Longtail Genetics: A General Outline

Text by Brian Reeder

It would seem that the genes controlling the long tail factors are very complex. In studying these birds, I have noted that the three main areas of the tail (main tail feathers or retrices, sickles and saddles) each are controlled by different factors. This is seen throughout the many longtailed breeds; the Onagadori, when having the fully expressed phenotype, has the highest number of these mutations, while birds such as Sumatra, Koeyoshi, Tomaru, or Kurokashiwa show the least number of these mutations. Other breeds such as Shokoku, Totenko, Minohiki, Phoenix or Yokohama seem to show an intermediate level between the two extremes.

The origin of the longtails undoubtedly begins with birds somewhat like we currently see in the least expressed forms of longtails (Sumatra, Tomaru, Kurokashiwa, etc.). From these birds mutations would have arisen that would have thus allowed the expression seen in such breeds as Shokoku, Totenko, etc. Finally then, these birds would have produced mutations allowing for the extreme expression seen in the Onagadori.

Let me now list the genes I propose for the longtails. There are three types of genes which effect the three tail areas. First there is Gt (growth) which is dominant and creates the accelerated growth seen in these birds as well as lengths up to three feet per year. Next there is Mtpf (multiple feathering) which is dominant and creates extra feathers in each areas effected. Finally there is nm (non-molting) which allows birds such as Onagadori to not molt and when raised in tombaku to not molt permanently. This gene is highly effected by environment and is recessive. Since birds such as Shokoku can non-molt for up to two years when reared in tombaku, it is likely that they carry a basic gene from which the extreme nm mutated. I call this gene Nm. It is dominant to nm. The two would be allelic.

If we go by the premise that Red Junglefowl is the only progenitor for domestic fowl, then we must consider all of these factors to be mutations away from wild type. However, the Green Junglefowl (Gallus varius) shows some of these traits. Green Junglefowl for instance have eight retrices and also show an unusual molting pattern, where retrices and sickles only molt once every eighteen months. I would propose then that the creation of Bekisar (Green Junglefowl males x Red Junglefowl or domestic fowl females) in the distant past has resulted in some small amount of Green Junglefowl genetics making their way into the domestic fowl and may yet be found in such fowl as longtails and long crowers, amongst others. This would then explain the unusual genes found in the longtails and would also indicate that some of these mutations are in fact "wild type"; i.e., the basic non-molting as seen in the Shokoku (Nm) and the multiple feathering seen in almost all longtailed fowl.

I would propose that Gt has three basic areas of effect (saddles, retrices and sickles) and since these can segregate and can be separated into true breeding lines as is seen in many longtails, these must be separate and not one gene factor. The same would apply to Nm/nm and Mtpf, as both factors can effect each of the three sections separately and can be set into true breeding forms. Then follows the genes as I propose for the longtails.

Gt complex
Gt~t (tail growth)
Gt~sc (sickle growth)
Gt~sd (saddle growth)

Mtpf complex
Mtpf~t (multiple tail feathering)
Mtpf~sc (multiple sickle feathering)
Mtpf~sd (multiple saddle feathering)

Nm complex
Nm~t (partial non-molting tail)
Nm~sc (partial non-molting sickles)
Nm~sd (partial non-molting saddles)

nm complex
nm~t (non-molting tail)
nm~sc (non-molting sickles)
nm~sd (non-molting saddles)

Now, let's look at the breeds and at what genes are segregating in each. I will start with the most basic forms and move forward to the most complex. It must be noted that the strains within each breed vary as to the homozygosity of their representative genes. Thus, each gene listed below is listed as “segregating," to indicate that they might not be homozygous (pure) in all cases.

1. Basic or primitive longtails -- Tomaru, Sumatra, Kurokashiwa, Satsuma-dori, Koeyoshi, Jitokko -- These breeds tend to have multiple feathering in all three areas and show Gt~sc, with a few very well bred lines showing Gt~t as well. Most of these breeds do not show saddle length. There seems to be no forms of Nm or nm in the majority of these birds. These then represent the most basic or primitive of the longtail group.

2. Intermediate level longtails -- Shokoku, Totenko, Minohiki, Ohiki (in most instances) -- These breeds tend to have multiple feathering in all three areas and also show Growth genes in all three areas. It would seem that these also have the Nm factor, the precursor to nm, in all three areas, though this varies from strain to strain within each breed. These birds show several mutations beyond the first category and are thus probably somewhat more "modern" or recent (as they currently appear) than those more primitive types. It is likely that the ancient forms of Shokoku and Totenko did not have all these mutations and that they have been selected up for this during the Edo, Meiji and Taisho periods of Japanese history. I would also point out that most lines of Yokohama and Phoenix (except those which are very Onagadori-like) also fall into this category.

3. Full expression of longtail genetics -- Onagadori and some lines of Ohiki with strong descent from the Onagadori -- This category shows the fullest expression of the various genes involved in this class of fowl. The Onagadori shows the mutation nm in all three areas of the tail, as well as the Multiple feathering genes and the Growth genes in all three areas. It must be stressed that not all lines show homozygosity for all these factors. Further, the homozygosity of the nm factors can only be proved if the males are reared in tombaku for three years plus, as even Shokoku and Totenko can non-molt for up to two years in tombaku. Thus non-molting for up to two years is not an indicator of true nm factors.

History tells us that the Onagadori sprang up from crosses of Shokoku and Totenko and possibly even Minohiki. From these early crosses (during the mid-eighteen hundreds) the Goshiki (five colored) form of the Onagadori arises. These early fowl were called Naga-o-dori or simply longtailed fowl. It is likely that the mutations from Nm to nm occurred during this period, as the truly amazing lengths of the most developed Onagadori occurred following this period, with the full true Onagadori emerging in the late Meiji and early Taisho period.


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