Phylogeny and characteristics of ruminants: Ruminants are a diverse group of mammals that includes families containing well-known taxa such as deer, cows, and goats. However, their evolutionary relationships have been contentious, as have the origins of their distinctive digestive systems and headgear, including antlers and horns (see the Perspective by Ker and Yang). To understand the relationships among ruminants, L. Chen et al. sequenced 44 species representing 6 families and performed a phylogenetic analysis. From this analysis, they were able to resolve the phylogeny of many genera and document incomplete lineage sorting among major clades. Interestingly, they found evidence for large population reductions among many taxa starting at approximately 100,000 years ago, coinciding with the migration of humans out of Africa. Examining the bony appendages on the head—the so-called headgear—Wang et al. describe specific evolutionary changes in the ruminants and identify selection on cancer-related genes that may function in antler development in deer. Finally, Lin et al. take a close look at the reindeer genome and identify the genetic basis of adaptations that allow reindeer to survive in the harsh conditions of the Arctic. Science , this issue p. eaav6202 , p. eaav6335 , p. eaav6312 ; see also p. 1130

True morels (Morchella, Pezizales) are a popular edible and medicinal fungus with great nutritional and economic value. The dynamics and regulatory mechanisms during the morphogenesis and maturation of morels are poorly understood. In this study, the metabolomes and transcriptomes of the mycelium (MY), primordium differentiation (PR), young fruiting body (YFB), and mature fruiting body (MFB) were comprehensively analyzed to reveal the mechanism of the morphogenesis and maturation of Morchella sextelata. A total of 748 differentially expressed metabolites (DEMs) and 5342 differentially expressed genes (DEGs) were detected, mainly enriched in the carbohydrate, amino acid, and lipid metabolism pathways, with the transition from the mycelium to the primordium being the most drastic stage at both the metabolic and transcriptional levels. The integrated metabolomics and transcriptomics highlighted significant correlations between the DEMs and DEGs, and specific amino acid and nucleotide metabolic pathways were significantly co-enriched, which may play key roles in morphological development and ascocarp maturation. A conceptual model of transcriptional and metabolic regulation was proposed during morphogenesis and maturation in M. sextelata for the first time, in which environmental factors activate the regulation of transcription factors, which then promote metabolic and transcriptional regulation from vegetative to reproductive growth. These results provide insights into the metabolic dynamics and transcriptional regulation during the morphogenesis and maturation of morels and valuable resources for future breeding enhancement and sustainable artificial cultivation.

Morels (Morchella spp.), as one of the rare macroascomycetes that can be cultivated artificially, possess significant economic and scientific values. Morel cultivation is highly sensitive to elevated temperatures; however, the mechanisms of their response to heat shock remain poorly understood. This study integrated transcriptomic and quantitative proteomic analyses of two M. sextelata strains with different thermotolerance (labeled as strains C and D) under normal (18 °C) and high temperature (28 °C) conditions. From over 9300 transcripts and 5000 proteins, both consistency and heterogeneity were found in response to heat shock between the two strains. Both strains displayed a capacity to maintain cellular homeostasis in response to heat shock through highly expressed cell wall integrity (CWI) pathways, heat shock proteins (HSPs), and antioxidant systems. However, strain D, which exhibited stronger thermotolerance, specifically upregulated the ubiquitin ligase Rsp5, thereby further promoting the expression of HSPs, which may be a key factor influencing the thermotolerance difference among M. sextelata strains. A conceptual model of the heat shock adaptation regulatory network in M. sextelata was proposed for the first time; the results provide novel insights into the thermotolerance response mechanisms of macroascomycetes and valuable resources for the breeding enhancement of thermotolerant morel strains.