Mouse Genome Informatics
hm1
    Man2b1tm1Psa/Man2b1tm1Psa
involves: 129 * C57BL/6J
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
cellular
• accumulation of translucent vacuoles are seen in the liver, pancreas, spleen, kidney, eye, thyroid gland, smooth muscle cells, bone, and nervous system (J:56659)
• the cytoplasmic vacuoles are membrane limited and appear either empty or contain some fine granular material (J:56659)

homeostasis/metabolism
• increased levels of neutral oligosaccharides are found in homogenates from the kidney, spleen, brain, and testis
• the urine contains high levels of mannose-containing oligosaccharides

nervous system
• some vacuolated neurons are seen in several nuclei including the substantia nigra, inferior olive, ambiguus nucleus, cuneate and gracile nuclei, and nuclei in the formatio reticularis (J:99812)
• the lateral globus pallidus contains several vacuolated neurons
• vacuolation is most evenly distributed in the neuronal perikarya of the CA2 and CA3 regions while the CA1 and dentate gyrus are weakly or not at all affected
• vacuolation is most evenly distributed in the neuronal perikarya of the CA2 and CA3 regions while the CA1 and dentate gyrus are weakly or not at all affected
• vacuoles are seen in the isocortex, most prominently in neurons of layers II/III and V/VI (J:56659)
• neurons in the neocortex are variably vacuolated and moderate vacuolation is seen by EM in Purkinje cells and some granular cells (J:99812)
• vacuoles are seen in the astrodendroglia and oligodendroglia but not as frequently as in the neurons
• in the brain vacuoles are most prominent in neurons (J:56659)
• axonal swellings are seen in the central white matter, and pre-terminal portions of the sensory trigeminal and vestibular nerve fibers with the axoplasm containing an accumulation of polymorphous material (J:56659)
• lysosomal storage is seen in the retinal photoreceptors
• less severe neuronal vacuolation is seen compared to the trigeminal ganglion
• marked vacuolation is seen in neurons in the trigeminal ganglion
• less severe neuronal vacuolation is seen compared to the trigeminal ganglion
• hippocampal slices from the CA1 region take longer to return to baseline after induction with a single high frequency stimulation and have a higher initial LTP magnitude in response to a second tetanization 2 hours after the initial stimulation

behavior/neurological
• a slight but consistent decrease in exploratory activity is seen in open field and dark box tests
• step-through latency is slightly but significantly decreased
• time to obtain reward during training to dig for a food reward in sand is consistently longer in homozygotes at 3 and 12 months of age and slower acquisition is seen during discrimination conditioning following training at 3 but not at 12 months of age
• at 3 months but not 12 months of age, during acquisition sessions in a water maze test time to reach the platform is increased, in the first probe trial homozygotes tend to remain in the start quadrant, and in later probe trial 3 month old homozygotes fail to show a preference for the target quadrant unlike wild-type mice
• 12 month old homozygotes spend less time in the target quadrant but do show a preference for the target quadrant

hematopoietic system
• accumulation of clear vacuoles is seen in Kupffer cells
• lysosomal storage is seen in the sinus endothelia, reticulum cells, macrophages, and trabecular fibroblasts of the red pulp

vision/eye
• lysosomal storage is seen in the ciliary epithelium
• lysosomal storage is seen in the smooth muscle
• lysosomal storage is seen in the retinal photoreceptors
• lysosomal storage is seen in the corneal endothelium
• lysosomal storage is seen in the corneal stroma cells

liver/biliary system
• accumulation of clear vacuoles is seen in sinus endothelial cells
• accumulation of clear vacuoles is seen in Kupffer cells
• accumulation of clear vacuoles is seen in hepatocytes

endocrine/exocrine glands
• prominent vacuolization is seen in the acinar cells

skeleton
• gross bone architecture is normal but lysosomal storage is seen in osteocytes and endosteal cells of many bones
• moderate vacuolation in the fibrocytes of the spiral ligament

hearing/vestibular/ear
• moderate vacuolation is seen in the fibrocytes of the spiral ligament and the nonspecialized flat epithelium lining the endolymphatic spaces of the cochlea and vestibular apparatus
• however, the organ of Corti and vestibular organ appear normal and brainstem auditory evoked potentials are normal
• moderate vacuolation in the fibrocytes of the spiral ligament

renal/urinary system
• the urine contains high levels of mannose-containing oligosaccharides
• clear vacuoles are seen in the epithelial cells of the proximal and distal tubules

growth/size
• body weight is slightly reduced at 2-3 months of age but is similar to wild-type at 4-5 and 11-12 months of age

immune system
• accumulation of clear vacuoles is seen in Kupffer cells
• lysosomal storage is seen in the sinus endothelia, reticulum cells, macrophages, and trabecular fibroblasts of the red pulp

digestive/alimentary system
• prominent vacuolization is seen in the acinar cells

muscle
• lysosomal storage is seen in the smooth muscle

cardiovascular system
• accumulation of clear vacuoles is seen in Kupffer cells

Mouse Models of Human Disease
OMIM IDRef(s)
Mannosidosis, Alpha B, Lysosomal; MANSA 248500 J:56659 , J:99812