Wheat grain development after anthesis is an important biological process, in which major components of seeds are synthesised, and these components are further required for germination and seed vigour. We have made a comparative RNA-Seq analysis between hexaploid wheat and its individual diploid progenitors to know the major differentially expressed genes (DEGs) involved during grain development. Two libraries from each species were generated with an average of 55.63, 55.23, 68.13, and 103.81 million reads, resulting in 79.3K, 113.7K, 90.6K, and 121.3K numbers of transcripts in AA, BB, DD, and AABBDD genome species respectively. Number of expressed genes in hexaploid wheat was not proportional to its genome size, but marginally higher than that of its diploid progenitors. However, to capture all the transcripts in hexaploid wheat, sufficiently higher number of reads was required. Functional analysis of DEGs, in all the three comparisons, showed their predominance in three major classes of genes during grain development, i.e., nutrient reservoirs, carbohydrate metabolism, and defence proteins; some of them were subsequently validated through real time quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR). Further, developmental stage–specific gene expression showed most of the defence protein genes expressed during initial developmental stages in hexaploid contrary to the diploids at later stages. Genes related to carbohydrates anabolism expressed during early stages, whereas catabolism genes expressed at later stages in all the species. However, no trend was observed in case of different nutrient reservoirs gene expression. This data could be used to study the comparative gene expression among the three diploid species and homeologue-specific expression in hexaploid.

Wheat is a major food crop and an important component of human diet throughout the world. There are two major types of cultivated wheat; one is tetraploid durum (pasta) wheat and another one is hexaploid bread wheat. Wheat grain is the reservoir of two major dietary components – carbohydrate and protein, which get accumulated during seed maturation and directly affects yield and quality. Hexaploid, having 6 copies of each chromosome differs to a great extent from tetraploid having 4 copies of each chromosome. Studying the gene expression pattern in developing grain would help in understanding the difference in metabolic process as well as involvement of the genes in these two types of wheat. A transcriptional comparison of developing grains was carried out between the two wheat genotypes; tetraploid (AABB:PDW233) and hexaploid (AABBDD:PBW343) using RNA-seq. Approximately 194 million raw reads were obtained from both libraries. After removal of contaminations, a huge proportion (>99%), of high quality reads were obtained, were aligned to reference genome. A total of 2324 up-regulated and 522 down-regulated genes were identified as differentially expressed between PDW233 vs PBW343. Gene ontology annotation and enrichment analysis gave further information about differentially expressed genes between durum and bread wheat. This information will help in understanding process grain reserve in tetraploid and hexaploid wheat in relation to their nutritional quality.

DOT1L is essential for early hematopoiesis but the precise mechanisms remain largely unclear. The only known function of DOT1L is histone H3 lysine 79 (H3K79) methylation. We generated two mouse models; a Dot1L-knockout (Dot1L-KO), and another possessing a point mutation in its methyltransferase domain (Dot1L-MM) to determine the role of its catalytic activity during early hematopoiesis. We observed that Dot1L-KO embryos suffered from severe anemia, while Dot1L-MM embryos showed minimal to no anemia. However, ex vivo culture of Dot1L-MM hematopoietic progenitors (HPCs) exhibited defective development of myeloid and mixed progenitors. DOT1L is a well-recognized, cell-type specific epigenetic regulator of gene expression. To elucidate the mechanisms underlying such diverse hematopoietic properties of Dot1L-KO and Dot1L-MM HPCs, we examined their whole transcriptomes. Extensively self-renewing erythroblast (ESRE) cultures were established using yolk sac (YS) cells collected on embryonic day 10.5 (E10.5). Dot1l-KO and Dot1l-MM cells expanded significantly less than the wildtype cells and showed slower progression through the cell cycle. Total RNA extracted from the wildtype and Dot1l-mutant ESRE cells were subjected to RNA-seq analyses. We observed that the majority (~82%) of the differentially expressed genes (DEGs) were upregulated in both of the Dot1L-mutants, which suggests that DOT1L predominantly acts as a transcriptional repressor in HPCs. We also observed that about ~40% of the DEGs were unique to either of the mutant group, suggesting that DOT1L possesses both methyltransferase domain-dependent and -independent functions. We further analyzed Gene Ontology and signaling pathways relevant to the DEGs common to both mutant groups and those that were unique to either group. Among the common DEGs, we observed upregulation of CDK inhibitors, which explains the cell cycle arrest in both of the Dot1L-mutant progenitors.