RNA methyltransferase BmMettl3 and BmMettl14 in silkworm (Bombyx mori) and the regulation of silkworm embryonic development.

N6-methyladenosine (m6A) is a ubiquitous reversible epigenetic RNA modification that plays an important role in regulating many biological processes, especially embryonic development. However, regulation of m6A methylation during silkworm embryonic development and diapause remains to be investigated. In this study, we analyzed the phylogeny of subunits of methyltransferases BmMettl3 and BmMettl14, and detected the expression patterns of BmMettl3 and BmMettl14 in different tissues and at different developmental stages in silkworm. To investigate the function of m6A on the development of silkworm embryo, we analyzed the m6A/A ratio in diapause and diapause termination eggs. The results showed that BmMettl3 and BmMettl14 were highly expressed in gonads and eggs. Moreover, the expression of BmMettl3 and BmMettl14 and the m6A/A ratio were significantly increased in diapause termination eggs compared with diapause eggs in the early stage of silkworm embryonic development. Furthermore, in BmN cell cycle experiments, the percentage of cells in the S phase increased when lacking BmMettl3 or BmMettl14. This work contributes to understanding the role of m6A methylation during insect embryogenesis and gametogenesis. It also provides a research orientation to further analyze the role of m6A methylation in diapause initiation and termination during insect embryonic development.

Cloning and expression analysis of CRY2 gene in Sorghum bicolor.

CRY2 is the apoprotein of cryptochrome 2 and CRY2 cDNA has been cloned from Sorghum bicolor in this study. The results of sequence analysis shows that it contains a complete open reading frame encoding a predicted protein of 690 amino acids sharing 87% identity with the CRY2 of rice, but only 45.5% with that of Arabidopsis and 57% with that of tomato. The DNA sequence of sorghum CRY2 contains three introns and four exons. RT-PCR results show that CRY2 has been transcribed in root, leaf and mesocotyl in sorghum seedlings. CRY2 protein has been shown by Western blot analysis to be present in mesocotyl, leaf and root, and to be accumulated in the dark and to be degraded under blue light.