Feature Archive 7 - 3rd quarter 2001
DOWNUNDER VARIETY RATS
In the latter half of 1999 I was sent a photo of an unusually marked rat, by a friend of mine interstate (Cisca), asking me if I'd ever seen anything like it. The rat in the photo, "Rodentranch Enigma"(pic A7.1) is what today is known as a DownUnder hooded. Back then though they'd nicknamed them Double Hooded. A few short weeks later I was on the phone to the breeder Cindy Cairns, and a few weeks after that we were at the airport picking up some of our own little DoubleHooded ratties.
Over the next few months I spoke regularly by phone to the breeder, asking questions about their mutation, and generally gasbagging about ratties for literally hours, I have the phone bill to prove it, eeeesh.
But they were all worth it.
I made the trip interstate to see the breeder in January of 2000, where I finally met the little guy in the photo, along with the rest of his family, of which one was a little rumpy manx female aptly named "Rodentranch Rarity"(pic A7.2) Enigma's daughter, who also happened to be a DownUnder thus telling us that this pattern was being caused by a dominant or at least semi-dominant gene, seeing as "Rarity's" mother was not DU .
'THE LOW DOWN'
About a year before the mutation of the DownUnder pattern, I was emailing with another fellow fancier interstate (Carol), who was telling me about some hairless rats they were getting from WA soon, saying that if they bred them, would I be interested in getting a baby or two. I certainly was interested, I'd seen lots of pics of Sphynx rats overseas and thought they were adorable.
Months after they got the Sphynx rats, things weren't going so well though. Seems the rats were developing a few different health problems with their eyes. While they had bred with them and outcrossed them, it appeared that if the babies were hairless, they also developed these problems. So we agreed to hold off getting some for a while and see how it all went.
Even though the hairless rats were fragile in their constitution, the rats themselves looked quite healthy (pic A7.3) up until such time as they developed one of the conditions.
The first DownUnder rat was in fact a black hooded hairless rat, and it was at a show one day that his unusual markings first became apparent, when he stood up on his back legs his belly was visibly pigmented.
It wasn't until the third litter from the F2's that another rat with this marking showed up, and while a percentage of this litter were hairless also, there was one DU in it and he was furred, this was Enigma.
Within 6 months of us getting our little rattie travelers, it became apparent that the ventral pattern was being inherited independently of the hooded pattern. How did we know this? Quite simply because we had some berkshire rats in one of the litters, with a ventral stripe right down the centre. This discovery is what caused Cindy to rethink the name Double Hooded, as it was now appearing on other patterned rats too.
So we were all throwing names around as to what we should call this new pattern. The way the name DownUnder was suggested was actually unintentional, by a friend of mine, and fellow rat fancier, in the UK, Sue Brown. When I was telling her about this wonderful new variety of rats, in her answering email, was the following passage.
>**As to a name: well, what can I say.... you have GOT to call it the "Australian ....something" because it's the only rat with markings DOWN UNDER!!!! ** (groooooan!)
As soon as I read that passage, I just knew that Cindy would love the name as much as I did, and the rest, as they say, is history.
Today the DownUnder pattern has been officially standardised by ANRA in three varieties. The DUHooded(pic A7.4), the DUSpotted(pic A7.5a & 7.5b) and the DUBerkshire(Pic 7.6). There is another variety of DU still in the experimental stages, DU Cardigan. A provisional standard has been written for this and states:-
Overall Impression: A Cardigan rat, with standardised Cardigan demarcation area as per Cardigan
Belly: Ventral Stripe in matching colour to top, not too wide, needs to be thin enough to
have an amount of white down either side to join up with the feet markings. Side
stripes to be as even as possible with minimal roaning, dappling & breakup in the
Feet: are white. Front feet halfway to the elbows, and back feet to the hocks.
Eye colour: To conform to body colour
Faults: White chin permissible but not desirable. Ventral stripes creeping too far up the sides
For a long while DU rats were only available in Black and Agouti colouring. But now they come in all the colours we have here in Qld. Mink, Cinnamon, Fawn, Lavender, Silverfawn & Dove and only more recently a different grey colour, we believe could be Blue, prompting the thought that maybe the DU lines are also going to be responsible for the mutation of the d gene or similar in Australia. This blue colour is now also available in standard hooded patterned rats too.
The first colour to be bred was dove, followed by mink, then silverfawn, then pretty much the other three colours all showed up at the same time.
