Single molecule mass photometry of nucleic acids

Mass photometry is a recently developed methodology capable of measuring the mass of individual proteins under solution conditions. Here, we show that this approach is equally applicable to nucleic acids, enabling their facile, rapid and accurate detection and quantification using sub-picomoles of sample. The ability to count individual molecules directly measures relative concentrations in complex mixtures without need for separation. Using a dsDNA ladder, we find a linear relationship between the number of bases per molecule and the associated imaging contrast for up to 1200 bp, enabling us to quantify dsDNA length with up to 2 bp accuracy. These results introduce mass photometry as an accurate, rapid and label-free single molecule method complementary to existing DNA characterization techniques.

Genetic Diversity on Amaranthus hybridus L., Amaranthus viridis L. and Amaranthus spinosus L. in parts of Rivers State, Nigeria

The Amaranth plants are annuals or short-lived perennials with over 103 species of flowering plants in the family Amaranthaceae, distributed nearly worldwide. Several amaranth species are useful as food crops and are grown both for their leaves and for their edible seeds, which are a nutritious pseudocereal (nongrass seeds used like cereal grains). This paper reports the genetic diversity of three species of Amaranthus (A. hybridus L., A. viridis L. and A. spinosus L.) in Rivers state of Nigeria. Result obtained from this research showed high rate of diversity. DNA characterization and sequencing of the species were done through plastid Ribulose-1,5biophosphate Carboxylase large chain (rbcL) genetic marker to determine the rate of genetic variation among members of this genus in our study area. The sequence figures were firstly compared on Basic Local Alignment Sequence Tool for validation. Phylogenetic and molecular evolutional analysis was conducted using MEGA version 7. The dendogram of the molecular phylogeny generated from MEGA 7 software shows elevated rate of variation among studied species.Keywords: Amaranthus, Genetic, Diversity, rbcl

Mitochondrial DNA Characterization of High Royal Jellyproducing Honeybees (Hymenoptera: Apidae) in China

China is the largest producer and exporter of royal jelly in the world. The high production of royal jelly in China is mainly attributed to a high royal jelly-producing lineage of honeybees (Apis mellifera) (HRJB). However, few studies have been conducted on the genetic characterization of HRJB. In this study, the mitochondrial DNA intergenic region between cytochrome oxidase I and II (COI-COII) and the mitochondrial NADH dehydrogenase subunit 2 sequences (ND2) were determined for 90 HRJB colonies, collected from the regions of China where HRJB originated, and 25 unimproved A. m. ligustica colonies from China. COI-COII sequence analysis revealed two mitotypes (C1 and C2d) in HRJB colonies and one mitotype (C1) in unimproved A. m. ligustica colonies. The main mitotype (C1) in HRJB accounted for 93% of the colonies. Based on ND2 sequences, four and two mitotypes were found in HRJB and unimproved A. m. ligustica colonies, respectively. Sequence alignment showed that nucleotides in three positions of the ND2 sequence were different between the main mitotype of HRJB and that of unimproved A. m. ligustica. Our study suggested that HRJB was bred from A. m. ligustica and possibly had genetic characteristics different from unimproved A. m. ligustica.