Phenotypes associated with this allele

• Allele Symbol: Col13a1^tm4.1Pih
• Allele Name: targeted mutation 4.1, Taina Pihlajaniemi
• Allele ID: MGI:6116692
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Col13a1^tm4.1Pih/Col13a1^tm4.1Pih	involves: C57BL/6	MGI:6316984

Genotype
MGI:6316984

hm1

• Allelic Composition: Col13a1^tm4.1Pih/Col13a1^tm4.1Pih
• Genetic Background: involves: C57BL/6

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

growth/size/body

decreased body weight ( J:242846 )

• decrease in body weight with aging

muscle

abnormal skeletal muscle fiber morphology ( J:242846 )

• the proportion of small muscle fibers in the diaphragm, but not soleus, is increased

centrally nucleated skeletal muscle fibers ( J:242846 )

• number of centrally located nuclei is elevated in the diaphragm but not in the soleus

abnormal diaphragm morphology ( J:242846 )

• increase in proportion of small muscle fibers and an elevated number of centrally located nuclei in the diaphragm muscle but are normal in the soleus

• however, no changes in the muscle fiber type distribution

nervous system

abnormal synaptic vesicle exocytosis ( J:242846 )

• active zone numbers are elevated in neuromuscular junctions, suggesting enhanced exocytosis

abnormal motor neuron morphology ( J:242846 )

• increase in terminal branching of the motor axons in neuromuscular junctions

abnormal neuromuscular synapse morphology ( J:242846 )

• acetylcholine receptor (AChR) clusters in the neuromuscular junction are abnormal from P56 onwards, becoming progressively larger and highly fragmented with the AChR+ area increased by 37% at P84

• acetylcholine vesicles are densely packed in the presynaptic termini and are 2.-7-fold more numerous

abnormal endplate potential ( J:242846 )

• maximal stimulation of motor nerves evokes end plate potentials (EPPs) with elevated amplitudes resulting in increased quantal content and repetitive stimulation at 30 Hz evokes an elevated amplitude at all phases of stimulation indicating that all vesicle pools are enlarged

• however, resting membrane potential of muscle fibers is unaltered

abnormal miniature endplate potential ( J:242846 )

• no difference in the amplitude of miniature endplate potentials (MEPPs) at neuromuscular junctions is seen but the MEPP frequency is increased, indicating increased spontaneous presynaptic activity

• calcium-independent release of the readily releasable pool of acetylcholine vesicles induced by hypertonic sucrose solution results in an increase in the frequency of evoked MEPPs, indicating an enlarged pool of cocked vesicles in the nerve termini of the diaphragm

cellular

abnormal endocytosis ( J:242846 )

• endocytosis is increased in the nerve termini in the diaphragm

abnormal synaptic vesicle exocytosis ( J:242846 )

• active zone numbers are elevated in neuromuscular junctions, suggesting enhanced exocytosis