Reindeer coat colour variants in Finland

A research program based on reindeer coat colour had its first field survey in Finland after the calving season of May 2009. This short notice advances the main observations of the survey where, besides the wild allele, a new mutant could be identified, at least at three colour loci: Agouti (A), White Spotting (S) and White (W).


Introduction
During a reindeer meeting at Vantaa (Finland) in 2006, delegates of the Reindeer Research Station (FGFRI) in Kaamanen (Finnish Lapland) and COGNOSAG (Committee on Genetic Nomenclature of Sheep and Goats) discussed to study genetics of reindeer coat colour in Finland.
The Reindeer Research Station is run by two full time scientists and three technicians, welcoming guest scientists.It has at its disposal a herd about 150 adult reindeer at Kutuharju experimental station with 43 km² of natural pasture.Kutuharju estate and the reindeer belong to the Association of Reindeer Herders (Paliskuntain yhdistys).
May 26-30, 2008, a round table meeting was held in Kaamanen summarized by Lauvergne (2009): the knowledge of reindeer coat colour was examined, and a research program in Finland was planned (Lauvergne, 2009).
A first field survey of this research project was operated in May and June 2009.

Argument
In every animal species after its domestication it happens that: 1) a number of viable mutations are no more eliminated under the pressure of natural se- lection which is acting in the wild (Darwin, 1859(Darwin, , 1868;;Geoffroy St Hilaire, 1861); 2) the mutations controlling coat or plumage colour are the most numerous mutations with visible effects to be maintained, illustrated in dogs (Sponenberg & Rotschild, 2001) and sheep (Sponenberg et al., 1996).
This property deserved to be proved in reindeer of which the domestication is believed to have started around one thousand years ago in different areas of Eurasia (Nieminen, 2005;Røed et al., 2008).

Results of the 2009 field survey
The program was carried out immediately after the spring calving season of May 2009 at the Kutuharju experimental herd and in several commercial herds near Rovaniemi in which living animals as well hides could be checked.Some colour pictures from the FGFRI archives were also checked.
Using the principle of comparative coat colour genetics in Mammals of Searle (1968) the field observations may be interpreted in terms of alleles segregating at the following loci: Locus A (Agouti).The colour pattern of most adult reindeer was the so called wild pattern which is very common among Mammals, with various kinds of striped hairs on the back and a white belly (Fig. 1a).One can postulate that this pattern is controlled by the wild allele A + at the Agouti (A) locus.Several adult animals were carrying another well known pattern among ruminants called badger face, with a black belly, usually induced by the badger face, A bf allele at the locus Agouti (A) (Fig. 1b).
Locus S (White spotting).Some adult reindeer were presenting an irregular white design also very common among mammals (see, for example the Holstein Friesian cattle) usually induced by the piebald S p allele at the White spotting (S) locus (Fig. 1c).
Locus W (White). Totally white reindeer are commonly seen in Finland.They could carry the white allele W wh usually described in Mammals at the White (W) locus (Fig. 1d).
Other colour patterns obviously induced by colour mutants could be observed more scarcely • A dark pattern at Agouti or at Extension (E) locus ?• A brown pattern at Brown (B) locus ?• Several white designs with a variable expressivity already described by Delaporte (2002) in Norway and also present in Finland but their identification could not be made during the 2009 field survey.

Interpretation and conclusion
Variants at three well known homologous loci in mammals could be already described in the few adult animals which were observed in the first field survey in which less than 300 animals could be checked alive or on pictures : Agouti locus (with allele A + and A bf ; White spotting locus (S) with alleles S + and S p , and White (W) locus with W + and W wh alleles.
Mutants are probably segregating at other loci such as A (Agouti), E (Extension) or B (Brown).These observations fit well with observations in other domesticated ruminants species.
The number of colour mutants in Finnish reindeer is not that great (at three, perhaps six loci) compared to 18 coat colour loci having segregated in the dog (Sponenberg & Rotschild, 2001) and 11 in sheep (Sponenberg et al., 1996) but reindeer is of a relatively recent domestication, perhaps 1000 years from now as seen above, compared to that of dogs and sheep, resp.17 000 and 11 500 years BP (Vigne, 2004).
These results are encouraging but deserve to be confirmed by more extensive field surveys and by analysis of segregation data etc.

Fig.
Fig. 1a-d.Adult colour phenotype induced by different alleles 1 .a) allele A + (wild) at the Agouti (A) locus; b) allele A bf (badger face) at the Agouti (A) locus; c) allele S p (piebald) at the White Spotting (S) locus; d) allele W wh (white) at the Dominant White (W) locus.