1. The document discusses a study examining the molecular basis of impaired extraocular muscle function in a mouse model with compound heterozygous mutations in the Ryr1 gene, which provides instructions for the ryanodine receptor 1 protein. 2. Molecular biology tests like PCR and immunoblotting showed alterations in muscle contraction proteins in the mice, including abnormal myosin heavy chain isoforms and decreased ryanodine receptor 1, producing congenital myopathy. 3. Studies of mice with heterozygous Ryr1 mutations demonstrated this causes skeletal muscle weakness and alterations in calcium handling during contraction due to myofibrillar disorganization and mitochondrial changes.

1. Manuela Villa Valdés
Isabella Villareal Restrepo
Universidad
Pontificia
Bolivariana-Medicina
Tercer Semestre

2. introduction
congenital myopathy:
Congenital myopathies are a group of genetic muscle disorders characterized
clinically by hypotonia and weakness, usually from birth, and a static or slowly
progressive clinical course.
Most common congenital myopathies:
● Central core and multiminicore myopathies (core myopathies)
● Centronuclear myopathy
● Nemaline myopathy

3. introduction
Mutation Ryr1:
● This gene provides instructions for making a protein called
ryanodine receptor 1 (RYR1).
● RYR1 channels play a critical role in muscles used for movement.
● Muscle contractions are triggered by an increase in the
concentration of calcium ions inside muscle cells.
● RYR1 channels are surrounding the sarcoplasmic reticulum. This
structure stores calcium ions when muscles are at rest. In response
to certain signals, the RYR1 channel releases calcium ions from the
sarcoplasmic reticulum into the cell fluid.

4. objective
Evaluate Molecular basis of impaired
extraocular muscle function in a mouse
model of congenital myopathy due to
compound heterozygous Ryr1
mutations.

5. Materiales y métodos
PCR en tiempo real
UTILIDAD
● Reveló diferencias entre ratones WT y DKI,
demostró un pequeño aumento en las
transcripciones Myh2 que codifican el MyHC2A
así como la isoforma embrionaria l Myh8 y de
la lenta isoforma Myh7.
● Conocer el nivel de Expresión de Ryr3.
Fragmento de ADN, copiado y amplificado
visualización en gel de agarosa
Presencia de ese fragmento de ADN
Incremento de esta fluorescencia es
proporcional al incremento de la cantidad de
moléculas de ADN amplificadas
Acumulación de ADN amplificado es
detectado y cuantificado a
Incorporación de Syrb green.

6. Materiales y métodos ● Anti-RyR1
● Anti-Cav1.1
● Anti-Cav1.2
● Anti- DHPR β1a
● Anti-calreticulin
● Anti-sarcalumenin
● Anti-calsequestrin-1
● Anti- calsequestrin-2
● Anti-SERCA1
● Anti-SERCA2
● Anti-JP-45
● Anti-parvalbumin
● Anti-MyHC
● Anti-MyHC-EO
Inmunoblot
Técnica analítica usada para detectar
proteínas específicas en una muestra
determinada, es selectiva y se logra
mediante el uso de un anticuerpo que
reconoce esta proteína.

7. materiales métodos
Utilidad:
● Detectar disfunción visual y
progresión de la enfermedad.
● No diferencia en la agudeza
visual entre WT, Ex36, Ex91 y
ratones DKI.
● ratones DKI apenas movían sus
ojos (no significativo)
Respuesta de optometría

8. Materiales y métodos
Análisis proteómico
Preparación
de muestras
1
Información
proteica
2
Identificación
proteica
3
Mapa celular
4
Genoma
Proteómica estructural Proteómica funcional

9. resultados
Inmunoblot

10. resultados

11. resultados
Inmunoblot

12. resultados
Western Blot
MyHC all: Control

13. DISCUSION
Elbaz, M., Ruiz, A., Bachmann, C.,
Eckhardt, J., Pelczar, P.,
Venturi, E., Lindsay, C., Wilson, A.D.,
Alhussni, A., Humberstone,
T. et al. (2019)
the mechanical properties of
isolated EDL and soleus muscles from the same transgenic DKI
mouse line were also severely reduced, albeit to a lower extent
compared with EOMs
Talmadge, R.J. and Roy, R.R. (1985) For separation of MyHC isoforms, high resolution
gel electrophoresis was performed
Elbaz, M., Ruiz, A., Eckhardt, J., Pelczar,
P., Muntoni, F., Boncompagni,
S., Treves, S. and Zorzato, F. (2019)
Both the proband and mouse model carrying the Ex36
frameshift mutation at the heterozygous state had a skeletal
muscle phenotype characterized by generalized muscle
weakness and fatigability. This was accompanied by fibre size
variability, a predominance of slow twitch fibres, fewer CRUs, a
decrease in the electrically evoked peak calcium transient aswell
as a decrease of RyR1 protein in their skeletalmuscles

14. conclusion
1. The importance of molecular biology can be evidenced in this medical article, since it was demonstrated
that through the study of different homozygous or heterozygous mutations, an alteration in the contraction
proteins of the extraocular muscles is presented, which generates extraocular muscle dysfunction .
1. By means of molecular biology tests that facilitate the determination of proteins of a specific test (such as
immunoblost), it was possible to verify that the presence of the incorrect isoforms of MyHC-EO, and lack of
MyHC-EO, produces affections in the extraocular muscle which, as in the case of the mice in the study,
triggered congenital myopathy
1. Studies of heterozygous mutations in the Ryr1 gene demonstrated that this is the cause of congenital
myopathy, and this manifests itself in and causes alterations in contraction due to the production of
myofibrillary disorganization, displacement and decrease in the number of mitochondria.

15. mapa conceptual- manuela villa valdés

16. mapa conceptual-isabella villarreal restrepo