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any people accept an that the white tiger a specific sub-kind of the tiger is. Aller they must I "leider" be disappointing, since is defectively a genetic one this phenomenon. The occurrence such whities is limited in a specific sub-way not but there are almost exclusively only Indian tigers those have a white skin. There are only rarely white tigers of other sub-kinds. This however, should not amaze if one considered, that the Indian tiger nowadays sets up 60% of the entire tigerpopulation round. This circumstance is to be owed to the unrestrained extermination hunt of the last millennium. For further information on this subject you shall see into the column "politics & protection".
As first it would may set up the question what causes this phenomenon. In this point, the answer is just now so easy as surprisingly. Albinism which has the same causes, as that with the human being of occurring albinism, exact sells itself around a kind. Next to all cats, albinism occasionally occurs. However, one provides a partial albinism in 95% of all cases. This meant that although the primary color the it is skin white, even moreer or less markedly black patrols available are. One finds a complete case of albinism only very rare - on the whole world, it would be allowed to be not more than 10 specimens. These models occur too next to the lion from albinism. Such animals are mostly confessed in circus and stage shows. The two German are above all magician Siegfried Fischbacher and Uwe Horn here, in a known manner as "Siegfried & Roy", to mention.
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At first I have to give in a decided manner me for it an insight into the reasons and the background of this metabolism illness before I deal more precisely with the individual subjects. Each can introduce what albinism "looks" know, however only few ones around the agency responsible summon. The following illustration shows the chromosome number 11:
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As one can already recognize by this illustration, the eleventh chromosome is responsible for two more known inheriting illnesses. This chromosome also houses the defective gene which causes sickling cell anaemia in addition to albinism. However, no further attention should be given to that.
A lack of the pigment melanin is in the case of albinism there. This pigment serves the organism as protective averages against uv-radiation. It is authoritative qualities like the iris color prominent for the skin/skin coloring, hairs generally and other are responsible. The most important enzyme in melanin production is the tyrosinase (see melanin metabolism). It catalyzes formation from dopa of amino acid tyrosin. The corresponding gene is on chromosome 11 at the gene place 11q14-q21. A defect in this gene leads to a known form of albinism.
Depending on model and markedness of the albinism, different genes on different chromosomes are involved. Shared the tyrosinase gene on chromosome 11 mentioned already, the P-gen on chromosome 15, dopa chrome tautomerase (TRP2) on chromosome 13, DHICA oxidase (TRP1) on chromosome 9, Hermansky-Pudlak syndrome (HPS) on chromosome 10 and ocula-albinism (OA1) on chromosome X. "X" however, not the roman number is not ten but the feminine sex chromosome.
One distinguishes the rarer total Pigmentlosigkeit (albinism totalis) with in general recessionary devolution of the partial pigment lack with that only specific body places are without pigment through what it often comes to a half-white skin (albinism partialis). The devolution is here in general dominant (= OCA, Okulocutaner albinism). If the iris of Aug is only concerned, then is presumably a rezessiv-X-chromosomal devolution (= OA, eyepiece albinism, rare) available. the reddish color of the very photosensitive eyes in the case of total albinism comes of the shining through blood vessels. If a partial albinism only occurs, the iris color mostly inclines to the bluish.
A special form of the albinism is the leukism (Albinismus circumscriptus). All conspicuousness like in the case of normal albinism are to be found almost here, yet the eyes are not affected and consequently, look as next to healthy tigers.
How is however this blue accomplished? Red is a primary color and through may add one becomes other colors never come to blue since blue is also a primary color. Each which has a good knowledge of chromatology however, will have the answer ready. The skin color is a compound of the three primary colors yes already. Through that may be inclined the melanin that is responsible for a strongly reddish part the remaining combination colour to bluish sounds. By the complete absence of melanin the iris becomes white, the reddish blood now guarantees the red iris (if someone a un logic presumed). The blood is of course still red since the blood coloring does not cause melanin but causes the hemoglobin The sickling cell anaemia mentioned already is an illness which influences the hemoglobin and/or the oxygen transportation in blood.
This illness also goes along with many viscosities. One finds a trouble of the seeing railroads like this in very many ones. In this way, no general loss of sight is meant but rather, variations in the seeing spectrum or too in the case of sharpness. Another trouble refers to the learning railroads. Many animals which fell ill with albinism (the human being including), may suffer to reduction of the learning property. These circumstance has to the the thesis led that white cat/tigresses are bad mothers On account of this learning trouble, these tigresses can not hear theirs junior staff if this is hungry for example or is in danger. Pups of white tigers become frequent therefore from other animals or too the human being, raised - as far as the circumstances make this possible.
