Chromosome‐level genome assembly of an important pine defoliator,Dendrolimus punctatus (Lepidoptera; Lasiocampidae)

Dendrolimus spp. are important destructive pests of conifer forests, and Dendrolimus punctatus Walker (Lepidoptera; Lasiocampidae) is the most widely distributed Dendrolimus species. During periodic outbreaks, this species is said to make “fire without smoke” because large areas of pine forest can be quickly and heavily damaged. Yet, little is known about the molecular mechanisms that underlie the unique ecological characteristics of this forest insect. Here, we combined Pacific Biosciences (PacBio) RSII single‐molecule long reads and high‐throughput chromosome conformation capture (Hi‐C) genomics‐linked reads to produce a high‐quality, chromosome‐level reference genome for D. punctatus. The final assembly was 614 Mb with contig and scaffold N50 values of 1.39 and 22.15 Mb, respectively, and 96.96% of the contigs anchored onto 30 chromosomes. Based on the prediction, this genome contained 17,593 protein‐coding genes and 56.16% repetitive sequences. Phylogenetic analyses indicated that D. punctatus diverged from the common ancestor of Hyphantria cunea, Spodoptera litura and Thaumetopoea pityocampa ~ 108.91 million years ago. Many gene families that were expanded in the D. punctatus genome were significantly enriched for the xenobiotic biodegradation system, especially the cytochrome P450 gene family. This high‐quality, chromosome‐level reference genome will be a valuable resource for understanding mechanisms of D. punctatus outbreak and host resistance adaption. Because this is the first Lasiocampidae insect genome to be sequenced, it also will serve as a reference for further comparative genomics.     

Atg3 promotes Atg8 lipidation via altering lipid diffusion and rearrangement

Atg3‐catalyzed transferring of Atg8 to phosphatidylethanolamine (PE) in the phagophore membrane is essential for autophagy. Previous studies have demonstrated that this process requires Atg3 to interact with the phagophore membrane via its N‐terminal amphipathic helix. In this study, by using combined biochemical and biophysical approaches, our data showed that in addition to binding to the membranes, Atg3 attenuates lipid diffusion and enriches lipid molecules with smaller headgroup. Our data suggest that Atg3 promotes Atg8 lipidation via altering lipid diffusion and rearrangement.     

The Antidepressant Effects of Resveratrol are Accompanied by the Attenuation of Dendrite/Dendritic Spine Loss and the Upregulation of BDNF/p-cofilin1 Levels in Chronic Restraint Mice

Neurochemical Research - Depression afflicts more than 300 million people worldwide, but there is currently no universally effective drug in clinical practice. In this study, chronic restraint...     

Repeated horizontal gene transfer of GALactose metabolism genes violates Dollo’s law of irreversible loss

Dollo’s law posits that evolutionary losses are irreversible, thereby narrowing the potential paths of evolutionary change. While phenotypic reversals to ancestral states have been observed, little is known about their underlying genetic causes. The genomes of budding yeasts have been shaped by extensive reductive evolution, such as reduced genome sizes and the losses of metabolic capabilities. However, the extent and mechanisms of trait reacquisition after gene loss in yeasts have not been thoroughly studied. Here, through phylogenomic analyses, we reconstructed the evolutionary history of the yeast galactose utilization pathway and observed widespread and repeated losses of the ability to utilize galactose, which occurred concurrently with the losses of GALactose (GAL) utilization genes. Unexpectedly, we detected multiple galactose-utilizing lineages that were deeply embedded within clades that underwent ancient losses of galactose utilization. We show that at least two, and possibly three, lineages reacquired the GAL pathway via yeast-to-yeast horizontal gene transfer. Our results show how trait reacquisition can occur tens of millions of years after an initial loss via horizontal gene transfer from distant relatives. These findings demonstrate that the losses of complex traits and even whole pathways are not always evolutionary dead-ends, highlighting how reversals to ancestral states can occur.