Introduction (April, 2003)
About three years ago, 2000 or so, I chanced upon the RMFE (Rat and Mouse Breeders
for Excellence) website, and I noticed an unstandardized variety from Australia
called ‘downunders’. The name made total sense since Australia is
indeed known as the ‘Land Down Under’, and the little Aussie rats
had the most amazing belly spotting (‘down under’) I have ever seen!
For anyone who has any familiarity with rodent coat color pigment development,
or mammal pigment development in general, it is one of those genes that ‘should
not happen’. It is a dominant gene. Initial suspicion was that it was
an allele of the hooded series, since the first downunders were discovered amongst
hooded rats. But, recent conjecture now leans toward the idea that this is a
totally separate gene that both modifies hooded alleles and interacts with hooded
alleles. (The common hooded alleles include self [HH], Irish [hihi], hooded
[hh], notched [hnhn], etc.)
Initial Inquiry
I made my initial inquiry with Tracey York of bRatpack and RatmanDu Ratteries
in May of 2002. My initial inquiry was quite casual, since the thought of actually
importing all the way from Australia literally seemed like an impossible dream.
I was quit intrigued by the downunder gene, and Tracey was extremely helpful
for questions. (I had lots of questions!) I had lucked out with my first contact,
since of course most breeders do not ship because of the difficult work involved.
Tracey already had much experience with shipments within Australia, and had
even done the first international shipment to Holland.
Decision to Include Aussie
Colors
For whatever reason, I had initially believed that the Australian colors were
UK imports – made sense to me, since what would be the statistical odds
that colors such as red-eyed dilution, mink or blue could possibly re-mutate
independently from the rest of the world? So, when Tracey mentioned to me that
Australia cannot allow imports since they are a rabies-free country, I really
started to wonder if the Aussie red-eyed dilution, mink, and blue could be repeat
mutations, or if they just might be unique new genes altogether… This
led to the first shipment delay, since my request had gone from just the downunders
themselves, to a request for the Aussie colors as well. My hope was to test
the colors with what we now find in the United States.
Delays to the Shipment
Just blame the weather, I guess… Timing was highly critical to the entire
shipment. The seasons between the Northern and Southern Hemispheres are pretty
much exact opposites. While I was making my requests during our summer, Tracey
was heading into the Aussie winter. So, some exceptional litters were born,
but we were still hoping for inclusion of the Aussie mink and blue genes, and
my last-minute request for the Aussie satin. Everything pretty much came together
by November 2002. Tracey had about five litters born within a month of each
other – that is one hefty undertaking – five litters to order! The
timing of the litters was also critical because the shipment was charged by
weight. Baby rats were expensive enough – I certainly did not wish to
pay for importation of fully adult rats! Of course, the final concern was that
we had to get these little ones over here before our own winter set in. (These
guys left their Aussie summer, and were welcomed here by our California winter
rains!)
What Finally Came Over
After all was said and done, I actually only brought over three downunders.
My boys included: one argente hooded downunder (son of the first Aussie odd-eye),
one black downunder, one black Berkshire, and one cinnamon carrying the Aussie
blue. My girls included: one black downunder carrying the Aussie satin, one
black cardigan carrying the Aussie satin, one blue agouti carrying the Aussie
mink, one cinnamon hooded, one powder blue hooded, and one mink English Irish.
The Aussie argente is their A_mmrr. The Aussie powder blue is their mmrr. (I
mention this in hopes that folks over here will not confuse the American terms
for ‘argente’ and ‘powder blue’ with the Australian
terms.)
Shipment Preparations
I will be totally honest to say that this was my very first international shipment.
As far as I know, this is the very first shipment ever between Australia and
the United States. One of the first items to attend to was all legal requirements
for entry into the United States, including veterinary certifications and USDA
notifications. I was, and still am, naïve about the official rules –
it took me about a month just to contact the correct USDA department, in order
to learn the requirements for a shipment of this nature. I was quit surprised
to learn that no quarantine was required from Australia to here – this
is because Australia is still a rabies-free country. Everything boiled down
to a veterinary inspection in Australia, and a USDA inspection upon arrival
in the USA. (Of course, they don’t make it easy – I had to wait
a few hours for the inspectors to show up – I probably had never paced
so much in my life!)