The most known white tigers come from the discipline of the maharaja of Rewa. All tigers from this discipline go back to an only masculine animal which was caught in Rewa in summer 1951. There was yet tiger might whitewash reports on others separated also in the jungle of India. White sub-kinds other tiger are hardly it, for above-mentioned reasons. There are very rarely traditions of complete whities. A tradition would come Narayan nth of V. that reported on a couple of total-albino-boytiger with pink eyes those did not have the least approach of patrols (not below special light). His report according to, these two tigers came from the province Cooch Behar.
However, one must say to discipline of the maharaja of Rewa some more. The blue eyes mentioned several times already which are also designated as "iceblue" only occur in this discipline. Me no other case is still confessed, is confessed where this feature also occurred. It appears be a specific defect of the genes. If these tigers take in excitement, the bluish color disappears and goes around into known yellow. A very striking indicator for the nature situation the tigers, that already a couple of people life would be allowed to which have saved (above all otherwise inexperienced animal tamers).
However, there are still other anomalies in addition to albinism in coloring of tigers. A very specific anomaly is a so-called Roetling or also Rufino. It gives tradition via a such Rufino only to to two. The first one comes from R. I. Pocock. It was a tigress which came from Elburs here. The skin of this tigress went into the possession later of R. L. Kennion over, the it in the first decade of the 20th century the British museum of Natural Histroy in London would donate. Is to be gazed in wonder there at this skin until the contemporary day. Over I also only can the skin itself that represent what is in the books. The complete black pigment seems to be missing. This read the very scarlet basic tint and the patrols honor seem pale. A similarly colored tiger was fired according to Z. Veselovský in 1976 at the Kaziranga Nationalparks (one of the most famous national parks of the world) boundary.
I would like to say a couple of short words still to the so-called "golden tigers" or tabbies. It also acts itself around a pigment trouble, that the skin the tiger a rare yellow tone loans. This money tone is very similar to the color of gold and therefore, was associated quite soon with this color. However, the too so-called "white-golden" tigers of which it is a question here resulted from a discipline and not natural of course. They were bred in the USA. For this, a white tiger is necessary which had both hereditary dispositions for white skin. This was crossed with normal colored tigers. Tigers of mixed colour resulted in this way. These tigers were in turn mated among each another. In this way were whitewash born (the tigers of Sigfried & Roy) and also rarely the "golden" or "white-golden" tigers. They are called as a increased endogamy product by some specialists, however, they are valid with exhibitors of all kinds (circus, zoo & co.) as valuable rare. Presumably only 20 of this tiger exists worldwide. They are next to these tigers cheek, chin, breast, stomach and temple areas are highly increasingly white. Back and necking areas are light brown with light brown patrols. Small picture gallery. There is only a coloring anomaly which is rarer: the black tigers.
The fur coloring of the black tigers is the "precise" opposite of albinism. It is a question of a metabolism trouble which an extreme overproduction of melanin results and is also mentioned melanism therefore them. There is no completely plausible evidence for a such tiger. One of the first mentions of black tigers are in the case of Marco Polo to find. However, he spoke of big black lions since no tigers were confessed him at former time. The size cat which he knew was the lion why it recorded this in his diary However, he recorded nothing more precise. We can not exclude therefore that Marco Polo saw a very big specimen of the black panther (leopard - Panthera pardus) simply. [more information about black tigers]
In entire literature, only six reports on black tigers were known, on which R. I. Pocock reported. However, is only a case which one to some extent can certainly to proofs there. He comes from a factory from James Forbes. Forbes was a talented painter, that incorporate around 1772 for the Indian John Company of India. The researcher Ch. Stonor arrived in the 20th century among the many aquarelles of Forbes a picture which one a big black striped cat is represented. After some enquiries, a letter also found by Stonor from Forbes in whom he described the black cat clearly as tiger. He spoke of a completely black Bengal tiger which only captivated with even blacker stripe drawing. The Forbes at no time interest showed with this painting to earn money and itself not around scientific recognition troubled ones, does one go out from that, that this letter and the aquarelle at the highest measure are authentic.
As last, I would still like the "blue tiger" from Fujian. Actual act it itself around a the six known cases of melanism that was described by H. R. Caldwell. The name "blue tiger" received this animal, because of his furs basic coloring was very dark, and that strongly resembled like the blue Persian cat.
