Genetics

C-locus

C-locus

C-series, or the albino locus. It consists of C, ci, cch, ce, cm, ch & c. This is very interesting locus, as these (except, of course, the top dominant C - full colour) genes dilute black, brown and yellow pigment - the three basic hair colours found in mice. This diluting effect is seen in both homozygous and heterozygous forms! In other words - now the real fun starts... Also note, that p- and c-loci are linked.

1. Full colour C

The top dominant of this series is the unmutated C, which gives fully coloured mouse whether it is present in double dose, or with any of the recessive alleles of this series.

Well, actually not so... a/a B/B p/p C/c and a/a b/b p/p C/c are clearly lighter in colour than their corresponding C/C -types. This phenomena occurs also with Ay, at and A. Furthermore, Ay and A mice C/c C/ch and C/ce genotypes are lighter than the homozygous C/C types. This effect is limited to the yellow portion (this is in genetical terms, so it means the golden brown section) in agoutis and in tanned mice to the belly.

Recessives discussed here include

  1. ci/* - Intense chinchilla, the maker of apricot (and so called lemon varieties).
  2. cch/cch - Chinchilla, homozygous forms
  3. cch/* - Chinchilla, heterozygous forms
  4. cm/* - Chichilla-mottle
  5. ce/ce - Extreme dilution, homozygous forms
  6. ce/* - Extreme dilution, heterozygous forms
  7. ch/ch - Himalayan, the point maker.
  8. c/c - Albino

C-locus is very interesting locus. All the recessives in the locus are co-dominant with each others. This means that they are no full dominance over lower alleles and all heterozygous forms show an intermediate colouring between the homozygous forms of both alleles present.