Whether a black alpaca, a white dromedary or a dark Bactrian camel: colour and fibre arise from the interplay of a few pigment genes and many genes for hair formation.
Anyone who knows the parentage and inbreeding level of their animals can plan matings for colour and fibre more precisely while preserving the genetic diversity of the herd. That is exactly what our tests and services for camelids are for.
Colour and fibre of a camelid fleece look like one overall impression, but they trace back to two different processes: the production of pigment in the hair root and the build-up of the fibre itself.
Hair colour arises in pigment cells (melanocytes) of the hair root. They produce eumelanin (black to brown) and pheomelanin (reddish brown to yellowish). If no pigment is made, or no pigment cells reach the hair, it stays white.
MC1R and ASIP decide which pigment is produced: an active MC1R receptor promotes eumelanin (black to brown), ASIP blocks it and shifts production towards pheomelanin (light brown, reddish brown to yellowish). KIT controls whether pigment cells reach skin and hair. If they are missing, white or spotting results (white patches on a coloured background). This basic principle applies to mammals in general. Which gene activity goes with which colour in camelids is shown in the entries below.
Black arises when the pigment cell makes almost only eumelanin. For this, MC1R must work and ASIP must be lost. This has been described in dromedaries and alpacas; in alpacas the findings are less clear.
In alpacas, brown needs a working MC1R and ASIP. In dromedaries, dark brown animals share the gene change of the black ones. The data are thin.
If ASIP is active, the light pheomelanin predominates. In dromedaries, light brown is considered the original colour. In alpacas, light colours are linked to ASIP.
In alpacas, classic grey traces back to a change in the KIT gene. Grey animals carry it in one copy only; two copies are presumably lethal. No findings exist for dromedaries.
White arises when pigment cells are missing or colour production fails. In dromedaries it is linked to a change in the MC1R gene. In alpacas, white is inherited dominantly, KIT is named as the gene, and the exact cause is not settled. Hearing impairment is common in blue-eyed white alpacas.
In spotting, pigment cells reach only parts of the skin, usually via KIT and neighbouring genes. In alpacas, a gene segment near KITLG has been described for the roan pattern (a mix of white and coloured hairs). No findings exist for dromedaries.
Thickness, crimp and length of a fibre are shaped by many genes, for example for keratins and for growth signals in the hair follicle. Each gene adds only a little; the sum makes the difference.
Fibre quality is not a single trait but a bundle of measurable properties, each with its own genetic and environmental share. The genetic share is given as heritability in percent. If, for example, fibre diameter varies within an alpaca herd, at a heritability of 25 to 30 % about a quarter to just under a third of this variation can be traced to genes, the rest to feeding, age and measurement. The heritabilities come from studies of alpacas in individual herds.
Measured in micrometres (µm). The finer the fibre, the softer the yarn. Fineness is partly heritable: heritabilities of about 25 to 30 % have been estimated for alpacas. Selection therefore works, but only step by step.
What matters is how much the diameter varies within a fleece and how many coarse, medullated hairs it contains. Medullation is also partly heritable (about 20 to 30 % in alpacas, and a higher value was estimated for Suri in one study).
Structure describes how the fibres grow: crimped, in locks or as straight hair. In alpacas it is governed by fleece type (Suri dominant over Huacaya).
Staple length and lustre determine how well the fibre can be spun, and the yield per animal determines profitability. Yield figures vary widely depending on whether only undercoat or all hair is counted.
The same basic principles show up very differently in the three species. The examples summarise the current state of knowledge.
Alpacas come in more than twenty shades, from white through beige and brown to black, plus spotted. Colour and fleece type (Suri, Huacaya) are separate traits. White can prevail as a dominant trait, but breeders report that colour outcomes are only partly predictable, which suggests that besides a few main genes, further genes contribute. The breeding goal is usually a fine, uniform fibre.
Light brown is considered the probable ancestral colour of the dromedary. An MC1R variant is described for white animals, in which one altered copy appears to be enough, while a change in ASIP is described for black and dark brown animals.
The Bactrian camel carries a dense coat of fine undercoat and coarser guard hair. The fine undercoat, which is collected during moulting, is the raw material for camel hair yarn.
The most important questions, answered briefly and clearly.
A few genes with a large effect control the base colour, above all MC1R and ASIP. Further genes influence white, spotting and shades. Because several genes work together, the outcome of a mating cannot always be predicted with certainty.
According to older pedigree analyses, white mostly prevails over black and brown. KIT is named as the responsible gene, but proposed variants were not confirmed. Hearing impairment is common in white alpacas with blue eyes.
Suri currently appears to prevail over Huacaya. A Huacaya animal therefore carries only Huacaya alleles, while a Suri animal may still carry a Huacaya allele. The gene concerned is not established; TRPV3 on chromosome 16 is named as a candidate.
Only to a limited extent. Fineness is determined by many genes with a small effect and, in addition, by feeding, age and health. More reliable than a single statement is measuring the fibre over several years, together with verified parentage.
You can find which DNA tests we offer for alpaca, llama and camel in the overview of all DNA tests for camelids.
These answers serve general information.