The complete telomere-to-telomere sequence of a mouse Y chromosome.

September 10, 2026| Source: Science (New York, N.Y.)

The mouse Y chromosome is essential for male reproduction, yet the GRCm39 reference contains 25 gaps, particularly in repetitive and complex regions. Here, we assembled a telomere-to-telomere Y chromosome (mT2T Y) of 95.21 Mb from a C57BL/6 mouse incorporating parental genomes. This assembly fills all gaps, corrects structural errors, and adds over 8.70 Mb of previously unassembled sequence to the reference genome. We annotated 142 previously unidentified genes, identified Y specific satellite arrays, and mapped homologous recombination loci in the pseudoautosomal region (PAR). Analysis of X Y homologous gene expression revealed a Y chromosome dosage compensation mechanism. By combining mT2T Y with T2T mhaESC, we completed the T2T assembly of all C57BL/6 chromosomes, designated T2T mhaESC+Y, providing a complete C57BL/6 reference genome.

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Historical trends show more declining than increasing species among European pollinators.

Anthropogenic global change presents a growing threat to insect pollinators. Yet, long-term, continental-scale assessments of their population trends remain limited. Here, we leveraged a curated database of over four million occurrence records, covering 88% of extant bee and hoverfly species in Europe, to assess persistence, richness, and occupancy trends over the past century. Species persistence at the European level was relatively high, with modern records available for 87% of bee and 89% of

Physical/TechNovember 3, 2026

The ABCD hypothesis.

If [Formula: see text] and [Formula: see text] are cardinals, then the cardinal exponentiation [Formula: see text] is the set of all functions from [Formula: see text] into [Formula: see text]. The ABCD hypothesis is the statement that for all infinite cardinals [Formula: see text] and [Formula: see text], [Formula: see text] if and only if [Formula: see text] and [Formula: see text]. The Axiom of Determinacy, AD, states that every two-player infinite game on [Formula: see text] has a winning st

Physical/TechOctober 29, 2026

The delocalized nature of chemical bonding at a catalytic metal surface.

Adsorbate bonding at metal surfaces requires hybridization of localized molecular orbitals with delocalized electronic bands of the metal; hence, the electronic wave function involved in bonding may extend far beyond the adsorption site. We revealed the consequence of this delocalization by determining the distance over which structural variations of the metal surface influence the molecule-metal bond strength. Velocity-resolved kinetics provided adsorption energies for three molecules bound at

Physical/TechOctober 29, 2026

Chiral altermagnon in MnTe.

Altermagnetism has been recognized as a magnetic phase that bridges the properties of ferro- and antiferromagnetism. The momentum-dependent spin splitting observed in these materials reflects their distinctive symmetry characteristics, which also establish the conditions for chiral magnons to emerge. Here we provide direct experimental evidence for a chiral magnon in the altermagnetic candidate manganese telluride (MnTe) revealed by circular-dichroism resonant inelastic x-ray scattering. This mo

Physical/TechOctober 27, 2026

Extensive glacier loss in the coterminous United States.

Glaciers populate the mountain ranges of the western conterminous United States and despite their importance to alpine hydrology, their area and volume change have never been comprehensively evaluated. Our study shows that since the mid-twentieth century about one-quarter of the glaciers have disappeared and the overall area and volume are reduced by one-third. The pattern of glacier shrinkage suggests most glaciers in the conterminous United States are largely maintained by local topographic in