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 genetinis 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.
Partenogenezė yra nelytinio dauginimosi forma, kuri nedalyvauja tręšimas of an egg by a sperm. The embryo is formed by the female on her own (without genetinis 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.
„Gimdymas iš mergelės“ be apvaisinimo spermatozoidu gali skambėti keistai, tačiau ši dauginimosi forma, kai apsieinama be patino, natūraliai pastebima daugelyje augalų rūšių, vabzdžių, replikų ir tt. Nepatogenetinės rūšys negimdo „mergalių“, nors ir turi. buvo dirbtinai sukeltas kiaušiniuose laboratorijoje, kad atsivestų varlių ir pelių palikuonys. Šie varlių ir pelių dirbtinės partenogenezės atvejai nepadarė varlių ir pelių patelių tinkamos pagimdyti nekaltai, nes buvo skatinami tik jų kiaušinėliai. embriogenezė laboratorinėmis sąlygomis. Tai pasikeitė dabar su ataskaita (paskelbta 28 dth July 2023) of non-parthenogenetic animals giving “virgin births” following genetinis 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 partenogenetinis skristi.
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 genetinis basis of facultative parthenogenesis in an animal as well as its induction through genetinis inžinerija.
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Šaltiniai:
- Sperling AL, et al 2023. genetinis basis for facultative parthenogenesis in Drosophila. Current Biology Published: 28 July 2023. DOI: https://doi.org/10.1016/j.cub.2023.07.006
- Kembridžo universitetas, 2023 m. Naujienos – Mokslininkai atranda nekalto gimimo paslaptį ir įjungia musių patelių gebėjimą. Galimas adresu https://www.cam.ac.uk/research/news/scientists-discover-secret-of-virgin-birth-and-switch-on-the-ability-in-female-flies Žiūrėta 2023-08-01.
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