Friday the 13th – Lucky
Day
That Friday morning was a tad nervous for us over here, for Tracey, and for
the ratties of course. As luck would have it, I awoke that morning with a fever,
and looked out the window to one of our first big winter rains. I don’t
drive, and the airport gets mighty expensive by taxi… But, just like giving
birth, I knew it was the day – there was no sending ‘em back! Since
this was my first international shipment, I initially went to baggage, in order
to inquire about where exactly to pick up the babies. (The ratties had landed
in Los Angeles, and transferred to United Airlines into San Francisco. I had
such a fear that they would be stopped in Los Angeles, without me to intercede
for them!) Long story short: to baggage, to cargo, to claims, to cargo, to claims,
to cargo, home…
The First Days
OMG! I just could not believe the colors! I was not sure of my frame of reference
– were the colors more like ‘rat’ colors, or ‘gerbil’
colors? (I have never raised hamsters, but perhaps the colors would be familiar
to hamster breeders as well.) For sure, the mink looked like our mink, the cinnamon
looked like our cinnamon, blacks looked like blacks, etc… But, the colors
just seemed ‘different’ some how… Maybe more vibrant? Different,
for sure. I was also very paranoid of them getting sick – it is not like
we can do this kind of shipment any time we wish – these were very precious
little critters! So, it was bland food like lab block and baby food and oatmeal
for the first few weeks. I was so worried that they would get intestinal upset,
from literally eating food they had never tasted before. As time passed, I did
relax. But, I suspect I will remain on edge till we can get this gene out to
interested breeders!
Rationale to Maintain Pure
Aussie Lines
At this point in time, Australia is considered a megacolon-free country. There
is much excellent online information regarding megacolon. This condition is
often associated with spotting genes. A very simplistic explanation is that
megacolon is a neurological disorder that affects the intestinal tract, such
that the afflicted rat cannot defecate, and therefore will die without medical
intervention. Even with intervention, death is the most common outcome for megacolon-afflicted
rats – death usually occurs within a few weeks of weaning. By appearance,
baby rats with megacolon appear ‘bloated’ about the belly, and yet
often have very gaunt faces due to improper nutritional intake. It can be quite
emotionally painful to watch such a baby die. Given such a somber picture, I
hope it can be seen that I am looking forward to spotted lines of rats that
will never suffer from megacolon. In addition, maintaining pure Aussie lines
will mean that we can continue the fine work begun in Australia, with regards
to colors and markings. One of my boys is the son of the very first Australian
odd-eyed rat. So, I believe we may be witnessing the beginning of some new exciting
gene combinations never before seen in this country.
Test of Aussie Mink
Since my girls were coming in younger than the boys, my first cross was my argente
dowununder, Lil Nemi, with my American dumbo velveteen ‘self’ mink
girl, AP Wagstaff (also carrying American blue and at least one eye dilution
gene). There seem to be at least two genes in this country that resemble mink.
I suspect that Wagstaff is the UK gene that is confirmed to be the true mink.
The apparently American gene is sometimes referred to as ‘mock mink’,
since the gene was sometimes seen in Russian blue lines that were exported to
Europe. ‘Mock mink’ does not breed true with the UK mink. Out of
Wagstaff’s litter of 12, 11 survived. All black or agouti – no minks
or red-eyed dilutes. (I suspected Wagstaff of carrying red-eyed dilution, even
though her blazed mother, RSCL Taffy, looks to be pink-eyed.) This litter result
must count as one strike. I cannot state at this time, with certainty, whether
Wagstaff carries the UK mink. I am a patient person, and so I know that I will
eventually determine which ‘mink’ we had tested.
Test of Aussie Red-eyed Dilution
After the puzzle of Wagstaff’s litter, I felt that I should test the red-eyed
dilution genes. I fully expected to see half of Wagstaff’s litter to be
red-eyed dilutes. Over the years, I have come across much literature that supports
the notion that new independent mutations of red-eyed dilution end up being
confirmed as repeat mutations. That is to say, if a rat appears to be a red-eyed
dilute, then it will be expected to breed true with any other rat that appears
to be red-eyed dilute as well. (This is not always literally true – sometimes
various gene combinations will result in a rat that appears to have ‘red’
or ‘ruby’ eyes, but the rat is not truly red-eyed dilute.) But,
for this case, I knew that my Aussie argente only carried the gene for the Aussie
red-eyed dilution. I knew that my American girl, OFR Waterfall, only carried
the gene for our American red-eyed dilution. I was totally shocked, and unprepared
to discover that the Australian red-eyed gene is distinct from our own American
version. (This was confirmed by the observation that all of the 13 babies are
black or agouti – we expected all fawn and beige.) This counts as strike
two for the Aussie genes! I am not aware of any other circumstance in the world
where this scenario has occurred. Perhaps this new Aussie gene will still be
located on chromosome one, as are other dilute genes such as pink-eyed dilution
and albinism? If not, then I will be totally baffled!
