STOCK Sftpa1^tm1Haw Tg(SFTPC-SFTPA1*)T2Jflo/Mmjax

Stock number: 037468
Product name: hTG SP-A1(6A4)

Research areas: Developmental Biology Research, Internal/Organ Research

Description

SP-A KO hTG SP-A1 mice express human SFTPA1 (surfactant associated protein A1 or SP-A1) variant 6A4 under the control of the human SFPTC promoter on a Sftpa1 null background. This strain may be useful for studying lung function, surfactant structure, host defense and inflammation.

Detailed description

SFTPA1 (surfactant associated protein A1 or SP-A1), SFTPA2 (surfactant associated protein A2 or SP-A2), and a pseudogene encode SP-A, a C-type lectin called collectin. Each SFTPA gene has several genetic variants found in the 3’ UTR and is responsible for differential binding of miRNA. SP-A1 is expressed in alveolar epithelial type II cells; SP-A2 is expressed in tracheal and bronchial submucosal gland cells in the lung. Rodents have only one SFTPA gene, Sftpa1. SP-A is involved in in surfactant homeostasis and in the defense against respiratory pathogens. It is also a modulator of lung function, surfactant structure, host defense and inflammation.

SP-A KO hTG SP-A1(6A4) mice constitutively express human SFTPA1 (variant 6A4) under the control of the human SFPTC promoter on a Sftpa1 null background. Variant 6A4 (GenBank HQ021436.1) may be associated with lung carcinoma and idiopathic pulmonary fibrosis. Mice homozygous for the KO and hemizygous for the transgene are viable and fertile. The donating investigator has not attempted to generate mice homozygous for the transgene. SP-A KO hTG SP-A1(6A4) mice lack tubular myelin as assessed by electron microscopy and have a distinctive response to various insults such as ozone exposure and/or infection as compared to other SP-A mouse strains.

Of note, the following SP-A mutants are distributed:
Mice expressing human SFTPA1 variants 6A2 (MMRRC Stock No. 69751) and 6A4 (MMRRC Stock No. 69748) .
Mice expressing human SFTPA2 variants 1A3 (MMRRC Stock No. 69749) and 1A0 (MMRRC Stock No. 69750).
Mice with the SP-A KO are distributed as MMRRC Stock No. 69752.

Development

The hTG SP-A1(6A4) transgenic construct contains the 3.7 kb human SFTPC (surfactant associated protein C) promoter, the 1.3 kb human SFTPA1 (surfactant associated protein A1) variant 6A4 coding sequence containing the 5’ and 3’ UTR and the entire coding region followed by an SV40 polyA signal. The linearized construct was microinjected into the pronuclei of fertilized C57BL/6 mice. Founder line T2 exhibits higher protein expression than the other founder lines.

The Sftpa1^tm1Haw allele was created by Dr. Samuel Hawgood (University of California, San Francisco). The SP-A (Sftpa1^tm1Haw) targeting vector was designed to replace exons 2, 3, and 4 including the translation start site of the Sftpa1 (surfactant associated protein A1) gene on chromosome 14 with a neomycin cassette. The construct was electroporated into (C57BL/6 x 129/Sv)F1-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric males were bred with CD-1 females.

hTG SP-A1(6A4) mice were crossed to SP-A KO mice on a mixed background. Mice are hemizygous for the transgene and homozygous for the KO allele. Sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Sftpa1^tm1Haw
Name: targeted mutation 1, Samuel Hawgood
MGI accession ID: MGI:2677859
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Sftpa1
Marker name: surfactant associated protein A1
Chromosome: 14
Strain of origin: (C57BL/6 x 129/Sv)F1
Molecular note: Exons 2, 3, and 4 including the translation start site as well as short segments of flanking intronic sequence were replaced with a PGK neomycin cassette. Resulting mice lacked mRNA transcripts and their protein product.

Allele

Symbol: Tg(SFTPC-SFTPA1*)T2Jflo
Name: transgene insertion T2, Joanna Floros
MGI accession ID: MGI:7365194
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(SFTPC-SFTPA1*)T2Jflo
Marker name: transgene insertion T2, Joanna Floros
Chromosome: UN
Strain of origin: C57BL/6
Molecular note: The transgenic construct contains the 3.7 kb human SFTPC (surfactant associated protein C) promoter, the 1.3 kb human SFTPA1 (surfactant associated protein A1) variant 6A4 coding sequence containing the 5' and 3'; UTR and the entire coding region followed by an SV40 polyA signal. Founder line T2 exhibit higher protein expression than the other founder lines.