While my first DU outcrosses only gave us agouti and black, we planned the matings, so that the second litters would produce different colours for us. From the first matings (3) we kept "C.Trinity" a black DU spotted carrying Mink & "C.Yo'the potter", an agouti DU Berkshire carrying mink & ruby-eye dilution.
We bred "Yo" to a lavender female carrying mink "C.Ariel", and in this litter was a baby that at first looked to be silverfawn, pink eyes and all, that very strangely later(5wks) darkened in both eye and coat colour to become a pale hued 'Fawn' DU Spotted.
Note:- This eye darkening phenomenon, was also witnessed in two other unrelated litters at around the same time. One of these litters had a rat that looked to be a dove hooded, at 5 weeks of age her eyes darkened to ruby and her coat along with it, to turn out lavender.
while it is still speculation on our part, we believe that the rats exhibiting this eye colour change may be genotype (A-mmpprr & aammpprr) we are currently testmating to find this out.
We bred "Trinity" to a mink hooded male, and though she should be carrying mink, all 4 of her babies were black. We wanted to keep one anyway, and decided upon the one who was an unusual charcoal colour, looking roaned up until about 5 weeks of age. "C.Jewel" So we're looking forward to breeding from her soon.
At this time we also bred our DUhooded agouti girl "RDU.Melisande" to our lavender boy "C.Zephrum", from this litter, we got 2 mink DU's of which we kept 1, a little girl, spotted "C.Fortune found", and the Cinnamon DUhooded girl "C.Mystery".
In this litter there was also a little lavender DU, but the mother appeared to cull off the majority of her babies, only ending up with 3 out of the 9 born. We have since re-homed her, and are hoping that this behaviour of hers is not hereditary, or it may have been passed onto her daughters.
So pretty much the only colours we have not actually bred in our own litters are dove and silverfawn.
There are a couple of points of note, with this DU mutation. Since the arrival of it, many of the litters contain perfect bareback pattern babies. So far it appears to be impossible to breed a bareback rat with the ventral DU stripe. Whether this is the case, or not only time will tell.
The next point, is the fact that the DU lines produce headspots(pic A7.7) in some of the babies. Up until the mutation of DU, we here in Australia weren't even lucky enough to get one white hair in the place where a headspot should be, let alone a whole spot. But many DU's have head spots, and there are also some rats born in these lines that are bordering on the capped pattern, complete with headspots.
Maybe the genes causing these perfect barebacks and mismarked capped rats are epistatic to the genes causing the DU pattern. Only time, selective breeding and accurate record keeping are going to answer these and other questions we still have about this pattern.
Of one thing though, we are fairly certain, and that is that the gene causing the DU pattern is not the dominant variegated gene H^e that is responsible for a lot of variegated pattern rats, and rats with headspots overseas. This is probably a fortunate thing though, as the H^e gene is known to have some health complications in some breeding scenarios.
Now a little bit about our the new grey colour we 'hope' to be blue.
The newest little surprise to come from this line, is a new colour that could only be described as a type of blue. (Pics A7.8 - A7.10) This colour was first observed on a DU hooded male "Becksley",(Pic A7.8) and his daughter "Thumbelina", (Pic A7.9). The colour is similar to photos of blue rats I've been sent from the UK and Europe. This is all speculation so far, as yet not proven. These rats have been testmated, and we are awaiting the results. But this colour is definitely different from our minks here.
There are a number of genes overseas that cause blue colouring in rats (not including the m gene -mink) and while it may be that this is a mutation of one of these already known genes, there is also the possibility that we may have a new & exclusive gene to Australia. To finally have the much sought after blue colouring in our fancy rats will be a definite cause for celebration.
Whatever we discover in the future about this pattern, and this line, one thing is for sure. It has produced a wealth of new rat varieties, and even a whole new Breed so far (in the manx). This is not only more than any rat fancier could ever hope for, especially all in such a small space of time (2 years), but also more than Australia has seen in the past few decades.
... and do you know, I wouldn't be surprised if the next thing to come out of this line is something as sensational as say, some form of mosaic, or even the himalayan pattern. I personally have my fingers crossed for the b gene mutation (chocolate).
Afterall if you think about it, this line in total, has so far produced, Hairless, tailless, DU patterns that don't appear to mix with some other patterns, headspots and variegation in coat pattern like we've never seen before here in Australia, and now what appears to be a new colour. In fact we've gained more varieties from this line, than we had in total to begin with.
Yours in Rodents