STOCK Csn1s1tm2Afk/H
| Status | Available to order |
| EMMA ID | EM:12388 |
| International strain name | STOCK Csn1s1tm2Afk/H |
| Alternative name | A1Lneo |
| Strain type | Targeted Mutant Strains : Knock-out |
| Allele/Transgene symbol | Csn1s1tm2Afk, |
| Gene/Transgene symbol | Csn1s1 |
Information from provider
| Provider | Andreas Kolb |
| Provider affiliation | Rowett Institute, University of Aberdeen |
| Genetic information | A transgenic mouse line carrying an antibody light chain transgene (A1L) together with a PGKneo selection marker cassette embedded into the alpha casein gene, replacing the endogenous alpha casein gene. Homozygous lactating females have a reduced milk protein concentration and the offspring show a reduced growth rate when nursed by A1Lneo homozygous females. The mice were generated by Genoway using ES cell technology. The alpha casein gene was first targeted using homologous recombination. This inserted a PGK-hytk selection marker cassette. Subsequently the PGK-hytk cassette was replaced by the A1L/neo cassette using cre recombinase-mediated cassette exchange. |
| Phenotypic information | Homozygous:Female mice homozygous for the A1Lneo mutation have a low milk protein concentration (reduced by more than 50%). In this regard, the A1Lneo mice show the same phenotype as described for the alpha-casein knock-out mice (Kolb, A.F., Huber, R., Lillico, S., Carlisle, A., Robinson, C., Neil, C., Petrie, L., Olsson, A., Sorensen, D.B., Whitelaw, C.B.A. Milk lacking alpha-casein leads to a life-long reduction in body size in mice, 2011, PLoS One, 6(7):e21775). The mouse strain can be used as a model to study the life-long effects of early nutrition. It can also be used to study the mechanisms of milk protein/casein micelle assembly and secretion. Male homozygous mice do not show any phenotype as the alpha casein gene is only expressed in the lactating mammary gland. The A1L antibody light chain protein is secreted into the milk of the A1Lneo females (both homozygous and heterozygous), but only at a concentration of around 1 mg/ml. In contrast the alpha-casein gene (which the A1L gene replaces) is expressed at around 30 mg/ml in mouse milk. The antibody light chain carries a human constant region and can therefore be easily measured in milk (against the background of murine IgG).Heterozygous:Female heterozygous mice express the A1L transgene in the lactating mammary gland and secrete the A1L antibody light chain protein into milk. Heterozygous females do not show a dramatic decrease in milk protein composition. We conclude that the main role of alpha casein in the process of milk production is that of a chaperone for the casein micelle (which carries most of the milk calcium and most of the milk protein). |
| Breeding history | The mice were originally bred on a C57BL/6 background (using 129/Sv ES cells). The strain was then bred onto a CD1 background to enable better cross-fostering (as CD1 mice are good foster mothers). We normally use cross-fostering of wild-type mice onto CD1 A1Lneo foster mothers for our experiments. |
| References | None available |
| Homozygous fertile | yes |
| Homozygous viable | yes |
| Homozygous matings required | no |
| Immunocompromised | no |
Information from EMMA
| Archiving centre | Mary Lyon Centre at MRC Harwell, Oxford, United Kingdom |