Parthenogenesis is asexual reproduction in which genetic contribution from male is dispensed with. Eggs develop to offspring on their own without being fertilised by a sperm. This is seen in nature in some species of plants, insects, reptiles etc. In facultative parthenogenesis the animal switch from sexual to parthenogenetic reproduction under difficult situations. Non-parthenogenetic species reproduce sexually and do not give “virgin births”. In a study reported recently, researchers achieved induction of facultative parthenogenesis and “virgin births” in Drosophila melanogaster (a non-parthenogenetic species) through maumbile engineering. The research team identified involved genes and demonstrated for the time first time how expressions of involved genes influence induction of facultative parthenogenesis in an animal.
Parthenogenesis ni aina ya uzazi isiyo na jinsia ambayo haihusishi mbolea of an egg by a sperm. The embryo is formed by the female on her own (without maumbile contribution from a male) which develops to give “virgin birth”. Parthenogenesis could be either obligate or facultative. In case of facultative parthenogenesis, the animal switch from sexual to parthenogenetic reproduction under difficult situations while obligate parthenogenesis is the situation when reproduction is mainly asexual through parthenogenesis.
"Kuzaa kwa bikira" bila kutungishwa na manii kunaweza kusikika kuwa ya ajabu lakini aina hii ya uzazi ambayo mwanamume hutolewa kwa kawaida inaonekana katika aina nyingi za mimea, wadudu, majibu nk. Aina zisizo za pathogenetic hazitoi "uzazi wa bikira" ingawa yameingizwa kwenye mayai kwenye maabara ili kuzaa watoto wa chura na panya. Matukio haya ya parthenogenesis bandia katika chura na panya hayakufanya chura na panya wa kike kuwa na uwezo wa kuzaa ubikira peke yao kwani mayai yao pekee ndiyo yalichochewa kutumbuliwa. kiinitete katika hali ya maabara. Hii imebadilika sasa na ripoti (iliyochapishwa mnamo 28th July 2023) of non-parthenogenetic animals giving “virgin births” following maumbile engineering. This is first such case of sexually reproducing animal turning parthenogenetic because of manipulations in their genes.
Two species of Drosophila were used in this study. Drosophila mercatorum species, which has sexually reproducing strain and parthenogenetically reproducing strain (facultative), was used to identify genes involved in parthenogenesis while Drosophila melanogaster which is a non-parthenogenetic species was used for gene manipulation to produce parthenogenetic kuruka.
The research team sequenced genomes of two strains of Drosophila mercatorum and compared gene activity in eggs of the two strains. This led to identification of 44 candidate genes with potential roles in parthenogenesis. Next was to test if manipulating candidate gene homologs would induce facultative parthenogenesis in Drosophila melanogaster. The researchers found a polygenic system – facultative parthenogenesis in Drosophila melanogaster (a non-parthenogenetic species) was triggered by increased expression of the mitotic protein kinase polo and decreased expression of a desaturase, Desat2 that was enhanced by increased expression of Myc. The eggs grew parthenogenetically mainly to triploid offspring. This is first demonstration of maumbile basis of facultative parthenogenesis in an animal as well as its induction through maumbile Uhandisi.
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Vyanzo:
- Sperling AL, et al 2023. The maumbile basis for facultative parthenogenesis in Drosophila. Current Biology Published: 28 July 2023. DOI: https://doi.org/10.1016/j.cub.2023.07.006
- Chuo Kikuu cha Cambridge 2023. Habari- Wanasayansi wagundua siri ya kuzaliwa na bikira, na kuwasha uwezo wa inzi wa kike. Inapatikana kwa https://www.cam.ac.uk/research/news/scientists-discover-secret-of-virgin-birth-and-switch-on-the-ability-in-female-flies Ilifikiwa mnamo 2023-08-01.
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