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1. Mammalian dihydropyrimidine dehydrogenase

   https://doi.org/10.1016/j.abb.2021.109066  

   Forouzesh, Dariush C.; Moran, Graham R. (December 2021, Archives of Biochemistry and Biophysics)
2. DNA methylation networks underlying mammalian traits

   https://doi.org/10.1126/science.abq5693  

   Haghani, Amin; Li, Caesar Z.; Robeck, Todd R.; Zhang, Joshua; Lu, Ake T.; Ablaeva, Julia; Acosta-Rodríguez, Victoria A.; Adams, Danielle M.; Alagaili, Abdulaziz N.; Almunia, Javier; et al (August 2023, Science)

   Using DNA methylation profiles (n= 15,456) from 348 mammalian species, we constructed phyloepigenetic trees that bear marked similarities to traditional phylogenetic ones. Using unsupervised clustering across all samples, we identified 55 distinct cytosine modules, of which 30 are related to traits such as maximum life span, adult weight, age, sex, and human mortality risk. Maximum life span is associated with methylation levels inHOXLsubclass homeobox genes and developmental processes and is potentially regulated by pluripotency transcription factors. The methylation state of some modules responds to perturbations such as caloric restriction, ablation of growth hormone receptors, consumption of high-fat diets, and expression of Yamanaka factors. This study reveals an intertwined evolution of the genome and epigenome that mediates the biological characteristics and traits of different mammalian species. 

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3. Mammalian middle ear mechanics: A review

   https://doi.org/10.3389/fbioe.2022.983510  

   Ugarteburu, Maialen; Withnell, Robert H.; Cardoso, Luis; Carriero, Alessandra; Richter, Claus-Peter (October 2022, Frontiers in Bioengineering and Biotechnology)

   The middle ear is part of the ear in all terrestrial vertebrates. It provides an interface between two media, air and fluid. How does it work? In mammals, the middle ear is traditionally described as increasing gain due to Helmholtz’s hydraulic analogy and the lever action of the malleus-incus complex: in effect, an impedance transformer. The conical shape of the eardrum and a frequency-dependent synovial joint function for the ossicles suggest a greater complexity of function than the traditional view. Here we review acoustico-mechanical measurements of middle ear function and the development of middle ear models based on these measurements. We observe that an impedance-matching mechanism (reducing reflection) rather than an impedance transformer (providing gain) best explains experimental findings. We conclude by considering some outstanding questions about middle ear function, recognizing that we are still learning how the middle ear works. 

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4. Stochastic Axons in the Mammalian Brain

   Janusonis, Skirmantas; Mays, Kasie C.; Metzler, Ralf; Vojta, Thomas (January 2021, 30th Annual Meeting of the Society for Computational Neurosciences)

   null (Ed.)
5. The evolution of mammalian brain size

   https://doi.org/10.1126/sciadv.abe2101  

   Smaers, J. B.; Rothman, R. S.; Hudson, D. R.; Balanoff, A. M.; Beatty, B.; Dechmann, D. K.; de Vries, D.; Dunn, J. C.; Fleagle, J. G.; Gilbert, C. C.; et al (April 2021, Science Advances)

   null (Ed.)

   Relative brain size has long been considered a reflection of cognitive capacities and has played a fundamental role in developing core theories in the life sciences. Yet, the notion that relative brain size validly represents selection on brain size relies on the untested assumptions that brain-body allometry is restrained to a stable scaling relationship across species and that any deviation from this slope is due to selection on brain size. Using the largest fossil and extant dataset yet assembled, we find that shifts in allometric slope underpin major transitions in mammalian evolution and are often primarily characterized by marked changes in body size. Our results reveal that the largest-brained mammals achieved large relative brain sizes by highly divergent paths. These findings prompt a reevaluation of the traditional paradigm of relative brain size and open new opportunities to improve our understanding of the genetic and developmental mechanisms that influence brain size. 

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