Test of Aussie Blue
I will cut to the chase – this was the only gene that we confirmed is
identical to American and English blue. Just for general info, I will state
that the blue rats currently seen in the fancy were discovered about 1990. As
luck would have it, the gene mutated twice in about 1990, and was independently
discovered in a UK pet shop at the same time as the gene was discovered in an
American pet shop. I don’t know the UK history well, but I can say that
the American discovery was made by local RMHF fancier Sylvia Butler, in her
pet shop in Danville, CA. For my current cross, I bred my Aussie cinnamon boy,
Donner (carrying Aussie blue) to my American blue dumbo girl, OFR Ashbury (carrying
Siamese). Ashbury’s delivery lasted about four hours – the longest
I had ever witnessed for a rat. She gave birth to at least 12 babies, but would
not nurse or tend to any, till the last was delivered. I was frantically pacing
for her. I was extremely tempted to foster the babies onto Waterfall, who gave
birth to 13 babies in less than one hour, the very same day. With 13 babies,
I did not see how I could add 12 to Waterfall! Thankfully, Ashbury began to
care for her babies after the last was born. Eight survived. Of those eight,
two are blue and one appears to be a blue agouti. So, it only takes one blue
baby to confirm the genes are identical! (Since Donner was heterozygous for
Aussie blue, not homozygous, we did not expect a full litter of blue babies.)
Recent Upset over Aussie
Blue
Literally the same day that Waterfall and Ashbury delivered (March 4th, 2003),
I chanced upon the Internet the recent concerns of the Aussie blue gene. The
most notable expression is excessive bleeding, as during birthing or after a
minor injury. Reports of deaths have been made for the Aussie blues from such.
Other symptoms may include reduced fertility (male or female), smaller litters
and excessive stillborn, possible depressed immune system, failure to thrive,
etc. The symptoms have been compared to what is seen in von Willebrand disease
(vWD) in humans. In humans, vWD is considered an autosomal dominant gene. For
an affected human, this would mean that half of all offspring would be expected
to inherit and express the gene. For our rats in question, I am not certain
how a vWD-type disease would be inherited with the gene for blue (d), since
blue in rats is an autosomal recessive gene. (That is, a rat must inherit two
copies of the gene to be visibly blue.) I did a quick online search of the Rat
Genome Database (RatMap) and found two references in rats, when I did a locus
description query input of ‘von Willebrand disease‘. The query gave
back the locus symbols [Mvwf] predicted at chromosome 10, and [Vwf] predicted
at chromosome four. I happen to work for the UCB School of Public Health, and
so I did a PubMed search for ‘rats and von Willebrand disease’.
I got 21 hits, but I suspect many of those hits would not be relevant. But,
at least it suggests that there *might* be rat models of vWD that have been
studied in the past, and so that alone could shed light on the current situation
now seen in the Aussie blues. As a final note on this (for now!), I will add
that both the UK and USA early blues were seen to have similar concerns, though
I cannot state whether the Aussie blues are more affected than the others. New
theories are pending…
Early Concerns for Downunders
The downunders have only been around for a few years, since about 1999 or so.
I am not familiar with the early history, but the early reports for some of
the lines included eyeless conditions such as eyes of uneven size or one missing
eye. The mode of transmission is not certain, but it appears that the tendency
has been successfully bred out of the downunders. The eyeless condition seems
to have been unknowingly exported to the UK (via Dutch imports of downunders
from Australia – downunders were not directly imported into the UK from
Australia). At this time, I am not aware of any new or recent cases of downunders
with any eye concerns, and so I believe the American import is completely clear.
I am not the best person to cover the early downunder history, but I am also
under the impression that some of the early downunders may have had some personality
problems. (I believe the very first downunder was a hairless male extracted
from laboratory origins, and so that could be the reason the lines had variable
temperaments.) In spite of these concerns, I am happy to say the imported rats
have all been well tempered and just as people-oriented as any rats I have seen
here. (Then again, the first hybrid litter born was just about the most active
babies I have ever seen! Not skittish, but unbelievably active and inquisitive
– never sitting still...)
