyploidy refers to a type of polyploidization in which an organism has multiple copies of its own genome, rather than a mixture of genomes from two different species. Autopolyploidy can sometimes lead to the restoration of fertility in a sterile hybrid if the infertility is due to problems with chromosome pairing during meiosis.
If a hybrid has an odd number of chromosomes, it can have difficulty pairing the chromosomes correctly during meiosis, leading to infertility. Autopolyploidization can increase the number of chromosomes, resulting in the formation of multiple copies of each chromosome, which can assist with proper chromosome pairing during meiosis, leading to the restoration of fertility.
However, it’s important to note that autopolyploidy is not a guaranteed solution for restoring fertility in all sterile hybrids, as the infertility may be due to other factors such as mutations or structural changes in the chromosomes. Additionally, autopolyploidy can lead to other genetic issues and may result in plants that are larger and less adapted to their environment, so the process must be approached with caution and a thorough understanding of the biology of the hybrid and the species involved.
In summary, while autopolyploidy can sometimes lead to the restoration of fertility in a sterile hybrid, it is not a guaranteed solution and must be approached with caution, taking into account the specific biology of the hybrid and the species involved.
REFERENCES:
- Modulation of Prdm9-controlled meiotic chromosome asynapsis… https://elifesciences.org/articles/34282
- The genetic basis of cytoplasmic male sterility and fertility restoration…
https://www.nature.com/articles/s41467-021-21225-0 - Split-gene system for hybrid wheat seed production | PNAS
https://www.pnas.org/doi/10.1073/pnas.1402836111 - Melonek, Joanna, et al. “The Genetic Basis of Cytoplasmic Male Sterility and Fertility Restoration in Wheat – Nature Communications.” Nature, 15 Feb. 2021, www.nature.com/articles/s41467-021-21225-0.
- “The Genetic Basis of Cytoplasmic Male Sterility and Fertility Restoration in Wheat – PubMed.” PubMed, 15 Feb. 2021, pubmed.ncbi.nlm.nih.gov/33589621.