• Human sperm quality declines during the past 35 years. Risk factors for low sperm quality involve environmental issues (e.g., pesticides and heavy metals), lifestyle (e.g. tobacco, alcohol drinks). Obesity with associated diabetes is another risk factor. In recent PLoS Biology, Daniel Natt and colleagues used a two-step diet intervention model to study how diet affects sperm’s motility.
  • Transcriptome profiling using next generation sequencing has become routine in biological research. Typically, researchers do RNA extraction, poly(A) selection or ribosomal RNA depletion, first and second strand cDNA synthesis, sequencer adapter ligation, and final library PCR amplification.
  • CUT&RUN (cleavage under targets and release using nuclease) is an epigenomic profiling method developed by the group of Dr. Steven Henikoff at Fred Hutchinson Cancer Research Center. CUT&RUN is performed in situ on immobilized, intact cells without crosslinking. DNA fragmentation is achieved using micrococcal nuclease fused to Protein A and/or Protein G (pA/G-MNase).
  • On Feb 23, 2020, CDC (Centers for Disease Control and Prevention) is responding to an outbreak of respiratory disease caused by a novel coronavirus, which was first detected in Wuhan, China. This virus has been officially named “SARS-CoV-2” (formerly called 2019-nCoV), which now has been detected in 32 locations internationally. This virus can be person-to-person transmitted, there are around 80,000 confirmed cases (updated Feb 24, 2020).
  • Extrachromosomal DNA (ecDNA) is any DNA that is found off the chromosomes. Typically, for instance, in human cells, mitochondrial DNA (mtDNA) is one type of ecDNA. Today we are going to talking about another type --- extrachromosomal circular DNA (eccDNA), which is derived directly from genomic DNA.
  • RNA plays a special role in life science. It can be as genetic materials like DNA, it can catalyze specific biochemical reactions, which is similar to the action of the protein. Due to its single strand, it forms many secondary structures, providing more variation ------ a significant evolutionary advantage compared to DNA. One specific RNA type whenever is discovered will become a fascinating research topic, such as miRNA, piRNAs, non-coding RNAs, circular RNAs.
  • Next generation sequencing evolves into such a large ‘postgenomic’ era. NovaSeq -- a lastest Illumina sequencer can collect an entire human genome for < $1000 in several days. Now, it is a big challenge to interpret the data and how to get useful information from such a long A, T, G, C string.
  • In human genes, more than 95% of multi-exon genes undergo pre-mRNA alternative splicing. “One gene, more spliced isoforms” ------ this strategy is the most important contributor to protein diversity. However, researchers debate that in the transcriptome, ~ 30% genes have antisense transcripts, big parts of isoforms may be just mis-spliced, they are degraded through NMD (Nonsense-mediated Decay), cannot produce proteins.
  • Single-cell analysis has been becoming popular for understanding the patterns of genomic or transcriptomic variations in complex organs. Quick Biology has given lots of examples that how single cell sequencing technology accelerates researchers’ work. Most single cell platforms are droplet-based methods. In recent Genome Research, Li and his colleagues from Cold Spring Harbor developed a new assay, called BAG-seq.
  • In life science, single cell resolution at molecular level is growing in popularity. Science Journal reviews recent advances into how single cell genomics is being used to develop personalized phenotyping strategies that cross subcellular, cellular, and tissue scales to link our genome to our cumulative cellular phenotypes. By single cell strategy, we not only catalog our human cell types, but we can also track how a cell develops, differentiate.