PEA15 loss of function and defective cerebral development in the domestic cat

MFSD2A frameshift variant in Kerry Hill sheep with microcephaly

Microcephaly is a rare neurodevelopmental disorder characterized by reduced skull circumference and brain volume that occurs sporadically in farm animals. We investigated an early-onset neurodegenerative disorder observed in seven lambs of purebred Kerry Hill sheep. Clinical signs included inability to stand or severe ataxia, convulsions, and early death. Diagnostic imaging and brain necropsy confirmed microcephaly. The pedigree of the lambs suggested monogenic autosomal recessive inheritance. We sequenced the genome of one affected lamb, and comparison with 115 control genomes revealed a single private protein-changing variant. This frameshift variant, MFSD2A: c.285dupA, p.(Asp96fs*9), represents a 1-bp duplication predicted to truncate 80% of the open reading frame. MFSD2A is a transmembrane protein that is essential for maintaining blood-brain barrier homeostasis and plays a key role in regulating brain lipogenesis. Human MFSD2A pathogenic variants are associated with a neurodevelopmental disorder with progressive microcephaly, spasticity, and brain imaging abnormalities (NEDMISBA, OMIM 616486). Here we present evidence for the occurrence of a recessively inherited form of microcephaly in sheep due to a loss-of-function variant in MFSD2A (OMIA 002371-9940). To the best of our knowledge, this is the first report of a spontaneous MFSD2A variant in domestic animals.

Genoarchitectonic Compartmentalization of the Embryonic Telencephalon: Insights From the Domestic Cat

The telencephalon develops from the alar plate of the secondary prosencephalon and is subdivided into two distinct divisions, the pallium, which derives solely from prosomere hp1, and the subpallium which derives from both hp1 and hp2 prosomeres. In this first systematic analysis of the feline telencephalon genoarchitecture, we apply the prosomeric model to compare the expression of a battery of genes, including Tbr1, Tbr2, Pax6, Mash1, Dlx2, Nkx2-1, Lhx6, Lhx7, Lhx2, and Emx1, the orthologs of which alone or in combination, demarcate molecularly distinct territories in other species. We characterize, within the pallium and the subpallium, domains and subdomains topologically equivalent to those previously described in other vertebrate species and we show that the overall genoarchitectural map of the E26/27 feline brain is highly similar to that of the E13.5/E14 mouse. In addition, using the same approach at the earlier (E22/23 and E24/25) or later (E28/29 and E34/35) stages we further analyze neurogenesis, define the timing and duration of several developmental events, and compare our data with those from similar mouse studies; our results point to a complex pattern of heterochronies and show that, compared with the mouse, developmental events in the feline telencephalon span over extended periods suggesting that cats may provide a useful animal model to study brain patterning in ontogenesis and evolution.

Cats - telomere to telomere and nose to tail

Feline genomic medicine can decode human variants of uncertain significance (VUSs). Telomere-to-telomere genome assemblies are feasible for all felid species, supporting genetic evolution and speciation studies. Their highly conserved genomic organization compared to humans suggests cats may also decipher the intergenic variation affecting the 3D chromosome structures influencing gene regulation.