Transgenic safety issues cause more and more controversies with the planting area of transgenie crops increased year by year. Gene flow from transgenie crops to wild relatives through pollen dispersal is one of the fo...Transgenic safety issues cause more and more controversies with the planting area of transgenie crops increased year by year. Gene flow from transgenie crops to wild relatives through pollen dispersal is one of the focus problems. Gene splitting technique provides a new strategy for the control of transgene flow by bio-logical containment. The construction of gene splitting technique is based on protein trans-splicing mediated by intein. Currently, it has been proved in Arabidopsis, tabaoco, wheat, etc. that active and functional proteins can be reassembled by intein mediated protein trans-splicing after gene splitting, which provides theoretical basis and experimental supporting for the limit of transgene flow by gene splitting technique. The theoretical basis of gene splitting technique and research progresses of its application on the control of transgene flow were reviewed in this paper.展开更多
Determining and comparing mitochondrial genomes(mitogenomes)are essential for assessing the diversity and evolution of mitochondria.Ciliates are ancient and diverse unicellular eukaryotes,and thus are ideal models for...Determining and comparing mitochondrial genomes(mitogenomes)are essential for assessing the diversity and evolution of mitochondria.Ciliates are ancient and diverse unicellular eukaryotes,and thus are ideal models for elucidating the early evolution of mitochondria.Here,we report on six new mitogenomes of spirotrichs,a dominant ciliate group,and perform comparative analyses on 12 representative species.We show that:(1)the mitogenomes of spirotrichs are linear structures with high A+T contents(61.12-81.16%),bidirectional transcription,and extensive synteny(except for the nad5,ccmf and cob genes in Euplotia);(2)the non-split of NADH dehydrogenase subunit 2 gene(nad2)is a plesiomorphy of ciliates,whereas it has evolved into a split gene in Spirotrichea(apart from Euplotes taxa),Oligohymenophorea,and Armophorea;(3)the number of small subunit ribosomal proteins(rps)encoded in mitogenomes increases in the later branching classes of ciliates,whereas rps8 shows a loss trend during the evolution of Euplotes taxa;(4)the mitogenomes of spirotrichs exhibit A/T codon bias at the third position,and the codon bias is mainly due to DNA mutation in oligotrichs,hypotrichs and Diophrys appendiculata;(5)the phylogenetic position of D.appendiculata is unstable and controversial based on both phylogenetic analyses and mitogenome evidence.In summary,we investigated the mitogenome diversity of spirotrichs and broadened our understanding of the evolution of mitochondria in ciliates.展开更多
基金Supported by Major Project of China on New Varieties of GMO Cultivation(2013zx08010-003)National Natural Science Foundation of China(31100408)
文摘Transgenic safety issues cause more and more controversies with the planting area of transgenie crops increased year by year. Gene flow from transgenie crops to wild relatives through pollen dispersal is one of the focus problems. Gene splitting technique provides a new strategy for the control of transgene flow by bio-logical containment. The construction of gene splitting technique is based on protein trans-splicing mediated by intein. Currently, it has been proved in Arabidopsis, tabaoco, wheat, etc. that active and functional proteins can be reassembled by intein mediated protein trans-splicing after gene splitting, which provides theoretical basis and experimental supporting for the limit of transgene flow by gene splitting technique. The theoretical basis of gene splitting technique and research progresses of its application on the control of transgene flow were reviewed in this paper.
基金supported by the Laoshan Labo-ratory(No.LSKJ202203202)the Natural Science Foundation of China(32030015,32300386,32270558)+2 种基金China Postdoctoral Science Foundation(2022M722019)US National Institutes of Health Grant(P40OD010964)a supporting project(RSP2024R10)at King Saud University,Saudi Arabia.
文摘Determining and comparing mitochondrial genomes(mitogenomes)are essential for assessing the diversity and evolution of mitochondria.Ciliates are ancient and diverse unicellular eukaryotes,and thus are ideal models for elucidating the early evolution of mitochondria.Here,we report on six new mitogenomes of spirotrichs,a dominant ciliate group,and perform comparative analyses on 12 representative species.We show that:(1)the mitogenomes of spirotrichs are linear structures with high A+T contents(61.12-81.16%),bidirectional transcription,and extensive synteny(except for the nad5,ccmf and cob genes in Euplotia);(2)the non-split of NADH dehydrogenase subunit 2 gene(nad2)is a plesiomorphy of ciliates,whereas it has evolved into a split gene in Spirotrichea(apart from Euplotes taxa),Oligohymenophorea,and Armophorea;(3)the number of small subunit ribosomal proteins(rps)encoded in mitogenomes increases in the later branching classes of ciliates,whereas rps8 shows a loss trend during the evolution of Euplotes taxa;(4)the mitogenomes of spirotrichs exhibit A/T codon bias at the third position,and the codon bias is mainly due to DNA mutation in oligotrichs,hypotrichs and Diophrys appendiculata;(5)the phylogenetic position of D.appendiculata is unstable and controversial based on both phylogenetic analyses and mitogenome evidence.In summary,we investigated the mitogenome diversity of spirotrichs and broadened our understanding of the evolution of mitochondria in ciliates.
