Polymerase chain reaction(PCR) was used to amplify 5S rRNA spacer from wild rice(Oryza rufipogon and O.nivara) and cultivated rice(indica and japonica varieties of O.sativa L).The results show that there is spacer len...Polymerase chain reaction(PCR) was used to amplify 5S rRNA spacer from wild rice(Oryza rufipogon and O.nivara) and cultivated rice(indica and japonica varieties of O.sativa L).The results show that there is spacer length variation within and between species,and the typical indica and japonica varieties have their unique banding patterns of amplified 5S rRNA spacers,whereas intermediate showed no specific amplification profile of spacer regions.The 5S rRNA genes in intermediate are either identical with that of indica variety or that of japonica variety.These data suggest that the spacer length polymorphisms can be used to distinguish between closely ralated species and subspecies.展开更多
Cultured Apostichopus japonicus in China suffers from a kind of skin ulceration disease that has caused severe economic loss in recent years. The disease,pathogens of which are supposed to be bacteria by most research...Cultured Apostichopus japonicus in China suffers from a kind of skin ulceration disease that has caused severe economic loss in recent years. The disease,pathogens of which are supposed to be bacteria by most researchers,is highly infectious and can often cause all individuals in the same culture pool to die in a very short time. The 16S rRNA gene phylogenesis of the culturable bacteria from the lesions of diseased individuals was conducted to study the biodiversity of the bacterial communities in the lesions and to identify probable pathogen(s) associated with this kind of disease. S. japonica samples were selected from a hatchery located in the eastern part of Qingdao,China. Bacterial universal primers GM5F and DS907R were used to amplify the 16S rRNA gene of bacteria colonies,and touchdown PCR was performed to amplify the target sequences. The results suggest that γ-proteobacteria(Alteromonadales and Vibrionales) of CFB group,many strains of which have been also determined as pathogens in other marine species,are the predominant bacterial genera of the diseased Apostichopus japonicus individuals.展开更多
Hypotrichs are one of the highly differentiated ciliated lineages which play important roles in ecological, environmental,evolutionary and basic biological studies. In the present study, we investigated the living cha...Hypotrichs are one of the highly differentiated ciliated lineages which play important roles in ecological, environmental,evolutionary and basic biological studies. In the present study, we investigated the living characteristics, infraciliature, nuclear apparatus, ontogenesis and phylogenetic position of a marine hypotrichous ciliate, Apokeronopsis wrighti Long et al., 2008, which was isolated from coastal waters in Shenzhen, China. The new isolate resembles the type population in terms of morphological characteristics, morphometrics, and SSU rRNA gene sequence that is with a 99.7% similarity. Ontogenesis of A. wrighti is characterized by oral primordium for the proter as well as marginal and dorsal kineties anlagen in both filial products formed de novo, and the cirral row arranged along the paroral and endoral arises from several anterior frontoventral-transverse cirral streaks. Phylogenetic analyses based on SSU and concatenated gene data suggest that five species of Apokeronopsis form a monophyletic clade, and the genus Apokeronopsis is closely related to Thigmokeronopsis and Metaurostylopsis.展开更多
文摘Polymerase chain reaction(PCR) was used to amplify 5S rRNA spacer from wild rice(Oryza rufipogon and O.nivara) and cultivated rice(indica and japonica varieties of O.sativa L).The results show that there is spacer length variation within and between species,and the typical indica and japonica varieties have their unique banding patterns of amplified 5S rRNA spacers,whereas intermediate showed no specific amplification profile of spacer regions.The 5S rRNA genes in intermediate are either identical with that of indica variety or that of japonica variety.These data suggest that the spacer length polymorphisms can be used to distinguish between closely ralated species and subspecies.
文摘Cultured Apostichopus japonicus in China suffers from a kind of skin ulceration disease that has caused severe economic loss in recent years. The disease,pathogens of which are supposed to be bacteria by most researchers,is highly infectious and can often cause all individuals in the same culture pool to die in a very short time. The 16S rRNA gene phylogenesis of the culturable bacteria from the lesions of diseased individuals was conducted to study the biodiversity of the bacterial communities in the lesions and to identify probable pathogen(s) associated with this kind of disease. S. japonica samples were selected from a hatchery located in the eastern part of Qingdao,China. Bacterial universal primers GM5F and DS907R were used to amplify the 16S rRNA gene of bacteria colonies,and touchdown PCR was performed to amplify the target sequences. The results suggest that γ-proteobacteria(Alteromonadales and Vibrionales) of CFB group,many strains of which have been also determined as pathogens in other marine species,are the predominant bacterial genera of the diseased Apostichopus japonicus individuals.
基金supported by the Natural Science Foundation of Shaanxi Province(Nos.2023-JC-QN-0214,2023JC-QN-0185)the Postdoctoral Science Foundation of Shaanxi Province(No.2023BSHEDZZ199)the Fundamental Research Funds for the Central Universities(No.GK202207019)。
文摘Hypotrichs are one of the highly differentiated ciliated lineages which play important roles in ecological, environmental,evolutionary and basic biological studies. In the present study, we investigated the living characteristics, infraciliature, nuclear apparatus, ontogenesis and phylogenetic position of a marine hypotrichous ciliate, Apokeronopsis wrighti Long et al., 2008, which was isolated from coastal waters in Shenzhen, China. The new isolate resembles the type population in terms of morphological characteristics, morphometrics, and SSU rRNA gene sequence that is with a 99.7% similarity. Ontogenesis of A. wrighti is characterized by oral primordium for the proter as well as marginal and dorsal kineties anlagen in both filial products formed de novo, and the cirral row arranged along the paroral and endoral arises from several anterior frontoventral-transverse cirral streaks. Phylogenetic analyses based on SSU and concatenated gene data suggest that five species of Apokeronopsis form a monophyletic clade, and the genus Apokeronopsis is closely related to Thigmokeronopsis and Metaurostylopsis.
