|Synonym(s)||ASP, As, agouti, agouti signal protein|
|Chromosomal Location||154,791,402-155,051,012 bp (+)|
FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] In mice, the agouti gene encodes a paracrine signaling molecule that causes hair follicle melanocytes to synthesize pheomelanin, a yellow pigment, instead of the black or brown pigment, eumelanin. Pleiotropic effects of constitutive expression of the mouse gene include adult-onset obesity, increased tumor susceptibility, and premature infertility. This gene is highly similar to the mouse gene and encodes a secreted protein that may (1) affect the quality of hair pigmentation, (2) act as a pharmacological antagonist of alpha-melanocyte-stimulating hormone, (3) play a role in neuroendocrine aspects of melanocortin action, and (4) have a functional role in regulating lipid metabolism in adipocytes. [provided by RefSeq, Jul 2008]
PHENOTYPE: Agouti acts in the hair follicles, primarily affecting the relative amount and distribution of yellow pigment (phaeomelanin) and black pigment (eumelanin) in hairs of the coat. Some alleles show lethal effects or are associated with obesity. [provided by MGI curators]
|Amino Acid Change|
|Institutional Source||Beutler Lab|
Ensembl: ENSMUSP00000105319 (fasta)
|Gene Model||not available|
|Meta Mutation Damage Score||Not available|
|Is this an essential gene?||Probably nonessential (E-score: 0.178)|
|Candidate Explorer Status||CE: no linkage results|
Linkage Analysis Data
|Alleles Listed at MGI|
|Mode of Inheritance||Unknown|
|Local Stock||Sperm, gDNA|
|Last Updated||2021-10-06 11:54 AM by Diantha La Vine|
The killer whale mouse arose as a spontaneous mutant in the aoba stock (Figure 1). The mouse's dorsal coat is solid black, but the ventral coat is tan, similar to the black and tan (at; MGI:1855941) mouse carrying a mutation in the agouti locus.
|Nature of Mutation|
The coat color phenotype of killer whale mice strongly suggested a mutation of agouti; this has not been verified by complementation testing and the nature of the mutation is not known.
|Illustration of Mutations in
Gene & Protein
The agouti (a; alternatively, nonagouti) gene encodes the 131-amino acid secreted agouti signaling protein (ASP) (Figure 2). ASP functions in pigment type switching in melanocytes by inhibiting the function of the melanocortin 1 receptor (MC1R), subsequently promoting the production of pheomelanin (red/yellow pigment).
For more information about a, please see the record yellowbelly.
The phenotype observed in the killer whale mice resembles that of the at (black and tan; MGI:1855941) mice in that the at mice exhibit black coloration dorsally and have a yellow ventrum (1). TThe a mutation in the at mice is a spontaneous 6 kb insertion between exon 1C and exon 2 (~2.1 kb 3’ from exon 1C); the insertion contains a retrovirus-like transposable element VL30 with an internal 526 bp direct repeat (2). IAs a result of the VL30 insertion, the hair cycle-specific promoter/regulatory elements that control a expression on the dorsum are impaired. In the at mice, most, if not all, expression of a is believed to be controlled by the ventral-specific promoter. In the at mice, yellow pigment is synthesized throughout the hair cycle, leading to a ventrum that is yellow, while the dorsal hairs are black (3). We hypothesize that the expression pattern of a in killer whale mice mimics that in the at mice.
|Primers||Primers cannot be located by automatic search.|
1. Dunn, L. C. (1928) A Fifth Allelomorph in the Agouti Series of the House Mouse. Proc Natl Acad Sci U S A. 14, 816-819.
2. Bultman, S. J., Klebig, M. L., Michaud, E. J., Sweet, H. O., Davisson, M. T., and Woychik, R. P. (1994) Molecular Analysis of Reverse Mutations from Nonagouti (a) to Black-and-Tan (a(t)) and White-Bellied Agouti (Aw) Reveals Alternative Forms of Agouti Transcripts. Genes Dev. 8, 481-490.
|Science Writers||Anne Murray|
|Authors||Carrie N. Arnold, Bruce Beutler|