A fishy tale of long and short life span Fish have wide variations in life span even within closely related species. One such example are the rockfish species found along North Pacific coasts, which have life spans ranging from 11 to more than 200 years. Kolora et al . sequenced and performed a genomic analysis of 88 rockfish species, including long-read sequencing of the genomes of six species (see the Perspective by Lu et al .). From this analysis, the authors unmasked the genetic drivers of longevity evolution, including immunity and DNA repair–related pathways. Copy number expansion in the butyrophilin gene family was shown to be positively associated with life span, and population historical dynamics and life histories correlated differently between long- and short-lived species. These results support the idea that inflammation may modulate the aging process in these fish. —LMZ

Background Lacerta viridis and Lacerta bilineata are sister species of European green lizards (eastern and western clades, respectively) that, until recently, were grouped together as the L. viridis complex. Genetic incompatibilities were observed between lacertid populations through crossing experiments, which led to the delineation of two separate species within the L. viridis complex. The population history of these sister species and processes driving divergence are unknown. We constructed the first high-quality de novo genome assemblies for both L. viridis and L. bilineata through Illumina and PacBio sequencing, with annotation support provided from transcriptome sequencing of several tissues. To estimate gene flow between the two species and identify factors involved in reproductive isolation, we studied their evolutionary history, identified genomic rearrangements, detected signatures of selection on non-coding RNA, and on protein-coding genes. Findings Here we show that gene flow was primarily unidirectional from L. bilineata to L. viridis after their split at least 1.15 million years ago. We detected positive selection of the non-coding repertoire; mutations in transcription factors; accumulation of divergence through inversions; selection on genes involved in neural development, reproduction, and behavior, as well as in ultraviolet-response, possibly driven by sexual selection, whose contribution to reproductive isolation between these lacertid species needs to be further evaluated. Conclusion The combination of short and long sequence reads resulted in one of the most complete lizard genome assemblies. The characterization of a diverse array of genomic features provided valuable insights into the demographic history of divergence among European green lizards, as well as key species differences, some of which are candidates that could have played a role in speciation. In addition, our study generated valuable genomic resources that can be used to address conservation-related issues in lacertids.

Purpose To identify key retinal pigment epithelium (RPE) genes linked to the induction of myopia in guinea pigs. Methods To induce myopia, two-week-old pigmented guinea pigs (New Zealand strain, n = 5) wore −10 diopter (D) rigid gas-permeable contact lenses (CLs), for one day; fellow eyes were left without CLs and served as controls. Spherical equivalent refractive errors (SE) and axial length (AL) were measured at baseline and one day after initiation of CL wear. RNA sequencing was applied to RPE collected from both treated and fellow (control) eyes after one day of CL-wear to identify related gene expression changes. Additional RPE-RNA samples from treated and fellow eyes were subjected to quantitative real-time PCR (qRT-PCR) analysis for validation purposes. Results The CLs induced myopia. The change from baseline values in SE was significantly different ( P = 0.016), whereas there was no significant difference in the change in AL ( P = 0.10). RNA sequencing revealed significant interocular differences in the expression in RPE of 13 genes: eight genes were significantly upregulated in treated eyes relative to their fellows, and five genes, including bone morphogenetic protein 2 ( Bmp2 ), were significantly downregulated. The latter result was also confirmed by qRT-PCR. Additional analysis of differentially expressed genes revealed significant enrichment for bone morphogenetic protein (BMP) and TGF-β signaling pathways. Conclusions The results of this RPE gene expression study provide further supporting evidence for an important role of BMP2 in eye growth regulation, here from a guinea pig myopia model.