Flagellate, (subphylum Mastigophora), any of a group of protozoans, mostly uninucleate organisms, that possess, at some time in the life cycle, one to many flagella for locomotion and sensation.
Development of the equine chorionic girdle begins around day 25 of gestation, at which time the uninucleate trophoblast cells undergo a period of rapid proliferation (2).
As compared with the wild type, Gh-miR167 was expressed at a relatively higher level in the uninucleate microspore stage, which led to down-regulation of ARF4 by ten-fold in the GMS mutant anthers.
Zerfall reportedly occurs just at one stage in the life cycle of A. laticollaris CSH (Agamont I: McEnery and Lee 1976) and in other Foraminifera (Gamont: Føyn 1936; Goldstein 1997), implying that differential amplification occurs only in the uninucleate stage.
Similarly to Gh-miR156, Gh-miR167 was up-regulated in the uninucleate microspore stage of the GMS mutant anthers as compared with the WT, while its target gene (TC256045) encoding for ARF4 expressed at a much lower level.
Previous studies have demonstrated that the peak of male sterility mainly occurs in the uninucleate microspore stage of anthers in 'Dong A' GMS mutant [ 25].
In the current study, Gh-miR396 was differentially expressed between 'Dong A' WT and its GMS mutant anthers in the meiosis stage, and it had a higher level of expression in the GMS mutant anthers in the uninucleate microspore stage.
The much lower expression level of ARF4 may affect the auxin response pathway in the GMS mutant, which was consistent with the lower content of IAA in the uninucleate microspore stage of the GMS mutant anthers (Additional file 12).
Surprisingly, Gh-miRNA398 was up-regulated by twenty-fold and its target gene Cu/Zn SOD was reversely much lower expressed in the uninucleate microspore stage of GMS mutant anthers, as compared to the WT anthers.
All Foraminifera that have been studied, including Allogromia laticollaris CSH, go through Zerfall (German for decay), a process of DNA elimination and degradation in the uninucleate cell prior to reproduction (Føyn 1936; Goldstein 1997).
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