All eukaryotes probably have experienced a polyploidy event at some point in their evolutionary history. Other similar terms
Karyotype
A karyotype is the characteristic chromosome complement of a eukaryote species. The preparation and study of karyotypes is part of cytology and, more specifically, cytogenetics. Although the replication and transcription of DNA is highly standardized in eukaryotes, the same cannot be said for their karyotypes, which are highly variable between species in chromosome number and in detailed organization despite being constructed out of the same macromolecules. In some cases, there is even significant variation within species. This variation provides the basis for a range of studies in what might be called evolutionary cytology. Homoeologous chromosomes
Homoeologous chromosomes are those brought together following inter-species hybridization and allopolyploidization, and whose relationship was completely homologous in an ancestral species. For example, durum wheat is the result of the inter-species hybridization of two diploid grass species Triticum urartu and Aegilops speltoides. Both diploid ancestors had two sets of 7 chromosomes, which were similar in terms of size and genes contained on them. Durum wheat contains a hybrid genome with two sets of chromosomes derived from Triticum urartu and two sets of chromosomes derived from Aegilops speltoides. Each chromosome pair derived from the Triticum urartu parent is homoeologous to the opposite chromosome pair derived from the Aegilops speltoides parent, though each chromosome pair unto itself is homologous. Examples
Animals
Examples in animals are more common in non-vertebrates such as flatworms, leeches, and brine shrimp. Within vertebrates, examples of stable polyploidy include the salmonids and many cyprinids (i.e.
Calcinosis cutis  is a type of calcinosis wherein calcium deposits form in the skin. A variety of factors can result in this condition. The most common source is dystrophic calcification, which occurs in soft tissue as a response to injury. In addition, calcinosis is seen in Limited Cutaneous Systemic Sclerosis, also known as CREST syndrome (the "C" in CREST). In dogs, calcinosis cutis is found in young, large breed dogs and is thought to occur after a traumatic injury. Causes
Calcinosis may result from a variety of causes such as:

Trauma to the region
Inflammation (bug bites, acne)
Varicose veins
Infections
Tumors (malignant or benign)
Diseases of connective tissue
Hypercalcemia
HyperphosphatemiaCalcinosis cutis is associated with systemic sclerosis. Diagnosis
Types
Calcinosis cutis may be divided into the following types:: 527–530 
Dystrophic calcinosis cutis
Metastatic calcinosis cutis
Iatrogenic calcinosis cutis
Traumatic calcinosis cutis
Idiopathic calcinosis cutis
Idiopathic scrotal calcinosis
Subepidermal calcified nodule
Tumoral calcinosis
Osteoma cutis

Treatment
Intralesional corticosteroids may be beneficial. Colchicine has been shown to be effective in certain populations. The efficacy of other treatments, such as magnesium or aluminum antacids, sodium etidronate, diphosphonates and diltiazem is unclear, but they have been reported to be serviceable in refractory calcinosis. Surgical options may be considered, particularly if there is associated ulceration. Gallery
See also
Calcinosis
List of cutaneous conditions

References


== External links ==