GENOME SIZE DETERMINATION OF CUCUMBER (CUCUMIS SATIVUS), HONEYDEW (CUCUMIS MELO INODORUS) AND ROCK MELON (CUCUMIS MELO CANTALUPENSIS) VIA FLOW CYTOMETRY

The family of Cucurbitaceae consists of species with economical and nutritional value. Morphologically, there are only few differences between Cucumis species. The interspecific and intraspecific variation in the genome size of the Cucumis species are not discovered yet. Due to this, this study aims to determine the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis using flow cytometry (FCM) method. Nuclei suspension of selected Cucumis species were extracted using LBO1 lysis buffer by manual chopping technique and stained by propidium iodide priot to FCM analysis. Genome size of C. sativus, C. melo inodorus (Honeydew) and C. melo cantalupensis (Rockmelon) were determined by using Glycine max (Soybean) as an external reference standard (2C = 2.5 pg). This study found that the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis estimated to be 2.83 pg, 3.00 pg and 3.47 pg respectively. The genome size data obtained from this study can be used in future genome studies as well as species characterization.

Key bacterial taxa and metabolic pathways affecting gut short-chain fatty acid profiles in early life

Infant gut microbiota development affects the host physiology throughout life, and short-chain fatty acids (SCFAs) are promising key metabolites mediating microbiota-host relationships. Here, we investigated dense longitudinally collected faecal samples from 12 subjects during the first 2 years (n = 1048) to identify early life gut SCFA patterns and their relationships with the microbiota. Our results revealed three distinct phases of progression in the SCFA profiles: early phase characterised by low acetate and high succinate, middle-phase characterised by high lactate and formate and late-phase characterised by high propionate and butyrate. Assessment of the SCFA–microbiota relationships revealed that faecal butyrate is associated with increased Clostridiales and breastfeeding cessation, and that diverse and personalised assemblage of Clostridiales species possessing the acetyl-CoA pathway play major roles in gut butyrate production. We also found an association between gut formate and some infant-type bifidobacterial species, and that human milk oligosaccharides (HMO)-derived fucose is the substrate for formate production during breastfeeding. We identified genes upregulated in fucose and fucosylated HMO utilisation in infant-type bifidobacteria. Notably, bifidobacteria showed interspecific and intraspecific variation in the gene repertoires, and cross-feeding of fucose contributed to gut formate production. This study provides an insight into early life SCFA–microbiota relationships, which is an important step for developing strategies for modulating lifelong health.