ABSTRACT
With the development of high-throughput sequencing technology, circular RNAs (circRNAs) have gradually become a hotspot in the research on non-coding RNA. CircRNAs are produced by the covalent circularization of a downstream 3' splice donor and an upstream 5' splice acceptor through backsplicing, and they are pervasive in eukaryotic cells. CircRNAs used to be considered byproducts of false splicing, whereas an explosion of related studies in recent years has disproved this misconception. Compared with the rich studies of circRNAs in animals, the study of circRNAs in plants is still in its infancy. In this review, we introduced the discovery of plant circRNAs, the discovery of plant circRNAs, the circularization feature, expression specificity, conservation, and stability of plant circRNAs and expounded the identification tools, main types, and biogenesis mechanisms of circRNAs. Furthermore, we summarized the potential roles of plant circRNAs as microRNA (miRNA) sponges and translation templates and in response to biotic/abiotic stress, and briefed the degradation and localization of plant circRNAs. Finally, we discussed the challenges and proposed the future directions in the research on plant circRNAs.
Subject(s)
MicroRNAs , RNA, Circular , RNA, Plant , Animals , MicroRNAs/genetics , MicroRNAs/metabolism , Organelle Biogenesis , Plants/genetics , Plants/metabolism , Protein Biosynthesis/physiology , RNA, Circular/genetics , RNA, Circular/metabolism , RNA, Plant/genetics , RNA, Plant/metabolism , Research/trends , Stress, Physiological/geneticsABSTRACT
Apomixis has been widely concerned because of its great potential in heterosis fixation. Artificial apomixis is an important direction of current apomixis research. Mitosis instead of Meiosis (MIME) produces diploid gametes that is identical with the maternal genetic composition and is a key step in the artificial creation of apomixes. This paper reviews the occurrence of MIME and its application in crop apomixis and the problems encountered, in an aim to provide reference for expanding the application of MIME in crop apomixis.
Subject(s)
Apomixis , Crops, Agricultural/genetics , Meiosis , Mitosis , Diploidy , Germ CellsABSTRACT
OBJECTIVE: To investigate the relation between TGF-beta1 in allograft and chronic allograft nephropathy (CAN). METHODS: The levels of urine TGF-beta1 were tested in 146 recipients whose renal function were normal from September 1, 2000 to January 31, 2001. Twenty recipients with the highest level of urine TGF-beta1 were classified in group A, while 20 other recipients with the lowest level of urine TGF-beta1 were classified in group B. In these two groups biopsies were carried out in 14 cases and 12 cases respectively, and TGF-beta1 mRNA in the biopsies was measured by RT-PCR. The levels of TGF-beta1 in the blood were also measured in the two groups. Three years later, the renal function was compared between the two groups. Biopsies were carried out in renal recipients whose creatinine is higher than normal. RESULTS: The level of TGF-beta1 in the blood showed no significant difference between the two groups; 3 years after transplantation, the loss of renal function in group A was severer than that in group B. The number levels of CAN cases in group A was larger than that in group B. The expression levels of TGF-beta1 and TGF-beta1 mRNA of the allografts were higher in group A than in group B; there were statistically significant differences between the two groups. CONCLUSION: The findings suggest that there is an association between TGF-beta1 in kidneys and CAN. The level of urine TGF-beta1 after renal transplantation may predict future renal function.