Strain Detail Sheet

Phenotype:
Homozygous phenotype: Approximately 70% of homozygous mice die before PN60 (median survival 27 days after birth). Those mutants that survived beyond PN50–60 (~30%) are distinguished by a disheveled appearance and lack of spontaneous activity compared with heterozygote or wild-type littermates, but appear to live a normal life span although appear infertile. In most cases, the cause of death was uncertain, but when observed, death was preceded by indications of forebrain seizures, including vocalization before displaying straub tail, splayed hindlimbs,and facial clonus. Gross histological examination of brains from homozygous mutant adult and PN22–24 mice revealed no apparent neuroanatomical abnormalities and particularly no morphological deficits in hippocampal formation are apparent. Electrophysiological analysis demonstrated enhanced neural short-term plasticity assess by paired-pulse facilitation

Heterozygous phenotype: none detected, viable and fertile

Mammalian Phenotype Terms:(provided by MGI)      Extend all MPTs
      assigned by genotype

Snap25^tm2Mcw/Snap25^tm2Mcw

        involves: C57BL/6J

• mortality/aging
  • partial postnatal lethality (MGI Ref ID J:94005)
    • 8 out of 25 mutants died between between P14 and weaning at P21
  • premature death (MGI Ref ID J:94005)
    • 17 out of 25 mutants died before P60, with a median survival of 27 days after birth
• behavior/neurological phenotype
  • akinesia (MGI Ref ID J:94005)
    • the ~30% of mutants that survived beyond P50-60 lacked spontaneous activity
  • myoclonus (MGI Ref ID J:94005)
    • indications of forebrain seizures included splayed hindlimbs and vocalization before displaying straub tail
• growth/size phenotype
  • decreased body weight (MGI Ref ID J:94005)
    • at 3-4 weeks after birth, mutants were smaller with 72-82% of the body weight of heterozygous or wild-type littermates
• muscle phenotype
  • myoclonus (MGI Ref ID J:94005)
    • indications of forebrain seizures included splayed hindlimbs and vocalization before displaying straub tail
• reproductive system phenotype
  • infertility (MGI Ref ID J:94005)
    • both males and females are infertile
• nervous system phenotype
  • enhanced paired-pulse facilitation (MGI Ref ID J:94005)
    • ncreased facilitation of glutaminergic transmission for 50-100 msec after an initial stimulus in CA1 hipppocampal synapses
  • myoclonus (MGI Ref ID J:94005)
    • indications of forebrain seizures included splayed hindlimbs and vocalization before displaying straub tail
• integument phenotype
  • disheveled coat (MGI Ref ID J:94005)
    • the ~30% of mutants that survived beyond P50-60 had a disheveled appearance

Founder genetic background: 129

Strain genetic background: C57BL/6

Strain Development:
The vector construct was designed as described in Bark et al., 2004 and contained a TKneo gene flanked by LoxP sites. Chimeric males were crossed with C57BL/6J strain and selected initially by RFLP Southern blots and then by PCR for for the neo selection gene. After 7 generation the strain has been maintained by brother:sister matings since about 2000. After 6-7 backcrosses to C57BL/6J, a TKneo excision revertant was generated by crossing the mice with a strain bearing the protamine-Cre transgene and screening for loss of the floxed TKneo minigene (O'Gorman et al., 1997). These mice have been also maintained by brother:sister

Donor: Michael C. Wilson, Ph.D., University of New Mexico Health Sciences Center

Primary Reference:

Bark C; Bellinger FP; Kaushal A; Mathews JR; Partridge LD; Wilson MC, Developmentally regulated switch in alternatively spliced SNAP-25 isoforms alters facilitation of synaptic transmission., J Neurosci 2004 Oct 6;24(40):8796-805. (Medline PMID: 15470145 )

Additional charges may apply for any special requests. Shipping costs are in addition to the basic distribution/resuscitation fees. Information on shipping costs and any additional charges will be provided by the supplying MMRRC facility.

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MMRRC Item # Description	Distribution Fee/unit (US $)	Units	Notes
032652-UNC-RESUS Litter recovered from cryo-archive	$2,022.00 Non-Profit	Litter	Recovered litter1; additional fees for any special requests.

¹ The distribution fee covers the expense of resuscitating mice from the cryo-archive; you will receive the resulting litter. The litter will contain at minimum one breedable mutant carrier; the actual number of animals and the gender and genotype ratios will vary. (Typically, multiple breeder pairs can be established from the recovered litter.) Prior to shipment, the MMRRC will provide information about the animals recovered. If you anticipate or find that you need to request specific genotypes, genders or quantities of mice in excess of what is likely from a resuscitated litter, you may discuss available options and pricing with the supplying MMRRC facility.

² An aliquot contains sufficient material (volume and concentration) for at least two IVF or several artificial inseminations (based on our procedures). The MMRRC makes no guarantee concerning success of these procedures when performed outside the MMRRC facilities.

³ An aliquot contains a sufficient number of embryos (in one or more vials and based on the transfer success rate of the MMRRC facility) to transfer to at least two recipients. The MMRRC makes no guarantee concerning embryo transfer success experienced in the recipient investigator's laboratory. Neither gender nor genotype ratios are guaranteed.