Phenotypes associated with this allele

• Allele Symbol: Styxl2^tm1Nju
• Allele Name: endonuclease-mediated mutation 1, Model Animal Research Center of Nanjing University
• Allele ID: MGI:7736256
• Summary: 4 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
cn1	Pax7^tm1(cre)Mrc/Pax7^+ Styxl2^tm1Nju/Styxl2^tm1Nju	involves: 129S1/Sv * 129X1/SvJ	MGI:7736631
cn2	Myf5^tm3(cre)Sor/Myf5^+ Styxl2^tm1Nju/Styxl2^tm1Nju	involves: 129S4/SvJaeSor	MGI:7781773
cn3	Pax7^tm1(cre/ERT2)Gaka/Pax7^tm1(cre/ERT2)Gaka Styxl2^tm1Nju/Styxl2^tm1Nju	involves: 129S * C57BL/6	MGI:7781779
cn4	Styxl2^tm1Nju/Styxl2^tm1Nju Tg(ACTA1-cre/Esr1*)2Kesr/0	involves: C3H * C57BL/6	MGI:7781777

Genotype
MGI:7736631

cn1

• Allelic Composition: Pax7^tm1(cre)Mrc/Pax7⁺; Styxl2^tm1Nju/Styxl2^tm1Nju
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ

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

mortality/aging

neonatal lethality, complete penetrance ( J:351096 )

• although born at the expected Mendelian ratio, all homozygous pups die within a few hours after birth; no live pups older than 1 day are recovered

homeostasis/metabolism

cyanosis ( J:351096 )

• at P1, the skin of newborn pups appears cyanotic

respiratory system

primary atelectasis ( J:351096 )

• pulmonary alveoli fail to open in newborn pups

muscle

abnormal sarcomere morphology ( J:351096 )

• at P1, TEM analysis showed severe disruption of the sarcomeric structures in both the diaphragm and hindlimb muscles

• however, some residual sarcomeres are still present in skeletal muscles

abnormal skeletal muscle morphology ( J:351096 )

• at P1, pups show defective sarcomeres in striated muscles; skeletal muscles of P1 pups show an obvious increase in protein levels of non-muscle myosin IIs (MYH9 and MYH10)

Genotype
MGI:7781773

cn2

• Allelic Composition: Myf5^tm3(cre)Sor/Myf5⁺; Styxl2^tm1Nju/Styxl2^tm1Nju
• Genetic Background: involves: 129S4/SvJaeSor

mortality/aging

neonatal lethality, complete penetrance ( J:351096 )

• all homozygous pups die within 1 day after birth

muscle

abnormal sarcomere morphology ( J:351096 )

• at P1, TEM analysis showed severe disruption of the sarcomere structures in skeletal muscles

• however, some residual sarcomeres are still present in skeletal muscles

Genotype
MGI:7781779

cn3

• Allelic Composition: Pax7^{tm1(cre/ERT2)Gaka}/Pax7^{tm1(cre/ERT2)Gaka}; Styxl2^tm1Nju/Styxl2^tm1Nju
• Genetic Background: involves: 129S * C57BL/6

muscle

abnormal sarcomere morphology ( J:351096 )

• at 30 days after acute cardiotoxin (CTX)-induced hindlimb muscle injury in adult tamoxifen-treated mice, the length of individual sarcomeres in regenerated gastrocnemius muscles is shorter than in control muscles

impaired skeletal muscle contractility ( J:351096 )

• at 30 days after acute CTX-induced hindlimb muscle injury in adult tamoxifen-treated mice, the twitch force generated by fully regenerated gastrocnemius muscles is reduced by ~30% relative to control muscles, while tetanic force is not affected, suggesting that sarcomeres formed de novo in regenerating myofibers are partially defective

impaired skeletal muscle regeneration ( J:351096 )

• at 30 days after acute CTX-induced hindlimb muscle injury in adult tamoxifen-treated mice, the length of individual sarcomeres in regenerated gastrocnemius muscles is shorter than in control muscles, indicating impaired de novo sarcomere assembly in regenerating adult skeletal muscles

• at 10 days after acute BaCl₂-induced muscle injury in adult tamoxifen-treated mice, protein levels of non-muscle myosin IIs (MYH9 and MYH10) remain high in regenerating tibialis anterior muscles, whereas MYH9 and MYH10 are nearly undetectable in control muscles, suggesting delayed degradation of non-muscle myosin IIs during de novo sarcomere assembly

Genotype
MGI:7781777

cn4

• Allelic Composition: Styxl2^tm1Nju/Styxl2^tm1Nju; Tg(ACTA1-cre/Esr1*)2Kesr/0
• Genetic Background: involves: C3H * C57BL/6

muscle

muscle phenotype ( J:351096 )

N • in vitro, gastrocnemius muscles isolated from tamoxifen-treated adult mice generate normal twitch and tetanic force relative to control muscles, suggesting normal contractile function with no change in the maintenance of existing sarcomeres in adult skeletal muscles