In addition to these deviations gives it however still numerous other known phenomena. I think that not advantageous to it would be all anomalies known me to count here Who however yet inter eat has to find out more information that can send a question by mail to me (link at the end of this page). I am pleased with every human being who has greater interest on these miracle full animals. One should not above all forget astonishment, should forget that it is a question here of illnesses. With albinism or the other mentioned troubles, they are not to be underestimated. The nature is already in a troubled manner to bring such mutations through the natural selection extinct. That employs such sick animals especially gladly for show purposes may be is especially sad. Politics & protection
I would like to still lose a couple of words finally for this topic for the inheritance studies. Since the described phenomena are based on genetic causes, this might hold for positioned. I would not like to however get in deep but would like to only clarify the principles. For this purpose, I would like to present you the Austrian monk Gregor Johann Mendel.
Mendel became 1822 at the 22. Juli as a son of a farmer family in Heinzendorf (the contemporary Hynèice in Czech) borne. He entered the Augustinian cloister of Bruenn (the contemporary Brno in Czech), that as a center for the lesson and investigation was confessed and would work later than teacher of technical school of Bruenn. During this time, Mendel was occupied intensely with the exploration of inheritance and evolution of plants which increased in the garden of the cloister. He undertook numerous crossroadses experiments to peas in between 1856 and 1863 through artificial dusting. He crossed seven different sperm kinds and studied the qualities of the plants resulting from it. He summarized the results of these experiments later in three rules designated after it. Moreover he embossed the terms dominant and recessionary, those employed since today in genetic.
Mendel's rules
1. Mendel rule (uniformity rule, reciprocity rule):
In his first experiments crossed for Mendel pure inherit large pea lines those distinguished in a feature, e. g. dwarf and increase lines. He received hybrids those showed no compound of both qualities as descendants separate external to that large grew parent corresponded. As a declaration, he formulated inheriting units which we today call genes and which occur often in different state forms (space elk). One distinguishes dominante (A) and recessionary (a) state forms of a gene where the dominante suppresses the effect of the recessionary allel for allel and appears externally. Mendel recognized ones that genes occur generally in pairs in normal body cells however, itself during the origin of the sex cells (egg- and sperm cells) divide up. In this case, every gene from a such pair reaches a sex cell. During the union of egg- and sperm cell result again a gene pair, in the the dominante allel (in the mentioned case for the high-growth) the effect of the recessionary one (for dwarf growth) covered over. These results supply the basis for 1. Mendel rule, according to the a crossroadses two pure inherit parents those distinguish in one or several features, a uniform (uniforme), half inherit (Aa) daughter generation produce. The uniformity of the daughter generation is not influenced if the in each case other parent shows the appropriate feature (reciprocal crossroadses).
2. Mendel rule (split rule, dominate rule):
Around to prove, that there are such inheriting units, crossed for Mendel
the first generation that large grew hybrid peas (Aa×Aa) among one
another. How in this case it turned out be, would emerge small in the
first daughter generation again grew peas (aa) on, namely small grew and
large grew in the relationship one for three. He drew the conclusion from
it that itself the genes in the pairs AA, found Aa and aa had. As he found
during further crossroadses experiments, went out the pure erbium gene
AA-plants descendants tall during autogamy only forwards and the descendants
of the aa-exemplars were always small. At the crossroadses of the Aa-hybrids,
the same number relationship mit 3 : 1 found itself among the
descendants again. on account of these experimental results described
to Mendel that 2. Mendel rule, according to the the descendants of a crossroadses
Misch inherit individuals no more uniform are but you splitting external
appearance in a specific number relationship. This number relationship
is influenced both through the number of the features in which the parents
distinguish (gene places) and by devolution. One distinguishes a dominant-recessionary
devolution of an intermediate devolution (the dominante allel suppresses
the effect of the recessionary one) (both the effect Allele is recognizable;
a Misch inherit individual accepts a middle appearance). During a dominant-recessionary
devolution, the external appearance of the daughter generation splits
into the relationship 3 : 1 if only a feature is considered
be as soon as during an intermediate devolution in the relationship 1 : 2 : 1.
3. Mendel rule (rule of the independent division of the space elk pairs):
How further crossroadses experiments showed with parents generations, that itself in two or several features distinguished, the individual gene places and therefore the feature markedness are passed independent from each other on and are free combinable with each other. Very gadget is the 3. Mendel rule only for genes which are on different chromosomes valid. The seven features of the peas which Mendel examined were localized by chance to different chromosomes. Otherwise, he would have received no statistical distribution of the feature combinations. Mendel's rules became the pure basis of the modern genetics.