General Characteristics of
the Aussie Rats
Overall, the Australian rats have thus far proven to be generally smaller in
size than what I have seen in the USA. I guess time will tell if the American
palette for ‘super-sized’ rats will accept the smaller Australians
as they are. Tracey York is a show judge, and I can definitely say her rats
are very beautiful and sweet. Tracey has also done a wonderful job of breeding
for colors. (To my mind, these qualities are more important than size.) I have
noticed that the girls in particular really like to burrow into their bedding,
especially when their cage is freshly cleaned. The mamas will totally bury their
babies. These guys are tasters – they put everything into their mouths,
and I have the nibbled shirts to prove it. They have thus far all proven to
be people-oriented and quite mischievous. (One girl decided to camp out in our
bathroom for a week!) Tracey has worked with some of her lines, such as her
English Irish, for over eight years. She has worked on longevity – some
of her rats have been known to live over four years. (I guess they need that
extra energy, to keep ‘em going for four years!) Overall, I have found
these charismatic rats to be wonderful fun and true delights.
Downunder Availability
The first hybrid litter is now out to four breeders, who are all online:
Cassandra Barlow (Romping Rats Rattery,
Oregon):
http://www.geocities.com/luckies4me/index.html
Jennifer Flores (Li’l Rugrats, California):
http://www.lilrugrats.com/
Debbi Needham (Odd Fellows Rattery,
Washington):
http://www.skyclyde.com/
Sandy Sprague (Angel Paws Rattery, California):
http://angelpawsrattery.tripod.com/
We have covered all the Western states. The next set will probably be going to Missouri. My hope is that with wise planning, the downunders can reach all the major rat fancier groups within the next year or two. I guess just 47 states (and Canada) to go.
NWDUs Yahoo Group: http://groups.yahoo.com/group/NWDUs/
We have just started a new yahoo group, ‘New World Downunders’.
I chose the ‘new world’ theme because in a sense, we are indeed
entering unknown terrain. We have genes not seen in Australia, and so the potential
for new gene combinations is unknown and full of promise – especially
with the new possibilities for color combinations. I had also tried to think
of a name that was inclusive of Canada, and possibly others in the Americas
that may fancy rats. So far, this group has been quite enlightening with regards
to questions and insights from around the world. The moderators are Cassandra
Barlow and Debbi Needham. I am very happy that we are receiving strong support
and advice from downunder breeders in other parts of the globe. I am also glad
that there has been tolerance for tangent topics! (I see this gene as a possible
‘enhancement’ to varieties already existing here. So, downunders
will not exist all by themselves – they will soon be dumbos, rexes, velvets,
American colors, etc. Tangents just might spark inspiration for new combinations!)
Online Resources
There are many elements in this intro article that would be difficult for the
typical rat fancier to locate. Plus, the updates have come in fast and furious.
Therefore, I tried to list just a few online resources, to get interested folks
on the road. This list is not all-inclusive by a long shot, and I know that
there are many more excellent resources available online.
Aussie Blue Gene Alert:
Scamper’s Rattery: http://www.uq.net.au/~zzpbolit/
Aussie Blue Rat Searchable Database:
AusRFS (NSW):
http://www.ausrfsnsw.com/index.php?page=/pages/newsarchives/news2003032801.php
Downunder Standards and Varieties:
AusRFS (NSW): http://www.ausrfsnsw.com/
AusRFS Qld: http://ausrfs.org.au/qld/
NFRS: http://www.nfrs.org/
Megacolon:
AFRMA: http://www.afrma.org/
Rat Fan Club: http://www.ratfanclub.org/
RMCA: http://www.rmca.org/
RMFE: http://www.rodentfancy.com/rmfe/
Online Rat Database:
RatMap The Rat Genome Database: http://ratmap.gen.gu.se/
Ratteries of Interest:
bRatpack Rattery / RatmanDU Rattery: http://www.ratmandu.com/index.html
Milo Stud: http://www.milostud.pwp.blueyonder.co.uk/index.html
Mischief Makers Rattery: http://www.rats.dynam.ac/
Pendragon Rattery: http://www.pendragonrats.co.uk/
The Rats of Alpha Centauri: http://www.alphacentauri-rats.co.uk/
von Willebrand Disease:
Allaboutbleeding.com: http://www.allaboutbleeding.com/
Hemophila Resources of America: http://www.hrahemo.com/index.html
Yahoo Groups for Genetic Information:
RFRB: http://groups.yahoo.com/group/RFRB/
Ratgenetics: http://groups.yahoo.com/group/ratgenetics/